Density altitude strikes again

[Mxsmanic]

A brand-new video showing a small airplane crash from inside the aircraft:

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

The video claims that a combination of density altitude and an "air pocket"
brought the aircraft down into the trees, but all I see are effects of density
altitude and what looks like the beginning of a stall.

Everyone survived. The passengers walked away from the totaled aircraft, the
pilot was badly injured but will recover fully, and the cameras were
completely unaffected.

It's interesting that the FAA produced a corny but informative video on
density altitude half a century ago, and it's still pertinent today:

http://www.youtube.com/watch?v=RZCb6nw_T4U

It almost looks as if the movie were made in the same area as the crash.

[Mxsmanic]

NTSB report (preliminary): WPR12LA283

June 30, 2012
N773C Stinson 108
Bruce Meadows Airport, Stanley Idado
Airport elevation 6370 feet
Temperature 27° C
1 crew, 3 passengers

[Mike Adams[_1_]]

Mxsmanic > wrote:

> NTSB report (preliminary): WPR12LA283
>
> June 30, 2012
> N773C Stinson 108
> Bruce Meadows Airport, Stanley Idado
> Airport elevation 6370 feet
> Temperature 27° C
> 1 crew, 3 passengers

This accident received huge mainstream media coverage featuring in-cockpit
video recordings. Here's one of them:
http://www.liveleak.com/view?i=835_1344412426

Yes, looks like a classic high DA accident. Airplane was never able to
climb to a decent altitude.

Mike

[Mxsmanic]

Mike Adams writes:

> This accident received huge mainstream media coverage featuring in-cockpit
> video recordings. Here's one of them:
> http://www.liveleak.com/view?i=835_1344412426

If it bleeds, it leads.

[sambodidley[_2_]]

"Mike Adams" > wrote in message
.. .
> Mxsmanic > wrote:
>
>> NTSB report (preliminary): WPR12LA283
>>
>> June 30, 2012
>> N773C Stinson 108
>> Bruce Meadows Airport, Stanley Idado
>> Airport elevation 6370 feet
>> Temperature 27° C
>> 1 crew, 3 passengers
>
> This accident received huge mainstream media coverage featuring in-cockpit
> video recordings. Here's one of them:
> http://www.liveleak.com/view?i=835_1344412426
>
> Yes, looks like a classic high DA accident. Airplane was never able to
> climb to a decent altitude.
>
> Mike

If DA stands for Dumb Ass it meets all of the conditions of such.<g>

[[email protected]]

On Saturday, August 11, 2012 9:50:05 PM UTC-4, Mxsmanic wrote:

> If it bleeds, it leads.

In Saudi Arabia, women walk *behind* men.

.. . . . . . . . .

[Dudley Henriques[_3_]]

On Thursday, August 9, 2012 7:42:24 PM UTC-4, Mxsmanic wrote:
> A brand-new video showing a small airplane crash from inside the aircraft:
>
>
>
> http://www.youtube.com/watch?v=yDu0jYiz-v8
>
>
>
> The video claims that a combination of density altitude and an "air pocket"
>
> brought the aircraft down into the trees, but all I see are effects of density
>
> altitude and what looks like the beginning of a stall.
>
>
>
> Everyone survived. The passengers walked away from the totaled aircraft, the
>
> pilot was badly injured but will recover fully, and the cameras were
>
> completely unaffected.
>
>
>
> It's interesting that the FAA produced a corny but informative video on
>
> density altitude half a century ago, and it's still pertinent today:
>
>
>
> http://www.youtube.com/watch?v=RZCb6nw_T4U
>
>
>
> It almost looks as if the movie were made in the same area as the crash.

This clip is getting our attention (flight safety workgroup) as a human factors issue.
Obviously there was poor planning for the takeoff. Density altitude and gross weight were indeed factors.
What has piqued our interest isn't what's obvious but rather how this pilot ignored so many visual cues and performance cues during the takeoff run, all of which should have been telling him to abort.
He ignored these clues over the extended run over terrain where the takeoff could have been aborted at any time.
Finally airborne, the aircraft was barely able to maintain level flight at an angle of attack so close to max Cl that ANY attempt at bank would have increased the stall speed to the max Cl thus causing a stall in turn which would most likely have been fatal at ground contact.
If anything is to be learned from this accident as far as our workgroup specifically is concerned, it will involve the human factors in play during the actual takeoff run.
It's interesting work.
Dudley Henriques

[Dylan Smith[_2_]]

On 2012-08-15, Dudley Henriques > wrote:
> What has piqued our interest isn't what's obvious but rather how this
> pilot ignored so many visual cues and performance cues during the
> takeoff run, all of which should have been telling him to abort.

Never underestimate the power of denial.

[Vaughn]

On 8/14/2012 11:04 PM, Dudley Henriques wrote:

>
> This clip is getting our attention (flight safety workgroup) as a human factors issue.

Dudley, I assume (perhaps wrongly) that was a commercial flight. That
pilot may have made that same slow takeoff in that same loaded plane
hundreds of times. So naturally he "knew" the plane would make it.
....Only today was the day that a clinker was caught in an exhaust valve
so he was missing 50 RPM, or today was the day that a bit of rare wind
sheer gave him an unexpected tailwind on his upwind leg.

I once took off in a "not so strong" 152 after having carelessly left
the mag switch not quite all the way into the "both" detent. The
difference was only 50 rpm, so I missed that cue. By the time I figured
out that this takeoff was marginal, I was committed. I did a circuit
without ever making it to pattern height.

The lesson learned was golden, but I still kick myself in the ass.

Vaughn
>

[Mxsmanic]

Dudley Henriques writes:

> What has piqued our interest isn't what's obvious but rather
> how this pilot ignored so many visual cues and performance cues
> during the takeoff run, all of which should have been telling him
> to abort. He ignored these clues over the extended run over
> terrain where the takeoff could have been aborted at any time.

One wonders if he would have behaved the same way if he were alone in the
aircraft. And one wonders how much experience with high-altitude takesoffs and
landings he had. Perhaps he didn't want to disappoint his passengers (one of
whom was his son). Some people give people priority over safety and remain
popular (until they crash), others give safety priority over people and become
unpopular (although they live to a ripe old age).

[Dudley Henriques[_3_]]

On Wednesday, August 15, 2012 6:21:10 AM UTC-4, Dylan Smith wrote:
> On 2012-08-15, Dudley Henriques > wrote:
>
> > What has piqued our interest isn't what's obvious but rather how this
>
> > pilot ignored so many visual cues and performance cues during the
>
> > takeoff run, all of which should have been telling him to abort.
>
>
>
> Never underestimate the power of denial.

Quite to the contrary, our interest lies more on the REASONS a pilot accepts flight into error.

DH

[Dylan Smith[_2_]]

On 2012-08-20, Dudley Henriques > wrote:
> On Wednesday, August 15, 2012 6:21:10 AM UTC-4, Dylan Smith wrote:
>> Never underestimate the power of denial.
>
> Quite to the contrary, our interest lies more on the REASONS a
> pilot accepts flight into error.

As I said: never underestimate the power of denial. I don't know the
experience or history of this pilot, but for a moment if we assume he's
taken off with this load and at this density altitude plenty of times.
He knows performance is bad, but he's climbed out fine but slowly.
But this time he forgot to set the mixture for best power, and never
realises it.

After he takes off and then settles back down to the ground, the power
of denial is this. "Oh, I've done this before, I must have just
tried to lift off too early". Then he's off the end of the airfield
but still over flat land. "It'll climb soon, it always has". His
mind is powerfully telling the possibly more sensible part of him
in a loud voice that it'll all come out OK in the end if we just press
on a little further, and to ignore all the signs that in fact things
will not turn out well, in other words, the power of denial.

There's probably some pschological term for this, but every day I
see people unable to resist the power of denial, that it happens to
pilots too is not unusual and we need to recognise it to stop it from
flying us into the trees.

[Gilbert Smith[_2_]]

Dylan Smith > wrote:

>On 2012-08-20, Dudley Henriques > wrote:
>> On Wednesday, August 15, 2012 6:21:10 AM UTC-4, Dylan Smith wrote:
>>> Never underestimate the power of denial.
>>
>> Quite to the contrary, our interest lies more on the REASONS a
>> pilot accepts flight into error.
>
>As I said: never underestimate the power of denial. I don't know the
>experience or history of this pilot, but for a moment if we assume he's
>taken off with this load and at this density altitude plenty of times.
>He knows performance is bad, but he's climbed out fine but slowly.
>But this time he forgot to set the mixture for best power, and never
>realises it.
>
>After he takes off and then settles back down to the ground, the power
>of denial is this. "Oh, I've done this before, I must have just
>tried to lift off too early". Then he's off the end of the airfield
>but still over flat land. "It'll climb soon, it always has". His
>mind is powerfully telling the possibly more sensible part of him
>in a loud voice that it'll all come out OK in the end if we just press
>on a little further, and to ignore all the signs that in fact things
>will not turn out well, in other words, the power of denial.
>
>There's probably some pschological term for this, but every day I
>see people unable to resist the power of denial, that it happens to
>pilots too is not unusual and we need to recognise it to stop it from
>flying us into the trees.

It is quite simple. You identify a point on the runway where you quit
if not off the ground. This should not be before each flight, but
selected before your first use of the airstrip and adhered to come
what may. Ideally a board at the side of the strip marked with the
distance in yards from the threshold.

I have aborted many take-offs in this way, and the great thing is you
don't even have to think about it.

[Dylan Smith[_2_]]

On 2012-08-20, Gilbert Smith > wrote:
> It is quite simple. You identify a point on the runway where you quit
> if not off the ground.

It can be more complex than this. About four years ago I witnessed
a serious stall/spin crash. It was a rather marginal microlight being
tested at gross weight by an experienced pilot and the owner.

Where I live it's not much above sea level, but this aircraft didn't
have great climb performance. Off the end of the runway in use are some
low hills (actually, a glacial terminal moraine left by the last Ice Age)
probably only 150 feet high at most. They don't look in any way imposing
from the airfield, they are a good 3/4 mile off the end of a runway that's
the best part of a mile long, and probably not really high in the thoughts
of the pilot.

However, the "clutching hand" from these hills goes way above their tops
and can require good climb performance to escape. The hills are much more
sheer sided than they look from the far end of the runway, and the
sink can be very strong. I was actually on downwind at the time and
watching his position as I was planning a stop-and-go landing, and he
broke ground well before the halfway point of the runway. After doing my
stop-and-go, I lowered the nose just to check on his progress - knowing
I would probably be faster - only to see the wreckage on top of the
hill. (Fortunately they both survived, the owner was just bashed and
bruised but the pilot was more seriously injured. Another thing in
their favour was that there happened to be a Royal Navy Sea King in the
air on routine exercises only 20 minutes flying time away, fully
crewed and equipped for transporting casualties)

From his point of view, the takeoff was nominal, he was off before the
halfway point and climbing, apparently enough to clear the hills.

[Bug Dout]

Dylan Smith > writes:

> As I said: never underestimate the power of denial. I don't know the
> experience or history of this pilot, but for a moment if we assume he's
> taken off with this load and at this density altitude plenty of times.

Or, I assume he probably sensed something wrong on the takeoff run but
felt social pressure to make the flight with has pax. I've always
believed the best pilot has some asshole in him or her: the ability to
say "we're not flying today" regardless of the hopes of others for the
flight.
--
Before I travelled my road I was my road.
--Antonio Porchia, Voces, 1943, translated from Spanish by W.S. Merwin