I received my primary flight training at Wright-Patterson Air Force Base under the guidance of a Lt. Colonel who had flown fighters and bombers - a rare career. I was used to mixing with “heavies” there, and encountered a C-141’s wake turbulence on short final at less than 200’. The C-141 had been cleared for a touch-and-go so I set up to land about a third of the way down the 12,600’ runway, to stay above the 141, and land in the area where he should not have been producing a vortex. I figured out later than he had executed a low pass rather than touch-and-go. The aircraft began to stall (felt the burble of the detached airflow) and instantly pitched violent to the left. Thanks to Col. Pettigrew’s training, I slammed the throttle to max and pushed the nose down hard to unload the airplane. It accelerated quickly to the point where the roll stopped at somewhere between 45 and 60 degrees. I cleared the turbulence and rolled wings level well left of the runway. Me to tower: “is a go around”. Tower after a significant pause: “Copy that”. The controller had routed me too close behind the heavy and I accepted the clearance and had a plan to deal with possible wake turbulence. Unfortunately, the C-141 didn’t touch down or his wake from climb out drifted across the runway and into my flight path. Fortunately, my training saved me and two passengers that day.
One thing that almost bit me was during the taxi to the departure runway. I was a newly upgraded CP-ASEL and had flown a rented Piper Arrow from KMQS (near Lancaster, PA) to KCVG (Covington-Cincinnati airport in KY). I had grown up in NKY and was there to visit family. At that time, KCVG was a hub for Delta. When it came time to head back home it was in the middle of a Delta departure push. I asked for an intersection departure on the non-active 10,000' north south runway - and it was denied. ATC had me taxi to behind a string of 757's and ahead of some 737's. Even though I had stopped far short of the tail of the 757 in front of me, the Piper Arrow rocked hard every time he throttled up to advance. In my mind, I could see me being lifted up and ending like a bug on the windscreen of the 737 behind me. In all of my training and flying, no one had ever mentioned the danger of being behind a large aircraft on the taxi way!
I hit wake turbulence on my solo cross country while flying a Rans S-20, I hit the turbulence of a G-II. It was an eye opener for sure. I went from level flight to a 45 degree bank in a matter of milliseconds. Obviously I had no training for the situation at the time, but instinctively turned away from the low wing while dropping the nose even though I was only about 1000’ agl. Wake Turbulence is REAL. Great video
I second your upset recovery training recommendation! I took upset recovery due to my frequent use of air carrier airports in a Mooney. Twelve years later I survived a 90 degree bank upset at 200 AGL landing at Ketchikan, Alaska. It was an aerobatics-conditioned response: unload, apply coordinated rudder and aileron, level the wings, apply speed-appropriate elevator back-pressure, continue to landing. Most pilots I see in training will immediately pull in any upset. Had I pulled at Ketchikan, my wife and I would have died when we impacted the approach lights inverted. Unfortunately, upset training presents a significant risk: you may find yourself buying a Pitts S-2C (or some other aerobatic aircraft) because you are having that much fun -- as I did at 8 hours into the training.
Well done, Scott! As a young solo student pilot many, many, many moons ago before WT was "a thing", ATC cleared me for takeoff after a C-124 had made a low approach, and I flew into the wake at ~300 ft and the airplane rolled hard left despite full right aileron input. Lady Luck allowed me to fly out of the vortex with the tower querying if I was OK... I responded rather shakily that all was well, after which I confirmed I had not color coded my underwear. Lucky to fly away in one piece, I took a chip from the "luck" pile and placed it on the "experience" pile for future events.
Some of the pilots where I flew took the WT training in a T6, although I was too junior to go along. The key thing they learned when an encounter flips you over is to finish the roll. Most pilots instinctively try to split S out of it, unless they get the aerobatic recovery training. I used to take my homebuilt regularly (commuting to work) into a very large but uncontrolled airport (11000 ft runway) that had a Fedex facility, so early in the am I would have to fit myself in with DC-10 freighters and such arriving every 30 minutes or so on the ATF. If a heavy was on approach while I was inbound, I would go orbit a landmark on the upwind side of the airport until he landed, and if the wind was under 10 knots I would always land in the opposite direction and take the tailwind. No big deal with 11000 feet. Even if a heavy was aways out still, I'd go orbit and wait for him and go after, usually using the opposite direction, not wanting to force a missed approach if I got a flat or something on landing and couldn't taxi clear. I did have what I think was a weak residual wake encounter from a DC-10 that had landed a couple minutes before, about 3 miles south of the approach path at 1000 ft, as I was heading to land the opposite way, thinking I was well clear. Silky smooth morning air, then a jolt like driving over a curb at 40 mph, then silky smooth again.
I've flown Cirrus aircraft for years and I think this video is spot on! Pro tip: I fly into BUSY Class B airports on a regular basis (LAX/SFO/DFW etc) and I NEVER take a "cleared for the visual rwy XX" if there are BIG IRON flying in. There are just too fast to really assess as a "slow" GA pilot where that aircraft will be. I rarely ever accept a short approach for the same reason. To those afraid to speak up to ATC,. don't be; they will almost always give you and approach to fly and maintain separation and put you in a position to more easily follow the traffic in front.. Also, another point: I do believe if you are "cleared for the visual" then ATC is NOT necessarily responsible to maintain optimal separation between you and the big iron IN REGARDS to WAKE turbulence avoidance. An finally, I have flown into KTYS where this accident occurred and there is one available runway and ITS REALLY BUSY with airliner traffic. I believe the deceased pilot was "cleared for the visual" in this case. Great channel and thanks for the analysis!
@@FlyWirescottperdue Hi Scott retired controller here , that is a yes and no answer. If you have the preceding AC in sight and are to cleared to follow than the pilot is responsible for separation and wake turbulence clearance. If on the other hand you do not have the preceding in sight but have the airport the controller can clear for a VA but the controller is responsible for separation and wake turbulence clearance. hope this helps . OG, ZAU C90 retired
Always great video Scott! A reminder to fellow pilots, FAA advisory circular AC 90-23G pg 6 sec 8 a. Is a great place to know when atc is separating you from wake turb or when the clearance to "follow the airbus, cleared to land" means the pilot is responsible for separating themselves from the wake. Clearances like this are used every day but very poorly taught what they mean in flight training. Keep up the great work!
Nearly 50 years ago my IP and I were on short final in a T-38 when we suddenly found ourselves in a 90 degree right bank over the over run. We had flown into the wingtip vortices of another T-38 that had landed ahead of us on a parallel runway that was upwind from our runway. I can share this because I was not solo. My IP immediately applied max power and rolled the aircraft upright and then requested a closed pattern because we were very low on fuel. We landed without further incident.
Had an incident in Reno 1979 flying a 4 place piper loaded, was instructed to make right base to land. No large aircraft in sight but kept air speed @ 100 to use up of the long runway - thank GOD! Snapped into at least a 45 degree bank 50 feet from the ground, was shook up enough I forgot to close flight plan. Last x country only flew local with no heavies after that.
It's not just airliners. I was on base to land at an uncontrolled field where a big executive helicopter had just taken off. Rather than fly upwind a little, turn, and leave the pattern, the S72 pilot decided to fly directly back up the approach corridor. I encountered his rotor wake at 500 feet and short final, and was thrown into instant knife edge flight. The airplane wanted to keep rolling. I'd done aerobatics years before and (very briefly) considered continuing the roll and returning to level flight. "I think I can do this." But not at 500 feet. There just wasn't time, and I'd welded this into my head: whenever you catch yourself saying "I think I can do this" it's time for a different plan. With full aileron deflection we flew out of the ring vortex and I was able to regain control at the threshold. Fly well above any jet traffic ahead on landing, and land beyond his point of touchdown. And keep an eye out for helicopters while you're at it.
First of all - it sounds like the helo pilot flew a non-standard departure, that's not cool. Second, I was lucky to avoid a similar experience while flying student solo cross country. I flew to a Class D airport and was sequenced to land behind something with a military call sign on the left of two parallel runways. I was having a hard time seeing it (camo colors and all that). But he was cleared for a touch and go, and he called "on the go" just as I saw him. I was at about 1/2 mile and about to put my third flap in when I saw the Blackhawk pull up hard away from the runway and turn left/away. I requested a go-around, and when the tower said "you want to what?" I told them I was going around. The had me make a right turn, cross over the parallel runway, and join the right downwind for the other parallel runway. Coincidentally, that manuever had me essentially buzzing the tower lol. Which I didn't really notice because I was busy cleaning up the plane, making sure I had positive rate, and looking out for other airplanes. Anyway, my point was that I was certainly not going to try to land on that runway with three flaps, slow, in a baby Cherokee right after a big helo had performed a touch and go on the same spot!
My wife's parents lived in a house inline with the final approach of our local airport. Theirs was the last house the aircraft passed directly over before landing. I sometimes thought I could almost see the rivets on the bottom of the aircraft as they passed over. It was amazing how long after an aircraft had flown over that you could still hear the wind turbulence caused by the wing vortex. It was almost like there was a phantom aircraft following a bit behind the real aircraft. When it was a 707 passing over, it was real spooky listing to an airliner that wasn't there pass overhead.
Once again, thanks for the reminder! I make it a point to watch every one I see posted, even though it leaves a blank look on my face and an overall feeling of sadness that can last for a long time. We know all this. I've seen charts, graphs, videos and examples of it happening time and again. But when will we all learn?!? Maybe if you keep it up we will. 8( Kind regards, --gary
I experienced this as a passenger on a small regional jet, right at landing. The aircraft suddenly rolled to about a 40-degree angle right above the runway and seeing the wing and its shadow almost meet on the runway was unnerving to say the least. It was surprisingly quick, and so was the pilot's reaction to it, fortunately.
Great job thanks Scott, .. and yes of course never underestimate wake turbulence and it’s potential effects. : In about 1995 I was pilot flying (FO), in a 747-400 departing Frankfurt in Germany on a very dark and wet night. A KLM 747 departed in front of us and we were immediately behind him, with minimum separation. We were also probably heavier than he was as we were on the way to Singapore- and very near max weight, (whereas he was on the way to London as I recall, so likely much less fuel.) Just after wheels up our 747 started started rolling rapidly right. I almost immediately reached full left aileron, backed off control column pressure, and yet we were STILL rolling fairly rapidly right. I then started also feeding in some rudder at which point I regained control, and managed to bring wings back to level. I think we reached about 50 to 60 degrees angle of bank, (though neither of us were sure about that as it happened so quickly.) To say it was scary is a massive understatement- both the Captain and I thought for a few seconds that we’d had major structural failure - maybe flaps, and were going to keep rolling right until it was all over. (We were much too close to the ground to have room for recovery had the roll continued.) I can tell you, it took quite some time for the adrenaline to work it’s way out! However I still can’t get my head around the actions of the American Airlines 587 Airbus pilot who repeatedly used full left/right rudder until the tail failed structurally, even though apparently some of their training was along those lines. That was bizarre in the extreme, so sad. Cheers.
Great story 738, thanks for sharing. And NO, the FO who was Pilot Flying on 587 did NOT act according to his training. The AA AAMP program did NOT teach to use the rudders the way he used them!
@@FlyWirescottperdue Thanks Scott. Love your work. In all my 30k hours, including GA and Boeing 737s (300/400/800, 767 200/300, and 747 100/200/300 & 400), I have never ever been taught nor EVER seen the need to use rudder pedals like that. Every aeroplane has a breaking point. I’m very glad to hear it wasn’t AA training that taught him to do that. As I said: Sad.😔
Good video, I (SR22 pilot) learned a lot from it. One comment - the CAPS system did save the life of the passenger. He was injured, but survived. As you say, it doesn't replace the need to fly the plane in a situation like this, but it was able to save a life when the pilot couldn't recover from an EXTREMELY difficult situation. I don't think the recovery rate for any GA pilots getting inverted turning final below 1,000 feet is going to be good regardless of the type of plane they are flying...
If the pilot was killed by the impact and was sitting inches away from the passenger, it is illogical that the parachute had anything to do with the passengers survival. A parachute has very specific situations where it is valuable. Basically: - unrecoverable engine failure over mountains or dense urban areas - unrecoverable disorientation in IMC In an engine failure with flat, open areas around, an emergency landing is safer than the parachute since (with a parachute) you have no control where you land (you could end up on a freeway in front of a semi or on railroad tracks in front of a train, so landing in a field is safer - not safe, safer). If you find yourself in the second situation, you done screwed up and a parachute could be a successful hail Mary, although again you have no control over where you land.
Jon, I think you made my point. The Pilot needs to fly the airplane to have any chance at all. In this case the Pax was lucky he was in a strong airplane that happened to hit just right. Add to that he was lucky to get out of the fireball. The fireball should tell you that the chute was partially inflated.
@@homomorphic I don't understand what the seating arrangement has to do with it, but either way wouldn't it be just as illogical to assume the chute didn't save the passenger as it would be to assume it did? Logic tells me the CAPS deployment wouldn't and didn't make this crash any worse, which And the situations might be specific, but they aren't that limited. There are at least few soaking wet but otherwise uninjured pilots who would probably back me up on this. Also cirrus might have agreed with you early on, but later pivoted their training to emphasize the chute as being a lot closer to a first response than a last resort.
@@Milkmans_Son If the impact was sufficient anywhere in the cockpit to kill someone, then the parachute didn't work. How is that not obvious? If the parachute works, then there won't be sufficient impact to kill someone.
@@homomorphic You know what isn't obvious? Your point. Let's say my thinking is as binary as yours and I agree: Yep, it didn't work. Never mind they were too low and the wrong side was facing up, still didn't work. Never mind someone survived who otherwise might not have. It didn't work, therefore what? Therefore they should't have deployed it? The manufacturer shouldn't offer the option? What is your point?
Scott is right. Any airplane at any altitude can be upset by wake. I was Captain in an MD-80 descending through 18,000’ nearly 20 miles behind a Virgin 747. He was so far ahead I couldn’t see him. The aircraft started to buffet and that was my first clue I was in his wake. Then the airplane rolled left. I clicked off the autopilot and applied right aileron. When I got to full right aileron the roll was going through 30°. At that point I knew that it was going to roll over if I didn’t do something different. I zeroed the aileron and pulled through the wake to clean air. Needless to say the flight attendants were upset as we got to 45° before we cleared the wake. They thought we were going over. Luckily the passengers were in there seats with the seatbelt signs on. Anyway. Thanks for the good talks.
@@FlyWirescottperdue Thanks Scott. And that link to that upset training is really great. Way better than anything I’ve had in my thirty years of airline flying. That push technique when you’re past 90° is really important. If you get the nose of a big jet downhill for very long you are never going to get in back up in less than 20,000 feet. I’ve seen students in the sim attempt to pull while inverted and never recover to level flight from any altitude. These jets are just way to slippery to get going downhill very steep. That Giant 767 is a prime example. Thanks and keep up the good videos.
Excellent presentation. I was flying a Caravan full of people behind a heavy at least a couple of miles ahead of me and got a bit lower than I should've. I was aware of that, but because there was at least a 40~45 kt headwind right down the runway (yes, it was howling!) I figured the wind would dissipate any residual wake. Nope. Got slammed instantly into a 90° left bank. No time to think, just went full right aileron with right rudder and got it back to normal. The whole event was over in a couple of seconds. Had about 6K hrs at the time and a fair amount of aerobatic experience in sailplanes.
I could have been on that fateful 427 flight but changed plans after a meeting in Pittsburgh was cancelled. Instead I took a flight to ABE and drove home from there. I was not aware of the crash until I came home and found my wife in tears. That day and its aftermath is burned in my memory especially since I flew into Pittsburgh quite often. Only a week after the accident in an approach to a PIT landing we hit some turbulence and my heart was in my throat. For quite awhile there was this sense of edginess in all of us passengers. I followed NTSB reporting and in the end I believe their investigation turned out to be the longest ever - possibly 10 years? I'm not sure where you got your wake turbulence information but I believe the cause was attributed to a rudder PCU over range that caused the rudder to move in the opposite direction relative to pilot command input.
@@FlyWirescottperdue maybe there is more than one similar accident? because I am sure back in the day I read a report that blamed a hydraulic hard-over for an accident in Pittsburgh involving a Jumbo... do not quite remember the details, but... ...as for wake turbulence, I always remember the one in Mexico City, it was not the biggest plane, but with the ground casualties (the Embraer crashed into a densely packed workers neighborhood) it added up to one of the really bad accidents...
@FlyWirescottperdue Your assertion is misleading at best, and it is you who need to go re-read the accident report. "The National Transportation Safety Board determines that the probable cause of the USAir Flight 427 accident was a loss of control of the airplane resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide." It is true that the initial upset that led to extreme control inputs from the pilots was the wake vortex encounter. It is also true that the pilots could have theoretically recovered from the rudder hard-over had they not been inputting up elevator, as this significantly reduced aileron authority to below what would be needed to maintain cross-controlled level flight. However, the pilots had less than 10 seconds to recognize the rudder hard-over had occurred before the aircraft became unrecoverable, and it was not a known problem at the time. In other words, they didn't have a chance. Please do your research before laying fault at the feet of victims who lost their lives due to an engineering flaw. RIP USAir 427 pax and crew.
I was so lucky to learn these lessons before putting them into action. Pete Thompson, Gave me so much advice about stall characteristics close to the ground. God rest his soul he died in his sleep.
I had a Harrier fly low over me on excercise. For the next few seconds there was a high pitched noise that dissipated. I assume that was the wake turbulence.
Great video! When I went to school for Aero Engineering we learned a little story about our prof who flew a 172 thru a wake and did a whole roll before being able to react. Wake is no joke, thank you for sharing. We all need to keep aware more.
I was on my PPL solo cross county in 1990 from KDXR in CT to Albany, NY KALB. I was landing behind a line of C5a's from Stewart AFB that I watched passing me to the West on my way North. When I was entering the pattern they cleared me to land on runway 01 a few minutes after the last C5a landed. As a student I asked the tower about possible wake turbulence since they had cautioned me about it when I was still 10 miles out, but the tower stated "I was probably ok... and cleared to land" again. As a young and new student pilot I deferred to his expertise, only to be nearly flipped upside down at 200' and a thousand feet or so from the threshold. My left wing was pointed straight at the ground in a second or two, then despite banking full deflection to the right I started to go slightly inverted. A few seconds later the airplane righted itself and I declared a go-around with my heart pounding out of my chest. The controller said over the air just... "sorry 'bout that!" Thus the lesson learned to take ownership of the aircraft and ignore anything or anyone - even a controller in a position of authority - that's encouraging an action that seems unsafe. It all ended well with me calling in my safe arrival to flight-service and with a tale to tell!
I always thought the US Air crash near Pittsburgh was entirely due to an un-commanded rudder reversal and hard-over caused by a hydraulic valve that would fail under certain temperature conditions. I didn't realize the crew's handling of the controls was a contributing factor. Good info.
Scott Perdue states that in reaction to wake turbulence, the crew "PUT the 7-3 into a snap roll", and that "the controls were mishandled all the way to the ground...sadly". The obvious implication here is that had the crew not mishandled the controls, the outcome would have been different. Either the NTSB got it wrong (hey Dan G, you watching?), or this is one of those "Don't believe everything you hear on RUclips" moments.
@@6StringPassion. well said, I never believe any of these guys, but this one was two miles away from me and many friends worked at that airline. Perhaps the YT individual should read the report instead of impugn the integrity of the pilots who perished. It was stated clearly that the 727had little to do with the events as they unfolded. What some of these hacks won’t do for clicks. Another hangar pilot who holds court at the local airport, it’s why I do my own research.
I experienced a hair-raising moment at Williamtown Airport (New South Wales, Australia) in the early 70's. Flying a MB326H Macchi, I was number five in the landing sequence behind four Mirage IIIO aeroplanes. Most aeroplanes create wingtip vortices, but with Mirage aeroplanes having delta wings they are more pronounced. At low speeds, a delta wing requires a nose up attitude (high angle of attack) to maintain lift. If you can imagine the turbulent air created by four Mirages all within a lineal distance of about 4 km, then you would understand the impact this had on my relatively small and light Macchi. Well, on final approach to land at about 500 ft above the ground, all of a sudden I flew into those unseen vortices and in a split second my aeroplane rolled sharply, about 120 degrees to the left. I considered ejecting, but thought to myself, all I’m going to do is bury my head in the dirt, as the aeroplane was still rolling into the inverted position. I immediately applied maximum thrust, a lot of right rudder and some aileron to slowly roll back to a normal flying attitude. Fortunately, it worked, but this manoeuvre now had my Macchi pointing in the direction of downwind, with the potential to meet aircraft flying in the opposite direction head-on. Fortunately, no other aircraft were in the circuit, so all was ok. I extended out a bit further before re-joining for a normal landing. I must admit, this shook me up a little.
Thanks, makes sense. If I read correctly, the 757 has a wingtip vortex actually worse than a 747. Going in and out of big airports in little airplanes we have to remain vigilant watching where the big guys are going as to the relative wind. Landing long and mid-field departures exiting upwind when possible. I was #2 following a Delta 727 into Salt lake one late March evening in a C-150 doing a ferry trip to Dallas. Even on another runway you have to think about that. There was a shop at the Auburn California Airport that specialized in C-210's. I wandered in the open hangar door to chat with a mechanic and asked what 2-210's were in for, "that one over there, the pilot pulled the gear up just as he lifted off and the wheels dropped in their cycle and the prop struck the runway, and that one took off right behind a 737, ran smack into a wing vortex that slammed him back into the runway". Everyone survived was the good news.
I have landed an SR22 right behind an A320 more than once, but I was never closer than 4-5 miles, so didn’t ever feel any wake turbulence. 750 feet is plenty of altitude for the BRS to work as advertised, but not if you’re inverted. The chute will open below the plane. It obviously worked to some extent since the passenger survived
I reckon I've watched most (if not all) of your vids and it seems that a key ingredient to most upsets...is push to unload the aircraft. That it goes against every cell in our screaming monkey brains as we're staring at the trees getting bigger...is why it takes real life flight training in a real aircraft to get muscle memory and instinct to override our inner apes. Thanks for not getting tired of hearing yourself repeat the same lessons. I have no doubt that lives are being saved.
Was flying a beach 99 when got too close to My heavy and front. Full Aaron and full rudder would only keep it upright. Then the other side of the wake yet and it was the opposite direction. Lucky that day
For clarification: under wake turbulence reclassification a sr22 following an a320 requires 4 miles of separation. However, the controller relied on “visual following” along with a wake turbulence advisory to sequence the the sr22 between the a320. Visual following supersedes the need need for 4 mile separation because the pilot is expended to do what is needed to maintain their separation from the wake producing aircraft. All this said, many great points were brought up! At the airport I work at, because we are single runway operations for the next year or so - I rely on visual following to get smaller prop aircraft close in behind “airliners”. If I can’t get it to work, now I’m forced to run additional mileage on the aircraft behind to make that sequence work. By then, it’s generally too late and someone has to be broken out and re-sequenced. My question is the sr22 was already 200’ below the a320 when turn base to final. The sr22 was already in a bad spot - why not ask for a 360 or something else to help themselves? Easy to Monday-morning quarterback, but this speaks to the awareness pilots need to have when they are operating around large and heavy aircraft. Safe flights and blue skies!
Mike, thanks for watching and reaching out. If the pilot of the SR22 was going to fly that close, and he did take responsibility for separation... he needed to fly ABOVE the flight path of the A320.
@@FlyWirescottperdue I completely agree which is why I brought up the awareness part. I think what you said about practicing unusual situations is the best point of the video. There’s something to be said with being comfortable in uncomfortable situations.
I was a t-37 student in 1970 before wake turbulence we called it was well known landing at Buckley field in Denver luckily my instructor was flying when we went to 90 degrees of bank at about 100 feet. Then we noticed a c-124 taxing to park. If you can’t be smart it helps to be lucky.
I have had 45 degrees angle of bank happen at an alarming rate in a Tecnam P-92 following a Cessna 182 on downwind. It didn't get dangerous but it was startling and made for an excellant teaching point for the student. Had we been close to the ground it would have been a different story. It's all relevant...
Excellent video Scott. I remember during primary training, 35 years ago, my CFI described and taught me about wing tip vortices. It especially stuck with me when he mentioned a friend, flying a light twin, got flipped on his back but survived the encounter.
Hey Scott.....quick story about USAir 427. I was at United in the right seat of a 737-300. Was flying from IAH to ORD on the last leg of my trip. I lived in PIT at the time and was trying to get back to ORD to get the jumpseat home to PIT on 427. We ended up having a mechanical in IAH and was about 2 hours late getting back to ORD. I was pissed at missing my commuter flight home until I went down to ops and saw on the TV USAir 427 had crashed going into PIT. Had it not been for a mechanical delay I probably would have been on that flight. Chills..... Also one additional note on the crash itself, not only were the pilots on the controls together probably fighting each other, the autopilot was never disengaged so they were wrestling with that as well. My AME who was a USAir pilot and lived in PIT was one of the primary investigators on the accident with the NTSB. Thanks for your videos. I have enjoyed the WW2 fighter videos also.
Scott, you might be thinking of AA Flight 587 that lost the vertical stabilizer and rudder going out of JFK. The FO grossly overused the rudder pedals and broke it.
Yes, shortly after 911. And it was an overcompensation for wake turbulence. British Airway pro-actively reviewed their flight data log and retrained pilots that showed had demonstrated overuse of the rudder control on the Airbus.
Another important lesson from the AAL587 accident is the false concept that "as long as you're below Maneuvering Speed full control deflection will stall that airfoil before structural damage will occur." Obviously not true, but many pilots, including me, were trained with that understanding.
@@bobbyg212 They are still training this. As a ASEL student I did my night cross country three years ago with a ATP student/CFII out of one of the flight schools here in PHX. He told me exactly that - "as long as you are below maneuvering speed, full deflection will stall the plane before it hurts it....kind of like a circuit breaker". I was like "yeah.......no lol".
@@thekill2509 The real killer with that accident was repeated aggressive full left/right deflection. Just one single full deflection would almost certainly not have overstressed the tail. I thought the behaviour was bizarre at the time, and STILL do twenty years later.
I’m a student pilot in UK PPL…several exams test on wake turbulence, wind shear and microburst…mainly about avoiding same…where they can be predicted. I’m having enough ‘fun’ on crosswind landings on short runways.
G'day Scott, Hmmmn, way back when Bert Rutan was popularising WingTipFins/"Tiplets" the Equation was passed around suggesting that in any "normal" flight regieme 60% of the Drag being generated came from the Wings, and 60% of a Wing's Drag was generated by it's Wingtip Vortices. So if your Airliner is taking off using 150,000 pounds of Thrust (= 150,000 Hp as a rough approximation for "Squirt Engines") then the Lift = Weight/Thrust = Drag Equation, the Wing is generating 90,000 Hp of Drag, and 54,000 Hp of that is coming off the Wingtip Vortices - so each Vortex comprises 27,000 Hp contained in the rotating expanding "Funnel" coming off each Wingtip. And Rutan wanted to suppress Tip-Vortex Formation to improve the L/D Ratio of the whole Aeroplane. When Gliding, Thrust still equals Drag, and because the Thrust is sourced via Gravity pulling the Airframe downhill, and because 550 Pounds moving vertically 1 foot in 1 second equals 1Horsepower worth of Work, the Thrust generated from gliding downhill may be calculated. If the 200,000 pound machine is gliding down at 750 ft per minute, then 200,000/550 = 363.6 and 363.6 x (750/60) = 363.6 x 12.5 = 4,545 Hp from Gravity going into the Airframe, while gliding Deadstick. (4545x0.6) x 0.6 =1,636.2 /2 = 818 Hp at per each Wingtip Vortex, coming off an Airliner weighing 89.2 Tons, as it glides down to land. According to this here Kangaroo-feeder/Low-Speed Aerodynamics-Consultant, Emeritus, retired from the Weight-Shift/3-Axis Control Interface... (!). I'm certain those figures are not precisely accurate - but by Rule-of-Thumb they'll be pretty close to being not wrong.... 30 times the power to climb out, compared to gliding downhill, 27,000 Hp or 818 Hp - either one will turn a little GA Puddlejumper upside down and then throw it away..., as pennance for sniffing too closely after the Big Girl's trailing Pheromones...(lol) ! I hope the old Rutanian Formula helps to quantify what goes on, When one's eagerness all goes wrong. Have a good one... Stay safe. ;-p Ciao !
Scott, I’ve been flying for 17 years in all sorts of weather and this video worries me more than any of the others you’ve done. I remember nearly losing it behind a jet coming into PNE many years ago. Just last year I recall being slotted in between multiple 757s landing at JAC in my Columbia after 1500 miles of flying to get there, thinking about staying above their glide path for this reason. I sure know I didn’t have 5 miles separation on that visual into Jackson.
Wait a second. As far a flight 427 I read a book on this accident long ago and it was determined that the cause of the accident was that the "popcan valve" reversed and the the rudder went in the opposite direction of the pilots inputs. The NTSB final report confirms that finding. From the NTSB final report. " The National Transportation Safety Board determines that the probable cause of the USAir Flight 427 accident was a loss of control of the airplane resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide.[
I did not read the full NTSB report (319 pages…) but I did read all 34 findings and the probable cause. I do not agree there was any mishandling of the controls on USAir 427.
@FutureSystem738 Late to the party here, but seeing as the original investigation took a decade and we are still talking about its findings a quarter-century later, what's another two years? Bottom line is that Mr. Perdue is drawing his own conclusions. His assertions are not in line with the NTSB's official probable cause, which cited mechanical failure of the rudder dual servo control. This led to an opposite-from-commanded rudder hardover. Mr. Perdue is, in my opinion, inappropriately overemphasizing the role of pilot miscontrol in the mishap as a means to drive home his point about proper management of wake vortex upset.
Use to jog outside near a gym in a business park. It was directly under the landing path on the east side of John Wayne airport south of LA. The jets would pass over head on a calm evening with flaps extended, a big roar, then silence for a long time, like half a minute maybe. Then there would be this lasting cracking sound in the air, loud and violent, no wind. Finally figured out it was the descending vortices. Yeah, I believe an little sr22 would flip dead bug in one of those.
@@edb7742 I still can't say that's absolutely what it was. The delay made the jet and the sound seem uncorrelated but it happened every time with the same delay. And the sound did seem to come from the air, not something loose on the ground. But it does seem ridiculous to say that air can crackle like that.
The more I learn about incidents and accidents, I believe that glider flying should be compulsory part of the training syllabus. One just learns to trust the airframe more than the engine (because there is none in a glider to begin with) and you experience wake turbulence in the aerotow, so you learn to visualise (in your mind) where it will be with respect to the preceding aircraft.
I got in the habit when flying behind biggies and biz jets to keep the heat on. Not like I don't have plenty of runway. I have hit wake several times and I don't want to be going slow within reason and what the airframe can handle. Speed is life.
Even with training. Being suddenly inverted at 750ft will be a tough situation for most pilots. Even with training. I can see maybe if they know it's coming. AND are well trained..... then maybe.. I would say the best way to avoid impacting the ground from that hard an upset at 750ft is to not have it happen. (More separation between an airliner and GA planes on approach) separation is way safer than asking the trailing plane to fly above the other planes flight path.. way less margin for error there
The Pittsburgh crash was possibly precipitated by the turbulence but the cause of the crash was determined to be the failure of the Rudder actuator. The rudder actuators were found to be a problem when you introduced hot hydraulic fluid into it after having it at altitude and it being in a cold state of function period once they tested it by bringing it down to the temperature of 35000 feet and then introducing hot hydraulic fluid into it it would hard over and would not release with any deflection of the rudder. The only way to reduce the deflection is by trying to force the rudder in the opposite direction that you're wanting to go which is something that most Pilots cannot contemplate period And I don't even know that that would work well. The only reason I'm familiar with it is because I actually conferred on that accident because I had called them and regards to a similar problem we had with the F-111 it was caused by adverse yaw control system. It didn't turn out being related to the 737 issue however on hearing how that flight went down I suggested that the rudder was pushed hard over and not released. And it was possibly a Rudder actuator issue.
Haha, right man! Wake Turbulence can be a beeyoch! One time I was flying high with this nice girl and we had taken that old KemoSabe trail up to Horsheweitz pass to check out the air brigade defence machine setting up their advanced airwac sqwuack comptroller in the valley but I started to get some vibration in the motor mounts on my old beater hotrod on account of I had just cut on the Roots blower from a GreyHound bus to my aircooled helicopter Tucker engine in the back of car #52 off the line. MAN, it was abadass ride lifting the front wheels at least half track running 9's in the quarter cuz of all the weight transfer and my chick would ride in the back to help settle the torque steer on account she was a bigger gal and fit squarely in that chopped off tub behind the rails of the Tucker chassis where she could just hang on and straddle the plumbing tube roll cage bars. Luckily, no one was injured... except my heart the day she left for a man with a Gasser Willy */w\TMFR/w\*
The NTSB found a problem in the design of the Boeing 737's rudder control system. Specifically, a valve called a servo valve could jam and swing the hinged piece of the tail, called a rudder, all the way to one side. In 1999, the NTSB made its theory official: The servo valve jam caused Flight 427 to roll left and spiral to the ground in about 28 seconds on approach to Pittsburgh
Have you ever paused just short of a runway threshold - maybe 1/4 to 1/2 of a mile - to watch airplanes landing over your head? At times, after the passage of a large airplane like a 737 or even an RJ you can hear what sounds like model rockets shooting and zooming around overhead. Sometimes this vortices reach the ground near you and kick up dirt and debris. Yep, they're real alright.
I'm not sure I understand your comments on the US Air crash. The NTSB clearly stated that the cause was mechanical failure -- the infamous servo valve that jammed, causing a rudder hardover that essentially pushed the plane into the ground. The failure caused an earlier crash in 1991 as well. You make it sound like it was pilot error.
@@FlyWirescottperdue Right, it may have been precipitated by the wake encounter. And yes, it appears the US Air pilots did indeed misapply the controls. But the NTSB clearly states in its final report that the probable cause of the crash "was a loss of control ... resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit ... " It's important to note also that the same rudder malfunction was the primary cause of the crash of United 585 in 1991, and the incident involving Eastwind 517 in 1996, which thankfully was able to land safely. In any case, regardless of the pilots' actions, I'm just a little surprised you did not at least mention the mechanical malfunction as the chief cause of the crash -- not pilot error, as anyone who did not know about the servo valve problem would assume by watching this video. By the way, I very much enjoy your videos. I subscribe to Flywire, Juan Browne and Dan Gryder, among others, and all are good in their own way. But your videos are far and away the clearest, most concise, least biased and best explained. As an aviation writer for the AP and several of the trades, I really appreciate that.
A story which was passed to me relates to a Cessna single engine aircraft in Western Australia's Pilbara region. The pilot was a John Rolleston who had been a instructor and also had aerobatic experience. After a take-off, his aircraft was rolled inverted by a willy-willy, a form of clear-air mini-tornado generated by hot weather. He did not attempt to roll upright but instead continued to climb away inverted as best he could in the hope of the engine lasting until a safe altitude was reached which it did. He then rolled upright. W.A. aviators may have a better and more correct version of this event.
Thanks for sharing. IF the airplane had a carburetor it would have quite immediately when he went negative g. If it had fuel injection it would have run about another 15-20 seconds. I suspect this is a story. A good story only needs to be 10% true.
@@FlyWirescottperdue I believe he crashed that aircraft or another like it when flying low up a gully which had a sudden ending which he could not outclimb. He apparently put it down in the creekbed and survived. He owned or managed Glenflorrie Station ESE of Onslow, Western Australia. He used the Cessna for mustering checking windmills and trips to town. There have been a few folk who who have come badly undone in low altitude energetic flight aerial-mustering before the Robinson R22 helicopters became the better way to do it. People are killing themselves in those now. One other story was that he was flying a musterer's cook out to the musterer's camp or an outstation when a fuel tank ran dry. The lady apparently freaked when he lowered the nose, switched tanks and restarted the engine. He was my father's instructor in a Royal Aero Club of Western Australia Cessna 172 during 1960 at Carnarvon, Western Australia. My oldie was a WW2 RAAF vet. He missed out on an opportunity postwar to transition into a commercial pilot's licence. He got the flying bug again after 12 years of absence but the hike of life insurance premium discouraged him. He also commented at the time, that after flying a Beaufighter with a 1650hp Hercules motor on each side, a Cessna was no comparison. As an 11 yr old kid then it was observable to me his initial enlivenment then decline of interest. I think he always regretted it as he became quite interested when by chance I shot some inflight vision from a Tiger Moth during a flight which had became spontaneously available. He said, "I always wanted you to do that". The Tiger Moth was his basic trainer at Cunderdin in Western Australia during WW2.
My 22 yr old son is a new pilot building his hours out of VNY. One day with his instructor, they hit wake turbulence on an approach. I only know this because he told my husband but not me. That tells me it was a serious scare for him and he didn't want his mom to know. He has a landing habit of "coming in high". I wonder if that is a practice resulting from the wake experience.
I was almost certain (as were many at NTSB) that 427 was lost due to rudder actuator failure - I don’t believe for one second the crew induced the hardover. AA587 was in fact rudder abuse as you and the final report made clear but there are major differences between the A300 incident and the two identical 73NG crashes where the vertical remained in tact but the event was precipitated by a rudder hard over .
There was an unrecognized flaw with the PCU in the 737. But the lock up was triggered by misapplication of rudder on the part of the flight crew... and they did it because of the upset caused by flying through the wake of the 737. The UA 585 crash was not identical to the 427 crash, with the exception that the PCU locked up in that accident as well. Details matter. The flight crew also misapplied Aileron and Elevator in the 427 crash and that was a major part of the crash. The PCU didn't fail by itself and if it had the airplane was flying at a speed it should have been able to overcome the roll/yaw from the hard over rudder.
Great video Scott. Question; how do the blue angles and thunderbirds who fly so close together mange to avoid each other’s wake turbulence? How fatal/ critical is it to safety if they hit it in such close proximities?
Only the slot in a diamond formation is vulnerable to the wake and that airplane steps down to stay out of it.. When you are on the wing, you are ahead of it. Otherwise you deconflict flight paths. In an Air-to-Air fight on the Offense, if you see you will go through the wake of the preceding airplane you unload and go through it as quickly as you can. I've seen pules of up to 6g when doing that.
Suffered a severe upset as a student pilot on takeoff due to helicopter wake. Only the extra responsiveness of the aerobatic-rated plane I was flying saved me. As you say a hard push on the stick and full rudder/aileron input righted the plane. Took a scoop out of the luck bag and put it in the experience bag that day. Aerobatics and unusual attitudes saves.
On my first solo in a C152 a large helicopter taxied across the RWY when I was late downwind and then hovered about 50m to the side about 1/3 way down. ATC asked him to hover as far form the RWY as possible as he had a student pilot on first solo. (he might even have set down by the time I arrived at the threshold??) I was nicely lined up but just before flare I was suddenly off the left had side of the RWY. I somehow managed to get back to wings level and rescue the landing. I was very relieved and happy but was later annoyed with myself because firstly, knowing about the helicopter I should have done a high level go around and secondly, when I was suddenly off to the side of the RWY I should have taken my second opportunity to go around ( I was happy doing go arounds as I thought they were easier than actually landing!!). I really like that scoop of luck bag into the experience bag saying!
I'm pretty sure the "mature vortex" you speak of in the photo is the primary vortex off the wingtip of the 757, not one from a previous airplane. The tight visible vortex off the flap due to the extreme pressure gradient at the corner of the flap should not be mistaken as the primary vortex. I've never been able to see the broad primary vortex from a large aircraft unless it is passing through visible moisture, i.e. a cloud or mist. If you stand under the approach path of a large aircraft near the runway threshold, wait a few seconds and you will feel a huge disturbance in the air and often you will hear sharp sounds of shearing as the vortex mixes with the surrounding air.
@@FlyWirescottperdue I respect your channel immensely, and I won't push my opinion beyond this reply because I can't be certain either. However, I'm an airline pilot like you and also an aerospace engineer, and the setup just looks right to me. The more important point is that the tight vortex off the flap is a minor threat compared to the massive vortex from the wingtip which normally cannot be seen. Since there are undoubtedly pilots watching who don't do this for a living, I would hate to see them confuse the two. The large vortex in the photo is fairly well defined to, IMO, be from an airplane that passed 2 to 3 minutes beforehand. I guess it doesn't really matter. It's there either way. Anyway, thanks.
My dad had a surprise snap roll on final once. He was flying with a student, making an approach but was a little high. Dad suggested performing a slip, but the student performed a snap roll by mistake. This would not have been a problem except that the student panicked and let go of the controls half way through the roll, so now they are at low altitude, and low speed and inverted. Dad recovered the plane before they hit the ground but there were grass stains on the tail and the tips of the propeller and wheat was tangled in the landing gear. The student did eventually get his license.
Thanks Scott. Great debrief. Besides getting some aerobatic training, do you know of any place that offers light aircraft UPRT training specifically? Just to emphasize the importance and how it applies to all aircraft no matter the size, UPRT is a regular part of airline training now. Even in the heavies. Thanks again, very valuable stuff!
Maybe should be a restriction for private/light plane pilot's until they receive additional training if they are going to use airports with commercial size planes. Have carriers in mixed category airports have a visual wake apparatus installed like the test planes in the video so their vortices can be seen by other planes.
Wake Turbulence Avoidance awareness and procedures is part of the Private Pilot curriculum and is covered very well in the FAA "Pilot's Handbook of Aeronautical Knowledge". Here is a small excerpt: "Avoiding Wake Turbulence Wingtip vortices are greatest when the generating aircraft is “heavy, clean, and slow.” This condition is most commonly encountered during approaches or departures because an aircraft’s AOA is at the highest to produce the lift necessary to land or take off. To minimize the chances of flying through an aircraft’s wake turbulence: • Avoid flying through another aircraft’s flightpath. • Rotate prior to the point at which the preceding aircraft rotated, when taking off behind another aircraft. • Avoid following another aircraft on a similar flightpath at an altitude within 1,000 feet. [Figure 4-11] • Approach the runway above a preceding aircraft’s path when landing behind another aircraft, and touch down after the point at which the other aircraft wheels contacted the runway. [Figure 4-12]"
Didn’t old school WW2 fighter pilots experience wake turbulence when trying to shoot down enemy planes from the rear? How did they deal with the turbulence?
I totally agree with pushing the stick forward when an unwanted roll sets in - but this guy was inverted, so shouldn't he have pulled back on the yoke to unload the wing i.e. do the counter-intuitive thing and put the nose towards terra firma?...
NO NO NO. Pull the yoke and you just die faster. See the video link I put in the description below this vide. I do this exact recovery. First action in any upset is unload... in an inverted nose low, be more aggressive.
Charles, you got the part right about getting the nose pointed further down, but Scott is right in the sense that if your elevator is trimmed for level flight (gives you AOA for +1G lift at certain airspeed), and you roll inverted, you will still be getting +1G lift inverted (for the short moment you have the same speed and more lift as speed increases) but this will turn your nose faster into the ground than you should for proper unloaded (0G) flight. So you do need to push the yoke to cancel out the trim + horizontal stabilizer effect for unloaded (0G) flight independent of the roll you have, and pulling would increase the lift into the ground, making the situation worse. I had not actually realised this, so this was a good point, I can't imagine experiencing such a thing. It would be great to develop the right reactions if simulators would have this kind of simulated training.
"Caution-wake turbulence" tells me to stay above their approach and land beyond their touchdown point; it's in my old flying training and handbooks. I guess the expensive new HUD wouldn't point that out.
@@danpolk My fear is that irreplaceable flying skills and knowledge are being replaced by the joy of new avionics; and in this case, the joy of holding a 3.000 degree or whatever, glideslope still placed the aircraft in visually followed, heavy traffic's, wake vortex.
I received my primary flight training at Wright-Patterson Air Force Base under the guidance of a Lt. Colonel who had flown fighters and bombers - a rare career. I was used to mixing with “heavies” there, and encountered a C-141’s wake turbulence on short final at less than 200’. The C-141 had been cleared for a touch-and-go so I set up to land about a third of the way down the 12,600’ runway, to stay above the 141, and land in the area where he should not have been producing a vortex. I figured out later than he had executed a low pass rather than touch-and-go. The aircraft began to stall (felt the burble of the detached airflow) and instantly pitched violent to the left. Thanks to Col. Pettigrew’s training, I slammed the throttle to max and pushed the nose down hard to unload the airplane. It accelerated quickly to the point where the roll stopped at somewhere between 45 and 60 degrees. I cleared the turbulence and rolled wings level well left of the runway. Me to tower: “is a go around”. Tower after a significant pause: “Copy that”. The controller had routed me too close behind the heavy and I accepted the clearance and had a plan to deal with possible wake turbulence. Unfortunately, the C-141 didn’t touch down or his wake from climb out drifted across the runway and into my flight path. Fortunately, my training saved me and two passengers that day.
Great story!
One thing that almost bit me was during the taxi to the departure runway. I was a newly upgraded CP-ASEL and had flown a rented Piper Arrow from KMQS (near Lancaster, PA) to KCVG (Covington-Cincinnati airport in KY). I had grown up in NKY and was there to visit family. At that time, KCVG was a hub for Delta.
When it came time to head back home it was in the middle of a Delta departure push. I asked for an intersection departure on the non-active 10,000' north south runway - and it was denied.
ATC had me taxi to behind a string of 757's and ahead of some 737's. Even though I had stopped far short of the tail of the 757 in front of me, the Piper Arrow rocked hard every time he throttled up to advance. In my mind, I could see me being lifted up and ending like a bug on the windscreen of the 737 behind me.
In all of my training and flying, no one had ever mentioned the danger of being behind a large aircraft on the taxi way!
Thanks for watching and sharing Mike!
@@FlyWirescottperdue Good evening from a former Army E-4. I loved flying. Decided to bite the bullet and become one of your patreons.
I hit wake turbulence on my solo cross country while flying a Rans S-20, I hit the turbulence of a G-II. It was an eye opener for sure. I went from level flight to a 45 degree bank in a matter of milliseconds. Obviously I had no training for the situation at the time, but instinctively turned away from the low wing while dropping the nose even though I was only about 1000’ agl. Wake Turbulence is REAL. Great video
Good on ya, Jay!
I second your upset recovery training recommendation!
I took upset recovery due to my frequent use of air carrier airports in a Mooney. Twelve years later I survived a 90 degree bank upset at 200 AGL landing at Ketchikan, Alaska. It was an aerobatics-conditioned response: unload, apply coordinated rudder and aileron, level the wings, apply speed-appropriate elevator back-pressure, continue to landing. Most pilots I see in training will immediately pull in any upset. Had I pulled at Ketchikan, my wife and I would have died when we impacted the approach lights inverted.
Unfortunately, upset training presents a significant risk: you may find yourself buying a Pitts S-2C (or some other aerobatic aircraft) because you are having that much fun -- as I did at 8 hours into the training.
Excellent!!
Well done, Scott!
As a young solo student pilot many, many, many moons ago before WT was "a thing", ATC cleared me for takeoff after a C-124 had made a low approach, and I flew into the wake at ~300 ft and the airplane rolled hard left despite full right aileron input. Lady Luck allowed me to fly out of the vortex with the tower querying if I was OK... I responded rather shakily that all was well, after which I confirmed I had not color coded my underwear.
Lucky to fly away in one piece, I took a chip from the "luck" pile and placed it on the "experience" pile for future events.
Some of the pilots where I flew took the WT training in a T6, although I was too junior to go along. The key thing they learned when an encounter flips you over is to finish the roll. Most pilots instinctively try to split S out of it, unless they get the aerobatic recovery training. I used to take my homebuilt regularly (commuting to work) into a very large but uncontrolled airport (11000 ft runway) that had a Fedex facility, so early in the am I would have to fit myself in with DC-10 freighters and such arriving every 30 minutes or so on the ATF. If a heavy was on approach while I was inbound, I would go orbit a landmark on the upwind side of the airport until he landed, and if the wind was under 10 knots I would always land in the opposite direction and take the tailwind. No big deal with 11000 feet. Even if a heavy was aways out still, I'd go orbit and wait for him and go after, usually using the opposite direction, not wanting to force a missed approach if I got a flat or something on landing and couldn't taxi clear. I did have what I think was a weak residual wake encounter from a DC-10 that had landed a couple minutes before, about 3 miles south of the approach path at 1000 ft, as I was heading to land the opposite way, thinking I was well clear. Silky smooth morning air, then a jolt like driving over a curb at 40 mph, then silky smooth again.
You seem to be a very safety conscious pilot!
I've flown Cirrus aircraft for years and I think this video is spot on! Pro tip: I fly into BUSY Class B airports on a regular basis (LAX/SFO/DFW etc) and I NEVER take a "cleared for the visual rwy XX" if there are BIG IRON flying in. There are just too fast to really assess as a "slow" GA pilot where that aircraft will be. I rarely ever accept a short approach for the same reason. To those afraid to speak up to ATC,. don't be; they will almost always give you and approach to fly and maintain separation and put you in a position to more easily follow the traffic in front.. Also, another point: I do believe if you are "cleared for the visual" then ATC is NOT necessarily responsible to maintain optimal separation between you and the big iron IN REGARDS to WAKE turbulence avoidance. An finally, I have flown into KTYS where this accident occurred and there is one available runway and ITS REALLY BUSY with airliner traffic. I believe the deceased pilot was "cleared for the visual" in this case. Great channel and thanks for the analysis!
Totally agree - "unable" is your friend. Give those big boys some space.
Thanks Gone to Earth... and you are right, when 'cleared the visual' the pilot is responsible for separation and wake turbulence clearance.
@@FlyWirescottperdue Hi Scott retired controller here , that is a yes and no answer. If you have the preceding AC in sight and are to cleared to follow than the pilot is responsible for separation and wake turbulence clearance. If on the other hand you do not have the preceding in sight but have the airport the controller can clear for a VA but the controller is responsible for separation and wake turbulence clearance. hope this helps . OG, ZAU C90 retired
@@ogc90 And din this case the Cirrus pilot said he had the A320 insight.
I never leave an airport or arrive at one based solely on the tower. I am extremely concerned about wake turbulence so it’s my call.
Excellent and a perfect detailed reminder for proper reasoning by the pilot and training for this situation. Thank You
Always great video Scott! A reminder to fellow pilots, FAA advisory circular AC 90-23G pg 6 sec 8 a. Is a great place to know when atc is separating you from wake turb or when the clearance to "follow the airbus, cleared to land" means the pilot is responsible for separating themselves from the wake. Clearances like this are used every day but very poorly taught what they mean in flight training. Keep up the great work!
Thanks so much Scott. I fly a ‘46 Champ so wake turbulence is always on my mind and this was a good reminder.
Nearly 50 years ago my IP and I were on short final in a T-38 when we suddenly found ourselves in a 90 degree right bank over the over run. We had flown into the wingtip vortices of another T-38 that had landed ahead of us on a parallel runway that was upwind from our runway. I can share this because I was not solo. My IP immediately applied max power and rolled the aircraft upright and then requested a closed pattern because we were very low on fuel. We landed without further incident.
Great story, Harold, thanks for sharing!
Thanks Scott. Great review as always.
Had an incident in Reno 1979 flying a 4 place piper loaded, was instructed to make right base to land. No large aircraft in sight but kept air speed @ 100 to use up of the long runway - thank GOD! Snapped into at least a 45 degree bank 50 feet from the ground, was shook up enough I forgot to close flight plan. Last x country only flew local with no heavies after that.
Like your style and your practical approach. Handy hints for a part-time, low-hours recreational pilot like me. Cheers.
It's not just airliners. I was on base to land at an uncontrolled field where a big executive helicopter had just taken off. Rather than fly upwind a little, turn, and leave the pattern, the S72 pilot decided to fly directly back up the approach corridor. I encountered his rotor wake at 500 feet and short final, and was thrown into instant knife edge flight. The airplane wanted to keep rolling.
I'd done aerobatics years before and (very briefly) considered continuing the roll and returning to level flight. "I think I can do this."
But not at 500 feet. There just wasn't time, and I'd welded this into my head: whenever you catch yourself saying "I think I can do this" it's time for a different plan.
With full aileron deflection we flew out of the ring vortex and I was able to regain control at the threshold.
Fly well above any jet traffic ahead on landing, and land beyond his point of touchdown. And keep an eye out for helicopters while you're at it.
First of all - it sounds like the helo pilot flew a non-standard departure, that's not cool. Second, I was lucky to avoid a similar experience while flying student solo cross country. I flew to a Class D airport and was sequenced to land behind something with a military call sign on the left of two parallel runways. I was having a hard time seeing it (camo colors and all that). But he was cleared for a touch and go, and he called "on the go" just as I saw him. I was at about 1/2 mile and about to put my third flap in when I saw the Blackhawk pull up hard away from the runway and turn left/away. I requested a go-around, and when the tower said "you want to what?" I told them I was going around. The had me make a right turn, cross over the parallel runway, and join the right downwind for the other parallel runway. Coincidentally, that manuever had me essentially buzzing the tower lol. Which I didn't really notice because I was busy cleaning up the plane, making sure I had positive rate, and looking out for other airplanes. Anyway, my point was that I was certainly not going to try to land on that runway with three flaps, slow, in a baby Cherokee right after a big helo had performed a touch and go on the same spot!
Scott, your videos are always excellent. This one is no exception. Thanks for your analysis.
My wife's parents lived in a house inline with the final approach of our local airport. Theirs was the last house the aircraft passed directly over before landing. I sometimes thought I could almost see the rivets on the bottom of the aircraft as they passed over. It was amazing how long after an aircraft had flown over that you could still hear the wind turbulence caused by the wing vortex. It was almost like there was a phantom aircraft following a bit behind the real aircraft. When it was a 707 passing over, it was real spooky listing to an airliner that wasn't there pass overhead.
Once again, thanks for the reminder! I make it a point to watch every one I see posted, even though it leaves a blank look on my face and an overall feeling of sadness that can last for a long time. We know all this. I've seen charts, graphs, videos and examples of it happening time and again. But when will we all learn?!? Maybe if you keep it up we will. 8( Kind regards, --gary
RIP Charlie. He was a fantastic guy. Hangered 4 door from me and I maintained that aircraft since he had it. Blue skys and tailwinds!
Indeed. A big loss to aviation as well!
I experienced this as a passenger on a small regional jet, right at landing. The aircraft suddenly rolled to about a 40-degree angle right above the runway and seeing the wing and its shadow almost meet on the runway was unnerving to say the least. It was surprisingly quick, and so was the pilot's reaction to it, fortunately.
Great job thanks Scott, .. and yes of course never underestimate wake turbulence and it’s potential effects. :
In about 1995 I was pilot flying (FO), in a 747-400 departing Frankfurt in Germany on a very dark and wet night.
A KLM 747 departed in front of us and we were immediately behind him, with minimum separation. We were also probably heavier than he was as we were on the way to Singapore- and very near max weight, (whereas he was on the way to London as I recall, so likely much less fuel.)
Just after wheels up our 747 started started rolling rapidly right. I almost immediately reached full left aileron, backed off control column pressure, and yet we were STILL rolling fairly rapidly right. I then started also feeding in some rudder at which point I regained control, and managed to bring wings back to level. I think we reached about 50 to 60 degrees angle of bank, (though neither of us were sure about that as it happened so quickly.)
To say it was scary is a massive understatement- both the Captain and I thought for a few seconds that we’d had major structural failure - maybe flaps, and were going to keep rolling right until it was all over. (We were much too close to the ground to have room for recovery had the roll continued.) I can tell you, it took quite some time for the adrenaline to work it’s way out!
However I still can’t get my head around the actions of the American Airlines 587 Airbus pilot who repeatedly used full left/right rudder until the tail failed structurally, even though apparently some of their training was along those lines. That was bizarre in the extreme, so sad. Cheers.
Great story 738, thanks for sharing. And NO, the FO who was Pilot Flying on 587 did NOT act according to his training. The AA AAMP program did NOT teach to use the rudders the way he used them!
@@FlyWirescottperdue Thanks Scott. Love your work.
In all my 30k hours, including GA and Boeing 737s (300/400/800, 767 200/300, and 747 100/200/300 & 400), I have never ever been taught nor EVER seen the need to use rudder pedals like that.
Every aeroplane has a breaking point.
I’m very glad to hear it wasn’t AA training that taught him to do that.
As I said: Sad.😔
Great advice upset recovery is in my next sim.
Good video, I (SR22 pilot) learned a lot from it. One comment - the CAPS system did save the life of the passenger. He was injured, but survived. As you say, it doesn't replace the need to fly the plane in a situation like this, but it was able to save a life when the pilot couldn't recover from an EXTREMELY difficult situation. I don't think the recovery rate for any GA pilots getting inverted turning final below 1,000 feet is going to be good regardless of the type of plane they are flying...
If the pilot was killed by the impact and was sitting inches away from the passenger, it is illogical that the parachute had anything to do with the passengers survival.
A parachute has very specific situations where it is valuable. Basically:
- unrecoverable engine failure over mountains or dense urban areas
- unrecoverable disorientation in IMC
In an engine failure with flat, open areas around, an emergency landing is safer than the parachute since (with a parachute) you have no control where you land (you could end up on a freeway in front of a semi or on railroad tracks in front of a train, so landing in a field is safer - not safe, safer).
If you find yourself in the second situation, you done screwed up and a parachute could be a successful hail Mary, although again you have no control over where you land.
Jon, I think you made my point. The Pilot needs to fly the airplane to have any chance at all. In this case the Pax was lucky he was in a strong airplane that happened to hit just right. Add to that he was lucky to get out of the fireball. The fireball should tell you that the chute was partially inflated.
@@homomorphic I don't understand what the seating arrangement has to do with it, but either way wouldn't it be just as illogical to assume the chute didn't save the passenger as it would be to assume it did? Logic tells me the CAPS deployment wouldn't and didn't make this crash any worse, which
And the situations might be specific, but they aren't that limited. There are at least few soaking wet but otherwise uninjured pilots who would probably back me up on this. Also cirrus might have agreed with you early on, but later pivoted their training to emphasize the chute as being a lot closer to a first response than a last resort.
@@Milkmans_Son If the impact was sufficient anywhere in the cockpit to kill someone, then the parachute didn't work. How is that not obvious?
If the parachute works, then there won't be sufficient impact to kill someone.
@@homomorphic You know what isn't obvious? Your point. Let's say my thinking is as binary as yours and I agree: Yep, it didn't work. Never mind they were too low and the wrong side was facing up, still didn't work. Never mind someone survived who otherwise might not have. It didn't work, therefore what? Therefore they should't have deployed it? The manufacturer shouldn't offer the option?
What is your point?
Scott is right. Any airplane at any altitude can be upset by wake. I was Captain in an MD-80 descending through 18,000’ nearly 20 miles behind a Virgin 747. He was so far ahead I couldn’t see him. The aircraft started to buffet and that was my first clue I was in his wake. Then the airplane rolled left. I clicked off the autopilot and applied right aileron. When I got to full right aileron the roll was going through 30°. At that point I knew that it was going to roll over if I didn’t do something different. I zeroed the aileron and pulled through the wake to clean air. Needless to say the flight attendants were upset as we got to 45° before we cleared the wake. They thought we were going over. Luckily the passengers were in there seats with the seatbelt signs on. Anyway. Thanks for the good talks.
Great story and thanks for sharing!
@@FlyWirescottperdue Thanks Scott. And that link to that upset training is really great. Way better than anything I’ve had in my thirty years of airline flying. That push technique when you’re past 90° is really important. If you get the nose of a big jet downhill for very long you are never going to get in back up in less than 20,000 feet.
I’ve seen students in the sim attempt to pull while inverted and never recover to level flight from any altitude. These jets are just way to slippery to get going downhill very steep. That Giant 767 is a prime example. Thanks and keep up the good videos.
Excellent presentation.
I was flying a Caravan full of people behind a heavy at least a couple of miles ahead of me and got a bit lower than I should've. I was aware of that, but because there was at least a 40~45 kt headwind right down the runway (yes, it was howling!) I figured the wind would dissipate any residual wake. Nope. Got slammed instantly into a 90° left bank. No time to think, just went full right aileron with right rudder and got it back to normal. The whole event was over in a couple of seconds. Had about 6K hrs at the time and a fair amount of aerobatic experience in sailplanes.
Correctamundo 💯
Scott love your videos. Direct, and to the point, with great visual aids that are directed to pilots. Well done.
Per usual useful practical information for proper airmanship. Thanks Scott!
Got rolled about 60 degrees just from the wake of a learjet. Made a believer out of me.
Great job Scott , I wish we had guys like you on utube 50 years ago when I began flying . Thanks Mark Battista
This man is a great teacher
Thanks Scott. Great as always. I always love your ground school.
Great video, comments, and link! Thanks Scott!
Love these discussions Scott. Thanks for putting them together and promoting upset recovery training. That Stearman is looking good 👍
I could have been on that fateful 427 flight but changed plans after a meeting in Pittsburgh was cancelled. Instead I took a flight to ABE and drove home from there. I was not aware of the crash until I came home and found my wife in tears. That day and its aftermath is burned in my memory especially since I flew into Pittsburgh quite often. Only a week after the accident in an approach to a PIT landing we hit some turbulence and my heart was in my throat. For quite awhile there was this sense of edginess in all of us passengers. I followed NTSB reporting and in the end I believe their investigation turned out to be the longest ever - possibly 10 years? I'm not sure where you got your wake turbulence information but I believe the cause was attributed to a rudder PCU over range that caused the rudder to move in the opposite direction relative to pilot command input.
CJ... Go read the report again. The initial upset was flying through the wake, misapplication of controls cemented the accident.
@@FlyWirescottperdue maybe there is more than one similar accident? because I am sure back in the day I read a report that blamed a hydraulic hard-over for an accident in Pittsburgh involving a Jumbo... do not quite remember the details, but...
...as for wake turbulence, I always remember the one in Mexico City, it was not the biggest plane,
but with the ground casualties (the Embraer crashed into a densely packed workers neighborhood)
it added up to one of the really bad accidents...
@FlyWirescottperdue Your assertion is misleading at best, and it is you who need to go re-read the accident report.
"The National Transportation Safety Board determines that the probable cause of the USAir Flight 427 accident was a loss of control of the airplane resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide."
It is true that the initial upset that led to extreme control inputs from the pilots was the wake vortex encounter. It is also true that the pilots could have theoretically recovered from the rudder hard-over had they not been inputting up elevator, as this significantly reduced aileron authority to below what would be needed to maintain cross-controlled level flight. However, the pilots had less than 10 seconds to recognize the rudder hard-over had occurred before the aircraft became unrecoverable, and it was not a known problem at the time. In other words, they didn't have a chance.
Please do your research before laying fault at the feet of victims who lost their lives due to an engineering flaw. RIP USAir 427 pax and crew.
Good video, packed with solid tips and educational commentary.
Very nicely done. Your videos seem to be the most balanced and rational amongst others doing similar material. Thank you
I need some upset/recovery training...thanks Scott. Great video.
Very nice and clear explanation. Good graphics and videos. I always like to hear a professional's opinion.
Another well reasoned and educational video. Thanks for presenting it.
I was so lucky to learn these lessons before putting them into action. Pete Thompson, Gave me so much advice about stall characteristics close to the ground. God rest his soul he died in his sleep.
I had a Harrier fly low over me on excercise. For the next few seconds there was a high pitched noise that dissipated. I assume that was the wake turbulence.
Great video! When I went to school for Aero Engineering we learned a little story about our prof who flew a 172 thru a wake and did a whole roll before being able to react. Wake is no joke, thank you for sharing. We all need to keep aware more.
Outstanding. Thank you, Sir.
The diet is working - you look great, Old Boy!
I was on my PPL solo cross county in 1990 from KDXR in CT to Albany, NY KALB. I was landing behind a line of C5a's from Stewart AFB that I watched passing me to the West on my way North. When I was entering the pattern they cleared me to land on runway 01 a few minutes after the last C5a landed. As a student I asked the tower about possible wake turbulence since they had cautioned me about it when I was still 10 miles out, but the tower stated "I was probably ok... and cleared to land" again. As a young and new student pilot I deferred to his expertise, only to be nearly flipped upside down at 200' and a thousand feet or so from the threshold. My left wing was pointed straight at the ground in a second or two, then despite banking full deflection to the right I started to go slightly inverted. A few seconds later the airplane righted itself and I declared a go-around with my heart pounding out of my chest. The controller said over the air just... "sorry 'bout that!" Thus the lesson learned to take ownership of the aircraft and ignore anything or anyone - even a controller in a position of authority - that's encouraging an action that seems unsafe. It all ended well with me calling in my safe arrival to flight-service and with a tale to tell!
Excellent story Paul!!
Thank you for sharing. Stay safe - hope things go well.
I always thought the US Air crash near Pittsburgh was entirely due to an un-commanded rudder reversal and hard-over caused by a hydraulic valve that would fail under certain temperature conditions. I didn't realize the crew's handling of the controls was a contributing factor. Good info.
You are 100% right.
there was another one like that in Denver area
It was from an un-commanded rudder, the NTSB did not blame the crew
Scott Perdue states that in reaction to wake turbulence, the crew "PUT the 7-3 into a snap roll", and that "the controls were mishandled all the way to the ground...sadly". The obvious implication here is that had the crew not mishandled the controls, the outcome would have been different. Either the NTSB got it wrong (hey Dan G, you watching?), or this is one of those "Don't believe everything you hear on RUclips" moments.
@@6StringPassion. well said, I never believe any of these guys, but this one was two miles away from me and many friends worked at that airline. Perhaps the YT individual should read the report instead of impugn the integrity of the pilots who perished. It was stated clearly that the 727had little to do with the events as they unfolded. What some of these hacks won’t do for clicks. Another hangar pilot who holds court at the local airport, it’s why I do my own research.
I experienced a hair-raising moment at Williamtown Airport (New South Wales, Australia) in the early 70's. Flying a MB326H Macchi, I was number five in the landing sequence behind four Mirage IIIO aeroplanes. Most aeroplanes create wingtip vortices, but with Mirage aeroplanes having delta wings they are more pronounced. At low speeds, a delta wing requires a nose up attitude (high angle of attack) to maintain lift. If you can imagine the turbulent air created by four Mirages all within a lineal distance of about 4 km, then you would understand the impact this had on my relatively small and light Macchi. Well, on final approach to land at about 500 ft above the ground, all of a sudden I flew into those unseen vortices and in a split second my aeroplane rolled sharply, about 120 degrees to the left. I considered ejecting, but thought to myself, all I’m going to do is bury my head in the dirt, as the aeroplane was still rolling into the inverted position. I immediately applied maximum thrust, a lot of right rudder and some aileron to slowly roll back to a normal flying attitude. Fortunately, it worked, but this manoeuvre now had my Macchi pointing in the direction of downwind, with the potential to meet aircraft flying in the opposite direction head-on. Fortunately, no other aircraft were in the circuit, so all was ok. I extended out a bit further before re-joining for a normal landing. I must admit, this shook me up a little.
I imagine! Thanks for sharing!
Always Great Fly Wire!
Thanks, makes sense. If I read correctly, the 757 has a wingtip vortex actually worse than a 747. Going in and out of big airports in little airplanes we have to remain vigilant watching where the big guys are going as to the relative wind. Landing long and mid-field departures exiting upwind when possible. I was #2 following a Delta 727 into Salt lake one late March evening in a C-150 doing a ferry trip to Dallas. Even on another runway you have to think about that. There was a shop at the Auburn California Airport that specialized in C-210's. I wandered in the open hangar door to chat with a mechanic and asked what 2-210's were in for, "that one over there, the pilot pulled the gear up just as he lifted off and the wheels dropped in their cycle and the prop struck the runway, and that one took off right behind a 737, ran smack into a wing vortex that slammed him back into the runway". Everyone survived was the good news.
I have landed an SR22 right behind an A320 more than once, but I was never closer than 4-5 miles, so didn’t ever feel any wake turbulence. 750 feet is plenty of altitude for the BRS to work as advertised, but not if you’re inverted. The chute will open below the plane. It obviously worked to some extent since the passenger survived
I like that f-15 with a piston problem sound
I reckon I've watched most (if not all) of your vids and it seems that a key ingredient to most upsets...is push to unload the aircraft. That it goes against every cell in our screaming monkey brains as we're staring at the trees getting bigger...is why it takes real life flight training in a real aircraft to get muscle memory and instinct to override our inner apes. Thanks for not getting tired of hearing yourself repeat the same lessons. I have no doubt that lives are being saved.
Thanks Joe, I really hope so! And you have it exactly right... unload the airplane is the first step in any upset!
Great presentation as always 👍🏼 “Push-Roll-Power” should be ingrained in our brains.
Was flying a beach 99 when got too close to My heavy and front. Full Aaron and full rudder would only keep it upright. Then the other side of the wake yet and it was the opposite direction. Lucky that day
For clarification: under wake turbulence reclassification a sr22 following an a320 requires 4 miles of separation. However, the controller relied on “visual following” along with a wake turbulence advisory to sequence the the sr22 between the a320. Visual following supersedes the need need for 4 mile separation because the pilot is expended to do what is needed to maintain their separation from the wake producing aircraft.
All this said, many great points were brought up! At the airport I work at, because we are single runway operations for the next year or so - I rely on visual following to get smaller prop aircraft close in behind “airliners”. If I can’t get it to work, now I’m forced to run additional mileage on the aircraft behind to make that sequence work. By then, it’s generally too late and someone has to be broken out and re-sequenced.
My question is the sr22 was already 200’ below the a320 when turn base to final. The sr22 was already in a bad spot - why not ask for a 360 or something else to help themselves? Easy to Monday-morning quarterback, but this speaks to the awareness pilots need to have when they are operating around large and heavy aircraft.
Safe flights and blue skies!
Mike, thanks for watching and reaching out. If the pilot of the SR22 was going to fly that close, and he did take responsibility for separation... he needed to fly ABOVE the flight path of the A320.
@@FlyWirescottperdue I completely agree which is why I brought up the awareness part. I think what you said about practicing unusual situations is the best point of the video. There’s something to be said with being comfortable in uncomfortable situations.
One of my high school classmates was on that US Air in PIT .. such a tragedy ... RIP to all .. thanks for the info SP
I was a t-37 student in 1970 before wake turbulence we called it was well known landing at Buckley field in Denver luckily my instructor was flying when we went to 90 degrees of bank at about 100 feet. Then we noticed a c-124 taxing to park. If you can’t be smart it helps to be lucky.
Thank you for the information.
I have had 45 degrees angle of bank happen at an alarming rate in a Tecnam P-92 following a Cessna 182 on downwind. It didn't get dangerous but it was startling and made for an excellant teaching point for the student. Had we been close to the ground it would have been a different story. It's all relevant...
Excellent video Scott. I remember during primary training, 35 years ago, my CFI described and taught me about wing tip vortices. It especially stuck with me when he mentioned a friend, flying a light twin, got flipped on his back but survived the encounter.
Hey Scott.....quick story about USAir 427. I was at United in the right seat of a 737-300. Was flying from IAH to ORD on the last leg of my trip. I lived in PIT at the time and was trying to get back to ORD to get the jumpseat home to PIT on 427. We ended up having a mechanical in IAH and was about 2 hours late getting back to ORD. I was pissed at missing my commuter flight home until I went down to ops and saw on the TV USAir 427 had crashed going into PIT. Had it not been for a mechanical delay I probably would have been on that flight. Chills..... Also one additional note on the crash itself, not only were the pilots on the controls together probably fighting each other, the autopilot was never disengaged so they were wrestling with that as well. My AME who was a USAir pilot and lived in PIT was one of the primary investigators on the accident with the NTSB. Thanks for your videos. I have enjoyed the WW2 fighter videos also.
Great story! Thanks!
Your AME was a 76 Capt. I forgot his name now. Practicing MD and 76 Capt.......not fair?!
Scott, you might be thinking of AA Flight 587 that lost the vertical stabilizer and rudder going out of JFK. The FO grossly overused the rudder pedals and broke it.
Yes, shortly after 911. And it was an overcompensation for wake turbulence. British Airway pro-actively reviewed their flight data log and retrained pilots that showed had demonstrated overuse of the rudder control on the Airbus.
Exactly right John!
Another important lesson from the AAL587 accident is the false concept that "as long as you're below Maneuvering Speed full control deflection will stall that airfoil before structural damage will occur." Obviously not true, but many pilots, including me, were trained with that understanding.
@@bobbyg212 They are still training this. As a ASEL student I did my night cross country three years ago with a ATP student/CFII out of one of the flight schools here in PHX. He told me exactly that - "as long as you are below maneuvering speed, full deflection will stall the plane before it hurts it....kind of like a circuit breaker". I was like "yeah.......no lol".
@@thekill2509 The real killer with that accident was repeated aggressive full left/right deflection.
Just one single full deflection would almost certainly not have overstressed the tail.
I thought the behaviour was bizarre at the time, and STILL do twenty years later.
Much respect Sir. Thanks
I’m a student pilot in UK PPL…several exams test on wake turbulence, wind shear and microburst…mainly about avoiding same…where they can be predicted. I’m having enough ‘fun’ on crosswind landings on short runways.
G'day Scott,
Hmmmn, way back when Bert Rutan was popularising WingTipFins/"Tiplets" the Equation was passed around suggesting that in any "normal" flight regieme 60% of the Drag being generated came from the Wings, and 60% of a Wing's Drag was generated by it's Wingtip Vortices.
So if your Airliner is taking off using 150,000 pounds of Thrust (= 150,000 Hp as a rough approximation for "Squirt Engines") then the Lift = Weight/Thrust = Drag Equation, the Wing is generating 90,000 Hp of Drag, and 54,000 Hp of that is coming off the Wingtip Vortices - so each Vortex comprises 27,000 Hp contained in the rotating expanding "Funnel" coming off each Wingtip.
And Rutan wanted to suppress Tip-Vortex Formation to improve the L/D Ratio of the whole Aeroplane.
When Gliding, Thrust still equals Drag, and because the Thrust is sourced via Gravity pulling the Airframe downhill, and because 550 Pounds moving vertically 1 foot in 1 second equals 1Horsepower worth of Work, the Thrust generated from gliding downhill may be calculated.
If the 200,000 pound machine is gliding down at 750 ft per minute, then
200,000/550 = 363.6
and 363.6 x (750/60)
= 363.6 x 12.5
= 4,545 Hp from Gravity going into the Airframe, while gliding Deadstick.
(4545x0.6) x 0.6
=1,636.2 /2
= 818 Hp at per each Wingtip Vortex, coming off an Airliner weighing 89.2 Tons, as it glides down to land.
According to this here Kangaroo-feeder/Low-Speed Aerodynamics-Consultant, Emeritus, retired from the Weight-Shift/3-Axis Control Interface... (!).
I'm certain those figures are not precisely accurate - but by Rule-of-Thumb they'll be pretty close to being not wrong....
30 times the power to climb out, compared to gliding downhill, 27,000 Hp or 818 Hp - either one will turn a little GA Puddlejumper upside down and then throw it away..., as pennance for sniffing too closely after the Big Girl's trailing Pheromones...(lol) !
I hope the old Rutanian Formula helps to quantify what goes on,
When one's eagerness all goes wrong.
Have a good one...
Stay safe.
;-p
Ciao !
Scott, I’ve been flying for 17 years in all sorts of weather and this video worries me more than any of the others you’ve done. I remember nearly losing it behind a jet coming into PNE many years ago. Just last year I recall being slotted in between multiple 757s landing at JAC in my Columbia after 1500 miles of flying to get there, thinking about staying above their glide path for this reason. I sure know I didn’t have 5 miles separation on that visual into Jackson.
Wait a second. As far a flight 427 I read a book on this accident long ago and it was determined that the cause of the accident was that the "popcan valve" reversed and the the rudder went in the opposite direction of the pilots inputs. The NTSB final report confirms that finding. From the NTSB final report.
" The National Transportation Safety Board determines that the probable cause of the USAir Flight 427 accident was a loss of control of the airplane resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide.[
Read the report again my friend. The initial upset was as I said, the flight crew misapplied the controls leading to the PCU locking up.
I did not read the full NTSB report (319 pages…) but I did read all 34 findings and the probable cause. I do not agree there was any mishandling of the controls on USAir 427.
@@janerikkant3646 Thats what I found too
@@viking965 Scott is correct. Watch his later video.
@FutureSystem738 Late to the party here, but seeing as the original investigation took a decade and we are still talking about its findings a quarter-century later, what's another two years?
Bottom line is that Mr. Perdue is drawing his own conclusions. His assertions are not in line with the NTSB's official probable cause, which cited mechanical failure of the rudder dual servo control. This led to an opposite-from-commanded rudder hardover. Mr. Perdue is, in my opinion, inappropriately overemphasizing the role of pilot miscontrol in the mishap as a means to drive home his point about proper management of wake vortex upset.
Well said.
Use to jog outside near a gym in a business park. It was directly under the landing path on the east side of John Wayne airport south of LA. The jets would pass over head on a calm evening with flaps extended, a big roar, then silence for a long time, like half a minute maybe. Then there would be this lasting cracking sound in the air, loud and violent, no wind. Finally figured out it was the descending vortices. Yeah, I believe an little sr22 would flip dead bug in one of those.
That's very interesting and didn't know that descending vortices make specific sounds.
@@edb7742 I still can't say that's absolutely what it was. The delay made the jet and the sound seem uncorrelated but it happened every time with the same delay. And the sound did seem to come from the air, not something loose on the ground. But it does seem ridiculous to say that air can crackle like that.
Thanks!
New Flywire post: my week is now complete Scott. :-)
The more I learn about incidents and accidents, I believe that glider flying should be compulsory part of the training syllabus. One just learns to trust the airframe more than the engine (because there is none in a glider to begin with) and you experience wake turbulence in the aerotow, so you learn to visualise (in your mind) where it will be with respect to the preceding aircraft.
Very professional Scott , will double down on staying well clear behind and above heavies , thank you for sharing
Great job!
I got in the habit when flying behind biggies and biz jets to keep the heat on. Not like I don't have plenty of runway. I have hit wake several times and I don't want to be going slow within reason and what the airframe can handle. Speed is life.
Thank you!
Even with training. Being suddenly inverted at 750ft will be a tough situation for most pilots. Even with training. I can see maybe if they know it's coming. AND are well trained..... then maybe.. I would say the best way to avoid impacting the ground from that hard an upset at 750ft is to not have it happen. (More separation between an airliner and GA planes on approach) separation is way safer than asking the trailing plane to fly above the other planes flight path.. way less margin for error there
Absolutely true!
The Pittsburgh crash was possibly precipitated by the turbulence but the cause of the crash was determined to be the failure of the Rudder actuator. The rudder actuators were found to be a problem when you introduced hot hydraulic fluid into it after having it at altitude and it being in a cold state of function period once they tested it by bringing it down to the temperature of 35000 feet and then introducing hot hydraulic fluid into it it would hard over and would not release with any deflection of the rudder. The only way to reduce the deflection is by trying to force the rudder in the opposite direction that you're wanting to go which is something that most Pilots cannot contemplate period And I don't even know that that would work well. The only reason I'm familiar with it is because I actually conferred on that accident because I had called them and regards to a similar problem we had with the F-111 it was caused by adverse yaw control system. It didn't turn out being related to the 737 issue however on hearing how that flight went down I suggested that the rudder was pushed hard over and not released. And it was possibly a Rudder actuator issue.
The wake upset is what precipitated the flight crew to misapply the flight controls leading to the lockup of the PCU valve.
Haha, right man! Wake Turbulence can be a beeyoch! One time I was flying high with this nice girl and we had taken that old KemoSabe trail up to Horsheweitz pass to check out the air brigade defence machine setting up their advanced airwac sqwuack comptroller in the valley but I started to get some vibration in the motor mounts on my old beater hotrod on account of I had just cut on the Roots blower from a GreyHound bus to my aircooled helicopter Tucker engine in the back of car #52 off the line. MAN, it was abadass ride lifting the front wheels at least half track running 9's in the quarter cuz of all the weight transfer and my chick would ride in the back to help settle the torque steer on account she was a bigger gal and fit squarely in that chopped off tub behind the rails of the Tucker chassis where she could just hang on and straddle the plumbing tube roll cage bars.
Luckily, no one was injured... except my heart the day she left for a man with a Gasser Willy */w\TMFR/w\*
Danke!
Thanks Milos! I appreciate your support!
427 was due to equipment failure, not wake vortex. They did hit some wake but it didn’t cause the accident.
The NTSB found a problem in the design of the Boeing 737's rudder control system. Specifically, a valve called a servo valve could jam and swing the hinged piece of the tail, called a rudder, all the way to one side.
In 1999, the NTSB made its theory official: The servo valve jam caused Flight 427 to roll left and spiral to the ground in about 28 seconds on approach to Pittsburgh
The wake encounter precipitated the flight crew to misapply the controls... leading to the lockup of the PCU.
Have you ever paused just short of a runway threshold - maybe 1/4 to 1/2 of a mile - to watch airplanes landing over your head? At times, after the passage of a large airplane like a 737 or even an RJ you can hear what sounds like model rockets shooting and zooming around overhead. Sometimes this vortices reach the ground near you and kick up dirt and debris. Yep, they're real alright.
One still day day golfing at Bear Creek near DFW I could hear the vortices coming down from landing 777s. Pretty wild.
I'm not sure I understand your comments on the US Air crash. The NTSB clearly stated that the cause was mechanical failure -- the infamous servo valve that jammed, causing a rudder hardover that essentially pushed the plane into the ground. The failure caused an earlier crash in 1991 as well. You make it sound like it was pilot error.
It was precipitated by the wake encounter that led the flight crew to misapply the controls. Watch the video again.
@@FlyWirescottperdue Right, it may have been precipitated by the wake encounter. And yes, it appears the US Air pilots did indeed misapply the controls.
But the NTSB clearly states in its final report that the probable cause of the crash "was a loss of control ... resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit ... "
It's important to note also that the same rudder malfunction was the primary cause of the crash of United 585 in 1991, and the incident involving Eastwind 517 in 1996, which thankfully was able to land safely.
In any case, regardless of the pilots' actions, I'm just a little surprised you did not at least mention the mechanical malfunction as the chief cause of the crash -- not pilot error, as anyone who did not know about the servo valve problem would assume by watching this video.
By the way, I very much enjoy your videos. I subscribe to Flywire, Juan Browne and Dan Gryder, among others, and all are good in their own way. But your videos are far and away the clearest, most concise, least biased and best explained. As an aviation writer for the AP and several of the trades, I really appreciate that.
@@RMR1 Indeed...
A story which was passed to me relates to a Cessna single engine aircraft in Western Australia's Pilbara region. The pilot was a John Rolleston who had been a instructor and also had aerobatic experience. After a take-off, his aircraft was rolled inverted by a willy-willy, a form of clear-air mini-tornado generated by hot weather. He did not attempt to roll upright but instead continued to climb away inverted as best he could in the hope of the engine lasting until a safe altitude was reached which it did. He then rolled upright. W.A. aviators may have a better and more correct version of this event.
Thanks for sharing. IF the airplane had a carburetor it would have quite immediately when he went negative g. If it had fuel injection it would have run about another 15-20 seconds. I suspect this is a story. A good story only needs to be 10% true.
@@FlyWirescottperdue I believe he crashed that aircraft or another like it when flying low up a gully which had a sudden ending which he could not outclimb. He apparently put it down in the creekbed and survived.
He owned or managed Glenflorrie Station ESE of Onslow, Western Australia. He used the Cessna for mustering checking windmills and trips to town.
There have been a few folk who who have come badly undone in low altitude energetic flight aerial-mustering before the Robinson R22 helicopters became the better way to do it. People are killing themselves in those now.
One other story was that he was flying a musterer's cook out to the musterer's camp or an outstation when a fuel tank ran dry. The lady apparently freaked when he lowered the nose, switched tanks and restarted the engine.
He was my father's instructor in a Royal Aero Club of Western Australia Cessna 172 during 1960 at Carnarvon, Western Australia. My oldie was a WW2 RAAF vet. He missed out on an opportunity postwar to transition into a commercial pilot's licence.
He got the flying bug again after 12 years of absence but the hike of life insurance premium discouraged him. He also commented at the time, that after flying a Beaufighter with a 1650hp Hercules motor on each side, a Cessna was no comparison.
As an 11 yr old kid then it was observable to me his initial enlivenment then decline of interest. I think he always regretted it as he became quite interested when by chance I shot some inflight vision from a Tiger Moth during a flight which had became spontaneously available.
He said, "I always wanted you to do that". The Tiger Moth was his basic trainer at Cunderdin in Western Australia during WW2.
Great job on this one Scott!!!!
My 22 yr old son is a new pilot building his hours out of VNY. One day with his instructor, they hit wake turbulence on an approach. I only know this because he told my husband but not me. That tells me it was a serious scare for him and he didn't want his mom to know. He has a landing habit of "coming in high". I wonder if that is a practice resulting from the wake experience.
My father got thrown inverted by a B52 near Mather AFB during the 80's
I was almost certain (as were many at NTSB) that 427 was lost due to rudder actuator failure - I don’t believe for one second the crew induced the hardover. AA587 was in fact rudder abuse as you and the final report made clear but there are major differences between the A300 incident and the two identical 73NG crashes where the vertical remained in tact but the event was precipitated by a rudder hard over .
There was an unrecognized flaw with the PCU in the 737. But the lock up was triggered by misapplication of rudder on the part of the flight crew... and they did it because of the upset caused by flying through the wake of the 737. The UA 585 crash was not identical to the 427 crash, with the exception that the PCU locked up in that accident as well. Details matter.
The flight crew also misapplied Aileron and Elevator in the 427 crash and that was a major part of the crash. The PCU didn't fail by itself and if it had the airplane was flying at a speed it should have been able to overcome the roll/yaw from the hard over rudder.
Upset?
Push!
Roll!
Thrust
Great video Scott.
Question; how do the blue angles and thunderbirds who fly so close together mange to avoid each other’s wake turbulence?
How fatal/ critical is it to safety if they hit it in such close proximities?
Only the slot in a diamond formation is vulnerable to the wake and that airplane steps down to stay out of it.. When you are on the wing, you are ahead of it. Otherwise you deconflict flight paths. In an Air-to-Air fight on the Offense, if you see you will go through the wake of the preceding airplane you unload and go through it as quickly as you can. I've seen pules of up to 6g when doing that.
Suffered a severe upset as a student pilot on takeoff due to helicopter wake. Only the extra responsiveness of the aerobatic-rated plane I was flying saved me. As you say a hard push on the stick and full rudder/aileron input righted the plane. Took a scoop out of the luck bag and put it in the experience bag that day. Aerobatics and unusual attitudes saves.
On my first solo in a C152 a large helicopter taxied across the RWY when I was late downwind and then hovered about 50m to the side about 1/3 way down. ATC asked him to hover as far form the RWY as possible as he had a student pilot on first solo. (he might even have set down by the time I arrived at the threshold??)
I was nicely lined up but just before flare I was suddenly off the left had side of the RWY. I somehow managed to get back to wings level and rescue the landing. I was very relieved and happy but was later annoyed with myself because firstly, knowing about the helicopter I should have done a high level go around and secondly, when I was suddenly off to the side of the RWY I should have taken my second opportunity to go around ( I was happy doing go arounds as I thought they were easier than actually landing!!).
I really like that scoop of luck bag into the experience bag saying!
I'm pretty sure the "mature vortex" you speak of in the photo is the primary vortex off the wingtip of the 757, not one from a previous airplane. The tight visible vortex off the flap due to the extreme pressure gradient at the corner of the flap should not be mistaken as the primary vortex. I've never been able to see the broad primary vortex from a large aircraft unless it is passing through visible moisture, i.e. a cloud or mist. If you stand under the approach path of a large aircraft near the runway threshold, wait a few seconds and you will feel a huge disturbance in the air and often you will hear sharp sounds of shearing as the vortex mixes with the surrounding air.
I don’t think so.
@@FlyWirescottperdue I respect your channel immensely, and I won't push my opinion beyond this reply because I can't be certain either. However, I'm an airline pilot like you and also an aerospace engineer, and the setup just looks right to me. The more important point is that the tight vortex off the flap is a minor threat compared to the massive vortex from the wingtip which normally cannot be seen. Since there are undoubtedly pilots watching who don't do this for a living, I would hate to see them confuse the two. The large vortex in the photo is fairly well defined to, IMO, be from an airplane that passed 2 to 3 minutes beforehand. I guess it doesn't really matter. It's there either way. Anyway, thanks.
My dad had a surprise snap roll on final once. He was flying with a student, making an approach but was a little high. Dad suggested performing a slip, but the student performed a snap roll by mistake. This would not have been a problem except that the student panicked and let go of the controls half way through the roll, so now they are at low altitude, and low speed and inverted.
Dad recovered the plane before they hit the ground but there were grass stains on the tail and the tips of the propeller and wheat was tangled in the landing gear.
The student did eventually get his license.
Dang! Your Dad did a good job!
Thanks Scott. Great debrief. Besides getting some aerobatic training, do you know of any place that offers light aircraft UPRT training specifically? Just to emphasize the importance and how it applies to all aircraft no matter the size, UPRT is a regular part of airline training now. Even in the heavies. Thanks again, very valuable stuff!
See Mark King in Santa Paula, CA. Or Patty Wagstaff in Florida.
Maybe should be a restriction for private/light plane pilot's until they receive additional training if they are going to use airports with commercial size planes. Have carriers in mixed category airports have a visual wake apparatus installed like the test planes in the video so their vortices can be seen by other planes.
Wake Turbulence Avoidance awareness and procedures is part of the Private Pilot curriculum and is covered very well in the FAA "Pilot's Handbook of Aeronautical Knowledge". Here is a small excerpt: "Avoiding Wake Turbulence
Wingtip vortices are greatest when the generating aircraft is “heavy, clean, and slow.” This condition is most commonly encountered during approaches or departures because an aircraft’s AOA is at the highest to produce the lift necessary to land or take off. To minimize the chances of flying through an aircraft’s wake turbulence:
• Avoid flying through another aircraft’s flightpath.
• Rotate prior to the point at which the preceding aircraft rotated, when taking off behind another aircraft.
• Avoid following another aircraft on a similar flightpath at an altitude within 1,000 feet. [Figure 4-11]
• Approach the runway above a preceding aircraft’s path when landing behind another aircraft, and touch down after the point at which the other aircraft wheels contacted the runway. [Figure 4-12]"
Didn’t old school WW2 fighter pilots experience wake turbulence when trying to shoot down enemy planes from the rear? How did they deal with the turbulence?
be careful flying below your target.
I totally agree with pushing the stick forward when an unwanted roll sets in - but this guy was inverted, so shouldn't he have pulled back on the yoke to unload the wing i.e. do the counter-intuitive thing and put the nose towards terra firma?...
NO NO NO. Pull the yoke and you just die faster. See the video link I put in the description below this vide. I do this exact recovery. First action in any upset is unload... in an inverted nose low, be more aggressive.
Charles, you got the part right about getting the nose pointed further down, but Scott is right in the sense that if your elevator is trimmed for level flight (gives you AOA for +1G lift at certain airspeed), and you roll inverted, you will still be getting +1G lift inverted (for the short moment you have the same speed and more lift as speed increases) but this will turn your nose faster into the ground than you should for proper unloaded (0G) flight. So you do need to push the yoke to cancel out the trim + horizontal stabilizer effect for unloaded (0G) flight independent of the roll you have, and pulling would increase the lift into the ground, making the situation worse. I had not actually realised this, so this was a good point, I can't imagine experiencing such a thing. It would be great to develop the right reactions if simulators would have this kind of simulated training.
I thought the pit accident was rudder hard over from the PCU.
Read the report.
Pretty much go with the roll. Once you’re in a roll and inverted. Keep going in the same direction.
I don't agree... if you're lucky that might work out... but regardless you must PUSH! Unload the airplane, period.
"Caution-wake turbulence" tells me to stay above their approach and land beyond their touchdown point; it's in my old flying training and handbooks. I guess the expensive new HUD wouldn't point that out.
I agree, he might have also been distracted in giving a sales presentation to a potential customer.
There’s no need to knock down someone’s choice of aircraft or avionics. Cmon.
@@danpolk My fear is that irreplaceable flying skills and knowledge are being replaced by the joy of new avionics; and in this case, the joy of holding a 3.000 degree or whatever, glideslope still placed the aircraft in visually followed, heavy traffic's, wake vortex.
Yep, the Pilot's Handbook of Aeronautical Knowledge covers it pretty well.