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Cessnaflyer

The dangers of density altitude

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This is a famous one where the results did not work out with a stall/spin two fatalities. Very sad to watch.

http://www.liveleak....=316_1249535759

 

The spooky thing is that less than 60 seconds befofe the crash, the poor guy is commenting how pretty the lake is - he had no warning.It seems he had no physical signs the engine was struggling at that stage until he attempted climbing more.

Hard to see from the video how it happened but heading toward that mountain instead of turning earlier is hard to understand, maybe they needed to inspect that area for the infestation.

 

Is there any way I can download these to keep as reference? I have the firefox addon that downloads Youtube videos but it doesn't seem to work on LiveLeak...


Dan.W

20.jpg

 

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The spooky thing is that less than 60 seconds befofe the crash, the poor guy is commenting how pretty the lake is - he had no warning.It seems he had no physical signs the engine was struggling at that stage until he attempted climbing more.

Hard to see from the video how it happened but heading toward that mountain instead of turning earlier is hard to understand, maybe they needed to inspect that area for the infestation.

 

Is there any way I can download these to keep as reference? I have the firefox addon that downloads Youtube videos but it doesn't seem to work on LiveLeak...

 

There are copies of it on youtube as well.


Chris Miller

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Thanks, I think you've opened a can of worms now though because I've started watching all kinds of density alt mistakes.

 

This is the first one that came up, rather crazy:

 

From the pilot:

This was me, Selina, in GYYF. I think it was 1999 or 2000.

What can I say? It was hot, I had 2 passengers and thought I knew more than I did about short field takeoffs. This little field is just outside of Victoria B.C. and once we were in the air we headed straight to Nanaimo's LONG runway to land and assess damages. The only victims, other than my pride, were the gear fairings as I did a bit of landscaping on the way out.


Dan.W

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Yeah that is always a great one. What really got him in trouble as well is that he was trying to pull it into the air which gave him a lot more induced drag than he could handle for most of the takeoff run.


Chris Miller

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Anyone else watching that video like a really good horror movie? :o Geez, that takeoff really hit me because I saw the plane in the tree or water. But thanks for posting and adding the quote from the pilot. Awareness not always comes that gently.

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Dcy3AjbP.jpg

 

Nice tablet o_0


Quote from MS Flight Team Lead: "We’ve made some guesses"

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What really got him in trouble as well is that he was trying to pull it into the air which gave him a lot more induced drag than he could handle for most of the takeoff run.

 

Form drag too... and starts with forward stick which might not be correct procedure...

 

Must have seen end of the runway rushing up and tried to rotate as you say... seen by the tail dropping just after passing the camera-person... rather than lifting off and accelerating in ground effect to Vx.

 

This is a famous one where the results did not work out with a stall/spin two fatalities. Very sad to watch.

 

Did you notice how he turned (right) into the rising terrain? It appeared a left turn would have been into lower terrain, plus a left hand turn might have been the more "familiar" (possibly less chance of steepening the bank).

 

For anyone interested in actual flight and new to stalls... one of the maneuvers you learn to perform is an accelerated stall... the reason being an airplane's stall speed increases proportionally with the square root of the load factor (lift to weight ratio). The more g's you pull, the higher the stall speed. An airplane in a level 60° banked turn will pull 2 g's.

 

Again I see a chain of events... delayed reaction to rising terrain... turning into the ridge... he must have been climbing near stall before the turn (should have been at least at Vx )... L-19 Aircraft Manual I have states to use of 30° flaps for Vx (was airplane properly configured?).

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Did you notice how he turned (right) into the rising terrain? It appeared a left turn would have been into lower terrain, plus a left hand turn might have been the more "familiar" (possibly less chance of steepening the bank).

 

For anyone interested in actual flight and new to stalls... one of the maneuvers you learn to perform is an accelerated stall... the reason being an airplane's stall speed increases proportionally with the square root of the load factor (lift to weight ratio). The more g's you pull, the higher the stall speed. An airplane in a level 60° banked turn will pull 2 g's.

 

Again I see a chain of events... delayed reaction to rising terrain... turning into the ridge... he must have been climbing near stall before the turn (should have been at least at Vx )... L-19 Aircraft Manual I have states to use of 30° flaps for Vx (was airplane properly configured?).

 

Factor in that the altitude of the aircraft was near or over 10,000' (I can't remember the exact figure). The aircraft just isn't going to perform.

 

The former story reminds me of a recurring theme in the Cub my friend and I friend fly. There are no published climb speeds, and his aircraft is equipped with VGs. We do everything (approach, climb, maneuvers) at 55MPH. Short field technique, in theory, says you should keep the tail on the ground and then accelerate to Vx in ground effect. The thing is, I can get the A/C over a "50' obstacle" with much more margin when I immediately get the tail off of the ground. On the other hand, I can get off of the ground much faster by holding the stick back. Quite the conundrum to face while on the takeoff roll... *facepalm* Hope they didn't ding it up too badly.


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Short field technique, in theory, says you should keep the tail on the ground and then accelerate to Vx in ground effect. The thing is,

 

Yes I fully agree Zach (as you point out with actual experience... I was implying with the "might not be correct procedure" as I don't know)... will depend on the aircraft and whatever STC mods that have been subsequently made.

 

 

Btw... just looked up the NTSB report on the other which stated "CRASHED AT THE 10,200-FT LEVEL"... "THE DENSITY ALTITUDE WAS ABOUT 13,000 FT."

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Yes I fully agree Zach (as you point out with actual experience... I was implying with the "might not be correct procedure as I don't know)... will depend on the aircraft and whatever STC mods that have been subsequently made.

 

 

Btw... just looked up the NTSB report on the other which stated "CRASHED AT THE 10,200-FT LEVEL"... "THE DENSITY ALTITUDE WAS ABOUT 13,000 FT."

 

Consider my anecdote an "agreeance" with you, and an elaboration.

 

And yup. I thought it was over 10,000'! Holy smokes.


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