Airplane down at Addison (KADS)

MauleSkinner said:
This is my answer...
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Pure speculation on my part, but Vmca assumes a feathered prop, correct? If the prop didn't feather in this case, that would seem to be a contributing factor. The POH calls for the pilot to maintain engine power after an engine failure so that the auto-feather can function. So, what if the pilots did exactly that (maintained take off power), but the prop didn't feather as intended? Someone up this tread said the video showed the prop wasn't feathered before it rolled over. I honestly can't see that in the video myself. But if that's true, that seems significant.
 
PPC1052 said:
Pure speculation on my part, but Vmca assumes a feathered prop, correct? If the prop didn't feather in this case, that would seem to be a contributing factor. The POH calls for the pilot to maintain engine power after an engine failure so that the auto-feather can function. So, what if the pilots did exactly that (maintained take off power), but the prop didn't feather as intended? Someone up this tread said the video showed the prop wasn't feathered before it rolled over. I honestly can't see that in the video myself. But if that's true, that seems significant.
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Yes, for the 350 Vmca assumes a feathered prop, and if it didn't feather, that would make a significant difference in controllability. It should, however, still be controllable, but power reduction on the good engine would help. Clearly, for whatever reason, this airplane didn't have adequate yaw correction in for the conditions that existed, and whatever the airspeed was in relation to published Vmca wouldn't be relevant, but I'd have to guess that the airplane was fast enough to not roll over initially, but slowed beyond it's control capability, again "for whatever reason".
 
After seeing the videos, I guess my question as a rank novice aviator is: At what point does the flight become theoretically irrecoverable? Even in the severe side slip, is it possible a guy can mash the rudder and get back to flying even with a prop windmilling?
 
David Herzfeld said:
After seeing the videos, I guess my question as a rank novice aviator is: At what point does the flight become theoretically irrecoverable? Even in the severe side slip, is it possible a guy can mash the rudder and get back to flying even with a prop windmilling?
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I'm guessing both pilots were already pushing the right rudder pedals to the stops.
 
David Herzfeld said:
After seeing the videos, I guess my question as a rank novice aviator is: At what point does the flight become theoretically irrecoverable? Even in the severe side slip, is it possible a guy can mash the rudder and get back to flying even with a prop windmilling?
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I couldn’t tell ya where it gets uncontrollable but my ME DPE said he’s been upside down twice at altitude from incredibly unprepared ME candidates. He recommended continuing the roll back to upright... at altitude... if one were to find themselves the unwitting recipient of same behavior by a student. LOL. (He also recommended to be faster than that in taking the aircraft and fixing it before that happens... but momma said there’ll be days like this...)
 
Cooter said:
If there is no more power driving the rotor, what causes the increase in RPM? It seems like RPM could only be preserved, not increased. Is that an effect of simulating power loss for training that wouldn’t necessarily occur in a real engine failure?
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A better explanation than those diagrams on what’s powering the rotor in an auto. Basically the TAF is forward the axis of rotation in the driving region creating thrust. That region will increase / decrease with collective changes. Also, factors such as weight, DA, forward speed and turns will increase / decrease rpm as well.

Blade twist is essentially for two reasons, better lift distribution in powered flight and provides for better autorotation characteristics for loss of power.

5A363CAC-B4B5-497E-BB25-8DCBAF2E27EA.jpeg
 
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Velocity173 said:
A better explanation than those diagrams on what’s powering the rotor in an auto. Basically the TAF is forward the axis of rotation in the driving region creating thrust. That region will increase / decrease with collective changes. Also, factors such as weight, DA, forward speed and turns will increase / decrease rpm as well.

Blade twist is essentially for two reasons, better lift distribution in powered flight and provides for better autorotation characteristics for loss of power.

View attachment 76379
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You fling wing guys deal with seriously cool chit, but memorizing all of it... unnnngh. LOL.
 
Velocity173 said:
A better explanation than those diagrams on what’s powering the rotor in an auto. Basically the TAF is forward the axis of rotation in the driving region creating thrust. That region will increase / decrease with collective changes. Also, factors such as weight, DA, forward speed and turns will increase / decrease rpm as well.

Blade twist is essentially for two reasons, better lift distribution in powered flight and provides for better autorotation characteristics for loss of power.

View attachment 76379
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Helicopter physics makes my brain hurt.
 
denverpilot said:
You fling wing guys deal with seriously cool chit, but memorizing all of it... unnnngh. LOL.
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Yeah the aerodynamics can get pretty crazy. Systems memorization as well. Friend of mine just started training on 747s with Atlas and said Black Hawk stuff was harder to learn than the 747. Couldn’t believe it.

Obviously they’re known to be a handful to fly but to reiterate what @IK04 said, SE failure in a twin helo on takeoff is usually a lot easier than fixed wing. There’s no asymmetric thrust to worry about. No extra drag from the dead engine and accompanying side slip. No critical engine either, except for one being stronger than the other. Basically if in your SE envelop, you just reduce collective a bit and keep trucking along.
 
Velocity173 said:
Yeah the aerodynamics can get pretty crazy. Systems memorization as well. Friend of mine just started training on 747s with Atlas and said Black Hawk stuff was harder to learn than the 747. Couldn’t believe it.
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Yep. Neat. Like @flyingcheesehead the aerodynamics hurts my brain, but from watching a bunch of heli instruction videos, in practical application it seems like it boils down to a handful of things to actually do/take specific actions, and a few no-nos to avoid. Simpler done than understood, for lack of a better phrase?

As you go up the food chain in the jets, systems gets harder but in the highly automated ones the memory items get shorter.

I laughed when my 787 buddy told me how many memory items there are in that airplane. Let’s just say you can count the boldface items on one hand.

And one of those is, “If a complete electrical failure, deploy the RAT.” LOL.
 
Well, the final report is out, and it's a doozy.
Report: Final
Docket: Docket

The basics: Loss of thrust on the left engine 7 seconds after liftoff, it veered to the right, rolled and crashed.

After reading both the report and a large part of the docket, here's the simple story:

The pilot was experienced but kind of a cowboy - He did not like to use checklists during normal (ie non-training, non-checkride) flights. He did not do a weight and balance, and the plane was around 600 pounds over gross and near aft CG limits, though they decided that did not contribute substantially to the accident. Finally, he lied on his medical application, though they decided that his medical status was unrelated to the crash, though I disagree vehemently on that with respect to one thing that likely caused the crash. More on that later. At least, he seemed to know his limitations and always took a second (non-required) pilot with him. However, he did not allow the other pilot(s) to manipulate the controls with passengers aboard. Finally, he liked to really yank the plane into the sky, and always rotated with both hands on the yoke.

Seven seconds after takeoff, the left engine reduced to near zero thrust, and the right engine backed off slightly as well. The prop did not feather and rudder boost was not activated. The pilot in the right seat said "You lost your left engine". The plane immediately began rolling slightly to the left and yawed significantly, and five seconds later was in an unrecoverable situation.

The NTSB's take on what happened is that the pilot took his hands off the power quadrant to rotate with both hands, and the left power lever came back to idle thanks to a poorly adjusted friction lock (which is an item on the checklists he didn't run). That would disable the rudder boost and auto-feather.

But the other thing they found is that the airplane should still have only yawed 11 degrees to the left, even if the pilot did nothing, and it actually yawed 20 degrees left. The pilot applied LEFT rudder when the LEFT engine failed.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot’s failure to maintain airplane control following a reduction of thrust in the left engine during takeoff. The reason for the reduction in thrust could not be determined. Contributing to the accident was the pilot’s failure to conduct the airplane manufacturer’s emergency procedure following a loss of power in one engine and to follow the manufacturer’s checklists during all phases of operation.
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Here's where it gets interesting. There is a statement in the docket from someone who wishes to remain anonymous that the pilot had serious problems with his right ankle, which he'd dislocated many years before. They found medical records showing that he was having pain in that ankle months before the crash...

One thing that did NOT make the report nor the docket, unsurprisingly given the potential for instructors to be found liable for the crash: Supposedly, the pilot, when he would go in for recurrent training, would tell the instructor that he was having trouble with his right ankle, and ask them to fail the right engine instead of the left (critical) engine. Every time... So, EVERY engine failure was ALWAYS a right engine failure, and the reaction was ALWAYS to apply LEFT RUDDER. And when an engine actually failed, he reverted to his training. :eek:

Yikes.
 
flyingcheesehead said:
Well, the final report is out, and it's a doozy.
Report: Final
Docket: Docket

The basics: Loss of thrust on the left engine 7 seconds after liftoff, it veered to the right, rolled and crashed.

After reading both the report and a large part of the docket, here's the simple story:

The pilot was experienced but kind of a cowboy - He did not like to use checklists during normal (ie non-training, non-checkride) flights. He did not do a weight and balance, and the plane was around 600 pounds over gross and near aft CG limits, though they decided that did not contribute substantially to the accident. Finally, he lied on his medical application, though they decided that his medical status was unrelated to the crash, though I disagree vehemently on that with respect to one thing that likely caused the crash. More on that later. At least, he seemed to know his limitations and always took a second (non-required) pilot with him. However, he did not allow the other pilot(s) to manipulate the controls with passengers aboard. Finally, he liked to really yank the plane into the sky, and always rotated with both hands on the yoke.

Seven seconds after takeoff, the left engine reduced to near zero thrust, and the right engine backed off slightly as well. The prop did not feather and rudder boost was not activated. The pilot in the right seat said "You lost your left engine". The plane immediately began rolling slightly to the left and yawed significantly, and five seconds later was in an unrecoverable situation.

The NTSB's take on what happened is that the pilot took his hands off the power quadrant to rotate with both hands, and the left power lever came back to idle thanks to a poorly adjusted friction lock (which is an item on the checklists he didn't run). That would disable the rudder boost and auto-feather.

But the other thing they found is that the airplane should still have only yawed 11 degrees to the left, even if the pilot did nothing, and it actually yawed 20 degrees left. The pilot applied LEFT rudder when the LEFT engine failed.



Here's where it gets interesting. There is a statement in the docket from someone who wishes to remain anonymous that the pilot had serious problems with his right ankle, which he'd dislocated many years before. They found medical records showing that he was having pain in that ankle months before the crash...

One thing that did NOT make the report nor the docket, unsurprisingly given the potential for instructors to be found liable for the crash: Supposedly, the pilot, when he would go in for recurrent training, would tell the instructor that he was having trouble with his right ankle, and ask them to fail the right engine instead of the left (critical) engine. Every time... So, EVERY engine failure was ALWAYS a right engine failure, and the reaction was ALWAYS to apply LEFT RUDDER. And when an engine actually failed, he reverted to his training. :eek:

Yikes.
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What is that line in the CFI books? Something about people reverting to their most basic training when the crap hits the fan? That last part is very sobering. And I get it. Try golfing opposite your natural hand and tell me which way the club goes on your first swing. Remind me at BFR time to have the instructor flip a coin on which engine I lose.
 
iamtheari said:
What is that line in the CFI books? Something about people reverting to their most basic training when the crap hits the fan? That last part is very sobering. And I get it. Try golfing opposite your natural hand and tell me which way the club goes on your first swing. Remind me at BFR time to have the instructor flip a coin on which engine I lose.
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Club still goes back, but I also switch hit when playing baseball, and throw with either hand naturally as well.
 
Low whistle. Fascinating.

Also not sure I would say a bum ankle is necessarily medically disqualifying but the pilot also decided not to figure out a proper way to adapt to it. He buys a decent brace, he never asks for continuous engine failures in only one direction again...

Kinda like deciding not to wear your glasses if you can't see without them. Easy fix.

$10 at CVS fixes the problem and breaks the accident chain.

Soooo.... The real problem wasn't medical. At least not in the ankle sense of medical. It was mental. Ego.

Another way to break the accident chain would have been one instructor says no, we aren't adapting the checkride for your bum ankle... Go to CVS, get a brace, see ya back here in an hour.

The airplane doesn't care about your ankle, old friend. Sorry.

I could see the anonymous person being one of those who let it slide. That mistake would bug ya.

You'd know you weren't the direct cause of the accident but you'd know you were part of the chain.

"I'll tell ya anonymously what really happened but keep my name out of it. A whole bunch of us let something slide that we shouldn't have... but it wasn't anything illegal or against any rules... Turns out we were all just dumb. We weren't the cause but we helped set the stage..."

Gives all new meaning to the old phrase, adapt or die, doesn't it.
 
denverpilot said:
Also not sure I would say a bum ankle is necessarily medically disqualifying but the pilot also decided not to figure out a proper way to adapt to it. He buys a decent brace, he never asks for continuous engine failures in only one direction again...
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It didn't sound like something that could be fixed by a mere brace. It wasn't weakness, it was severe pain.
 
flyingcheesehead said:
It didn't sound like something that could be fixed by a mere brace. It wasn't weakness, it was severe pain.
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Fair enough.

Still a good reminder you gotta say no if someone asks to only do half of what the airplane can have happen.

But I can see how easily one might fall into a trap of feeling like it is just being courteous because someone says "Oh, it's just bugging me today... Can we..."

But I can also see the NTSB being careful in wording not to fry every CFI the guy flew with or hinting the problem was aeromedicsl TOO hard.

Publish the anonymous tip and let folks who read these things realize there's a human behavior dynamic that can be a fine line between being courteous about what someone might have thought was a temporary mild injury and a problem that wasn't being dealt with.

Interesting twist really.

I sure strangely hope it was a CFI with integrity who figured it out and asked to remain anonymous and not someone who watched all the CFIs do it somehow. But I feel the latter is unlikely.

Probably a bit tough to fall asleep at night once you realize you've spotted the behaviour you should have challenged -- after the fact.
 
So if the pilot had actually done nothing - kept his hand on the throttle resulting in the left engine auto feathering and the rudder boosting to the right, and if he hadn't pushed left rudder - the plane would have had a decent chance of continuing the climb, no crash.
 
WDD said:
So if the pilot had actually done nothing - kept his hand on the throttle resulting in the left engine auto feathering and the rudder boosting to the right, and if he hadn't pushed left rudder - the plane would have had a decent chance of continuing the climb, no crash.
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The left engine had rolled back to zero thrust near liftoff. The NTSB found no issues with the engine, and surmised the pilot's failure to set the friction locks per two different checklists was the most likely cause for the reduction of thrust.

If that's accurate (and I think it is), the autofeather feature was disabled when the throttle closed.

The rudder boost was off. It was another checklist item that was ignored.

I don't put much credence into the ankle story. Multiple people would have been aware of that condition, not just one anonymous person.
 
I missed that - the engine was good and the throttle just slid back?
 
That’s mind boggling if that’s actually what took place. Among all else, it’s hard to imagine that a pilot wouldn’t notice a throttle lever creeping back far enough to cause a power reduction and not recognize it during emergency flows.
 
3393RP said:
I don't put much credence into the ankle story. Multiple people would have been aware of that condition, not just one anonymous person.
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I wouldn’t discount it completely. I doubt an ankle issue with right engine failures only is documented in his records and who would want to speak up now if they were compliant with a customer request and learn that it’s part of the accident chain? I don’t want to think that, but having seen some of the “passes” at training centers, I still leave room for the theory.
 
As already posted above, the ankle issue could come into play I suppose IF all of his training / recent training was on right engine out scenarios where he rained himself to always and thus only push left rudder with any engine out.


flyingcheesehead said:
Supposedly, the pilot, when he would go in for recurrent training, would tell the instructor that he was having trouble with his right ankle, and ask them to fail the right engine instead of the left (critical) engine. Every time... So, EVERY engine failure was ALWAYS a right engine failure, and the reaction was ALWAYS to apply LEFT RUDDER. And when an engine actually failed, he reverted to his training.
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iamtheari said:
What is that line in the CFI books? Something about people reverting to their most basic training when the crap hits the fan
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In this instance, yes, but admittedly an edge case.
 
MauleSkinner said:
Which is not the way you fly an airplane with a true V1, like this one.
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Interesting. I would assume on take off you want to ensure the throttles, mixtures, props, all stay where you want them! If the pilot has both hands on the yoke, who's protecting the throttles? I've seen vids on YouTube where that's the FO's job.. but what happens if the pilot is alone? Seems like a potential failure point..

EdFred said:
You use both hands on the yoke in a "true V1" plane?
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My same question.

Dave Theisen said:
Yup. That’s what they teach.
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Who's protecting the throttles?
 
One reason you take your hands off the thrust levers at V1 is so you are not tempted to abort. Two hands to rotate May be a factor, but I don’t need a second hand on the Bus side stick, and we still take hands off the levers.

All that said, I didn’t think a King Air had a “true V1”.
 
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