@@blancolirio What would cause the overspeed? A sudden increase in air-fuel mixture into the cylinders? Is that possible? Is the engine supercharged or turbo supercharged? Or a flattening of propeller pitch? I mean, we don’t know; but what are the possible causes?
I don't think we can read too much into that. The overspeed might have been preceded by a prop control failure, the nature of which we don't know, therefore we don't know the possible consequences of such a failure. Those consequences might include blade separation independent of prop speed.
Is that conclusion (which came first) being drawn from eyewitness testimony? Eyewitness testimony is very unreliable and an overspeed from hub failure seems WAY more plausible than, say, he hit the nitrous boost or something.
The mechanical failure made an emergency landing urgently necessary, but it was the lack of a good place for that landing which made this a fatal crash. The solo post-maintenance test flight saved the planned passenger from serious injury or death, which demonstrates that test piloting is both dangerous and necessary. RIP.
I find it extra tragic when a good pilot who did everything right and went out of his way to observe safety and best practices ended up not making it due to simple bad luck and circumstance. Sad
Thanks Juan, another excellent report. My sincere condolences to the pilot's friends and family. I would observe, as an engine guy - that any time I see or hear an engine overspeed suddenly - especially in a condition where one would normally expect the load to be increasing, my experience causes me to suspect that the load suddenly came off the engine. It is difficult to overspeed a fully loaded engine. Perhaps, a pitch control failure, unloading the engine? I will be waiting to hear what they end up determining the root cause of the overspeed was.
The sequence was most likely, that the hub failed, then the blades separated, then the revs went through the red line. A ground observer would see the blades separate first, then maybe 3 seconds later would hear the bang and then the revs rise.
Since over-speeding is a major concern, I'd think there would be a rev limiter set to a value within the normal operating parameters. My guess is something failed prior to the rev increase that caused the revs to rise even with rev limiter intervention.
I met this guy last year and saw this plane at the Cleveland Interational Air Show, he was really nice and answered a bunch of questions about the plane, homebuilding, his different kits, and business. Really sad. RIP sir.
@BlingtingSam I have been almost killed 3 times by million dollar aircrafts. One wich was a total loss due to engine failure 300 hours on the airframe . Their most concern, not " crappy " aircraft, and you, sir, are disrespect and uneducated. Have a nice day.
I would guess the engine RPM surged because the hub failed and there was no longer force required to turn the now departed prop. Really a sad ending to a pillar of the experimental community.
If the hub fail, the propeller rpm doesn't increase. In this case the propeller rpm increased, causing the destruction of the propeller, so I think the hub doesn't was the cause.
Or the other way around. A propeller control or governor issue could have made the RPM surge beyond design rpm which would then have caused the propeller or its hub to fail.
@@gustavosegal5881 Not the propeller rpm; that of the engine. The hub quite likely failed, thus removing all load from the engine & allowing the sudden & significant increase.
I had a 310P and had to rebuild the props. Learned way more than I wanted to know. The hubs keep the props from centrifugal forces exceeding 20 tons each if I remember right. When you have one fail it is catastrophic. It can rip the engine right out of the frame. Condolences to him, his family and friends.
Centrifugal force is a misnomer. It does not exist as a force in the realities of physics. Centripetal force is a real force that keeps an object moving in a circle, while centrifugal force is an apparent force that pushes an object away from the center of a circle: Centripetal force A real force that acts towards the center of a circle, or the axis of rotation, to keep an object moving in a circle.
@@danblumel The difference is mostly philosophical here, we are talking about the stresses upon the propeller hub. It also depends on your reference frame, which for the propeller hub is spinning at a few 1000 RPM … How about you tackle a force being expressed in units of inertial mass (20 tons) instead of units of force (about 196,000,000 Newton)?
@@danblumelThe centrifugal force is the problem because it pulls from center. Ie the hub being center and the ends of the props being the outer circumference. When a prop fails the hub is pulled from center from said force. The reason it is centrifugal is because of the imparted rotation from the connecting rods to the crank to the hub. Making it a force that wants to push away from center when a prop fails.
Not sure if it applies to this engine and gear box but I remember talking to someone about these LS automotive conversions. One of the major drawbacks was you couldn’t pull negative g because it would starve the oil pump for the propeller. If the hub has no oil pressure the propeller would drive full fine pitch thus increasing engine rpm. My guess is the propeller hub lost oil pressure somehow which drove the propeller to fine pitch which pushed the propeller rpm way above what it could handle and then the blades let loose and the engine went to its max rpm with no load on it.
The rev limiter on the engine should be set at rpm equivalent to prop rpm limit. So no way the engine can overspeed the prop. If he was flying fast and the governor failed and caused the prop to go to flat pitch, the prop could be passively driven to beyond its redline
Most aerobatic props work in reverse, or like a feathering hub if you will for this reason. Oil pressure to decrease pitch, so that if you do have oil starvation at the hub, you won't suddenly over-speed. Some other random aircraft have it that way as well.
@@toastrecon The NTSB report says he was trying to land on that road 1/4 mile west of the runway, and saw a car coming and changed his landing path to not impact the car. He didn't want to injure someone on the ground, and sadly was killed. A true aviator.
Yes, very sad. Roads are attractive when seen from above, but the combination of cars, signs, guard rails and power lines along roads can make them a dicy choice. Of course, when it's road or trees you gotta take the road.
As a glider pilot we are trained for low altitude breaks of an aero tow rope. One of the key factors that get drilled into you during training is to quickly find the best reachable landing area. A rope break under 200’ agl is considered too low to safely turn back to the airport. So landing ahead in some fashion is advised. Normally every airfield has around it a couple of options which can be better or worse depending on your altitude and wind. The brief satellite image of the airport in this case seemed to show some open fields in the area. Landing on a road is certainly more convenient for retrieval than a corn field but that road? So narrow with trees and power lines, yikes. Even in a non emergency situation that would have been a challenge. Maybe that was the only option. However, the point is to survive the landing first and foremost. Off airport landings are full of risks and the selection of the best place, quickly and under pressure is helped considerably by thinking about the best options before launch. I suspect power pilots don’t dwell on this subject as much as glider pilots do. But maybe some of the same instruction should be given. It can’t hurt.
Assuming he was passing north over the airfield when it happened, then staight ahead was the best option undoubtedly. Looks like a marshy area, followed by a water filled quarry, followed by the landfill. All of those look like better options for survivability. He was probably used to that narrow runway though and may have felt he could "thread the needle" on that side street. It's surprising he didn't stall on the 180 turn. You make a great point about knowing your options beforehand. Very little time for thought in those situations. A sad outcome indeed.
I’m sure this pilot had run through this scenario many times since it was his home airport. He actually accomplished the impossible turn but that just set him up for a perhaps impossible landing.
@@jimrankin2583 I'm not sure why he would have come up with such high risk options in that case. He was obviously a good pilot to have accomplished the impossible turn on what looks to be a high wing loaded plane, but it was all for naught with the landing site impediments. I take it this was not his own plane but someone elses? May have influenced his decision to try and save the aircraft.
hey Juan, the ding that goes along with your subscribe and turn on notifications graphic is very loud and high pitched (it’s actually quite painful to listen to!) would be great if that could be turned down or replaced!
Prop failure is not just a problem with experimental aircraft. My father had a prop disintegrate on an IO-520 which ripped the engine from the airframe. Luckily he had not yet taken off but still got hurt running off the end of the airstrip (about a 30 % downgrade into a gully - cropdusting....)
Just wanted to make 2 observations that speak to a man I never knew's character: 1- He purposefully left his passenger on ground for one final check after maintenance and 2- my amateur eyes seem to see an evasive move at the end of his flight to avoid hitting a car with a passenger(s) in it.. knowing his own life would be in more danger. Minimum 2 lives saved as his final choices on Earth. Incredible. RIP Mr. Williams.
That's probably all true, but unfortunately it points to the mistake of his choice of where to land when there were better options available. If he had chosen better, rather than saving the plane or saving someone else's life, he would have been able to focus on saving his own. He knew the area well, so he knew what his options were. This was an option but far from ideal in the case of the plane, the other people and especially his own life.
@boneseyyl1060 idk. I'm not a pilot, but from the looks of things off Google maps, the road to the right running parallel to the runway (rt 218) doesn't look a while lot better to have made the attempt. Same goes for clay st (the road on the north side that runs perpendicular to the runway). Gotta keep in mind he was only a couple hundred feet up basically flying a glider. He didn't really have any other options other than those 3 roads I mentioned. None looked good imo.
@@joemalinak7410 Not a pilot either Joe, but I do know a little about flying. You are thinking that his only options are to land on a road.. And if saving the plane is the main concern you might be right. But the main concern has to be surviving the crash. And as you say, at that low of an altitude it is going to be a crash and not a landing. At that altitude and with no engine, his only real choice is to point the nose at the ground to maintain airspeed. Turning in any direction increases the risk of stalling or losing lift. In these situations real pilots will tell you to maintain as straight a heading as possible, pick the clearest open area ( and roads are not clear open areas) leave the gear up and fly the plane into the ground. The plane will slide and take some damage but more often than not the pilot will walk away. Trying to save the aircraft over your life is a poor choice. He had those choices directly in front of him but chose to turn and try the road. And it cost him everything, not just a plane.
@boneseyyl1060 no, the roads were not the only places i assumed he could potentially land. I totally get what you're saying, but if you look at the area, the only real open area that I could see was at the north end of the runway across the street. At least only open area that i would guess was big enough that he could reach gliding to. Right where he was probably making the 180 for the street that he attempted to land on and a few hundred feet directly below him. At least that's what it looks like viewing the area on Google maps. Maybe you see something I missed. But that was my RUclips trained professional opinion 😁
@@joemalinak7410 Of course none of us really know what we would do in the that situation. Easy to sit with all the time in the world and decide. Having a plan beforehand helps and keep it simple. It's all you can really do. That open area in front was his best shot IMO. Sad that he won't be around to build more of those great looking planes.
This gentleman participated in the D day reenactment held yearly in Conneaut OH ,just east if Geneva. The event is coming up in the next week or two. He will be sorley missed. RIP
What a sad news. I've met with the gentlemen a few years ago during a shop tour I've undertaken in order to assess the fabrication of their kits aircraft. Such a nice person is lost. My condolence to hos family and friends. RIP John.
@@jaysmith1408 It's good that they can run on jet fuel. Also the low RPM helps. However, to get the most out of the high torque, you need variable pitch propellers.
That's awesome you posted one before you left for the airport! It was my absolute pleasure meeting you on the commute down South today. Have a great trip and I'll look forward to that new ceiling fan 😅.
Glad you’re back. I had to watch some guy named Holt, I think, to get updates on the Park fire. A few years ago I wouldn’t have given 2 hoots about the fire. Then I found you 🎸
Three people in my EAA chapter were flying behind auto engines (two Subaru and one Chevy). Two had off airport landings that substantially damaged the aircraft. One was able to return to the airport with a blown engine.
Unlike aero engines, auto engines aren't designed to be cruising at max power settings. Chevy LS engines cruise at around 35% power or 2000 - 3000 rpm.
@@maxmackinlay618I was just about to say that. They have a totally different duty cycle. They may have similar peak power but they are expected to it out it only for a small fraction of service life unlike aero engines that are designed to have very high outputs relative to their peak for most of the time.... It's a critical design factor.
I've been a huge fan of the LS engines since I bought my Z06 way back in 02... sixth gear on the interstate around eighty mph, it's just above idle rpm and gets 28-29 mpg. Drop down a few gears and it pulls hard to redline till 180 or so... incredible powerband even by todays standards. Seems like the perfect auto conversion on the surface, but for years Chevy had a tough time with drivetrains themselves, resorting to a crazy dual mass flywheel setup on the LT's to combat harmonics as a bandaid. There was an auto conversion featured in KitPlanes magazine years ago about a fellow name Tracy Crook(?) that detailed his Rx7 rotary conversion in a Vans RV that should be required reading for anyone considering such an undertaking. He gave great insight and detail from start to finish, including more than a few engine outs and near misses. I decided to pay the Lycoming tax and worry a little less haha
I could not get into any aircraft with a gearbox to the propeller...unless it is a turboprop designed from the ground up for aviation and nothing but aviation (as turboprops obviously are). There have always been good reasons as to why aero engines are designed to operate at the (up to) 2500 RPM approximate range.
He came so close to bringing it home but was faced with powerlines on the right and trees on the left. Clearly kept his cool and control of the aircraft right up to the end.
Been doing these since the 1980s? Damn. What a tragic loss. You can KNOW the risks, but they're still there. From Juan's reading of the summary, the driver of the car pulled over to the west as the pilot drifted east. Sounds like up to the end he was aware and trying to avoid other casualties. Godspeed, sir, and rest in peace.
I worked for John at Titan Aircraft for almost 3 years. I worked on this plane on several occasions, as well as several others. Anything that had an LS on it was very nose-heavy.
@@PeacefulRallyCar-pw3csfind me a 6 cylinder that's substantially lighter than an LS and makes similar power, especially with all the turbo hardware. Won't get as good of millage for the same power level either, boosted motors run a richer mixture
@@zakn3954 most modern V6 are going to be lighter than a V8 by around 50-100lbs. When something is hanging from the nose of the craft every pound matters. An inline 6 is likely going to be just as heavy if not heavier than a V8, plus it going to stick out further ahead shifting the weight even more forward making it even more nose heavy.
@@madmax2069 lol look it up you will be surprised that most Modern v6's actually weigh the same or more than an all aluminum pushrod motor. Dohc, vvt, DOD, all that just mean more weight.
Terrible loss to the Experimental Aircraft community. A metallurgical examination of the prop hub should show where the failure started and how it prorogated through the hub. It will also show if there were any existing cracks in the hub. It will be interesting to know how many hours were on the hub. Auto engines are so tempting....
Totally disagree, normally the hub failure would cause the surge in engine RPM, not the other way around. I'd default to harmonics, prop failure, hub failure, governor failure in that order before the engine given that it and the PSRU were completely in tact.
I own a Corvette with an earlier variant of this engine, the LS1. The LS3 is around 370 cu in and over 400 HP stock. They require a computer system to operate, unless the engine is very extensively modified. The computer in my car employs a "rev limiter" function, to avoid overspeeding the engine. I would imagine that if this LS3 were not modified to run without a computer, The engine could have been detuned to produce 300 HP, and rev limited to a value corresponding with the maximum safe propeller RPM. I am really curious about this engine installation, and what caused this failure. Godspeed to the pilot, and condolences to his family and friends.
We have no knowledge as to whether the engine speed was limited by the ECU. The fact that the engine overspeeded suggests that the engine speed was NOT limited by the ECU. The engine speed probably was limited only by the propeller pitch and pilot. It is easy to see now, with the benefit of hindsight, this was not sufficient redundancy. What now for all T51 owners?
I'm going along with the others. The prop hub failed and that was what caused the increased engine rpm. Hopefully the NTSB will be able to confirm this by syncing the audio and video from the recording.
As usual fantastic breakdown and analysis. So tragic to see one of these go down and with the designer onboard. RIP sir, hoping they find a flaw along the way…
@@B-System still, I would have asked for differentiation between just engine overspeed and prop overspeed. Engine over speed after failure is practically guaranteed. The absence of prop overspeed would be important to at what rpm the hub failed.
I knew John. Great human being, and a great stick and rudder pilot. I own a Titan Tornado II SS, and we'd had a conversation about it and aerodynamics 2-3 weeks prior. You're right, Juan. As owners and operators of experimental aircraft, we're test pilots. And we do pay more attention to our aircraft. We have to. My preflights are far more involved in an Experimental. Thanks for the great content, Juan. My thoughts and prayers go to John, his family, and everyone his life touched through the decades.
If you lose oil pressure and the prop goes to fine, the engine should not over-rev (if the base pitch is set correctly). The prop blades were from whirlwind but the hub was made by Titan said someone familiar with the build.
The owner pilot seemed very reasonable and quick to acknowledge the problems associated with making an auto engine work reliably in an aircraft. As he pointed out it’s the reduction units and other related system components that are more often the points of failure. I’ve always held the opinion that propeller reduction units are the stuff of industry. Just take a look inside the nose case of a big radial engine built in the forties. Very complicated, precision designed and manufactured planetary gears. I too like and fly almost exclusively experimental aircraft with the exception of my day job. But I never fly behind auto engines with experimental reduction units, belt drives or any of that stuff.
So hard for me to understand anyone taking chances like this since my dad died in a plane crash And September 12September 12, 1992We have no details from that accident Nor have we found any trace of his body or his aircraft.His aircraft number was N6759 sierra. I will send you the NTSB Accident report number.Thank you so much For checking into this for me! H. Paul miller's daughter Paula joy miller.
I could easily understand an rpm surge if the gearbox had failed, unloading the engine. The gearbox could have subsequently locked up, causing shear forces within the prop hub to make it come apart, but the investigation determined the gearbox was intact, so that theory would be ruled out. Could the rpm surge have been due to a sudden pitch change of the propeller, caused by a failure inside the prop hub just before it came apart? Condolences to his family, and glad to see someone fastidious enough to test things before taking someone else up.
John correctly identified the mating of the engine to the prop controller as a "problem" and not a challenge. His passing is a great loss to the Experimental community of builders and pilots, but still, as with all aviation accidents, another cautionary tale for improved flight safety. (An-2 crash survivor)
Originally by hearing the 180 turn, I expected the typical stall. He darn near made it. Not much room to thread the needle. May have over corrected as it looks like he angled into the trees or just at minimum control speed and unable to correct in time. Such a sad moment for family, friends and fellow pilots. Regardless of experience, with aviation all it takes is just once…😢
@MrJeffcoley1 I thought the same thing. Also, someone said the landing gear was coming down. After a major failure I would just want to pancake in and hope to walk away from the landing.
@@jgalexander510 Yeah if you look at Google Maps there were really no good options. Even the fields dead ahead are small and surrounded by tall trees. The bigger roads all have power lines on one side and trees on the other. Even so, he almost made it.
Prop first or engine first? Read the report. “When the airplane pitched up, he heard the engine go to a “super high RPM” and then the “entire prop hub shatters.” He observed several parts and pieces explode from the nose section of the airplane, and the engine noise subsequently went silent.” This one was close to home. Condolences to friends and family.
Sounds like he almost made it down. Every time I hear about the loss of an experienced pilot, it makes me think about what I could do to avoid a similar fate. Thats why this channel is so valuable.
I love your channel and I don’t fly a plane, never have but I love planes. I am watching the planes around the fires. I started that because of your channel. Best wishes and be safe
I initially thought it was odd that the car driver pulled over on the wrong side of the road but given the presence of the power lines that may have been a case of excellent situational awareness on his part.
Why they don't design and install a governor on those engines. May not be failure free, but adds a layer of protection. Saddened for the loss of life, it's a sobering event to see this kind of thing happening. Thank you for bringing us this video
Does the engine show evidence of overspeed? V8 exhaust note is unique among aviation engines so it would be hard to say that witness statements would be sufficient to know actual RPM. If in fact overspeed, was there an rpm limiting device? Did it fail? Was it set too high? A lot of open questions still on this one.
Dang Juan!! What a loss!! I know this is hindsight, but already headed N., if had enough altitude, couldn't he have opted for a Lake Erie plane wash, w/wheels up water landing, swam away, & lived to fly again another day!!??
Well, it's a report from an eyewitness on the ground, so I would guess that he heard the engine rev before he saw the debris separate. Sound travel delay would put the overrev event even further before the debris event than he would have perceived.
The hub could partially fail (causing the blades to go flat pitch) unloading the engine enough to overspeed the prop which would then physically break apart the hub. Alternatively the hub could just have failed in some way and the overspeed happened after the blades came free.
As as an auto mechanic for 50 years...I can't imagine trusting an automotive engine to fly me. That is not what they were made for. I continue to marvel at the ruggedness , simplicity, redundancy, and built in performance limitations of the airplane engine. They can literally chuck off a cylinder and keep running, piston flailing in the air. I just don't know why you wouldn't want that.
People don’t want it because it’s not been barely improved in 50 years while auto engines have been improved greatly. Also, most people haven’t experienced an auto engine failing in 2,000 hours of use unless it was a simple dead battery.
At the same time, I have never had a car engine fail to start in 25+ years, anyone with any piston engine airplane experience knows thats not a typical experience. Ive never had a car engine fail catastrophically while driving nor do I think I personally know of someone who did, so that is on 10s of 1000s of hours, while I do know 2 people who had their rugged airplane engine fail catastrophically in flight (they are both fine) and thats probably on 100s, at most 1000s of hours. One of them was an engine with 25 hours total flight time. How many car engines have you seen explode in the first few days of driving it? And my car engine doesnt need to be rebuild every 50 hours, it will do 5000 hours with minimal maintenance. And thats not even mentioning cost. Or fuel efficiency. I certainly do see the appeal, but I recognize that the reality is more complex
It has nothing to do with the automotive engine. Most of the failures occurred at the propeller reducing gears. Even for the vaunted spitfires and mustangs, rolls Royce had a lot of problems designing the propeller gear for the Merlin engine. This is why you don’t see a lot of high speed rotating gearing on anything because it can be complex to design to run reliably
You seem to be a bit misinformed on quite a few things. Aircraft engines need to be rebuilt roughly every 2,000 hours. The reason your car lasts 5,000 is because it is using a tiny percentage of its potential horsepower the vast majority of the time. Aircraft are run at 70-100% power the vast majority of the time. If you ran your car at redline all day it would not last long. Also the first 100 hours are the most dangerous time for any new engine, automotive and aviation. Just look at all the issues Toyota is having right now. The only way you’ve never had a car fail to start in 25 years is if you buy a new car fairly often. Most aircraft are 30 years old minimum.
I can certainly understand the attraction of flying, but as a non-pilot observer reading the almost daily barrage of ghastly fatal GA incidents that include the most proficient and experienced pilots within your community.... bless y'all, you have much bigger balls than I do.
Based on the comments, this MUST require a speed limiter on the engine. I'm a GM engineer and this is trivial to do on modern engines, via software. The LS3 is an older engine but can easily be retrofitted with simple actuators, and one electronic module. Modern kids do the Raspberry PIs in STEM classes. Turbines have the same problems, and those problems were resolved decades.
@@chris1451 A speed limiter would have prevented the engine exceeding the set maximum RPM. They work if a car is in park or neutral, with zero load on the engine, and the gas pedal floored.
@@PhilipFly11 rev limiters work when the engine is under a predictable load be it the near zero load at idle or the predictable increasing while the accelerator is floored. Ever hear of a money-shift? it is a common enough death to many engines where the engine is being forced to over-rev by the transmission - the rev limiter cannot do anything to prevent it. An engine at high power then being unloaded the engine will over-rev usually to a lesser degree than a money shift- but damage to the engine is still likely. Even the Pratt and Whitney PT6 turbine engine family has experienced a similar failures despite having overspeed protections included - the overspeed governor and fuel topping governor. The gearbox through a metallurgical failure will decouple from the power turbine and the power turbine will fly apart when it over-revs since there is no load to counteract the force from the gas flow
@@PhilipFly11 I perfectly understand how a rev limiter works. It would have done NOTHING for this crash. The prop broke THEN the engine over reved. Read the first comment. Geez.
I did the research on this powerplant last year to evaluate the project and it didn't take long to reject that crate motor from GM as received. As an A&P, there was far too much risk factor to consider it as a project. By the time I had reconfigured the engine to be serviceable, I was left with 3 useable parts - the crankshaft and both seals at either end of it. All other parts including the block would have to change to satisfy strength, oiling system redesign, fuel and ignition system and all the necessary additional components and parallel computers to build the engine with self correcting redundancy and 80 lbs or so less weight. The propeller and gear reduction still bothered me as there is little structural excess, but there are other options. The airboat guys have been doing this for years and better gearbox and prop combinations are available. I would have ended up with a test cell testing routine somewhere in the neighborhood of 7 months to get comfortable with what reliability and performance that I can resonably expect. Not impossible but not like that.
thanks for the information. The key with this engine and gearbox in this aircraft is that the engine can be used at low throttle settings and rpm and still provide lots of thrust, so it is not stressed at all compared to what it is capable of. But yes, the fuel and ignition systems are the weak points.
The propeller was a Whirlwind Aviation prop, a sister company of Whirlwind Propeller, in El Cajon, CA. Since about 2 1/2 years ago, the companies went separate ways.
Fuel injected engines like the GM LS engine are computer controlled that have adjustable Rev limiting features. There’s no way the engine could over speed the set limit under any circumstances, especially in this case while under load. The engine hit the set limit RPM only after the load (the gearbox and propeller) was was suddenly disconnected. What was seen and heard was the failure of the gearbox or prop hub failing that caused the engine to rev to the set limit and the pilot then pulling off the throttle. As a caveat with my statement is that I don’t know what ECU is used in this application. If not a GM supplied unit, pretty much all aftermarket controllers offer the same functionality as GM units in automotive applications. Meaning RPM control would be the same. Additionally, many aftermarket ECU’s or PCM’s offer (as do most GM units) transmission input and output shaft speed sensors that can sense slippage. Some also offer driveshaft speed sensors, all of which could easily be adapted to gearbox and propeller speed monitoring that will instantly reduce engine power output or cut power to the ignition coils when shaft speeds exceed parameters.
sorry for the lost of an experienced EAA pilot. perhaps the engine didn't need the added oil? Would like more info on the LS3's condition (I'm a Vette owner, it's a great engine) I also don't understand why he opted for a residential street with trees ... rather than the runway right behind him with apparently plenty of energy. Nice Coverage Juan. Thank you.
They have a real company backing them that’s spent thousands of hours on R&D to get them to work properly. Rotax and the Austro motors aren’t even remotely comparable to the applications on 99% of auto conversion homebuilts.
Unless the engine suddenly found a way to make a LOT more hp, it sounds like the prop pitch had to have suddenly gone to a very fine position, unloading the engine while it's throttle was mostly open. Failed prop governor, perhaps?
My feeling is the urge to save the airplane was overwhelming, witness the turnback and lowering the gear. I agree, straight ahead into a field was doable, he had the advantage of no drag from a windmilling 4 blade prop, and a bunch of altitude to work with. Very sad. Similar outcome to the Howard Hughes racer replica accident a few years ago, prop governor failure and instead of using the chute, pilot tried to save the airplane by landing into rough terrain.
Interesting line on page 4: "Evidence of oil spray and an oil coating was observed on the belly of the fuselage, left wing, oil cooler area, tailwheel assembly and elevator." On a plane with a continuous speed prop like the accident airplane was, if you lose oil pressure to the prop hub the blades move into their lowest-pitch/highest-RPM position. So...if he lost oil pressure to the hub in some way - either losing an oil seal in the hub or breaking an oil line - that would explain both the overspeed condition and all the oil on the aircraft. And, unfortunately, because the hub disintegrated in flight and the gearbox tore itself off the engine (which would also explain a broken oil line) during the impact, it's a theory we really can't prove. Remember, Howard Hughes nearly died because of something similar when one of the props on his XF-11 lost oil pressure to a prop hub.
Sorry to hear about this...Looks like a nifty design; I saw a pair of these perform at a local (N. Ohio) airshow 10 years ago; both were powered by the Honda Odyssey 3.5 liter v-6, also rated at 300HP...
Looks like a landfill to the north. Questionable terrain, but no trees. Wonder if he should have tried to put it down on the landfill straight ahead instead of turning into a tree-lined street.
An unfortunate accident. Flying into Oshkosh in '81 in a Cessna 170, Steve Wittman in his V-8 Olds Tailwind passed me like I was parked. The only time I considered a car engine.
That road would not have been my first choice for a forced landing. Looking at the surrounding area there was a field directly in front of him, with a couple more to the east.
This time of year, the field is probably full of corn. It might have been safer than a narrow tree-lined road, but it might not have seemed safer in the split-second needed to make the decision.
This sounds like loss of oil pressure or a governor failure. Kevin Eldredge had a failure at Reno in his Nemesis NXT, #42 "Relentless." This sounds identical. I was there for that. It lost oil pressure (sounded like it lost an oil filter), draining the entire engine rapidly around pylons 7, 8, & 9, through a roughly 4g turn. The prop immediately went fine and caused an overspeed, causing the blades to depart. I do not believe this was a prop hub failure, though the hub failing was likely a cascading result of another failure. It is highly unlikely it had anything to do with gearbox, and may not have anything to do with it being a conversion. As mentioned, we've seen this on typical "aircraft" engines as in the Reno example.
I agree - loss of oil pressure to the prop causing fine pitch and overspeed. An engine computer with overspeed protection would have been unable to keep the windmilling propeller from overspeeding. Car engines belong on cars unless they are FAA certified.
I wonder if he clipped the tree because he turned slightly to the left to avoid the oncoming car. The driver of the car reported seeing him coming head on and pulling off the road to his left. They each went left to avoid a collision.
It seems unclear which happened first. Did the prop hub fail first, causing the blades to separate, which suddenly reduced the rotating mass and drag, causing the surge in engine RPM? Or did the engine surge in RPM first, overstressing the prop blades & hub causing them to fail?
If you look at many of the auto conversions in aircraft, the installs are just extremely scary. The wiring is usually awful and the fuel, coolant and oil lines (if there are any) are usually just bargain bin garbage. Viking Aircraft Engines doesn't even use a pressurized cooling system, because they refuse to run AN hoses and have trouble with the coolant hoses popping off of their fittings! It's just the wild west with most of those guys.
![FNAF vs TF2 - Episode 2 [SFM]](http://i.ytimg.com/vi/z5b3V2-VLb0/mqdefault.jpg)
No, to be clear and as presented in the video. The prop hub failure was PRECEEDED by a gross PROP OVERSPEED.
@@blancolirio What would cause the overspeed? A sudden increase in air-fuel mixture into the cylinders? Is that possible? Is the engine supercharged or turbo supercharged?
Or a flattening of propeller pitch?
I mean, we don’t know; but what are the possible causes?
I don't think we can read too much into that. The overspeed might have been preceded by a prop control failure, the nature of which we don't know, therefore we don't know the possible consequences of such a failure. Those consequences might include blade separation independent of prop speed.
Not a pilot, but I take prop full forward to mean pitch was was correct, not flat.
@@sirbike That referred to the prop control lever in the cockpit, not the condition of the prop itself.
Is that conclusion (which came first) being drawn from eyewitness testimony? Eyewitness testimony is very unreliable and an overspeed from hub failure seems WAY more plausible than, say, he hit the nitrous boost or something.
Hats of to the pilot for check flying the plane before he took the other pilot up. RIP.
You mean hats off?
@@slappy8941Most people with common sense know what he meant.
@@slappy8941 What do you gain by pointing out one of the most common types in the universe?
@@smugfrog8111 What do you gain by complaining about it, especially without proofreading?
@@gandydancer9710 Haahaha! OK, That is funny. I literally typo'd "Typo"
However, still. My question is valid, yours is not.
The mechanical failure made an emergency landing urgently necessary, but it was the lack of a good place for that landing which made this a fatal crash. The solo post-maintenance test flight saved the planned passenger from serious injury or death, which demonstrates that test piloting is both dangerous and necessary. RIP.
Very sad loss for his family and the experimental aircraft community.
Damn that sucks, met him a few times and really enjoyed talking to him about the Titans. RIP buddy
I find it extra tragic when a good pilot who did everything right and went out of his way to observe safety and best practices ended up not making it due to simple bad luck and circumstance. Sad
Yep. General aviation in an experimental plane is Russian roulette 😅
@@BlingtingSam What?
But that's not what happened at all.
Thanks Juan, another excellent report. My sincere condolences to the pilot's friends and family.
I would observe, as an engine guy - that any time I see or hear an engine overspeed suddenly - especially in a condition where one would normally expect the load to be increasing,
my experience causes me to suspect that the load suddenly came off the engine.
It is difficult to overspeed a fully loaded engine.
Perhaps, a pitch control failure, unloading the engine? I will be waiting to hear what they end up determining the root cause of the overspeed was.
I concur.....if it had a variable pitch prop that's about the only was she's gonna do a freewheel redline rev...
The sequence was most likely, that the hub failed, then the blades separated, then the revs went through the red line. A ground observer would see the blades separate first, then maybe 3 seconds later would hear the bang and then the revs rise.
@@hiscifi2986 ...the blades feathered flat n that let the motor go 9000 n then the hub failed in that order....
Since over-speeding is a major concern, I'd think there would be a rev limiter set to a value within the normal operating parameters. My guess is something failed prior to the rev increase that caused the revs to rise even with rev limiter intervention.
@@notter59 blades went flat
I met this guy last year and saw this plane at the Cleveland Interational Air Show, he was really nice and answered a bunch of questions about the plane, homebuilding, his different kits, and business. Really sad. RIP sir.
John was very kind to me when I was a line guy at the Geauga County Airport 7G8.. many years ago. This one was hard to see
I don’t know why these people risk their lives in these crappy aircraft
@BlingtingSam I have been almost killed 3 times by million dollar aircrafts. One wich was a total loss due to engine failure 300 hours on the airframe . Their most concern, not " crappy " aircraft, and you, sir, are disrespect and uneducated. Have a nice day.
I would guess the engine RPM surged because the hub failed and there was no longer force required to turn the now departed prop. Really a sad ending to a pillar of the experimental community.
My guess also. Prop hub was probably cracked long before it broke. Stress crack, bad metal, something.
9:00 could one calculate the prop rpm with those frames?
If the hub fail, the propeller rpm doesn't increase. In this case the propeller rpm increased, causing the destruction of the propeller, so I think the hub doesn't was the cause.
Or the other way around. A propeller control or governor issue could have made the RPM surge beyond design rpm which would then have caused the propeller or its hub to fail.
@@gustavosegal5881 Not the propeller rpm; that of the engine.
The hub quite likely failed, thus removing all load from the engine & allowing the sudden & significant increase.
I had a 310P and had to rebuild the props. Learned way more than I wanted to know. The hubs keep the props from centrifugal forces exceeding 20 tons each if I remember right. When you have one fail it is catastrophic. It can rip the engine right out of the frame. Condolences to him, his family and friends.
Centrifugal force is a misnomer. It does not exist as a force in the realities of physics. Centripetal force is a real force that keeps an object moving in a circle, while centrifugal force is an apparent force that pushes an object away from the center of a circle:
Centripetal force
A real force that acts towards the center of a circle, or the axis of rotation, to keep an object moving in a circle.
@@danblumel The difference is mostly philosophical here, we are talking about the stresses upon the propeller hub. It also depends on your reference frame, which for the propeller hub is spinning at a few 1000 RPM …
How about you tackle a force being expressed in units of inertial mass (20 tons) instead of units of force (about 196,000,000 Newton)?
@@danblumelThe centrifugal force is the problem because it pulls from center. Ie the hub being center and the ends of the props being the outer circumference. When a prop fails the hub is pulled from center from said force. The reason it is centrifugal is because of the imparted rotation from the connecting rods to the crank to the hub. Making it a force that wants to push away from center when a prop fails.
@@danblumelcentrifugal force is one of several false forces that are actually inertial tendencies but may as well not be for practical reasons
As long as we all understand that "centrifugal" refers only to the direction of and not the nature or origin of the force. My work here is done. 😄
Not sure if it applies to this engine and gear box but I remember talking to someone about these LS automotive conversions. One of the major drawbacks was you couldn’t pull negative g because it would starve the oil pump for the propeller. If the hub has no oil pressure the propeller would drive full fine pitch thus increasing engine rpm. My guess is the propeller hub lost oil pressure somehow which drove the propeller to fine pitch which pushed the propeller rpm way above what it could handle and then the blades let loose and the engine went to its max rpm with no load on it.
That's an interesting limitation and would seem to fit the nature of the failure. I'll be very interested to hear the final report on this.
Yep. The witness CLAIMS he heard the over-speed sound before the failure, and since sound would be delayed and visual was instantaneous...
@joeneu your comment is worth reading and considering
The rev limiter on the engine should be set at rpm equivalent to prop rpm limit. So no way the engine can overspeed the prop. If he was flying fast and the governor failed and caused the prop to go to flat pitch, the prop could be passively driven to beyond its redline
Most aerobatic props work in reverse, or like a feathering hub if you will for this reason. Oil pressure to decrease pitch, so that if you do have oil starvation at the hub, you won't suddenly over-speed. Some other random aircraft have it that way as well.
Dang, bad luck on landing! He almost made the glide in.
Yeah, he did everything he could, just clipped a tree at a very bad time. RIP and condolences to the family and his friends.
Wonder if his vision was obscured by oil film on windscreen?
@@toastrecon The NTSB report says he was trying to land on that road 1/4 mile west of the runway, and saw a car coming and changed his landing path to not impact the car. He didn't want to injure someone on the ground, and sadly was killed. A true aviator.
Yes, very sad. Roads are attractive when seen from above, but the combination of cars, signs, guard rails and power lines along roads can make them a dicy choice. Of course, when it's road or trees you gotta take the road.
As a glider pilot we are trained for low altitude breaks of an aero tow rope. One of the key factors that get drilled into you during training is to quickly find the best reachable landing area. A rope break under 200’ agl is considered too low to safely turn back to the airport. So landing ahead in some fashion is advised.
Normally every airfield has around it a couple of options which can be better or worse depending on your altitude and wind.
The brief satellite image of the airport in this case seemed to show some open fields in the area. Landing on a road is certainly more convenient for retrieval than a corn field but that road? So narrow with trees and power lines, yikes. Even in a non emergency situation that would have been a challenge. Maybe that was the only option.
However, the point is to survive the landing first and foremost. Off airport landings are full of risks and the selection of the best place, quickly and under pressure is helped considerably by thinking about the best options before launch.
I suspect power pilots don’t dwell on this subject as much as glider pilots do. But maybe some of the same instruction should be given. It can’t hurt.
Assuming he was passing north over the airfield when it happened, then staight ahead was the best option undoubtedly. Looks like a marshy area, followed by a water filled quarry, followed by the landfill. All of those look like better options for survivability. He was probably used to that narrow runway though and may have felt he could "thread the needle" on that side street. It's surprising he didn't stall on the 180 turn.
You make a great point about knowing your options beforehand. Very little time for thought in those situations. A sad outcome indeed.
I’m sure this pilot had run through this scenario many times since it was his home airport. He actually accomplished the impossible turn but that just set him up for a perhaps impossible landing.
@@jimrankin2583 I'm not sure why he would have come up with such high risk options in that case. He was obviously a good pilot to have accomplished the impossible turn on what looks to be a high wing loaded plane, but it was all for naught with the landing site impediments. I take it this was not his own plane but someone elses? May have influenced his decision to try and save the aircraft.
@@boneseyyl1060This was his own plane, he built it himself and he offers/offered the kit to build the plane to others.
I commented the same thing then read to find another similar comment....I don't understand either the field was right there!!!
hey Juan, the ding that goes along with your subscribe and turn on notifications graphic is very loud and high pitched (it’s actually quite painful to listen to!) would be great if that could be turned down or replaced!
I second this!
I agreed.. i was wondering this also
I agree, I’d be great if he could change it
I'll pass that along to the intern...."Kellen!"...;-)
Yeah, it startled me.
So sad. The EAA community HAS suffered a great loss. Condolences to his family. R.I.P.
Nice coverage as usual Juan, thanks for what you do.
Prop failure is not just a problem with experimental aircraft. My father had a prop disintegrate on an IO-520 which ripped the engine from the airframe. Luckily he had not yet taken off but still got hurt running off the end of the airstrip (about a 30 % downgrade into a gully - cropdusting....)
Just wanted to make 2 observations that speak to a man I never knew's character: 1- He purposefully left his passenger on ground for one final check after maintenance and 2- my amateur eyes seem to see an evasive move at the end of his flight to avoid hitting a car with a passenger(s) in it.. knowing his own life would be in more danger.
Minimum 2 lives saved as his final choices on Earth. Incredible. RIP Mr. Williams.
That's probably all true, but unfortunately it points to the mistake of his choice of where to land when there were better options available. If he had chosen better, rather than saving the plane or saving someone else's life, he would have been able to focus on saving his own. He knew the area well, so he knew what his options were. This was an option but far from ideal in the case of the plane, the other people and especially his own life.
@boneseyyl1060 idk. I'm not a pilot, but from the looks of things off Google maps, the road to the right running parallel to the runway (rt 218) doesn't look a while lot better to have made the attempt. Same goes for clay st (the road on the north side that runs perpendicular to the runway).
Gotta keep in mind he was only a couple hundred feet up basically flying a glider. He didn't really have any other options other than those 3 roads I mentioned. None looked good imo.
@@joemalinak7410 Not a pilot either Joe, but I do know a little about flying. You are thinking that his only options are to land on a road.. And if saving the plane is the main concern you might be right. But the main concern has to be surviving the crash. And as you say, at that low of an altitude it is going to be a crash and not a landing. At that altitude and with no engine, his only real choice is to point the nose at the ground to maintain airspeed. Turning in any direction increases the risk of stalling or losing lift. In these situations real pilots will tell you to maintain as straight a heading as possible, pick the clearest open area ( and roads are not clear open areas) leave the gear up and fly the plane into the ground. The plane will slide and take some damage but more often than not the pilot will walk away. Trying to save the aircraft over your life is a poor choice.
He had those choices directly in front of him but chose to turn and try the road. And it cost him everything, not just a plane.
@boneseyyl1060 no, the roads were not the only places i assumed he could potentially land. I totally get what you're saying, but if you look at the area, the only real open area that I could see was at the north end of the runway across the street. At least only open area that i would guess was big enough that he could reach gliding to. Right where he was probably making the 180 for the street that he attempted to land on and a few hundred feet directly below him. At least that's what it looks like viewing the area on Google maps. Maybe you see something I missed. But that was my RUclips trained professional opinion 😁
@@joemalinak7410 Of course none of us really know what we would do in the that situation. Easy to sit with all the time in the world and decide. Having a plan beforehand helps and keep it simple. It's all you can really do. That open area in front was his best shot IMO. Sad that he won't be around to build more of those great looking planes.
Thank you Juan! So sad for this loss of life.
This gentleman participated in the D day reenactment held yearly in Conneaut OH ,just east if Geneva. The event is coming up in the next week or two. He will be sorley missed. RIP
What a sad news. I've met with the gentlemen a few years ago during a shop tour I've undertaken in order to assess the fabrication of their kits aircraft. Such a nice person is lost. My condolence to hos family and friends. RIP John.
The Diamond DA42 does very well with its Mercedes Benz Turbo Diesel Engines. Certificated and everything. Worked on them a lot.
Was curious about diesels. They run fairly slowly, with gobs of torque.
I won't call that well if you have been following it since the Thielert days.
@@jaysmith1408 It's good that they can run on jet fuel. Also the low RPM helps. However, to get the most out of the high torque, you need variable pitch propellers.
@@MetaView7 thats when they first came out. I actually prefered Thielerts over Austros.
@@markotrieste they used constant speed. Pretty efficient still.
That's awesome you posted one before you left for the airport! It was my absolute pleasure meeting you on the commute down South today. Have a great trip and I'll look forward to that new ceiling fan 😅.
Thanks Greg!
Glad you’re back. I had to watch some guy named Holt, I think, to get updates on the Park fire. A few years ago I wouldn’t have given 2 hoots about the fire. Then I found you 🎸
Holt Hanley and Mark Finan both do a good job picking up the slack for Juan.
When the hub failed the engine load went to zero, which would allow it to suddenly overspeed. Not the other way around.
I agree. This is my theory as well
You can't know that.
Could also be runaway rpm -> hub failure -> even higher rpm for a few seconds -> down to idle.
@@--SPQR-- Yes agreed, could have been either. Still unanswered questions.
@@--SPQR--the issue with that would be for excessive RPM you'd also need loads of power.
@@kain0m Not if it was an adjustable or constant-speed propeller that failed.
Three people in my EAA chapter were flying behind auto engines (two Subaru and one Chevy). Two had off airport landings that substantially damaged the aircraft. One was able to return to the airport with a blown engine.
Unlike aero engines, auto engines aren't designed to be cruising at max power settings. Chevy LS engines cruise at around 35% power or 2000 - 3000 rpm.
💪
KXLL 8 years ago Corvair engine plane crashed pilot lived never flew again that plane had several engine problems
How many experimental planes are flying with the good old VW engines that powered the Beetle?
@@maxmackinlay618I was just about to say that. They have a totally different duty cycle. They may have similar peak power but they are expected to it out it only for a small fraction of service life unlike aero engines that are designed to have very high outputs relative to their peak for most of the time.... It's a critical design factor.
I've been a huge fan of the LS engines since I bought my Z06 way back in 02... sixth gear on the interstate around eighty mph, it's just above idle rpm and gets 28-29 mpg. Drop down a few gears and it pulls hard to redline till 180 or so... incredible powerband even by todays standards. Seems like the perfect auto conversion on the surface, but for years Chevy had a tough time with drivetrains themselves, resorting to a crazy dual mass flywheel setup on the LT's to combat harmonics as a bandaid.
There was an auto conversion featured in KitPlanes magazine years ago about a fellow name Tracy Crook(?) that detailed his Rx7 rotary conversion in a Vans RV that should be required reading for anyone considering such an undertaking. He gave great insight and detail from start to finish, including more than a few engine outs and near misses. I decided to pay the Lycoming tax and worry a little less haha
I could not get into any aircraft with a gearbox to the propeller...unless it is a turboprop designed from the ground up for aviation and nothing but aviation (as turboprops obviously are). There have always been good reasons as to why aero engines are designed to operate at the (up to) 2500 RPM approximate range.
He came so close to bringing it home but was faced with powerlines on the right and trees on the left. Clearly kept his cool and control of the aircraft right up to the end.
Been doing these since the 1980s? Damn. What a tragic loss. You can KNOW the risks, but they're still there.
From Juan's reading of the summary, the driver of the car pulled over to the west as the pilot drifted east. Sounds like up to the end he was aware and trying to avoid other casualties.
Godspeed, sir, and rest in peace.
Thanks for creating an informative video about what led to the crash. It's a terrible loss to the flying community. RIP, John.
I worked for John at Titan Aircraft for almost 3 years. I worked on this plane on several occasions, as well as several others. Anything that had an LS on it was very nose-heavy.
@@PeacefulRallyCar-pw3csfind me a 6 cylinder that's substantially lighter than an LS and makes similar power, especially with all the turbo hardware. Won't get as good of millage for the same power level either, boosted motors run a richer mixture
@@zakn3954 yes surely someone has thought of it already
@@zakn3954The T-51 flew with Suzuki and Honda V6s, both weighed significantly less (100 pounds or more).
@@zakn3954 most modern V6 are going to be lighter than a V8 by around 50-100lbs. When something is hanging from the nose of the craft every pound matters.
An inline 6 is likely going to be just as heavy if not heavier than a V8, plus it going to stick out further ahead shifting the weight even more forward making it even more nose heavy.
@@madmax2069 lol look it up you will be surprised that most Modern v6's actually weigh the same or more than an all aluminum pushrod motor. Dohc, vvt, DOD, all that just mean more weight.
Terrible loss to the Experimental Aircraft community. A metallurgical examination of the prop hub should show where the failure started and how it prorogated through the hub. It will also show if there were any existing cracks in the hub. It will be interesting to know how many hours were on the hub. Auto engines are so tempting....
Totally disagree, normally the hub failure would cause the surge in engine RPM, not the other way around. I'd default to harmonics, prop failure, hub failure, governor failure in that order before the engine given that it and the PSRU were completely in tact.
I agree with you
Ditto
Governor failure or not was irrelevant after the hub had exploded
I own a Corvette with an earlier variant of this engine, the LS1. The LS3 is around 370 cu in and over 400 HP stock. They require a computer system to operate, unless the engine is very extensively modified. The computer in my car employs a "rev limiter" function, to avoid overspeeding the engine. I would imagine that if this LS3 were not modified to run without a computer, The engine could have been detuned to produce 300 HP, and rev limited to a value corresponding with the maximum safe propeller RPM. I am really curious about this engine installation, and what caused this failure. Godspeed to the pilot, and condolences to his family and friends.
I would think it still had an ECU, probably a custom built and programmed one.
We have no knowledge as to whether the engine speed was limited by the ECU.
The fact that the engine overspeeded suggests that the engine speed was NOT limited by the ECU.
The engine speed probably was limited only by the propeller pitch and pilot.
It is easy to see now, with the benefit of hindsight, this was not sufficient redundancy.
What now for all T51 owners?
I'm going along with the others. The prop hub failed and that was what caused the increased engine rpm. Hopefully the NTSB will be able to confirm this by syncing the audio and video from the recording.
As usual fantastic breakdown and analysis. So tragic to see one of these go down and with the designer onboard. RIP sir, hoping they find a flaw along the way…
I wonder if the high-rpm condition came after the failure since the sound takes a second +/- to get to the witness.
The sound was reported before the prop departed, so if that's accurate that's against this hypothesis.
Oh my God! a concept in nature about things we know versus the things people claim to have seen and heard. Winner Winner! Chicken Dinner!
@@B-System still, I would have asked for differentiation between just engine overspeed and prop overspeed. Engine over speed after failure is practically guaranteed. The absence of prop overspeed would be important to at what rpm the hub failed.
@@bendeleted9155I'm sure whoever made that determination did so after watching the video recording.
@@csolivais1979 good point. We didn't get to see that.
I knew John. Great human being, and a great stick and rudder pilot. I own a Titan Tornado II SS, and we'd had a conversation about it and aerodynamics 2-3 weeks prior. You're right, Juan. As owners and operators of experimental aircraft, we're test pilots. And we do pay more attention to our aircraft. We have to. My preflights are far more involved in an Experimental. Thanks for the great content, Juan. My thoughts and prayers go to John, his family, and everyone his life touched through the decades.
But sometimes people get complacent.
A good friend, high time etc, on a short local flight ran his RV out of gas and died.
@@hotrodray6802 Agreed. I see it a lot, and all it takes is someone interrupting you during a preflight. Sorry for the loss of your friend.
If you lose oil pressure and the prop goes to fine, the engine should not over-rev (if the base pitch is set correctly).
The prop blades were from whirlwind but the hub was made by Titan said someone familiar with the build.
Also if we start putting ecms on airplane engines then we could also have fuel cutoffs to prevent overspeeding like car engines have
@@Heatherder They do and it did
I love all the respectful discussions we can have in this community, and disagree respectfully. Thanks, Guys.
The owner pilot seemed very reasonable and quick to acknowledge the problems associated with making an auto engine work reliably in an aircraft. As he pointed out it’s the reduction units and other related system components that are more often the points of failure. I’ve always held the opinion that propeller reduction units are the stuff of industry. Just take a look inside the nose case of a big radial engine built in the forties. Very complicated, precision designed and manufactured planetary gears. I too like and fly almost exclusively experimental aircraft with the exception of my day job. But I never fly behind auto engines with experimental reduction units, belt drives or any of that stuff.
So hard for me to understand anyone taking chances like this since my dad died in a plane crash And September 12September 12, 1992We have no details from that accident Nor have we found any trace of his body or his aircraft.His aircraft number was N6759 sierra. I will send you the NTSB Accident report number.Thank you so much For checking into this for me! H. Paul miller's daughter Paula joy miller.
So sad! I can't believe I didn't hear about this until now. I live close enough that my house was on the map.
Thanks Juan, my condolences to his family.
Thanks for the critiques Juan.
I could easily understand an rpm surge if the gearbox had failed, unloading the engine. The gearbox could have subsequently locked up, causing shear forces within the prop hub to make it come apart, but the investigation determined the gearbox was intact, so that theory would be ruled out. Could the rpm surge have been due to a sudden pitch change of the propeller, caused by a failure inside the prop hub just before it came apart? Condolences to his family, and glad to see someone fastidious enough to test things before taking someone else up.
Yep, most likely pitch control failed, blades went to flat pitch and allowed the overspeed which caused the hub to fail.
John correctly identified the mating of the engine to the prop controller as a "problem" and not a challenge. His passing is a great loss to the Experimental community of builders and pilots, but still, as with all aviation accidents, another cautionary tale for improved flight safety. (An-2 crash survivor)
Dam it man .....he did very well but the road was too narrow RIP
The P-51 never met Mr. Martin Baker. But Mr. Baker is the only one who can save you from an engine out deadstick at 300 ft over unforgiving terrain.
The only problem with that is to keep the seats live. It would cost more than the airplane so unless you’re a millionaire it’s unrealistic.
Originally by hearing the 180 turn, I expected the typical stall. He darn near made it. Not much room to thread the needle. May have over corrected as it looks like he angled into the trees or just at minimum control speed and unable to correct in time.
Such a sad moment for family, friends and fellow pilots.
Regardless of experience, with aviation all it takes is just once…😢
Those utility poles on the right side make this a mighty narrow landing space to shoot for. Bummer that there wasn’t a safer space to shoot for.
I wonder why he didn't just go straight ahead. Looks like lots of open fields, and a lake.
@MrJeffcoley1 I thought the same thing. Also, someone said the landing gear was coming down. After a major failure I would just want to pancake in and hope to walk away from the landing.
@MrJeffcoley1 open fields, wow, you are correct, do not make the impossible turn!
@@jgalexander510 Yeah if you look at Google Maps there were really no good options. Even the fields dead ahead are small and surrounded by tall trees. The bigger roads all have power lines on one side and trees on the other. Even so, he almost made it.
Prop first or engine first?
Read the report.
“When the airplane pitched up, he heard the engine go to a “super high RPM” and then the “entire prop hub shatters.” He observed several parts and pieces explode from the nose section of the airplane, and the engine noise subsequently went silent.”
This one was close to home. Condolences to friends and family.
My educated guess is either a loss of oil pressure of the prop regulator failed, causing it to rapidly adjust to fine pitch
Good report JB. So sad a story. Using something for not what it was intended for obviously has inherent risks.
Wow that’s sad 😔
I mean, at least he didn’t die in an old age home, but still…
I’ve seen a couple T-51s in South Africa.
Sounds like he almost made it down. Every time I hear about the loss of an experienced pilot, it makes me think about what I could do to avoid a similar fate. Thats why this channel is so valuable.
I love your channel and I don’t fly a plane, never have but I love planes. I am watching the planes around the fires. I started that because of your channel. Best wishes and be safe
I initially thought it was odd that the car driver pulled over on the wrong side of the road but given the presence of the power lines that may have been a case of excellent situational awareness on his part.
Terry Kronk’s scale P51 with a detuned LS3 and 4 blade suffered a somewhat similar but gearbox shaft failure in 2012. RIP we all miss you brother.
This sucks, I spent a long time talking to John at Sun n Fun in 2024 about the Titan 51. He will be sorely missed. RIP sir.
Juan, you and Sal should do a joint utube stream sometime. You both are excellent storytellers.
Thank you, Juan.
Sad that the pilot was not able to land successfully. He was careful not to take the passenger until he tested the plane.
Why they don't design and install a governor on those engines. May not be failure free, but adds a layer of protection. Saddened for the loss of life, it's a sobering event to see this kind of thing happening.
Thank you for bringing us this video
Well done Juan. Answers coming I hope!
Does the engine show evidence of overspeed? V8 exhaust note is unique among aviation engines so it would be hard to say that witness statements would be sufficient to know actual RPM. If in fact overspeed, was there an rpm limiting device? Did it fail? Was it set too high?
A lot of open questions still on this one.
Thanks for another but sad report.Condolences to his family,safe flights mate,🙏🙏👋👋👍🇦🇺
Dang Juan!! What a loss!! I know this is hindsight, but already headed N., if had enough altitude, couldn't he have opted for a Lake Erie plane wash, w/wheels up water landing, swam away, & lived to fly again another day!!??
More than likely the prop failure occurred first then the engine overrevved.
yup
👍🏻👍🏻👍🏻👍🏻
NTSB are no dummies, and they have video?
This is my dream affordable aeroplane. Terribly sad loss.
Very sad story.
How do you know that the engine surged in RPM first and THEN the hub failed. Why not the other way around? Thank you!
Well, it's a report from an eyewitness on the ground, so I would guess that he heard the engine rev before he saw the debris separate. Sound travel delay would put the overrev event even further before the debris event than he would have perceived.
I think from the video they concluded that it was an initial surge and a subsequent failure.
Because the propeller was destroyed by high rpm
EDIT: Not just an eyewitness report, the eyewitness recorded video.
The hub could partially fail (causing the blades to go flat pitch) unloading the engine enough to overspeed the prop which would then physically break apart the hub. Alternatively the hub could just have failed in some way and the overspeed happened after the blades came free.
As as an auto mechanic for 50 years...I can't imagine trusting an automotive engine to fly me. That is not what they were made for. I continue to marvel at the ruggedness , simplicity, redundancy, and built in performance limitations of the airplane engine. They can literally chuck off a cylinder and keep running, piston flailing in the air. I just don't know why you wouldn't want that.
Lol and yet that was not what the problem was! Also look at the guys that put lycomings in VW's. Not exactly the definition of reliable.
People don’t want it because it’s not been barely improved in 50 years while auto engines have been improved greatly. Also, most people haven’t experienced an auto engine failing in 2,000 hours of use unless it was a simple dead battery.
At the same time, I have never had a car engine fail to start in 25+ years, anyone with any piston engine airplane experience knows thats not a typical experience. Ive never had a car engine fail catastrophically while driving nor do I think I personally know of someone who did, so that is on 10s of 1000s of hours, while I do know 2 people who had their rugged airplane engine fail catastrophically in flight (they are both fine) and thats probably on 100s, at most 1000s of hours. One of them was an engine with 25 hours total flight time. How many car engines have you seen explode in the first few days of driving it? And my car engine doesnt need to be rebuild every 50 hours, it will do 5000 hours with minimal maintenance. And thats not even mentioning cost. Or fuel efficiency. I certainly do see the appeal, but I recognize that the reality is more complex
It has nothing to do with the automotive engine. Most of the failures occurred at the propeller reducing gears. Even for the vaunted spitfires and mustangs, rolls Royce had a lot of problems designing the propeller gear for the Merlin engine. This is why you don’t see a lot of high speed rotating gearing on anything because it can be complex to design to run reliably
You seem to be a bit misinformed on quite a few things.
Aircraft engines need to be rebuilt roughly every 2,000 hours. The reason your car lasts 5,000 is because it is using a tiny percentage of its potential horsepower the vast majority of the time. Aircraft are run at 70-100% power the vast majority of the time. If you ran your car at redline all day it would not last long.
Also the first 100 hours are the most dangerous time for any new engine, automotive and aviation. Just look at all the issues Toyota is having right now.
The only way you’ve never had a car fail to start in 25 years is if you buy a new car fairly often. Most aircraft are 30 years old minimum.
I can certainly understand the attraction of flying, but as a non-pilot observer reading the almost daily barrage of ghastly fatal GA incidents that include the most proficient and experienced pilots within your community.... bless y'all, you have much bigger balls than I do.
Far more auto fatalities every day. Yet you'll hop right in one and drive away.
@@barrygrant2907 Two things for sure, I will never be killed by a shark, and I will never be killed in a GA crash.
Based on the comments, this MUST require a speed limiter on the engine. I'm a GM engineer and this is trivial to do on modern engines, via software. The LS3 is an older engine but can easily be retrofitted with simple actuators, and one electronic module. Modern kids do the Raspberry PIs in STEM classes. Turbines have the same problems, and those problems were resolved decades.
Except it was the hub failure and loss of the propeller blades that made the engine overspeed. A rev limiter wouldn't have changed anything.
@@chris1451
A speed limiter would have prevented the engine exceeding the set maximum RPM. They work if a car is in park or neutral, with zero load on the engine, and the gas pedal floored.
@@PhilipFly11 rev limiters work when the engine is under a predictable load be it the near zero load at idle or the predictable increasing while the accelerator is floored. Ever hear of a money-shift? it is a common enough death to many engines where the engine is being forced to over-rev by the transmission - the rev limiter cannot do anything to prevent it. An engine at high power then being unloaded the engine will over-rev usually to a lesser degree than a money shift- but damage to the engine is still likely.
Even the Pratt and Whitney PT6 turbine engine family has experienced a similar failures despite having overspeed protections included - the overspeed governor and fuel topping governor. The gearbox through a metallurgical failure will decouple from the power turbine and the power turbine will fly apart when it over-revs since there is no load to counteract the force from the gas flow
@@PhilipFly11 I perfectly understand how a rev limiter works. It would have done NOTHING for this crash. The prop broke THEN the engine over reved. Read the first comment. Geez.
@@chris1451 Rev limiter on the Engine, not any of the other gearworks. Same problem in all road vehicles, easily resolved.
Sad to hear about his crash. I bought a Titan Tornado II from him back in the 90’s after taking a demo flight in one with him.
I did the research on this powerplant last year to evaluate the project and it didn't take long to reject that crate motor from GM as received. As an A&P, there was far too much risk factor to consider it as a project. By the time I had reconfigured the engine to be serviceable, I was left with 3 useable parts - the crankshaft and both seals at either end of it. All other parts including the block would have to change to satisfy strength, oiling system redesign, fuel and ignition system and all the necessary additional components and parallel computers to build the engine with self correcting redundancy and 80 lbs or so less weight. The propeller and gear reduction still bothered me as there is little structural excess, but there are other options. The airboat guys have been doing this for years and better gearbox and prop combinations are available. I would have ended up with a test cell testing routine somewhere in the neighborhood of 7 months to get comfortable with what reliability and performance that I can resonably expect. Not impossible but not like that.
thanks for the information. The key with this engine and gearbox in this aircraft is that the engine can be used at low throttle settings and rpm and still provide lots of thrust, so it is not stressed at all compared to what it is capable of. But yes, the fuel and ignition systems are the weak points.
The propeller was a Whirlwind Aviation prop, a sister company of Whirlwind Propeller, in El Cajon, CA. Since about 2 1/2 years ago, the companies went separate ways.
Fuel injected engines like the GM LS engine are computer controlled that have adjustable Rev limiting features. There’s no way the engine could over speed the set limit under any circumstances, especially in this case while under load. The engine hit the set limit RPM only after the load (the gearbox and propeller) was was suddenly disconnected. What was seen and heard was the failure of the gearbox or prop hub failing that caused the engine to rev to the set limit and the pilot then pulling off the throttle.
As a caveat with my statement is that I don’t know what ECU is used in this application. If not a GM supplied unit, pretty much all aftermarket controllers offer the same functionality as GM units in automotive applications. Meaning RPM control would be the same.
Additionally, many aftermarket ECU’s or PCM’s offer (as do most GM units) transmission input and output shaft speed sensors that can sense slippage. Some also offer driveshaft speed sensors, all of which could easily be adapted to gearbox and propeller speed monitoring that will instantly reduce engine power output or cut power to the ignition coils when shaft speeds exceed parameters.
sorry for the lost of an experienced EAA pilot.
perhaps the engine didn't need the added oil? Would like more info on the LS3's condition (I'm a Vette owner, it's a great engine)
I also don't understand why he opted for a residential street with trees ... rather than the runway right behind him with apparently plenty of energy.
Nice Coverage Juan. Thank you.
There are thousands of Diamond DA40s and DA42s flying happily with Austro engines which are converted Mercedes diesels.
They have a real company backing them that’s spent thousands of hours on R&D to get them to work properly. Rotax and the Austro motors aren’t even remotely comparable to the applications on 99% of auto conversion homebuilts.
Consider that diesels operate at lower RPM than gas burners
@@DanielJohnson-ec8rk 4000 - 5000 rpm is still too much for the direct drive of the prop. DA40 has roughly 2:1 gear ratio.
@@PecekMichal that’s why I said diesels run at lower RPM, generally not more than 2,000
@@DanielJohnson-ec8rk please show me one diesel engine in an airplane running at 2000rpm. The few I know of are running at around 4000rpm
Unless the engine suddenly found a way to make a LOT more hp, it sounds like the prop pitch had to have suddenly gone to a very fine position, unloading the engine while it's throttle was mostly open. Failed prop governor, perhaps?
Thanks for the detailed report on the world of experimental aircraft.
Should have gone for the field and left gear up .terrible sorry this happened.engine revved due to loss of weight.of prop RIPJohn
My feeling is the urge to save the airplane was overwhelming, witness the turnback and lowering the gear. I agree, straight ahead into a field was doable, he had the advantage of no drag from a windmilling 4 blade prop, and a bunch of altitude to work with. Very sad. Similar outcome to the Howard Hughes racer replica accident a few years ago, prop governor failure and instead of using the chute, pilot tried to save the airplane by landing into rough terrain.
May God comfort his family. My sincerest condolences.
Super sad. Tried to save himself but came up short. RIP.
The low pass just before the failure....greatly reduced his landing options.
Interesting line on page 4: "Evidence of oil spray and an oil coating was observed on the belly of the fuselage, left wing, oil cooler area, tailwheel assembly and elevator."
On a plane with a continuous speed prop like the accident airplane was, if you lose oil pressure to the prop hub the blades move into their lowest-pitch/highest-RPM position. So...if he lost oil pressure to the hub in some way - either losing an oil seal in the hub or breaking an oil line - that would explain both the overspeed condition and all the oil on the aircraft. And, unfortunately, because the hub disintegrated in flight and the gearbox tore itself off the engine (which would also explain a broken oil line) during the impact, it's a theory we really can't prove.
Remember, Howard Hughes nearly died because of something similar when one of the props on his XF-11 lost oil pressure to a prop hub.
Sorry to hear about this...Looks like a nifty design; I saw a pair of these perform at a local (N. Ohio) airshow 10 years ago; both were powered by the Honda Odyssey 3.5 liter v-6, also rated at 300HP...
It needs to make that power at the required 2,000- 3,000 engine rpm as discussed at 1:30.
That’s a tough one. I worked at Titan for a few years and knew John well. It was difficult to hear of his passing.
Looks like a landfill to the north. Questionable terrain, but no trees. Wonder if he should have tried to put it down on the landfill straight ahead instead of turning into a tree-lined street.
Very unfortunate. RIP. Good analysis, Juan.
An unfortunate accident. Flying into Oshkosh in '81 in a Cessna 170, Steve Wittman in his V-8 Olds Tailwind passed me like I was parked. The only time I considered a car engine.
That V-8 that Steve had sounded sweet, I flew in to OSH in ‘81 and heard it running on the ground and in the air…
Very sad indeed.
Thanks again Juan.
That road would not have been my first choice for a forced landing. Looking at the surrounding area there was a field directly in front of him, with a couple more to the east.
I looked at those too, maybe not a wheels down landing, but they seem good enough for a belly landing.
Yep - not sure why Juan didn't reinforce that. It's a reoccurring issue
He might have been too high at that point, but the landfill further North also looks like a possibility. No trees at least.
This time of year, the field is probably full of corn. It might have been safer than a narrow tree-lined road, but it might not have seemed safer in the split-second needed to make the decision.
@@StrongDreamsWaitHere I guess, I'd rather corn than a small road though. It's the insurance's plane the moment it breaks, not mine.
Outstanding analysis as always, Juan.
Thanx Juan , sad seemed like a great guy ! He was just a little off on his no stick landing !
This sounds like loss of oil pressure or a governor failure. Kevin Eldredge had a failure at Reno in his Nemesis NXT, #42 "Relentless." This sounds identical. I was there for that. It lost oil pressure (sounded like it lost an oil filter), draining the entire engine rapidly around pylons 7, 8, & 9, through a roughly 4g turn. The prop immediately went fine and caused an overspeed, causing the blades to depart. I do not believe this was a prop hub failure, though the hub failing was likely a cascading result of another failure. It is highly unlikely it had anything to do with gearbox, and may not have anything to do with it being a conversion. As mentioned, we've seen this on typical "aircraft" engines as in the Reno example.
I agree - loss of oil pressure to the prop causing fine pitch and overspeed. An engine computer with overspeed protection would have been unable to keep the windmilling propeller from overspeeding. Car engines belong on cars unless they are FAA certified.
I wonder if he clipped the tree because he turned slightly to the left to avoid the oncoming car. The driver of the car reported seeing him coming head on and pulling off the road to his left. They each went left to avoid a collision.
I was wondering that too. I feel bad for the driver in that case. Wrong place wrong time.
It seems unclear which happened first. Did the prop hub fail first, causing the blades to separate, which suddenly reduced the rotating mass and drag, causing the surge in engine RPM? Or did the engine surge in RPM first, overstressing the prop blades & hub causing them to fail?
If you look at many of the auto conversions in aircraft, the installs are just extremely scary. The wiring is usually awful and the fuel, coolant and oil lines (if there are any) are usually just bargain bin garbage. Viking Aircraft Engines doesn't even use a pressurized cooling system, because they refuse to run AN hoses and have trouble with the coolant hoses popping off of their fittings! It's just the wild west with most of those guys.
Was this a variable-pitch prop? The engine speed surge could have been the pitch mechanism going to flat pitch while the engine was under load.
very sad and tragic