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Plane crash video - Density Altitude

PostPosted: Fri Aug 10, 2012 1:03 pm
by chris
Most of you have probably already seen this video of a plane crash in Idaho from a camera holding passenger. If you havent, it is worth a watch to remind us to not get complacent about the hazards associated with mountain flying, weight and balance, and density altitude.

http://www.youtube.com/watch?v=yDu0jYiz-v8

Re: Plane crash video - Density Altitude

PostPosted: Sat Aug 11, 2012 12:45 am
by fastj22
Do you think it all about DA or was the engine just not running right? I though with the long takeoff run I would have aborted take off while I still had runway. After he broke ground, can't say I wouldnt do anything differently. Probably saved everyone's life but not trying to turn back and spinning into the ground.

Re: Plane crash video - Density Altitude

PostPosted: Sat Aug 11, 2012 1:54 am
by chris
No I dont think it was all about DA but it was definitely a major contributing factor. Maybe I should have thought out the subject line a little more.

Here are my speculations...

1. It was heavy
2. It was hot
3. It was a high altitude airport
4. It was mountainous terrain
5. Not leaned for best power

Its easy for me to say now cause I just watched a Youtube video from the comfort of my nice swivel chair and not in the pilots seat.... but I'd like to think that I would have put it down after it wouldn't climb. As soon as it droped back down on the runway. The wing was basically throwing in the towel and crying uncle. If not, there were a couple of minutes of flat land before the trees. That probably would've been a better place to sit it down rather than to try to nurse a struggling airplane above the obstacles ahead. But thats a tough call to make because It did look like for a couple of seconds it was going to climb slowly.

I think that there is some merit to a possible downdraft given the take off direction (assuming into the wind) and terrain. I would also consider that a contributing factor and not a cause.

I agree 100% with you on the turning back. He would have surely stalled and spun it into the ground. That was the right move after the point of no return.

If you look at the 6:18 mark, the pilots left hand is still on the yoke and the right hand is still on the throttle. At that point it had already plowed through most of the trees and was about to impact the ground. He flew it til he couldn't. Those are certainly some good things to point out. Not to mention the luck of avoiding damage to the cabin area and how the trees or whatever absorbed the energy enough to limit it to a survivable impact.

The flight just had too many things stacked against it. Shouldnt have taken off but it flew into the trees well.

This flight is like a video of my worst nightmare only it ended way better than I thought possible.

Lots to be learned from it.

Re: Plane crash video - Density Altitude

PostPosted: Sat Aug 11, 2012 9:56 am
by fastj22
I didn't realize how hot it was. The engine sounded fine and the pilot didn't look like he was trying to make any adjustments. A slight downdraft could have been the just the thing to put it into the trees.
Kinda reminded me of trying to do touch and goes in my C150 with a DA of 8500ft. Used a lot of runway and still felt like I wasn't going to clear the obsticles on the downwind. That was solo with half tanks. Did one circuit and put the plane back in its parking spot.

Re: Plane crash video - Density Altitude

PostPosted: Sun Aug 12, 2012 11:31 am
by 142YX
Why would he surely stalled and spun into the ground with a turn back? the airplane wasn't in a stall, was still making power.. you can turn an airplane in slow flight behind the power curve.

Re: Plane crash video - Density Altitude

PostPosted: Sun Aug 12, 2012 11:39 am
by chris
Fair enough. Attempting to turn back would have increased the chances of a stall spin scenario significantly. Also depending on when he initiated the turn the plane may have impacted trees in a banked attitude as opposed to wings level.

Re: Plane crash video - Density Altitude

PostPosted: Sun Aug 12, 2012 9:52 pm
by structurespilot
Good Post, it makes us all think, and remember all the things learned back in ground school. I think the downdraft did contribute to the crash. We also don't know how much the terrain rose up to meet him. I've had a scare in the mountains here, due to down drafts. They are not always violent, sometime they just gradually push you down. At that point all you can do is lean the engine for max performance, and start looking for a spot. Lucky for me I didn't have density alt. working against me too.

I've flown C150, 172, and C182 in the mountains, up to 12000' and the only one which felt like it had enough power was the C182, which I never loaded with 4 adults either.

In my multi engine training, we had to show our calculated DA, and required runway length, accelerate to stop distance (for an aborted TO), for each flight. Too bad the guy in the video hadn't taken the time to properly flight plan for the flight, using the temp, distance, and actual weights for the day. Plus the chances that the Stinson was developing the power that it did when the POH was written, are slim to none.

Also in Canada, on your commercial flight test, you fail if you do not pick a spot along the runway, to have developed enough power and rotate. You must also announce to the examiner, your decision as you pass the go no go point.

Thanks again for the post, stay safe everyone.

Norm

Re: Plane crash video - Density Altitude

PostPosted: Sun Aug 12, 2012 9:54 pm
by rizzz
I think I posted this before but for the people who haven't seen it,
Here's a similar crash video from inside the cockpit, DA is also a major contributor (apart from just plain recklessness on the pilot's behalf),
The pilot did try to turn back and stalled the airplane (although I am of the opinion he could have made the turn if he hadn't tried to turn so tight, he was almost performing a wing-over)
Sadly, the pilot and his passenger in the back did not survive this one:

http://www.youtube.com/watch?v=LzDSq6m2zV4

if you want to go up, pull the stick a little
if you want to go down, pull a little more,
if you want to go down fast, keep pulling!