Bo down Pembroke Pines, FL

[Ed Haywood]

An informative post, but wouldn't "no energy loss" require drag to be zero?

Good catch, mistype on my part, meant to say no altitude loss. Energy in the context of aerobatics is a much longer discussion, so I'll spare everyone the hijack.

 

[Palmpilot]

I’m not following. How would the airplane hold Vy after a power loss and not stall?.

By lowering the nose and descending. Vy is an airspeed, not an attitude.

My understanding is that if trim is set to eliminate control forces in the climb (which is what I do), then removing power and letting go of the controls will result in the nose dropping on its own. So I guess the question is whether the nose will drop quickly enough to avoid a stall. My impression is that it does so in the planes I have flown, but I have not experimented with it.

 

[Kenny Phillips]

My understanding is that if trim is set to eliminate control forces in the climb (which is what I do), then removing power and letting go of the controls will result in the nose dropping on its own. So I guess the question is whether the nose will drop quickly enough to avoid a stall. My impression is that it does so in the planes I have flown, but I have not experimented with it.

We experimented with this, but only in a Skyhawk and a 150, and if you trim out all control forces, you can yank the power and never come close to a stall. A Bo? Perhaps less benign.

 

[MFE]

Okay. By throwing it out there as a possibility on the forum it certainly came across, at least to me, as a viable option.

Thanks for clarifying.

I took it as "here's how much you lose if you DO stall in the attempt", like so many do.

 

[Ed Haywood]

A more realistic test IMO would have been to set trim to takeoff position and hold stick pressure for Vy, Vx or some other arbitrary climb attitude which is what quite a few pilots are doing just off the runway below pattern altitude.

This is a valuable discussion, so please excuse me if I come across a bit pedantic. But this is basic aeronautical knowledge, not some crackpot theory. My comments are in general, not directed at you specifically.

Takeoff trim setting in most light aircraft is specifically defined as that trim necessary to hold airspeed at Vx in takeoff configuration with no control forces. If you are flying a certificated aircraft, then a test pilot determined the correct marking for your aircraft during the certification process. That mark is not arbitrary.

If you are holding back pressure during your departure, then one of three things are true: A) you are slower than Vx; B) you have changed aircraft configuration (flaps, gear); or C) you are not trimmed for takeoff.

Pilots get confused about this because you apply back pressure to rotate. But you do that because condition A is true: rotation speed is slower than Vx. If you leave trim alone, the aircraft will accelerate to Vx and you will not need back pressure.

If you are trimmed for a specific airspeed (any airspeed) and your CG is within limits, when you reduce power your nose WILL drop to maintain airspeed, unless you actively apply control pressure to resist it. If you add power, your nose will rise. Again, basic aeronautical knowledge, not crazy theory.

Yes, every airplane is different. Yes, airplanes fly different as W&B varies. Yes, other factors apply to twins, canards, Lake amphibs, etc. But by all means go out and try it in your plane and see how it performs so you know for sure.

 

[Ed Haywood]

We experimented with this, but only in a Skyhawk and a 150, and if you trim out all control forces, you can yank the power and never come close to a stall. A Bo? Perhaps less benign.

The only germane difference would be low wing vs high wing. Thrust above or below induced drag vector does affect reaction to power changes. But the other major force vectors in the vertical plane are the same in every conventional aircraft. Gravity pulls down at the CG, while lift pushes up at the center of lift on the wing. Since CG is forward of center of lift, aircraft wants to rotate down, and downward force is needed at tail to push down and keep nose up. When you adjust trim, you are just slightly varying the amount of downward force on the tail from the built-in reverse AoA to achieve equilibrium at a given airspeed.

 

[Juliet Hotel]

Takeoff trim setting in most light aircraft is specifically defined as that trim necessary to hold airspeed at Vx in takeoff configuration with no control forces. If you are flying a certificated aircraft, then a test pilot determined the correct marking for your aircraft during the certification process. That mark is not arbitrary.

All these years and I never knew that. Never once heard actually. Learn something new every day. But honestly far as I can remember, never had the experience in any plane I've flown of setting trim to takeoff, then holding Vx and realizing 'hey what'd ya know, it flies hands off at this speed with that trim setting'. Not saying you're not correct, just that I've never noticed it to be the case.

 

[Ed Haywood]

All these years and I never knew that. Never once heard actually. Learn something new every day. But honestly far as I can remember, never had the experience in any plane I've flown of setting trim to takeoff, then holding Vx and realizing 'hey what'd ya know, it flies hands off at this speed with that trim setting'. Not saying you're not correct, just that I've never noticed it to be the case.

Yeah, for some reason it's not part of the basic curriculum. But google it and you'll see I ain't making it up. Then go out and play with it and you'll see it works. Not a super precise thing, as trim markings are rough approximations and everything I have said is a generalization, but the principle holds.

Here is a really good article on the subject. https://www.aviationsafetymagazine.com/features/pitch-trim-principles/#:~:text=The purpose of the takeoff,down in retractable gear airplanes).

I have experimented with a C-182. You can take off, fly the pattern, and land mostly hands off without ever changing trim from the takeoff mark. Takes back pressure at rotation and flare, and some throttle jockeying in the downwind to find level, but it works. Honestly I think it flew better that way than when constantly fiddling with trim.

Doesn't work as well in my Decathlon, because the power to weight ratio is different. With myself and half tanks, I am about 800 lbs lighter than a fully loaded 172 with the same 180 hp engine, and my CS prop set for climb. If I climb at Vx of 85mph, it's like a moon shot, almost a 45 degree climb. Can't see crap and I'm at pattern altitude by the end of the runway. Freaks you out, but the airspeed will hold at 85mph all the way up. I usually push the trim forward a bit to 100mph once I get above all obstacles just for comfort factor.

 

[jsstevens]

So you think it’s a good idea to train and plan to not effect any pitch control after a low altitude engine failure during takeoff, only steering for the field? Because at this point that’s exactly what I’m saying is a bad idea. In fact my earlier post stated that all the pedants ripped up was based on exactly what you are saying... but I think it’s a bridge way to far to even consider not positively controlling the aircraft in all axis of flight after an engine failure. That’s what our spy Matt is proposing and that’s what I’m taking issue with from this conversation.

No. He has suggested that the initial push to keep from stalling is not necessary. If you let the plane drop it’s nose as it’s trimmed it will do that for you. He’s not said keep you’re hands off after, just that initial change after the engine quits will happen safely in its own IF YOU LET GO OF PITCH.

Which is the same thing I found in the 172s I’ve flown. And I’ve tried several.

I was trained (not for emergency recovery) that the airplane will change pitch on its own to maintain the trimmed airspeed. Add power, the nose goes up and the plane climbs. After a few oscillations it’ll steady back on trimmed airspeed. Same for reducing power even to idle. Nose drops, it oscillates around pitch and airspeed a few times then steady on trimmed airspeed. Is that not what you were taught?

 

[Ed Haywood]

I am puzzled why pilots think you stall if your engine quits in a climb. Stall is not determined by airspeed. It is determined by Angle of Attack. When the angle between wing chord and relative wind exceeds critical AoA, smooth airflow is interrupted, your wing quits generating lift, and you stall.

If you cut power and airspeed decays, think about what the relative wind does. It gradually changes downward, following the aircraft flight path, which is parabolic. The aircraft is designed to seek equilibrium, which means that unless impeded by the pilot, the wing chord will change with the relative wind and the AoA will never exceed the critical angle. As long as the rate of change of attitude is equal to or greater than the rate of change of relative wind, you will not stall, regardless of how slow you are going.

This is a totally different issue than the size of the lift vector, which is proportional to AoA. The higher the AoA at a given airspeed, the more lift that is generated. Until of course you exceed the critical AoA, then no lift is generated and you stall.

That's how departure stall accidents happen. The pilot tries to increase (or maintain) lift by increasing AoA, and exceeds the critical angle.

If you lose power in a climb, do not try to maintain the size of the lift vector by increasing AoA. Allow the aircraft attitude to change to follow the relative wind, and you will not stall.

 

[Ed Haywood]

So you think it’s a good idea to train and plan to not effect any pitch control after a low altitude engine failure during takeoff, only steering for the field? Because at this point that’s exactly what I’m saying is a bad idea. In fact my earlier post stated that all the pedants ripped up was based on exactly what you are saying... but I think it’s a bridge way to far to even consider not positively controlling the aircraft in all axis of flight after an engine failure. That’s what our spy Matt is proposing and that’s what I’m taking issue with from this conversation.

Of course not. I am saying exactly as jsstevens summarized. You do not have to worry about instantly shoving pitch forward in the event of a power failure. The airplane will you do that for you if you are properly trimmed, which I recall you are (correctly) an advocate of. All you have to do is not fight it, and you will not stall. Pushing forward is helpful, but you are not going to fall out of the sky if you are too slow to react. That IMO is an internet myth. Like leaning during taxi.

Once the nose drops, whether naturally or by your positive action, you should do exactly as every pilot is trained in their first 10 hours. Set up for best glide, pick a landing site, and fly there. If above minimum turnback altitude, maybe that landing site is the airfield. If below, land straight ahead or at an angle. If you have not experimented with your aircraft to determine the minimum turnback altitude, then get with the program. When you do your experiment, you will learn exactly how your aircraft behaves when power is cut in climb attitude. If it's different than I am saying, then come back and tell me I am FOS and I'll gladly eat crow.

 

[Ed Haywood]

One data point that is not directly relevant to this situation, but might help explain my perspective. As an aerobatic pilot I spend training time learning to react to botched maneuvers. Sometimes you overcontrol or run out of energy and find yourself in all sorts of crazy unintended attitudes. Inverted, steep climb, steep bank angle, sometimes just hanging there in the air doing nothing. Think running out of energy and falling out of the top of a loop, or starting the hammerhead kick too late and falling sideways. Or pushing too hard on the second half of the 45 on a reverse cuban and entering an incipient inverted spin.

The reaction to all these things is the same. Center the controls and reduce power. No matter what absurd attitude you are in, the airplane WILL fall through the horizon and enter a dive. Let the plane fly itself. Once that happens, roll to upright, level the wings, and pull out.

Your spam can or super XC machine flies the same way. The nose is heavier than the tail, the CG is in front of the wings, and the tail is draggier than the nose. Left alone, it seeks equilibrium, which means it heads downhill like a lawn dart. The nose wants to follow the relative wind, which means the AoA wants to reduce itself. Let it. Planes don't stall ... pilots stall planes.

 

[Tantalum]

If you are pitched up for Vx and grenade an engine low to the ground on climb out you are guaranteed to be well below blue line and highly likely to fall below Vmc by the time you recognize and respond

Thanks, this is a great point

 

[nauga]

Takeoff trim setting in most light aircraft is specifically defined as that trim necessary to hold airspeed at Vx in takeoff configuration with no control forces.

At a single defined center of gravity I'm not intentionally being pedantic, test results under one set of conditions does not mean the results are valid for all conditions. Applying lessons learned with a forward CG when something happens with an aft CG may not give the desired results...to put it mildly.

Nauga,
referred

 

[Ed Haywood]

Be very careful about following this in a twin.

Let's just stipulate that twins are a totally different ballgame, and also that by the time you are flying twins, you are probably beyond entry level discussions.

 

[Ed Haywood]

At a single defined center of gravity I'm not intentionally being pedantic, test results under one set of conditions does not mean the results are valid for all conditions. Applying lessons learned with a forward CG when something happens with an aft CG may not give the desired results...to put it mildly.

Nauga,
referred

That's a fair point, and I don't consider good faith pursuit of understanding to be pedantic at all. But I would respond that this is why CG limits are established during design and confirmed during flight tests. Within that specified range, demonstrated flight behavior is sufficiently close to expected that it is not considered to be a hazard. For instance, we know that an aircraft loaded within CG range is recoverable from a stall because the CG is sufficiently forward of the center of lift. This was computed during design and verified during testing. Outside of that CG range, all bets are off.

 

[Palmpilot]

...an internet myth. Like leaning during taxi.

Leaning for taxi is a myth?

 

[PaulS]

I am puzzled why pilots think you stall if your engine quits in a climb.

Ed, I don't think anyone here or any competent pilot has said this. But, there apparently are a lot of accidents where the engine dies and the pilot ends up spinning it in. On top of that, in twins, in the last year there has been at least one, maybe more, where an engine is lost 50 feet above the runway, and the airplane flips over and augers a hole in the ground. We need to do better.

This discussion has been great, but the bottom line is we need to train for this stuff, hopefully with the correct concepts, and tackle this problem.

And for the poster who keeps saying that it is impossible to knock these statistics to zero with training, no ****e sherlock, nobody is saying that.

 

[GRG55]

Let's just stipulate that twins are a totally different ballgame, and also that by the time you are flying twins, you are probably beyond entry level discussions.

My post was responding specifically to a post by someone who is currently training for a multi.

 

[nauga]

That's a fair point, and I don't consider good faith pursuit of understanding to be pedantic at all. But I would respond that this is why CG limits are established during design and confirmed during flight tests. Within that specified range, demonstrated flight behavior is sufficiently close to expected that it is not considered to be a hazard.

Within the certified range stability characteristics and flying qualities are demonstrated acceptable, not similar throughout the range. Extrapolating forward CG characteristics to aft CG without appropriate corrections is risky.

Nauga,
who knows his envelope

 

[Matthew Rogers]

Otherwise - I went to the airport to do some testing with my C150 and.....I had a completely flat nose strut. I filled it back up with air, but wasn't about to go flying not knowing how long it would hold. One of the other owners will be there tomorrow and if it holds, he may either have the mechanic come out or do a test flight and see how it rides. So no more info about how it performs engine out vs. trim settings from me at this point.

I would certainly not argue that one should not touch the elevator controls at all in an emergency situation. However, consider a slightly higher engine out. We do immediately trim for best glide and you are basically hands off pitch control until short final, unless you need to change your speed to affect your sink rate. It does take a lot of pressure off (pun intended) the need to hold a specific airspeed all the way down with your brain power and hand control, freeing up both for other tasks like radio, knobs, maps, panicking , etc.

But I am glad for bringing up any info that gets a conversation going and helps someone learn something new.

 

[Matthew Rogers]

Perhaps we should close this thread and I will open a new one in Flight Following after I do some flight testing with my 150 to see how it may respond in an engine out at various trim settings. Whenever I get the nose strut figured out. Probably a good time to finally shim the steering collar to get rid of more play/shimmy.

 

[Kenny Phillips]

Let's just stipulate that twins are a totally different ballgame, and also that by the time you are flying twins, you are probably beyond entry level discussions.

But not above entry-level mistakes, per the accident database.

 

[kyleb]

The article that really sealed the deal for me was in Sport Aviation. Most discussions go around distance, bank angle and distance to glide with the turn at the end. BUT, the gist of this article was if your rate of climb is not significantly better than your best glide in FPM, it's mathematically impossible to get back to where you want to be. The best rate of climb in the 65 hp Chief is somewhere around 400 fpm in real world conditions at gross. Best glide is conservatively close to 500 fpm in real world conditions with 57 mph, no engine, dead prop. Makes it easy to say that until you get altitude in the bank and have made a turn to crosswind to cut the distance to the runway, it's going to be tough shedding to do the impossible turn.

Except you're probably operating off of a 5,000' runway and you're off the ground in 700'. You're probably at 400' crossing the end of the runway. When the SHTF, you don't need to glide all the way back to your takeoff point, only to the near end of the runway (or maybe all you need to do is clear the airport fence).

 

[Ed Haywood]

Except you're probably operating off of a 5,000' runway and you're off the ground in 700'. You're probably at 400' crossing the end of the runway. When the SHTF, you don't need to glide all the way back to your takeoff point, only to the near end of the runway (or maybe all you need to do is clear the airport fence).

Or in this case, operating off a 3200' runway, in an aircraft with an 1800' takeoff roll and 3000' obstacle clearance distance at max gross. With 2 pax they were well under gross, but it is reasonable to assume they were under 500' when they crossed the fence.

Here is a discussion among Bo pilots at the ABS. Consensus seems to be 1000-1200' minimum altitude loss to make a 180 turn. https://www.bonanza.org/community/m...rning-to-the-airport-after-an-engine-failure/

This outcome was sadly predictable.

 

[kyleb]

Here is a discussion among Bo pilots at the ABS. Consensus seems to be 1000-1200' minimum altitude loss to make a 180 turn. https://www.bonanza.org/community/m...rning-to-the-airport-after-an-engine-failure/

Did anyone establish the maximum altitude the aircraft reached and how far from the field it was? It would be interesting to run a few numbers based on that. However, I struggle to believe the 1,000-1,200' estimate from the Bonanza forums unless they were climbing at Vx. I realize my practice 180's in the RV don't exactly translate to a Bonanza, but that estimate is 2-3x what it would take me in the RV. Note - some of the Bonanza talk seems to include altitude needed to lower the gear and make the landing.

 

[steingar]

I bet they’d have no problem at all letting you do a spiraling ascent before departure.

My airport is one of the busiest in the state, and we're right under a class Charley. Trust me, they'd have a big problem with it. Besides, I didn't buy a fast airplane to orbit the airport, I bought it to go places. Orbiting the airport is for Skyhawk pilots.

 

[Palmpilot]

Did anyone establish the maximum altitude the aircraft reached and how far from the field it was?

I tried to look it up on FlightAware, but the only listing was from six days before the crash.

 

[exncsurfer]

Did anyone establish the maximum altitude the aircraft reached and how far from the field it was? It would be interesting to run a few numbers based on that. However, I struggle to believe the 1,000-1,200' estimate from the Bonanza forums unless they were climbing at Vx. I realize my practice 180's in the RV don't exactly translate to a Bonanza, but that estimate is 2-3x what it would take me in the RV. Note - some of the Bonanza talk seems to include altitude needed to lower the gear and make the landing.

That Grider video shows an estimated(by who?) path. I don't know if that drawing is based on anything other than speculation, but if it were accurate I wouldn't think they made 500ft based on that short path.

 

[Ed Haywood]

Did anyone establish the maximum altitude the aircraft reached and how far from the field it was? It would be interesting to run a few numbers based on that. However, I struggle to believe the 1,000-1,200' estimate from the Bonanza forums unless they were climbing at Vx. I realize my practice 180's in the RV don't exactly translate to a Bonanza, but that estimate is 2-3x what it would take me in the RV. Note - some of the Bonanza talk seems to include altitude needed to lower the gear and make the landing.

No idea, but the Bo pilot who tested it said he was surprised by what a boat anchor his plane became with power off. RVs are known for their efficiency, so they are probably not at all comparable.

 

[flyingcheesehead]

BUT, the gist of this article was if your rate of climb is not significantly better than your best glide in FPM, it's mathematically impossible to get back to where you want to be.

That depends greatly on the length of the runway you departed from and the wind at the time. If you have a strong headwind, it's not at all unlikely that if you lose it high enough to make the turn back that you'll end up going off the end of the runway. Likewise, with a really long runway, where you could land straight ahead on the runway for a while and only need to turn back when you're higher, even with a lower performance airplane you'll have a fair length of time where the turn back will be "easy" because if you can make the turn you can come up a mile or two "short" and still be on the runway.

For example, in this accident, if it was a (a pair of) 6,000 foot runway(s), the Bo gets down on the runway no problem.

I’m not following. How would the airplane hold Vy after a power loss and not stall?

I'm not following. Why would the airplane stall due to a power loss? You point the nose down and glide, just like you'd do after power loss at any speed.

I don’t need to know how many successfully performed it. The statistics show that those who tried to make the turn back, most commonly, ended up in a fatal situation.

How do you know "most commonly" without knowing how many successfully performed the maneuver?

This is one of those things that is, unfortunately, a complete mystery because there is no data for how many power losses there are without associated accidents. I wish the NTSB would start requiring reports of any sort of engine failure so that we at least had some clue both for this and for multi-engine aircraft.

 

[flyingron]

Attached is the prelim. Do I have to say how much I hate the new NTSB query system (CAROL)?

 

[PaulS]

Attached is the prelim. Do I have to say how much I hate the new NTSB query system (CAROL)?

"A witness at HWO reported that he heard an engine run-up being performed near taxiway Bravo before the airplane’s departure. He stated that the engine was sputtering, “like rough idle.” He heard cycling of the propeller “a few times” and the engine backfired when power was increased during each sequence. He further reported that the engine rpm sounded “…high, very high. From low to full rpm repeatedly which was more than a normal run-up. He was doing it fast.” The witness did not observe the airplane’s takeoff."

"The witness had diverted his attention when he heard the airplane suddenly experience a total loss of engine power, adding that it “failed completely.” At that time the airplane was about 100 to 200 ft past the departure end of the runway and at an altitude “definitely lower than 300 ft above ground level.” The airplane remained at the same attitude for 1 to 2 seconds, then started a “gentle” right bank while maintaining same pitch attitude. The airplane then “stalled,” spun, and pitched nose down. He heard a bang sound and noted an explosion."

We need to do better.

 

[Ed Haywood]

Witness accounts are often unreliable, but this one sounds fairly solid.

Obviously there were issues with pilot judgement for taking off after a questionable runup. IMO you're not a fully qualified pilot until you have taxied back to the hanger after making a No Go decision at runup. Can be a hard decision to make on the spot, but better than burning to death.

Attempting to turn back at 300 AGL in a Bonanza is madness. There is no question AT ALL that straight ahead is the only option in that aircraft in that situation.

 

[TrueCourse]

Discussing a turn back to the airport after an unexpected engine failure, although educational and entertaining, wasn’t even the key point of this accident. It appears deciding to take off with a potentially sick or underperforming engine that could expectedly fail may have been much more relevant.

 

[Ed Haywood]

Discussing a turn back to the airport after an unexpected engine failure, although educational and entertaining, wasn’t even the key point of this accident. It appears deciding to take off with a potentially sick or underperforming engine that could expectedly fail may have been much more relevant.

Disagree. Both issues are equally relevant to the outcome. Accident was survivable had the pilot not made a decision which was clearly contrary to training. This is pretty much the classic illustration of why pilots are taught not to turn back. And it lead directly to the death of a kid, because the pilot gave away his ability to select his impact point.

 

[PaulS]

I think the turn is irrelevant if you let the airplane stall.

 

[woodchucker]

I’m very skeptical of that, very.

I would wager that most all of us fly the initial climb in a trimmed configuration at or near Vy. If it was that easy to prevent a departure stall, the accident statistics would look a bit more rosier. I suggest you go out with an instructor and have them do some simulated power loss on departure scenarios at altitude and just watch how fast the airspeed and energy decays - it’s an eye opener.

This thread inspired me to do just that last week in our club Cherokee 180. My first time simulating that maneuver. During the turn back my cfi remarked we were dropping 1000 fpm. My turn varied between 30-40 degrees I suppose. 1000 feet wasn’t enough, although depending on the airport environment might have made at least the grass.

Going to try it again tomorrow in our Tiger.

 

[Sudburian]

The outcome for this accident was ok, one or two have long term injuries, but no one died.

Just wanted to see what others think, it just seems like a tall order to fly perfectly to the crash site.

Kathryn's Report: Cessna T210M Turbo Centurion, N761RG: Accident occurred August 07, 2020 in Hanna, Duchesne County, Utah

Student pilot here who saw this a while ago and am also curious what pilots have to say about the handling of the engine failure. Btw the front seat passenger suffered a very serious, possibly permanent spinal cord injury that may leave him in a wheelchair for the rest of his life.

 

[BrianNC]

'Flying Lessons' from Mastery Flight Training on the subject from the perspective of the low engine usage over the years and the overhaul being done 25 years ago, and 'deferring engine overhaul indefinitely'. Interesting paragraph here if it hasn't been brought up already:

A witness reported that he heard an engine run-up being performed before the airplane’s departure. He stated that the engine was sputtering, “like rough idle.” He heard cycling of the propeller “a few times” and the engine backfired when power was increased during each sequence. He further reported that the engine rpm sounded “...high, very high. From low to full rpm repeatedly which was more than a normal run-up. He was doing it fast.” The witness did not observe the airplane’s takeoff.

And: This brings us back to the new LESSON I derive from the additional information provided in the NTSB preliminary report on the tragedy that prompted this discussion: Why do we even bother with preflight inspections and Before Takeoff engine run-ups, if we’re going to ignore unexpected or abnormal indications and rationalize them away in our desire to fly anyway?


http://www.mastery-flight-training.com/20210408-flying-lessons.pdf