Plane crashes near spectators at Reno air races

[ChipBeck]

Gentlemen,

In a view from the back, it looks like the entire elevator is gone before impact which was certainly caused by flutter. A good friend of mine, Joe Frasca whose father own's Frasca Flight Systems, lost the entire wing of his aerobatic monoplane to flutter and he died trying to bail out. When an aircraft surface goes into flutter, it explodes off the plane violently. After building my Glasair III, doing the flutter testing was nerve wracking. At 320 MPH the right gear door went into flutter and exploded off the plane. It felt like a bomb went off under my butt and sent my blood pressure off the chart. No Glasair had ever been taken above 350 MPH and I took mine to 375 indicated after redesigning and beefing up both gear doors. Any change to a control surface that changes how it will vibrate (including a weight change) may cause flutter that would not have occurred in that parts original state. The loss of the trim tab on the elevator of that highly modified P-51 was the starting point for loosing the entire elevator. The plane would have flown fine if all it lost was that trim tab. Without the elevator, the pilot was doomed with no way to pull up and no time to bail out.

Chip

 

[FENZO]

I'm glad that crashed GT thread was locked, now I can focus on speculating about the crashed P-51. Yay! :bored

I wonder if on P-51forum.com they are discussing the toasted GT. :secret:

 

[GT38]

In a view from the back, it looks like the entire elevator is gone before impact which was certainly caused by flutter.

Haven't been able to find that photo (or video). Could you post it, or post a link to it? Thanks.

 

[CH53Driver]

It was always unnerving for me to go on an external load lift as a passenger in the 53 and to sit in the back and watch the tail boom flexing when lifting heavy loads. It's an extremely sad situation what happened in Reno. The findings will be interesting but as has already been stated, flutter definitely sounds like a prime culprit in this mishap.

 

[steved57]

I was waiting for your post Chip as I felt you would give the most informed explanation, very sad day indeed for the sport and the fatalities/injured.

 

[GT38]

More speculation...

http://www.foxnews.com/us/2011/09/2...-broken-seat-aviation-expert/?test=latestnews

Still can't find any photos/videos showing the entire elevator gone.

 

[2112]

A pilot buddy of mine thinks that when the plane pitched up so fast the G force literally pulled the pilot flat into the seat, rendering him unconscious if not killing him instantly.

 

[ChipBeck]

Still can't find any photos/videos showing the entire elevator gone.

It was a U-Tube video that has been pulled that showed that crash from the planes belly side. I have looked extensively and can't find it. I stop framed it just before impact and it looked like the entire elevator was gone. There aren't many pieces of that plane bigger than your fist to examine so it may take a while to confirm what I saw. Extreme G forces would not kill a pilot instantly as the brain has a 4 to 5 second reserve of oxygen even with 0 blood pressure so he would not black out instantly as has been speculated. The broken seat, extended tail wheel, and (if I'm right) missing elevator all started with the loss of that trim tab. The stock P-51 seat is armored and designed to protect the pilot like a roll bar in case the plane flips over on it's back while landing. All of the Gold Unlimited racers take that seat out to reduce weight and substitute a much lighter aluminum seat. A mutual friend and Aerobatic World Champion, Charlie Hillard, died right in front of me at the Sun & Fun Airshow in Florida when he flipped his Hawker Sea Fury over while landing and he had also removed the armored seat that would have saved his life.

Every one of those planes is so heavily modified that every flight is a test flight. The airshow business has been dying for 10 years now. This accident is the final blow. Insurance will be impossibly expensive and cities and airports will no longer clamor for them. Other than the big military shows, my old part time job is a thing of the past.

Chip

 

[ChipBeck]

Seat photos.

Gentlemen,

The top photo below shows the stock seat in a Sea Fury. It's similar to the stock seat in a P-51 in that it's hell for stout and in the event of a roll over on landing the entire seat will crush down into the plane and protect the pilot when the canopy crushes. The photo below shows Charlie Hillard's Sea Fury with that heavy seat replaced by a light weight aluminum seat with no roll over protection. Charlie suffocated before the crash crew could get him out with his head pinned forward after the canopy crushed. The lightweight components that are put together while building a race or aerobatic plane are not tested or certified by anybody but the aircraft owner as these are all Experimental Category aircraft. In the airshow business, the fatality rate is 2% PER YEAR. One out of every 50 performers will die every season. It's a tough business.

Chip

 

[GT38]

It was a U-Tube video that has been pulled that showed that crash from the planes belly side. I have looked extensively and can't find it. I stop framed it just before impact and it looked like the entire elevator was gone. There aren't many pieces of that plane bigger than your fist to examine so it may take a while to confirm what I saw. Extreme G forces would not kill a pilot instantly as the brain has a 4 to 5 second reserve of oxygen even with 0 blood pressure so he would not black out instantly as has been speculated. The broken seat, extended tail wheel, and (if I'm right) missing elevator all started with the loss of that trim tab. The stock P-51 seat is armored and designed to protect the pilot like a roll bar in case the plane flips over on it's back while landing. All of the Gold Unlimited racers take that seat out to reduce weight and substitute a much lighter aluminum seat. A mutual friend and Aerobatic World Champion, Charlie Hillard, died right in front of me at the Sun & Fun Airshow in Florida when he flipped his Hawker Sea Fury over while landing and he had also removed the armored seat that would have saved his life.

Every one of those planes is so heavily modified that every flight is a test flight. The airshow business has been dying for 10 years now. This accident is the final blow. Insurance will be impossibly expensive and cities and airports will no longer clamor for them. Other than the big military shows, my old part time job is a thing of the past.

Chip

Well, thanks for looking again.

Harry Doan was killed in a very similar accident when his A-1 Skyraider flipped over. All of this reminds me of an article I read decades ago (in Air Progress??) where the title, "Death in a Beautiful Package" summed up the lure of flying these aircraft. It was written back when you could buy a Corsair for $20K. I've known several people who were killed flying military surplus aircraft, some of them ex-military pilots themselves. It's a dangerous game, for sure.

A pilot buddy of mine thinks that when the plane pitched up so fast the G force literally pulled the pilot flat into the seat, rendering him unconscious if not killing him instantly.

I've never heard of someone killed from G-forces during flight (that is, other than impact G's), but I'm all ears if someone has specifics.

 

[FENZO]

Piling on...
Often failure of lift/control surfaces is contributed to flutter as a knee jerk reaction, even by the NTSB/FAA. The equations don't always support that, within the strict definition.

The horiz stab (tail) provides downforce (it is an upside down wing) to counteract the rotational nosedown moment of the primary lifting surface (wing). I've read where these racing planes have shortened wingspans and modified chord/cambers, which affects the aerodynamics at the tail, since they are behind them in the airstream. This results in requiring an extreme nosedown elevator trim (horiz surfaces 'up' at the tail). In other words, at high speed with neutral control the aircraft would pitch up without downward trim (good for turning). The loss of this trim condition, likely due to the modifications and speed (not flutter), caused the trim tab to fail (shock buffet, simple repeated aero overload, LCO, etc.). Which in turn would result in an abrupt climb, 11g they say. That would make your helmeted head almost instantaneously weigh ~150 lbs. So as he climbed his air speed reduced likely forcing his limp body to slump over the controls overcoming the aero forces causing a dive, then as airspeed increased in that dive it appeared as if he was pulling up, but that was again a result of the missing trim surface.

Ride in a convertible holding a stop sign above your head. It won't be flutter that causes your arms to fail at speed. No matter the official outcome, disposable income and brass balls killed this guy, which is ok IMO. Not so much for the spectators.

 

[ChipBeck]

That clear nose down picture shows that the entire elevator (not just the trim tab) was gone before impact with the ground.
the elevator on the P-51 is an aluminum skeleton that is fabric covered. It is very light weight.

Chip

 

[GT38]

It was a U-Tube video that has been pulled that showed that crash from the planes belly side. I have looked extensively and can't find it. I stop framed it just before impact and it looked like the entire elevator was gone.Chip

Is this first video the one you saw?

[video=youtube;OCC5YlQ7v60]http://www.youtube.com/watch?v=OCC5YlQ7v60[/video]

A few others I found...

[video=youtube;TA8fVDgz_9Y]http://www.youtube.com/watch?v=TA8fVDgz_9Y&feature=player_profilepage[/video]

[video=youtube;TaWB_7RGTQ4]http://www.youtube.com/watch?v=TaWB_7RGTQ4&feature=player_profilepage#t=16s[/video]

[video=youtube;YiDwLUqst7o]http://www.youtube.com/watch?v=YiDwLUqst7o&feature=player_profilepage[/video]

[video=youtube;NsvtMvdXtYc]http://www.youtube.com/watch?v=NsvtMvdXtYc&feature=player_profilepage[/video]

 

[2112]

Seems it loops in the wrong direction but still........

[video=youtube;mBd7cXoGbAo]http://www.youtube.com/watch?v=mBd7cXoGbAo[/video]