T-34A

On Fri, 28 Nov 2003 14:38:22 GMT, EDR wrote in
Message-Id: :


Another question that no one seems to be asking is, what prevented the
pilot and student from employing their parachutes as would be
expected?

When a wing comes off, the resulting centrifigal forces become to great
for a person to claw their way out.

Of course we don't know the forces experienced by those pilots during
their final moments with most of one wing missing. But I would guess,
that with only one wing generating lift, the aircraft entered a rapid
roll and dove for the ground. If that was indeed the final flight
mode, and the CG were not centered on the pilots(s), then they would
indeed experience G forces.

In my estimation, it is likely the pilot(s) were positioned above the
CG, and would have experienced centrifugal force in the direction
toward the canopy. Perhaps the severed portion of the wing hit the
cabin when it separated and frustrated their egress.

In article , Larry Dighera
wrote:

In my estimation, it is likely the pilot(s) were positioned above the
CG, and would have experienced centrifugal force in the direction
toward the canopy. Perhaps the severed portion of the wing hit the
cabin when it separated and frustrated their egress.

Why do you think the force vector is vertical and not lateral?

On Fri, 28 Nov 2003 17:15:03 GMT, EDR wrote in
Message-Id: :

In article , Larry Dighera
wrote:

In my estimation, it is likely the pilot(s) were positioned above the
CG, and would have experienced centrifugal force in the direction
toward the canopy. Perhaps the severed portion of the wing hit the
cabin when it separated and frustrated their egress.

Why do you think the force vector is vertical and not lateral?

I wouldn't expect the force vector to be acting in a vertical (as in
away from the Earth) direction, but in a direction away from the axis
of the roll. If the roll were centered on the aircraft's longitudinal
axis (as a snap roll is) and the pilot were positioned off that axis
toward the canopy, I would expect the force to act toward the canopy
if/when it stabilized.

The twisting moment of the roll might have initially induced some
lateral deflection of the victor, but once (if) it stabilized, there
would no longer be any lateral acceleration resulting from the roll,
only the centrifugal force would remain.

This is difficult to discuss without graphics.

In article , Larry Dighera
wrote:

On Fri, 28 Nov 2003 17:15:03 GMT, EDR wrote in
Message-Id: :

In article , Larry Dighera
wrote:

In my estimation, it is likely the pilot(s) were positioned above the
CG, and would have experienced centrifugal force in the direction
toward the canopy. Perhaps the severed portion of the wing hit the
cabin when it separated and frustrated their egress.

Why do you think the force vector is vertical and not lateral?

I wouldn't expect the force vector to be acting in a vertical (as in
away from the Earth) direction, but in a direction away from the axis
of the roll. If the roll were centered on the aircraft's longitudinal
axis (as a snap roll is) and the pilot were positioned off that axis
toward the canopy, I would expect the force to act toward the canopy
if/when it stabilized.

The twisting moment of the roll might have initially induced some
lateral deflection of the victor, but once (if) it stabilized, there
would no longer be any lateral acceleration resulting from the roll,
only the centrifugal force would remain.

This is difficult to discuss without graphics.

You've never flown aerobatics, have you?

On Fri, 28 Nov 2003 19:56:28 GMT, EDR wrote in
Message-Id: :

You've never flown aerobatics, have you?

I've only a couple of hours of aerobatic instruction.

In article , Larry Dighera
wrote:

You've never flown aerobatics, have you?

I've only a couple of hours of aerobatic instruction.

Think combined spin and roll at high rate (greater than 300 degrees per
second). The forces exerted are dynamic, they are constantly changing
in direction and magnitude. In the spin, the nose is pitching up and
down while the yaw and roll components vary; the loss of a wing or
portion of a wing also impart their own yaw/pitch/roll components. The
amplitudes of each component are constantly varying.

On Sat, 29 Nov 2003 15:30:06 GMT, EDR wrote in
Message-Id: :

In article , Larry Dighera
wrote:

You've never flown aerobatics, have you?

I've only a couple of hours of aerobatic instruction.

Think combined spin and roll at high rate (greater than 300 degrees per
second). The forces exerted are dynamic, they are constantly changing
in direction and magnitude. In the spin, the nose is pitching up and
down while the yaw and roll components vary; the loss of a wing or
portion of a wing also impart their own yaw/pitch/roll components. The
amplitudes of each component are constantly varying.

Are you relating a firsthand experience? Or have you got a cite?

I don't doubt that such circumstances, and others, are possible and
occur, but my expectation would be that in the majority of cases,
egress would be a real possibility.

The fact that the wing failure and separation occurred at ~4,000',
would provide only about 17 seconds before impact at a terminal
velocity of 160 mph if the surface were at sea level. I would expect,
that's not much time in such a situation.