Why Don’t Planes Use Reverse Thrust To Push Back?
HTML-код
- Опубликовано: 29 дек 2020
- When a plane departs an airport and pushes back from the gate, it uses a small but powerful ‘tug’ truck to reverse. But why don’t airlines save on the cost and use powerful jet engines to push back?
Article link: simpleflying.com/reverse-thru...
Video source links:
A330 Air China • Air China A330-300 I P...
A330-300 Delta • Delta Air Lines N810NW...
A380-800 Korean Air • Amazing Landing Airbus...
747 British Airways • British Airways 747-40...
A380 Air France • Air France - The Big Bird
737 Unloading cargo timelapse • Video
727 FedEx • Fedex Plane Lands at M...
717 Delta • Delta Air Lines 717-20...
737 OrcaLivery • Southwest Airlines Sea...
737 Ryanair • Ryanair Boeing 737-800...
A350-1000 Cathay Pacific • FIRST FLIGHT Cathay Pa...
Toyota Backup Camera • Toyota How-To: Backup ...
747 Qantas • Farewell VH-OJA
A320 Alitalia • Alitalia - Timelapse T...
Website: simpleflying.com/
Instagram: / simpleflyingnews
Twitter: / simple_flying
#Aviation #Flight #Avgeek
![Latto - Sunday Service (feat. Megan Thee Stallion & Flo Milli) [Remix] (Official Video)](http://i.ytimg.com/vi/9gL0F1xIt2I/mqdefault.jpg)
A year ago our flight delayed because tug went missing in airport for that our captain passenger announced "our plane can fly but can't reverse" 😂
So, the pilot lied to you because the plane can indeed reverse on the thrusters (engines) , he just chose NOT to do so. (wisely of course).
Alex NutCasio the pilot was JOKING
Alex NutCasio
U ever know what a joke is lol
aidan aylward was he? Joking?
Wish my fly trip captain could said something funny like that.
"We have a 747 pushing back with reverse thrust. That has been out of protocol since the 1980s sir. You can ALT+F4" - Airforceproud95
Yarp. That ran through my head, as well.
The one I remembered the guy requested a pushback on a 787 but got tired of it and just reversed on his own like nothing matters.
Meanwhile a 747 was literally grazing the control tower several times at like 90º bank (EDIT: those two might have been two different videos, but who knows on one a dude landed a 747 on an aircraft carrier too)
Don't forget the hot air balloons travelling at 200 knots
This is the exact reason why i'm watching this video rn
@Demscout Trolling a FAN in Flight Simulator X
You missed the main reason. Today’s high bypass engines have a minimum speed that the reversers can by deployed at. If deployed below that speed, the engine exhaust can be sucked into the engine inlet causing compressor stalls. Compressor stalls can cause engine damage. I had to do a boroscope (internal engine inspection) on a 737 that used its reversers below the minimum allowable speed to prevent it from going off of the end of an icy runway.
Interesting thing is that C-17 have high bypass turbofan and can do powerback. IIRC in high bypass turbofan only the bypass is redirected by reverser and the rest of the flow (including exhaust gases) is simply exiting from the back like under normal operation. In some older engines (non high bypass) there was a bucket type of reverser that was redirecting all the gases (including exhaust), and this kind of engine would probably be more likely to suffer compressor stall.
Also turboprops seems to be capable of powerback.
@@macieksoft - it’s not just exhaust...I was simplifying. It’s also turbulent airflow entering the engine. C-17 may not experience as much turbulent air entering the engine with them up high....maybe the same with low bypass engines since they are usually much longer. Each engine and application is different. Turbo prop is usually not an issue due to engine inlet configuration. All of the info is out there to find if you want to go more in depth.
Thanks for the explanation, so interesting!!
Am no aviation engineer but was wondering if there was some sort of limit switch or minimum speed required. Thanks for explaining it !
@@gpaull2 Turboprop in "beta" (reverse) is not redirecting the exhaust flow, just reversing the pitch on the propeller blades.
A few years ago, Airbus demonstrated a plane with electric motors in the landing gear. It looked like a good solution for pushback and taxi.
The enemy was weight.
If they had backup cameras on planes it would’ve worked
I was on a Delta 777 at Sydney Airport that performed a reverse thrust pushback from the gate. It was due to heavy rain, and they got permission from the tower to perform it. The captain informed us over the intercom they were about to perform the action. They originally told us they were going to use 2 engines, but then told us later they were only going to use 1 engine. The reason they told us that was so we weren’t scared when we saw only one engine working. The captain informed us that he guaranteed we would not go to Los Angeles without both engines working!
I mean imagine being at the gate being blown with 50+ mph winds from a plane pushing back.
I heard a DC9 pilot inform ATC that one of his engines had gone into reverse thrust while they were on approach. I heard it on the Flying Club radio while awaiting my flight lesson in Ottawa, Ontario in late 1996 or early 1997.
Highly unlikely that they actually had that happen if it didn’t result in a crash. There have been many crashes as a result of reversers deploying in flight.
@@gpaull2 Not if it was noticed and thrust was reduced to the reversed engine. It's the asymmetric thrust that causes problems not the reversed thrust itself.
The C-17 can intentionally reverse thrust in flight for an expedited descent.
@@PabloGonzalez-hv3td - True, and perhaps they would already be at idle, or close to it during decent. They were very lucky if it actually went into reverse thrust and lived to tell about it. More likely they just had a reverser indication (normally false). If a reverser deploys in flight at normal thrust settings there is a very small window to identify what is going on and put the effected engine to idle. I’ve been told that it’s about a three second window before control is window. Lots of accidents to show what happens if the pilots don’t react fast enough.
Yes there are several aircraft that can pull reverse in flight. Most turbo props and military aircraft, but there are some civilian jets that can do it. The DC8 is approved to use reverse thrust in flight. I believe that the DC9 could physically do it (nothing locking it out in flight), but it was not an approved procedure. That’s a lot different than an uncommanded asymmetric deployment that needs to be identified and rectified in just a few seconds.
@@gpaull2 one such accident you mention was the TAM flight 402 in 1996, tho that one happened on takeoff and as far as I recall wasn't informing the pilots properly that it had deployed the reverser, just pushed the thrust levers down automatically.
I wonder which one is more dangerous (assuming identical conditions of the pilots knowing it was deployed, and asymmetric thrust results), if it's on takeoff or approach to landing.
@@PabloGonzalez-hv3td The shuttle training aircraft (Gulfstream) flies approaches with reverse deployed to simulate the super steep glide angle of the shuttle, but that's a highly specialized aircraft.
I can hear AFP95 saying ‘thats been out of protocol, you are cleared to ALT F4’
In the 90’s, I used to fly in an out of Atlanta on business a lot. The Delta pilots would use reverse thrust on their planes to back out of the gates. It was really kind of cool.
Noise and FOD ingestion. In fact, before there were outright prohibitions on “power-back”, there were curfews. Also, ATC clearance was required.
Yes. About 20 yrs ago on a flight out of Boston. Reverse thrust was used to back away from the terminal. However, it was an Embraer Banderante - turboprop, not a jet. I experienced the same several times across the USA.
Q. "Why Don’t Planes Use Reverse Thrust To Push Back?"
A. Actually they do. Just because it's not done universally does not mean that it's not done at all.
My memory goes back to the mid '60s. Planes then parked parallel to the concourse and either used outdoor push up steps or dual long jetways that loaded/unloaded the larger planes (707s & DC-8s) from the front and back. It was much faster with two exits instead of one on planes that carried 150 passengers instead of 300. When they started they simply continued forward turning 90 degrees left or right and so didn't need a tug or reversers.
In the 70's and 80's when airport universally went to straight in parking at a single, shorter, front jetway, backing up became necessary so tugs were used. Some were simply the typical tractors used for baggage carts but became larger special machines as planes got bigger. During that time I do recall seeing and being on planes that pushed back with the thrust reversers. It was loud and I recall at the time thinking it added a lot of wear and tear on the reversers that might present a maintenance problem. I noticed over the years airlines stopped doing that, apparently for the reasons in this story and as I noticed. I do recall also it was usually done only on the rear engined planes (DC-9s/MD-80s and 727s).
Interesting recollection - thanks
Back in 2004, I boarded an American Airiines MD80 at DFW and most of the Maddogs used reverse thrust to push back. It was wild, but until I realized what was actually happening, the noise inside the terminal concourse was very noticeable. It literally sounded like a plane was getting too close to the building!
I saw something recently where they use a small electric motor in the nose wheel to push back the aircraft.
Both Airbus and Boeing have tested the systems. Works very well but the dead weight they carry for the rest of the flight reduced the airline interest. Was meant to allow Not only pushback but also taxing without the need to ride the brakes with the engines at idle.
@@chrissmith7669 maybe this could be a viable option for airlines operating out of remote airports with limited infrastructure.. but there are a lot of remote airports working just fine now so..
In the 1980s and 1990s, I flew out of Burbank Airport in California (BUR, now Bob Hope Airport) on 727 and MD-8x aircraft that backed away from the gate area with reverse thrust. In the aircraft you heard engine noise elevate but not to the level of takeoff thrust.
Burbank was always fun as a passenger. They still don't have bridges so you walk out onto the ramp then up stairs. The terminal windows are at ground level so you'd get a great view of other jets backing out and debris flying towards the building, but I never heard of a window being damaged.
Circa 1999 (if I recall correctly), American Airlines regularly used reverse thrust to back their MD80s out of what is now known as Terminal B at DFW. I both experienced this as a passenger and witnessed this while waiting as I was flying AA frequently between ORD and DFW in that era.
A twin otter is one of the few aircraft that can pull reverse pitch in flight. I’ve experienced the terrifying thrill of going into a very short bush strip with a steep approach that required that reverse thrust be pulled while still in the air. 😵
I've only been on a plane once that used jet powerback for departure, back in the 90s. The flight attendant forewarned passengers. I was (as usual) sitting in the back near the engines. It was probably a DC9. It was really REALLY loud. I loved it. I was fascinated. The louder the better. I'd love to see it done more, but it makes sense why it's not done.
I experienced that reverse-thrust pushback in 90s while traveling on AA B727 and MD80s, I saw it more often at ATL and DFW on the rear-engine aircrafts such as the ones I mentioned.
I used to fly on Eastern a lot in the 1980's. In Atlanta, They would powerback their DC-9's, 727's, and even their 757's. Sitting in the back of a 727 during a powerback was extremely LOUD.
I was an Eastern Airlines pilot in the 70s & 80s and we used reverse as standard operating procedures on DC-9, B-727 and B-757 aircraft at most gates. It was no big deal and saved having to wait for a tug. Big concern was "tail tipping" which was avoided by keeping your feet on the floor while backing so you wouldn't be on the brakes. After coming out of reverse you would move your feet up to the brakes. I did it on the DC-9 and B757 and I didn't notice any noise, but then I was at the front of the airplane.
I have quite a long time ago. I was flying a Delta Airlines flight out of Memphis before they got rid of it on an old DC 9. They actually pulled forward and then reversed out of the gate. It was pretty exciting being that I had never experienced it before or since
Using reverse thrust when aircraft is static means engine will be ingesting its own exhaust air back into the inlet and can reduce engine lifespan
In the late 80's Continental Airlines would use reverse thrust at their hub Houston Intercontinental Airport for almost all of their 727-200 or DC-9 departures from the gate to the taxiway. All other aircraft types used a tug for pushback and that was 737 or DC10 equipment.
back in the 70's Eastern Airlines in Atlanta used power pushback. one other negative: the terminal needs to be designed for FOD that is being thrown back at it: aka minimum windows or strenghtened windows that can take a blast of FOD, great vid!
They sometimes do. I was on a Continental Md8-something leaving Houston and the pilot used reverse thrust to back up.
I remember when they used to do this, was in a DC9 at the KC Airport where they pushed back from the gate using reversers. Was one of the few times I ever remember an airplane using reversers as opposed to a TUG.
Great video. ☺️
“Ladies and Gentlemen, Jerry has reversed into us. We sincerely apologize for this inconvenience.”
I flew a AA MD-80 out of DFW, I was surprised that the pilot used reverse thrust to move to the taxi way...
I can remember at least two occasions during the early to mid-1980s when the aircraft I was aboard backed away from the gate on their own power. In one case, we were aboard a McDonnell Douglas DC 9-Super 80 and in the other, we were aboard a 727. I always enjoyed the sensation of the backup thrust, but it did feel very strange. The airport was DFW if I recall.
Back in the 70's we my family would travel overseas to Okinawa, Hawaii using older military commercial jets that would use reverse thrusters to back up. My father was in the Air Force
American Airlines used to use reverse thrust on their DC9/MD80 at Dallas - I frequently experienced that push back. However, the engines are much higher and to the rear of the aircraft. I never thought it was a very efficient process.
Reverse thrust to back away from the terminal was SOP for Northwest DC-9s until they were retired in (I think) the early-mid 00s. It was kinda cool - the pilot would go forward a couple of feet, then throw it into reverse to back up. Pilots would come on the PA to inform the passengers of the procedure and advise it was going to be pretty noisy in the last few rows of coach.
Years ago while deployed to Afghanistan I flew on an Air Force C-17 in and out of the country. Both times it used reverse thrust to back out. I need to add that the plane wasn't parked at a gate. It was pretty much out in the open by itself.
Check also captain joe's video about it. Some turbo props can use reverse thrust under certain conditions, with certain rules, same applies with some particular jet engines like you said on some MD80. But always on a remote stand
I was on a AA B727 departing DFW and we did a powerback from the gate. It was around '85 or '86 from memory.
On more than one occasion I was on an AA/AA Eagle MD-8x series aeroplane on the route between Dallas & Austin when they used reverse thrust to get away from the gate. This would have been between 2004 & 2008 (based on the company I worked for at the time). I remember that I didn't feel inspired with confidence by the manoeuvre for all the reasons you mention in the video - I'm a qualified PPL and couldn't help but worry about the junk being sucked into the engines.
I’ve only seen it done once, in the early 90’s with an MD80’s or 90’s variant. Can’t remember which. The roar got everyone’s attention.
4 letters : FUEL
SAFETY trumps FUEL every time.
Save the fuel
Yeah no. It’s safety. The reverse thrusters are gonna rip apart everything on the ramp
Thanks
You are right with that point. It‘s even more economical to drive them to the runway. Sometimes you can see it at the A380 or A340. Or look at Fraport. They have Taxi bots. From the Terminal to the runway an aircraft needs up to 1000Kg of Kerosin
3 times when i was on a plane the pilot used reverse thrust to back away from the gate because there was no tug available it worked just fine. i have heard it is now not allowed.
Turbo props. Used to fly a DHC8-400. Multiple times used reverse thrust.
Back in the 1980's, a severe snow storm hit Washington DC. Because of the heavy snow, an Air Florida 737-200 at DCA was unable to be pushed back by the tug. The pilots decided to use reverse thrust, despite the snow and the engines being really close to the ground. Snow was kicked up and sucked back into the engines. Luckily - or unluckily - the engines were undamaged and still running, so the plane taxied to the runway. Unbeknownst to the pilots, some of the ingested snow had blocked critical airflow sensors in the engines, making the engine power readings unreliable. The instruments showed the pilots that the engines were producing more power than they actually were, so they took off with reduced thrust. This might not have been a problem on its own, but the heavy storm was putting snow and ice back on the wings, reducing their lifting capabilities and inducing extra drag. The plane stalled seconds after takeoff, struck the 14th street bridge, and plunged into the frozen Potomac River. Of the 79 on board, only 5 survived, all near the back. The plane also killed 4 people who were in their cars on the bridge.
The Moral of the story? Don't Power-Back.
I remember decades ago as a kid, flying on Braniff, they did powerbacks. I recall the equipment moving forward slightly, then slowly backing away from the gate. Lots of noise!
Years ago I was in a A318 or A319 landing in a short, wet and windy runway in Guatemala City, was unique experience when the pilot activate the reverse thrust just before the wheels touching the ground, the sound ultra loud, vibration and fuselage stress was breathtaking, near to fail... near to waste the all runway, hahahahaha the people when feeled safe, claped and cheers the pilots.
I’ve seen the c 17 globe master reverse by itself...
Yup. It does.
Even in the air
@@farazalam3325 typically done in a tactical descent.
Fly high, flaps on full, pitch up and throw the reversers on. Watched C-17’s practise them, it is crazy to see how quick they drop
I've been on a Windrose Airlines ATR 72-600 powering back from the stand at LWO airport this year :)
When I flew in a 727 in the 80’s, it used reverse thrust when backing out of the gate in Jackson, Mississippi before taxiing to take off.
Best fun fact on this channel, nice
Was on a PSA MD-80 at LAX that used reverse thrust to power off stand back in the 80's. Very noisy at the back.
“Reverse trucks are for losers”
-Swiss001
A few decades ago I was aboard a DC-9 that powered back from the gate. If I remember correctly, it was common for DC-9s to perform this procedure. There were probably two reasons the DC-9 could power back. One, it's reversers were canted to blow the jet blast away from the aircraft, and two, the engines were high mounted, and less likely to ingest debris.
Another major factor is how to stop when reversing - Just for laughs we'd do it in the simulator occasionally, and when you'd tap the brakes the nose would quite often leave the ground, and the tail would hit it. Lucky it's only a sim!
There are actually two more reasons. On the 170, we had a limitation that the reversers weren't even effective bellow 60 knots. In other words, they just don't produce enough energy to be effective to move the mass of the vehicle. I assume most modern jets are the same. Then there is Air Florida flight 90. The place was a 737-200, which was also capable of pushing back via reversers during a snow storm. It blew the ice on a pitot tube, freezing it even further. So when the plane took off it was far too slow and crashed into the 14 street bridge (it clipped at least one car) in Washington DC, and then into the Potomac river. Since then, all airliners in the US were banned from using reversers to push back.
Great video, however Piedmont Airlines was certified to do power backs on their 737-200's even though the engines are wing mounted. Their old training video on marshaller signals and powerback procedures is here on RUclips.
I saw a DC-9 do a power back at Chicago in the 80's, and the amount of snow it blew up was like a mini snow storm!
I remember experiencing it a number of times when I flew cross country alot in the '90s on Delta or American MD-80s or 90s.
Yep. American was notorious for using the power back procedure with their MD-80s at DFW at least up to 2001 when I worked at the airport. It was one of my favourite things to see, after the BA 747.
Twice I've been on an airliner that left the terminal using reverse thrust instead of a tug. The first time the tug wasn't immediately available. The second time, the tow bar that connects the tug to the front landing gear was broken. Each time, the pilot announced the maneuver and warned us that it would be noisy.
I asked my dad, a former air force pilot, about it. He mentioned the hazards described in the video and also another risk. If you hit the brakes too hard while moving backward you risk tipping the plane onto its tail. When using a tug, it's the tug's brakes that stop the plane once it's in position.
not a jet engine but i was marshalling a turbo prop and his taxi speed was to fast and he was not paying attention to my instructions and he over shot his mark by a long way to which i then had to get him to reverse the pitch of his props and marshal the aircraft in reverse onto his parking spot , but the skipper was cool he actually apologised and said he just got distracted by something in the cockpit , personally i think it was the pretty hot gate agent that was there
Value Jet used to power back with their DC-9s at ATL back in the 90s. I was surprised when they did this on my flight because it was not common with the other airlines I had flown.
Interesting, but I'm afraid you're not quite right on this one. These are all valid reasons, but they are all secondary to that of the engines themselves. Having spent 15 years on development of civil aerospace engines, I know that the primary reason is actually down to re-ingestion of air into the engine itself. Even on landing, reverse thrust is supposed to be cancelled and the reversers stowed prior to dropping below a certain speed threshold, this is mandated for everything except emergency situations. Above this speed, the forward motion of the nacelle through the air keeps the air from the reverser clear of the intake, however, below this speed, the re-directed air can get ingested back into the intake. This air (having been through the Fan once already) is already warmer (and therefore less dense) than the ambient atmosphere and is also very turbulent. As this air passes back through the fan it can result in Fan flutter or even stall... both of which can be damaging to the blades!! Back in the 70's and 80's there were a couple of instances of fan blade failures, which were attributed to damaged caused by powered push backs. As such, this restriction has been in place for all aircraft, and all engine and airframe manufacturers put a lot of development time into determining this minimum safe reverser speed.
I used to fly a turboprop that used to sometimes do powerbacks.
I had a flight with Norra from Tallinn to Helsinki 2 years ago with the ATR-72 where they used reverse trust for Push-back from the Terminal. This was due to a delay and many connecting passengers and the lack of having a push-back truck available.
DC-9's used powerback's with some frequency. Mainly due to the shape and configuration of the engines.
I've been on numerous aircraft that have used their thrust reversers to back away from a terminal or out of certain situations. It usually is pretty loud.
Another reason: when braking from reversing, the plane could tip over backwards
Na it wouldn't go back fast or break hard just to manouver, it doesn't tip back when it powers up on full thrust down the runway to take off does it.
i ws on numerous American Super 80 flights which used reverse thrust when departing the gates at DFW and IAH respectively.
They used to do it on the MD80 in US regional airports. Was banned.
Yes. I had been on two MD 80 plaines that use reverse trust in the 80s or 90s at smaller airports.
Eastern Airlines did power-backs at Tampa International Airport during the 1980's. Remember seeing Douglas DC-9's doing this. Also saw a Republic DC-9 do this at the same airport.
I was on an TWA 727 out of Orlando that did a power back. This was in 1990. My first and only time on a plane that did it.
Love the SEAWORLD plane
Yes I have been on a airplane that used back thrust to pull away from the gate. It's a small airport with no tugs in Paphos Cyprus
The turboprop-powered ATR-72s used locally on the islands where I live, routinely use reverse pitch to leave the gate.
DHC Dash8 also uses reverse at some of Scotland’s airports - handler on the ground with a coiled lead headset stood well forward of the aircraft guides them back.
Common practice on the DC9 on DL and Eastern flights…many a time in Memphis, Shreveport and Birmingham where airport operations were limited in the mid to late 70’s.
They do. The DM80/DC9 is approved for power backs
0:15 can we talk about how smooth that landing was?
And DELTA performed that landing
At Raleigh Durham International Airport in the late 80s and early 90s, American Airlines planes regularly used to use reverse thrusters to back out from the gate.
I've seen it done at smaller airports when they're reversing over the runway if the taxiway wasn't large enough for the aircraft to taxi on it; like military aircraft at a regional airshow.
I use to marshal out the C-17 from parking all the time using reverse thrusters down range. It was a common practice due to parking on the ramp.
I didn't know that the tow truck can actually pull the front wheels up. 😯
Years ago we had a member of our gliding club who flew the VC10 for BOAC.. I can't remember the circumstances, but he was otherwise stuck somewhere, so he tried to use the reverse thrust very carefully at which point he said he felt the front of the aircraft rising.. so on a VC10, it seems it does not work..
do planes use reverse thrust at any other time apart from landing?
Yes. Several times in DC-9s through the 90s on NWA in Minneapolis. I think Northwest was about the last US major airline to by the DC9.
In 1984 when Braniff came out of bankruptcy they did use the reverse thrusters on the Boeing
727 for gate departures at DFW, and LAS Mc Carrion.
The Air Force cargo haulers use the reverse function. They open the rear doors for visibility, and back up easily.
The first time I saw a C-17 back up, I was impressed.
in the 80's Northwest Powered back more often than not with the DC-9/MD 80 fleet in MSP and DTW. I was on Numerous flights through both hubs that originated in either TUS or PHX. The first segment we would be pushed back and the same A/C would power back the second leg.
I was on a midwest flight years ago that pushed back from the gate using reverse thrust.
i used to be a fueler at sacramento field back in the 80's and the 727's and dc-9's would power back from the jetways, some airlines did stop the practice due to FOD damage.
What about the force of the thrust cracking airline terminal windows????
In the 70’s all the jets I rode used revearsers to back up. Most were 727’s of course.
Best regard from the hangar
During the thrust reversing it is a heavy load on the structure on the engine and engine mounts
Also In the case of the aircraft c 17, I could imagine that this is often a structural control on the engines or thrust reverser structure
Years ago I was on a 757 that used reverse thrust out of a gate at EWR. Noisy!
At Grand Case Airport, St Marteen, some planes need to reverse down the runway before take off since the runway is quite short...
We do in an ATR72. Only for the remote parking.
Yes, Super80 fight out of Islip. It was very cool.
Did experience a 727 performing a Powerback maneuver many years ago at RDU.....when the airport was VERY small still.
One word....SAFETY
We did it while flying a Piedmont Air 737-200 in the 80’s.
There are some aeroplanes that are capable of doing this MD-80 DC-9 B737 with PW JT8Ds. For a High bypass turbofan these are MD-90 & B717 that are capable of doing a thrust pushback
Can you pls also cover the topic when Tug pushes a fully loaded plane, will it not put more pressure on landing gear by pushing it hard and how powerful Tug has to be to push a plane of that weight