Jammed Elevator

In article ,
Andrew Sarangan wrote:


Did the glove get stuck during the jump, or was it there when you took off?

It ended up there during the jumper exit.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

In article ,
Greg Esres wrote:


If the a/c didn't stall in the bank, then it likely wasn't going to
stall in straight flight, particuarly with only 1/3 "up" and a forward
CG.

Gee Greg, sure wish you had been in the airplane with me. You could
have explained to the airplane that it wasn't "likely" to do what it was
doing. Ok, perhaps it wouldn't have exceeded the critical AOA causing a
stall, but the pitch angle was going to be excessive. If left alone it
would have pitched over seeking trim speed with a resultant zoom right
back up. Not a ride I wanted to participate in...and I'm comfortable
with pitch and bank angles that most people probably are not comfortable
with.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

Opps! Should have typed "rudder when used with aileron"

john smith wrote:
You had two additional controls you failed to mention using, the rudder
and the elevator trim.
Elevator trim will increase/decrease pitch.
Rudder, when used with elevator will allow you to slip right or left and
control both pitch and airspeed.

Dale wrote:

I fly a Cessna P206 hauling skydivers. Today on one of the drops a
glove somehow managed to become jammed between the mass balance and
the end of the stab which jammed the elevator in about the 1/3 "up"
position. I could see two fingers sticking up above the elevator with
something flapping on the underside. The airplane was pitching up and
I had to roll into a bank to slice the nose down to keep from
stalling. I went through several repetitions of that until I found a
power setting that lessened the pitch-up, then I was able to force the
yoke forward slightly and stablized in a slight descent at 80kts IAS.
I got the boss on the radio and headed the airplane toward a deserted
area that would be okay to bail out over if needed and would be a good
place for the airplane to crash if it came to that. The jumpers had
exited at 13000, I was at about 11,500 when I got things stablized. I
got ready to bailout (tightened the leg straps, tightened the lap
belt, felt the lap belt release and the ripcord handle) and then
planned on how to fix the problem. I decided to try and force the
glove out by moving the elevator. I first pulled on the yoke and was
able to get almost full up elevator but it was still not free and took
a great deal of effort to move the yoke. This of course pitched me up
sharply so I rolled left and as the nose started down rolled level and
pushed the yoke forward. I was only doing about 60-65kts when I
pushed so I wasn't worried about breaking the airplane, but I'm here
to tell ya a 206 makes some odd noised when you push that hard
negative. G I think it was the air over the vent intakes...weird
sound. The elevator was still not free as I pitched over, I was
thinking it was looking more and more like I was going to have to
jump...I pulled hard on the yoke and this time things came free. The
glove (or whatever it was) was gone and the controls now worked
normally. A gentle descent and landing followed by a close look at
the airplane. The only damage was a slight bend in the stab top skin
where the glove was jammed. (The flightsuit can be cleaned G)

One risk of hauling skydivers is that a jumper may have a parachute
open on the step which can lead to the tail being damaged or removed
from the airplane. Because of this I've thought about what I would do
if that should occur. I've even practiced flying with the yoke held
in one position to simulate a jammed elevator. Today it paid off.

Unless the 206 has a stabilator, the trim works independent of the
elevator. It is an anti-servo tab.
See
http://www.angelfire.com/on/dragonfl.../servotab.html

Dale wrote:
The trim wouldn't work in this case...the elevator would not move.

The elevator trim would work in the case of a jammed elevator.

The trim would, however, work opposite to normal.

Karl

"Dale" wrote in message
...
In article ,
john smith wrote:

You had two additional controls you failed to mention using, the rudder
and the elevator trim.
Elevator trim will increase/decrease pitch.
Rudder, when used with elevator will allow you to slip right or left and
control both pitch and airspeed.


The trim wouldn't work in this case...the elevator would not move.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

"john smith" wrote in message
...
Unless the 206 has a stabilator, the trim works independent of the
elevator.

Don't fly Cessnas much, eh?

The trim control requires the elevator to be able to move in order to be
effective. If the elevator is stuck, it is possible to use the trim control
to effect *small* changes in pitch, but those changes will be opposite to
the normal effect of the trim control (i.e. nose down trim will cause nose
up pitch).

In this situation, the trim control effectively becomes a very tiny
elevator. Dale probably should've tried using it, but depending on the
amount of elevator deflection when it got stuck, it may or may not have been
very useful.

Pete

Dale wrote:
I decided to try and force the glove out by moving the
elevator. I first pulled on the yoke and was able to get almost full up
elevator but it was still not free and took a great deal of effort to
move the yoke....


One risk of hauling skydivers is that a jumper may have a parachute open
on the step which can lead to the tail being damaged or removed from the
airplane. Because of this I've thought about what I would do if that
should occur. I've even practiced flying with the yoke held in one
position to simulate a jammed elevator. Today it paid off.


I don't mean to argue with success, but your narrative does leave
me with a couple of questions. As I understand the situation, you've
managed to achieve a stable descent with your elevator stuck in a
pitch-up position. At this point I would be concerned that any attempts
to pull the yoke back would result in the elevator being stuck in an
even greater pitch-up position.

How difficult would it have been to land the aircraft using only
power, rudder, and ailerons?

Did you have some reason, not given in the narrative, for believing
that you would be able to return the elevator to at least its current
position?

Did the fact that you were ready (and able) to bail out if necessary
influence your decision-making? (In other words, would you have done
the same things if you knew you had to live [or die] with any
irreversible negative changes you imposed on the situation?)

Rich Lemert

Yes, Peter, I do know that.
It is very evident when preflighting an aircraft.
When you raise or lower the elevator, the trim tab moves variably with
the angle of the elevator.
In this case, you would use every available input to your advantage.

Peter Duniho wrote:
"john smith" wrote in message
...

Unless the 206 has a stabilator, the trim works independent of the
elevator.


Don't fly Cessnas much, eh?

The trim control requires the elevator to be able to move in order to be
effective. If the elevator is stuck, it is possible to use the trim control
to effect *small* changes in pitch, but those changes will be opposite to
the normal effect of the trim control (i.e. nose down trim will cause nose
up pitch).

In this situation, the trim control effectively becomes a very tiny
elevator. Dale probably should've tried using it, but depending on the
amount of elevator deflection when it got stuck, it may or may not have been
very useful.

Pete

Dale wrote in message ...
I fly a Cessna P206 hauling skydivers. Today on one of the drops a
glove somehow managed to become jammed between the mass balance and the
end of the stab which jammed the elevator in about the 1/3 "up"
position. I could see two fingers sticking up above the elevator with
something flapping on the underside. The airplane was pitching up and I
had to roll into a bank to slice the nose down to keep from stalling. I
went through several repetitions of that until I found a power setting
that lessened the pitch-up, then I was able to force the yoke forward
slightly and stablized in a slight descent at 80kts IAS. I got the boss
on the radio and headed the airplane toward a deserted area that would
be okay to bail out over if needed and would be a good place for the
airplane to crash if it came to that. The jumpers had exited at 13000,
I was at about 11,500 when I got things stablized. I got ready to
bailout (tightened the leg straps, tightened the lap belt, felt the lap
belt release and the ripcord handle) and then planned on how to fix the
problem. I decided to try and force the glove out by moving the
elevator. I first pulled on the yoke and was able to get almost full up
elevator but it was still not free and took a great deal of effort to
move the yoke. This of course pitched me up sharply so I rolled left
and as the nose started down rolled level and pushed the yoke forward.
I was only doing about 60-65kts when I pushed so I wasn't worried about
breaking the airplane, but I'm here to tell ya a 206 makes some odd
noised when you push that hard negative. G I think it was the air
over the vent intakes...weird sound. The elevator was still not free as
I pitched over, I was thinking it was looking more and more like I was
going to have to jump...I pulled hard on the yoke and this time things
came free. The glove (or whatever it was) was gone and the controls
now worked normally. A gentle descent and landing followed by a close
look at the airplane. The only damage was a slight bend in the stab
top skin where the glove was jammed. (The flightsuit can be cleaned G)

One risk of hauling skydivers is that a jumper may have a parachute open
on the step which can lead to the tail being damaged or removed from the
airplane. Because of this I've thought about what I would do if that
should occur. I've even practiced flying with the yoke held in one
position to simulate a jammed elevator. Today it paid off.

It sounds like somebodys joke almost killed you.
Was the glove present on takeoff?

Either way, thanks for the nice tale. The part about using either
a turn or a reduced power setting is invaluable to the rest of us.

As I recall, you said it stabilized at about 80 kts, reduced power, slight
descent.
Sounds like you had a nice approach set up. 80 might be a tad high for a
light
206. At what speed did it stabilize with no power?

Also sounds like the phugoid contributed to the adrenaline level.


Dale wrote in message ...
In article ,
Greg Esres wrote:


If the a/c didn't stall in the bank, then it likely wasn't going to
stall in straight flight, particuarly with only 1/3 "up" and a forward
CG.

Gee Greg, sure wish you had been in the airplane with me. You could
have explained to the airplane that it wasn't "likely" to do what it was
doing. Ok, perhaps it wouldn't have exceeded the critical AOA causing a
stall, but the pitch angle was going to be excessive. If left alone it
would have pitched over seeking trim speed with a resultant zoom right
back up. Not a ride I wanted to participate in...and I'm comfortable
with pitch and bank angles that most people probably are not comfortable
with.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html