Hawker down in Michigan

ADS-B data shows a gradual reduction in ground speed from 246 to 106 over a timespan of about 2 min, 20 sec after the aircraft rolls out on a northerly heading. Altitude is held at 15,000 ft during the speed reduction.

Weather at LAN was reported as clear sky, good viz. Sunset at the accident location was 2253Z with the accident time about 2127Z.
 
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If it helps with interpreting the groundspeed, the forecast winds aloft over that area at 15,000’ were 335@34, with temps somewhere around -5°C.
AquaLand said:
Weather at LNS
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Probably meant LAN, which was also reporting clear skies (but calm winds) at the time.
 
Headed to Duncan tomorrow AM at the nearby KAZO airport. Sadly I will not be surprised if this is the topic of conversation. Their mx facilities are at KBTL which is close by.
 
"... entered a sudden descent from an altitude of 14,775 ft and crashed within 30 seconds."
That's a hella descent rate, given the local elevation of ~850 ft, about 300 mph vertical speed. What flight regime would be unrecoverable from that height?
 
Other jets don't have their leading edges removed to check the TKS system.
 
VASAviation has the radar and comms.

They asked for a 14,000'-16,000' block altitude but, apparently, did the stall at 15,000' leaving only 1,000' for recovery. That would suggest that they were planning on an "old school" recovery where altitude loss is minimized.

A better procedure, in a swept-wing jet, is to PUSH and use several thousand feet of altitude to regain airspeed while pushing to ~.5g. The push unloads the wing and lowers the critical angle of attack giving more margin.
 
Larry in TN said:
They asked for a 14,000'-16,000' block altitude but, apparently, did the stall at 15,000' leaving only 1,000' for recovery. That would suggest that they were planning on an "old school" recovery where altitude loss is minimized.

A better procedure, in a swept-wing jet, is to PUSH and use several thousand feet of altitude to regain airspeed while pushing to ~.5g. The push unloads the wing and lowers the critical angle of attack giving more margin.
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Just got to experience that in the sim. Trying to power out of it took around three minutes, shoving the nose down and using up several thousand feet of altitude instead resulted in a recovery in seconds.
 
Thin wings and thin air make for quite a different experience.

Did some VERY radical playing around with the new EET (expanded envelope training) in the good old MD-80. Quite z bit higher than 15k, pretty eye opening.
 
flyingcheesehead said:
Just got to experience that in the sim. Trying to power out of it took around three minutes, shoving the nose down and using up several thousand feet of altitude instead resulted in a recovery in seconds.
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Trying to power-out with minimal altitude loss requires you to walk the tight rope for an extended period of time without a net. Swept-wing jets do not handle like straight-wing recips at the edge of a stall. That is why we've transitioned to upset recovery training instead of stall recovery training. "Push, Roll, Thrust, Stabilize"

In what airplane's sim were you doing that training?
 
Larry in TN said:
Trying to power-out with minimal altitude loss requires you to walk the tight rope for an extended period of time without a net. Swept-wing jets do not handle like straight-wing recips at the edge of a stall. That is why we've transitioned to upset recovery training instead of stall recovery training. "Push, Roll, Thrust, Stabilize"

In what airplane's sim were you doing that training?
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A320.

I did manage to break the sim on the last recovery. It's an unusual attitude, you start at 120º of bank (partially upside down) and by the time you roll nose up from that far over you're in a world of hurt. It got into an uncontrollable back-and-forth rolling motion - When I centered the stick with the wings approaching level it just kept rolling, so I went full stick against the roll and it was going to about 45º+ of bank before it'd start rolling in again. After the first time, I started trying to get ahead of it and went full stick against the roll just as the roll was starting. So, for example, when it hit the full 45º or whatever it was and stopped rolling right, I'd go full right stick to attempt to arrest the upcoming roll. It did NOT work.

In hindsight, I was probably stalling the wingtips by rolling it so hard, even though I was nose down and right up against the barber pole. Or it could have been mach effects. Or it could have been me forgetting that I was flying a computer and not an airplane. The instructor said I might have done better if I just left the stick neutral and let the computer take care of it, which is completely against my nature as a pilot.

In any case, after about 4-5 left-right cycles like that, the sim got mad and threw an error and we had to quit for a while and get a tech to work on it.
 
Every pilot a test pilot…. A lot of wear in any GA plane is done with unwarranted, or un-needed mx all be it in a service manual. That said, a stall test is a good example. Leading edge off? So what, if it looks right, it will be right or right enough at the end of the day in reality.
 
Skymac said:
Every pilot a test pilot…. A lot of wear in any GA plane is done with unwarranted, or un-needed mx all be it in a service manual. That said, a stall test is a good example. Leading edge off? So what, if it looks right, it will be right or right enough at the end of the day in reality.
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Apparently not, since we have this thread.
 
MauleSkinner said:
Apparently not, since we have this thread.
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Is this a failed stall test for the aircraft or a failed stall recovery for the crew? In these post-maintenance stall tests, do stall recoveries potentially require Yeager-level skills, or does the average type-rated pilot have the ability to recover from 99% or more of the problem stalls?
 
iamtheari said:
Is this a failed stall test for the aircraft or a failed stall recovery for the crew? In these post-maintenance stall tests, do stall recoveries potentially require Yeager-level skills, or does the average type-rated pilot have the ability to recover from 99% or more of the problem stalls?
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If the airplane was put together correctly, it’s simply verifying that the shaker and pusher activate at the proper speeds and recovering without an actual stall. If the airplane wasn’t put together correctly, it’ll probably stall one wing and roll over pretty quickly, at which point it becomes pretty sporty.

The procedure requires at least 10,000 feet above ground or a cloud layer to give room for recovery in the latter case.
 
iamtheari said:
Is this a failed stall test for the aircraft or a failed stall recovery for the crew?
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At this point "we" don't know if it was either one.
iamtheari said:
In these post-maintenance stall tests, do stall recoveries potentially require Yeager-level skills, or does the average type-rated pilot have the ability to recover from 99% or more of the problem stalls?
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...or something in between? I don't know about commercial ops but mil aviation in general requires designation/qualification to conduct functional test flights (i.e. post-maintenance tests). It does not require a full experimental test pilot qual and if the test requires slow flight or stalls in most cases the results are relatively benign (if not comparable to a perfect airplane). OTOH Legacy Hornet MECH/MSRM FCF tests might be less forgiving than the average bizjet, but that's not really what we're talking about here.

Part 91, as far as I can tell, is mostly a free-for-all.

Nauga,
who tests higher than he's willing to fall
 
Let’s also be willing to accept that the sim schools are just a stamp of approval these days… A required money grab.

I’ve flown with so many people during recurrents that don’t need to be flying the plane. Meanwhile, if you have the paper passes that’s all insurance cares about. If you haven’t witnessed this, you don’t have your eyes open.
 
nauga said:
I don't know about commercial ops but mil aviation in general requires designation/qualification to conduct functional test flights (i.e. post-maintenance tests). It does not require a full experimental test pilot qual and if the test requires slow flight or stalls in most cases the results are relatively benign
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A Hawker pilot in another corner of the internet stated that "the mx procedure actually mentions that a test pilot should perform the check".
 
AV8R_87 said:
A Hawker pilot in another corner of the internet stated that "the mx procedure actually mentions that a test pilot should perform the check".
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Should doesn't mean required, and a lot of operators are too cheap to pay for a test pilot.

A former employer of mine asked me to do the test. I said no way. The chief pilot and the DO went up and did it. Thankfully it went fine, but I wasn't going to take that chance so they could save a few grand.
 
AV8R_87 said:
A Hawker pilot in another corner of the internet stated that "the mx procedure actually mentions that a test pilot should perform the check".
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If that's truly the case then I'd bet money that the pub refers to a maintenance test pilot, not what we think of as a steely-eyed Yeagerish experimental test pilot.

Nauga,
who has been wrong before
 
nauga said:
If that's truly the case then I'd bet money that the pub refers to a maintenance test pilot, not what we think of as a steely-eyed Yeagerish experimental test pilot.
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I agree. That's how I read it.

Groundpounder said:
Should doesn't mean required, and a lot of operators are too cheap to pay for a test pilot.
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Yeah, Hawker did their best to warn operators/maintainers to not FAFO.
The old "You think safety is expensive? Wait until you have an accident." quote comes to mind.
 
nauga said:
If that's truly the case then I'd bet money that the pub refers to a maintenance test pilot, not what we think of as a steely-eyed Yeagerish experimental test pilot.
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Its a bit vague, but I seem to recall the stall test flight procedure recommended pilots with only knowledge of the stall warn system with any full stall checks requiring factory involvement, ie. test pilots. The old day job leased a Hawker for a period and while we never had to pull the leading edges, there were a couple other tests that they brought in a Hawker contract pilot to perform the flight test portion with our pilots.
 
AV8R_87 said:
Yeah, Hawker did their best to warn operators/maintainers to not FAFO.
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I’ve done the Hawker stall test procedure twice…it’s not a big deal, assuming it was put together correctly. The procedure gives the parameters to verify, as well as the way to approach those parameters.

The problem I had was that I was told, “David, we need you to do the stall test on this 800.”

“OK, what’s the test?”

“Just make sure it stalls straight ahead.”

“Do you have a procedure for it?”

“No, just make sure it stalls straight ahead.”

“Does the manufacturer provide any guidance on pass vs fail?”

“No.”

“How can they require a test with no way to tell if it passes?”

“Just make sure it stalls straight ahead.”

OK, I’ll hop on the airlines and go home now.”

“Well, there is this couple of pages…”

And that was from a fairly well-known Hawker shop that I won’t name.
 
Can someone explain why disassembly/re-assembly of the leading edges can't be confirmed "correctly done" by any types of visual and mechanical inspections, and it has to be "try and hope you don't die"??

Why any crew would volunteer to perform this test knowing that if something wasn't done correctly it could result in a horrible death (lots of time to think about it); with nothing they can do to recover even if they're doing everything correctly. Ain't enough money in the world...
 
sourdough44 said:
Can’t one just do an ‘approach to stall’? Get the warnings, then recover?
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The manufacturer’s test procedure doesn’t involve full stalls, if that’s what you’re wondering. In this case, I would assume that the airplane failed the test.
 
tobnpr said:
Why any crew would volunteer to perform this test knowing that if something wasn't done correctly it could result in a horrible death (lots of time to think about it); with nothing they can do to recover even if they're doing everything correctly. Ain't enough money in the world...
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If you die a horrible death, most likely you didn’t do it correctly. Unfortunately a lot of pilots think that because an instructor dragged them kicking and screaming up to standard in the simulator for the last several years that they’re proficient.
 
tobnpr said:
Can someone explain why disassembly/re-assembly of the leading edges can't be confirmed "correctly done" by any types of visual and mechanical inspections, and it has to be "try and hope you don't die"??
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Its my understanding there are some wing designs that are very specific in how they are reassembled. The Hawker and a few others have these types of wing designs. While there are ground checks and tests, the only way to confirm the settings are correct is to fly the aircraft in a specific manner to predefined reference points. If the stall system, etc. does not react at those points it fails the test, you land, readjust, and perform it again. Why a few crews end up in a smoking hole couldn't tell you but it usually points to the same causes.

tobnpr said:
Why any crew would volunteer to perform this test knowing that if something wasn't done correctly it could result in a horrible death
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There are lots of after maintenance flight checks that can test a pilots skill simply because you are usually checking the upper limits of the aircraft performance or the aircraft requires adjustments at those same limits. These stall checks, or turbine engine topping checks, or helicopter autorotation checks are some examples. However, it falls to the pilot to be honest with themselves if they feel comfortable or possess the skill set to comply with them.
 
MauleSkinner said:
If you die a horrible death, most likely you didn’t do it correctly. Unfortunately a lot of pilots think that because an instructor dragged them kicking and screaming up to standard in the simulator for the last several years that they’re proficient.
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I don't understand the underlying premise of your response.
I am under the impression that the stall test is required to confirm the proper and correct reassembly of the leading edges- not the capabilities of the crew to recover from a stall?

I build custom rifles. Before I (or a customer) touches off 60,000 + PSI inches from the front of my face, I have confirmed by physical dimensions and tolerances that the work is done correctly. Everything that can be manufactured and assembled has dimensions, tolerances, torque values, etc...

Still not understanding why potentially fatal stall recovery is a requirement?

ETA: Thanks Bell 206. posted at the same time.
 
tobnpr said:
I don't understand the underlying premise of your response.
I am under the impression that the stall test is required to confirm the proper and correct reassembly of the leading edges- not the capabilities of the crew to recover from a stall?
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If the stall test fails, and the airplane stalls, spins, or otherwise departs from controlled flight, the flight crew has to be able to recover.
tobnpr said:
Still not understanding why potentially fatal stall recovery is a requirement?
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It isn’t, any more than it’s a requirement in training for a Private Pilot certificate. But if the crew can’t properly recover, the outcome is the same.
 
So, I have a question/hypothesis:

Has something changed relatively recently in how stalls are practiced/demonstrated in the sim, emphasizizing minimum altitude loss?

There have been these two Hawker stalls, and I recall another one (vague memory, can't remember the type) where a crew got into a nasty stall because they were trying to recover with minimum altitude loss and ended up in repeated secondary stalls.

People here talk about needing to push the nose down in a pretty firm way and losing some altitude for a proper recovery.
 
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nauga said:
If that's truly the case then I'd bet money that the pub refers to a maintenance test pilot, not what we think of as a steely-eyed Yeagerish experimental test pilot.

Nauga,
who has been wrong before
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It would be an interesting note in the maintenance manual that an NTPS or DOD TPS graduate be a required crew member for this post maintenance check flight.
 
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