Density altitude strikes again

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 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

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

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).