Crashing on takeoff... how odd

"Greg Farris" wrote in message
...

Only a fools and idiots speculate on the cause of an airplane crash
before the facts are known.


Your self-assured tone notwithstanding, I question the veracity, as well
as the usefulness of this statement.

Idiots probably spend very little of their time speculating on the causes
of air crashes, while those who do so all day every day are professional
air accident investigators, who did not get their jobs by being fools.

Speculation is a normal and necessary activity in such situations, in no
way degrading to the memory of the victims, and indispensable to our
undersatnding of the accident process.

Wild or lurid scenari, accusation, diffamation and psychotic, paranoid
conspiracy theories do not qualify, as any reasoning person readily
understands.


He got it backward. Only a fool would speculate on the cause of an airplane
crash AFTER the facts are known.

Airplanes are heavier on takeoff than at any other time, and the margin
between their climb speeds and the stall is at its smallest. Ask anyone who
has done a V1 cut in training or on a checkride (jets only). I'm willing to
venture that the pilots of the accident plane did all of the appropriate
calculations for the longer runway. Seems to me that if a plane is cleared
for takeoff on a long runway but lines up on a shorter runway, there is a
lot of blame to be shared between the cockpit and the tower.

Bob Gardner

wrote in message
ups.com...
I remember a recent discussion with a pilot mate where I was mentioning
how illogical a crash-shortly-after-takeoff is, given that beyond V1
takeoff can safely be continued even with just one good engine. I'd
even told him that if I saw an aircraft airborne following takeoff, I'd
presume it safe.

Days after that tete-a-tete, a Fokker went down in Pakistan shortly
after taking off. And today the Bombardier at Kentucky.

Doesn't add up, does it? After all, if the engines are good and there's
no bomb going off, it should be pretty hard to crash an aircraft!

Ramapriya

Ronald Gardner wrote:
Well looks like a terrible mistake if he took off on 26 instead of 22:
CRJ200 ER
FAR take-off field length (SL, ISA) at MTOW 5,800 ft 1,768 m
FAR 121 landing field length (SL) at MLW 4,850 ft 1,479 m

CRJ200 LR
FAR take-off field length (SL, ISA) at MTOW 6,290 ft 1,918 m
FAR landing field length (SL) at MLW 4,850 ft 1,479 m

I strongly suspect that 6,290 figure is the length of runway for the
plane to accelerate to V1, take a engine cut, and stop on the runway
using only brakes, with no credit for reverse thrust. The distance for
a nominal takeoff roll is much shorter.

So sad . . . my prayers for the families of the folks on board,
passengers and crew.

John

Newps wrote:

Full nose up trim is immediately apparent on the application of power.
The fact that he let it get away from him says it all. It doesn't take
a lot of forward stick after takeoff to put the nose where it needs to be.


One more non-aviator question here - is upset recovery training not
normally part of the licensing procedure? What Larry described seems a
good example of upset.

Ramapriya

Bob Gardner wrote:

Airplanes are heavier on takeoff than at any other time, and the margin
between their climb speeds and the stall is at its smallest. Ask anyone who
has done a V1 cut in training or on a checkride (jets only). I'm willing to
venture that the pilots of the accident plane did all of the appropriate
calculations for the longer runway. Seems to me that if a plane is cleared
for takeoff on a long runway but lines up on a shorter runway, there is a
lot of blame to be shared between the cockpit and the tower.

If the tower cleared the airplane to the correct runway and the pilots
taxied to a different one, how does the tower share in this blame?

Matt

Larry Dighera wrote:



Full nose up trim is immediately apparent on the application of power.


Mmmm, that sounds like the voice of experience.

Any of your basic singles like most Cessna's, Cherokees, my Bonanza,
when you add power with full nose up trim the yoke comes right back to
you. This in no way makes the plane unflyable.



Wouldn't the aircraft have to reach some speed on the takeoff roll
subsequent to the application of power before the control force would
be apparent on the yoke? Or are you referring to another indication?

Nope, you notice it right away. The yoke is not where it's supposed to be.




I would think it is possible with some effort. What would be your
estimate of the required effort in pounds of push on the yoke to
overcome full up trim in a C-172?

Not sure of the exact amount but that is a certification requirement.
My 182 got pretty sporting if you had to do a go around. Since I mostly
flew alone it was a nose heavy airplane and I always landed with full
nose up trim. Not sure how to characterize how much force was required.
Let's say significant.

Part 23 establishes maximum stick force requirements. It does not take
superhuman strength to overcome full nose-up trim on takeoff.

Bob Gardner

"Newps" wrote in message
...


Larry Dighera wrote:



I once witnessed a Cessna C-172 crash on takeoff at Santa Monica
Airport (KSMO) in the early '70s. The aircraft rotated, and rocketed
skyward at a very high angle, stalled, and nosed into the runway. The
pilot escaped with a broken finger. The cause was a result of the
trim being set wrong. Don't forget your check list.



Full nose up trim is immediately apparent on the application of power. The
fact that he let it get away from him says it all. It doesn't take a lot
of forward stick after takeoff to put the nose where it needs to be.

Newps wrote:

Not sure of the exact amount but that is a certification requirement. My
182 got pretty sporting if you had to do a go around. Since I mostly
flew alone it was a nose heavy airplane and I always landed with full
nose up trim. Not sure how to characterize how much force was required.
Let's say significant.

I don't know the exact force either, but I could easily hold down the
nose of my 182 with full nose-up trim and full throttle. I'd guess
30-40 lbs of force, but that is just a guess. I can bench press
probably 160 lbs (I haven't lifted in 20 years so I'm getting wimpy),
which is 80 lbs per arm. I'm sure I wasn't using even half of my arm
strength to hold the nose at climb attitude hence my guess of it being
no more than 40 lbs and likely less than that.

Matt

Bob Gardner wrote:

Part 23 establishes maximum stick force requirements. It does not take
superhuman strength to overcome full nose-up trim on takeoff.

But part 23 was written before we all became overweight and out of shape
couch potatoes! :-)

Matt

Matt Whiting wrote:
It isn't that hard to overcome the trim on a 172. There are probably
airplanes where this isn't the case, but the 172 isn't one of them.

In theory, it should be possible on any plane. 14 CFR 23.677 (d) says:

"It must be demonstrated that the airplane is safely controllable and that
the pilot can perform all maneuvers and operations necessary to effect a
safe landing following any probable powered trim system runaway that
reasonably might be expected in service, allowing for appropriate time
delay after pilot recognition of the trim system runaway. The demonstration
must be conducted at critical airplane weights and center of gravity
positions."