Crosswind landing control..

"Dan" wrote in message
ups.com...
So, this damage is a result of slamming the nosewheel down, or applying
forward pressure after the wheels are firmly on the ground?

It would seem that forward pressure on the stick would not actually
_push_ the nosewheel down, but simply allow the weight of the engine to
settle onto the nosewheel sooner.. Does pushing actually apply more
downward force on the nosewheel than when the plane is sitting on the
ramp?

No, it doesn't, but when travelling at speed down the runway, pushing the
stick forward increases the angle of attack of the tail plane, (obviously),
and in effect, transfers more weight to the front of the a/c by making the
rear lighter. (I think I'm explaining this right!)
Oz Lander

My impression that the elevator applied varying levels of downward
force to balance the plane about the center of lift. I am not aware
that the elevator could even produce _upward_ force on the tail.

If it can't produce upward force, then the rear of the plane could be
made no lighter than when it is standing still, therefore it could
transfer no _additional_ weight to the nosewheel no matter what the
control inputs. Where is this logic flawed (seriously, I want to
understand if this is wrong...)


--Dan


Crash Lander wrote:
"Dan" wrote in message
ups.com...
So, this damage is a result of slamming the nosewheel down, or applying
forward pressure after the wheels are firmly on the ground?

It would seem that forward pressure on the stick would not actually
_push_ the nosewheel down, but simply allow the weight of the engine to
settle onto the nosewheel sooner.. Does pushing actually apply more
downward force on the nosewheel than when the plane is sitting on the
ramp?

No, it doesn't, but when travelling at speed down the runway, pushing the
stick forward increases the angle of attack of the tail plane, (obviously),
and in effect, transfers more weight to the front of the a/c by making the
rear lighter. (I think I'm explaining this right!)
Oz Lander

"Dan" wrote in message
ps.com...
My impression that the elevator applied varying levels of downward
force to balance the plane about the center of lift. I am not aware
that the elevator could even produce _upward_ force on the tail.


If the elevator couldn't generate an _upward_ force, then you couldn't pick
up the tail on an taildragger, right? Let me assure you, you can pick up the
tail on a taildragger.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Taildraggers, yes, absolutely. What about tricycle gear aircraft?

--Dan


Capt. Geoffrey Thorpe wrote:
"Dan" wrote in message
ps.com...
My impression that the elevator applied varying levels of downward
force to balance the plane about the center of lift. I am not aware
that the elevator could even produce _upward_ force on the tail.


If the elevator couldn't generate an _upward_ force, then you couldn't pick
up the tail on an taildragger, right? Let me assure you, you can pick up the
tail on a taildragger.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Dan" wrote in message
ups.com...
Taildraggers, yes, absolutely. What about tricycle gear aircraft?

--Dan


I'm not sure I understand the question.

Will the tail generate up? Sure, and elevator is an elevator.

Will the elevator pick the tail up? No because the nose wheel gets in the
way.

On the other hand, if you wack off that silly nose gear, move the mains
forward to where they belong, and add a tailwheel, your C150/2 is now a
Texas Taildragger (probably trademark) and you will be able to pick the tail
up with the elevator.

(all in good fun, eh?)

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
newseWdnYlvE6ilLOnYnZ2dnUVZ_hydnZ2d@wideopenwest .com...
"Dan" wrote in message
ps.com...
My impression that the elevator applied varying levels of downward
force to balance the plane about the center of lift. I am not aware
that the elevator could even produce _upward_ force on the tail.


If the elevator couldn't generate an _upward_ force, then you couldn't
pick up the tail on an taildragger, right? Let me assure you, you can pick
up the tail on a taildragger.


I agree 100% that the elevator can generate an upward force and pushing the
stick forward in a tricycle plane to put weight on the nose is NOT a good
idea in general. I would think it would be very easy to over do it.

Danny Dot

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

I agree 100% that the elevator can generate an upward force and pushing the
stick forward in a tricycle plane to put weight on the nose is NOT a good
idea in general. I would think it would be very easy to over do it.

Danny Dot

The bigger problem in wheelbarrowing is the too-fast touchdown.
The wing, if you remember your groundschooling, generates more lift at
a lower angle of attack at a higher airspeed, and a fast landing is at
a flatter attitude. Since the nosewheel usually keeps the airplane
slightly nose-high on the ground compared to flight attitude, the
nosewheel will land first, and without the control the mains offer, the
airplane becomes a really nasty taildragger. Forcing the elevator down
only make it worse, and having flaps deployed lowers the nose even
further for a given airspeed. Years ago one of our students ran a 150
off the runway into the snow and overturned it, just because he
wouldn't slow the airplane to the proper approach speed and get in on
the right glidepath. Trying to fix a bad approach by diving at the
runway and then forcing the airplane on long before it should land is a
sure way to get hurt and bust your airplane, sooner or later.
This thread was about crosswind landings. The biggest and most
common mistake I see there is the belief that the flight is over after
the wheels are on the ground. He will neutralize the controls,
including the ailerons, and in the rollout the wind could pick up the
upwind wing and flip the airplane over. More and more aileron should be
applied after touchdown until it's all used up, and then held there
until the rollout is complete. Even in taxing in a stronger wind the
controls should be used to prevent upset.

Dan

Capt. Geoffrey Thorpe wrote:
"Dan" wrote in message
ps.com...
My impression that the elevator applied varying levels of downward
force to balance the plane about the center of lift. I am not aware
that the elevator could even produce _upward_ force on the tail.


If the elevator couldn't generate an _upward_ force, then you couldn't pick
up the tail on an taildragger, right? Let me assure you, you can pick up the
tail on a taildragger.

Sure you can, but much of that lift is a pitch couple generated by
the prop's thrust line being so far above the locked mains while
standing still, and lifting of the tail while moving is largely due to
the wing's CP being well behind the mains. If you can see the elevator
in cruise flight you'll see that it is down some, to counteract the
downforce of the stabilizer.
The elevator's lifing force in some airplanes might not be
enough to maintain nose-up in inverted flight; aerobatic airplanes have
more elevator travel and the CP and CG may be closer together to reduce
the inherent stability.

On 3 Dec 2006 21:52:57 -0800, Dan wrote:
My impression that the elevator applied varying levels of downward
force to balance the plane about the center of lift. I am not aware
that the elevator could even produce _upward_ force on the tail.

If it can't produce upward force, then the rear of the plane could be
made no lighter than when it is standing still, therefore it could
transfer no _additional_ weight to the nosewheel no matter what the
control inputs. Where is this logic flawed (seriously, I want to
understand if this is wrong...)

Airplanes are normally trimmed (and loaded within limits) so the
horizontal stabilizer provides a relatively small downward force.
This gives positive pitch stability without a major increase in
drag.

If your model of how the elevator works was valid, it would be
impossible for an aircraft to fly inverted since even full down
elevator wouldn't be enough to counteract the nose-down pitch
moment.

You also have to consider that an aircraft on the ground would
pitch around an axis passing through the main landing gear,
not through the wing's center of lift.


ljd