Winter flying with retractable gear?

Robert,

Don't know where you got the idea a B-17 would "tip over" should the
gear be retracted with the tires rotating. The gear retracts in its
plane of rotation. As a result of your post, I got in touch with one
of the folks who gives checkrides in B-17s (and all other WWII
multi-engine aircraft) and was advised that the subject is discussed
from time to time, but is an old wives tale. Boeing does not call for
the brakes to be used after takeoff on their WWII bombers. I was told
that the CAF procedure is not to touch the brakes on the B-17 to stop
the wheels from rotating. The matter tends to be airplane specific,
on the B-29 they recently started using the brakes because they are
concerned about clearances with the gear doors/wells, but he said that
was the only one. If you look at the gear for many of the WWII and
later large aircraft, there are red marks on the tires that line up
with red marks on the wheels so the crew can see if the tire has slide
on the wheel.

All the best,
Rick

(Robert M. Gary) wrote in message . com...
(Paul Tomblin) wrote in message ...
This will be my first winter flying the club's Lance. One instructor told
me that you want to tap the brakes before retracting the gear to dislodge
any slush or snow so that it doesn't freeze in the wheel well, and I read
somebody else saying that you should hold off retracting the gear after
take-off for a little while to blow the slush and snow off. Should I do
one or the other or both?

There are two things here. Tapping the brakes is something started in
WWII because a B-17 would tip over when the gear come up if the wheels
were spinning (imagine the gyro action happening on those big wheels).
I believe most large aircraft today automatically apply brake pressure
when the hydro lifts the gear.
In the Mooney world we always read about Mooney pilots taking off,
getting slush in the gear and then freezing at altitude. I don't know
how tapping the brakes would change that though.

-Robert, CFI and Mooney owner

On Wed, 13 Oct 2004 13:54:18 -0400, Ron Natalie
wrote:

Robert M. Gary wrote:

The DE who did my private told me about a friend that went through
flight training with him in the B-17 and later the B-24(could have
been 25 though). He crashed after take off because of this and spent
the rest of his life with scaring on his face from the burns.

The B-24 and B-25 gear folds such that there would be some precession
effect. The B-17 just can't have any. The gear swings forward and up
along the plane of rotation.

Even if there is precession on the gear the one on one side moves the
opposite direction of the other. The forces cancel out as far as the
airplane would be concerned.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger wrote:

Even if there is precession on the gear the one on one side moves the
opposite direction of the other. The forces cancel out as far as the
airplane would be concerned.

You're assuming that both mains would come up simultaneously. This was not the case
with some of the old military birds. I don't know if the B-24 or B-25 gear does this
or not.

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to have
been looking for it.

G.R. Patterson III wrote:

Roger wrote:

Even if there is precession on the gear the one on one side moves the
opposite direction of the other. The forces cancel out as far as the
airplane would be concerned.


You're assuming that both mains would come up simultaneously. This was not the case
with some of the old military birds. I don't know if the B-24 or B-25 gear does this
or not.

The don't come up at the same time in my plane. Navions all wiggle a little bit
during gear retraction as those fat tires come up one slightly before the other.

But as heavy as a B24 is (and heavy on the controls too) I can't see even one gear
coming up and one staying down and it being made of lead would roll that thing over.

Ron,

You're right. The gear retraction isn't going to cause the airplane
to roll over and crash, good grief. Where do these tales begin?
Maybe with a pilot who screwed up and had to find something to blame
other than himself?

All the best,
Rick

Ron Natalie wrote in message om...
G.R. Patterson III wrote:

Roger wrote:

Even if there is precession on the gear the one on one side moves the
opposite direction of the other. The forces cancel out as far as the
airplane would be concerned.


You're assuming that both mains would come up simultaneously. This was not the case
with some of the old military birds. I don't know if the B-24 or B-25 gear does this
or not.

The don't come up at the same time in my plane. Navions all wiggle a little bit
during gear retraction as those fat tires come up one slightly before the other.

But as heavy as a B24 is (and heavy on the controls too) I can't see even one gear
coming up and one staying down and it being made of lead would roll that thing over.

On 12 Oct 2004 08:26:18 -0700, (Robert M. Gary)
wrote:

There are two things here. Tapping the brakes is something started in
WWII because a B-17 would tip over when the gear come up if the wheels
were spinning (imagine the gyro action happening on those big wheels).
I believe most large aircraft today automatically apply brake pressure
when the hydro lifts the gear.
In the Mooney world we always read about Mooney pilots taking off,
getting slush in the gear and then freezing at altitude. I don't know
how tapping the brakes would change that though.

-Robert, CFI and Mooney owner

Don't see how this can be possible. You're saying that if the brakes
aren't tapped to stop the rotation of the tires before they arrive at
their wheel wells, this four engine bomber which may be carrying a
load of bombs simply tips over? At 120mph? What makes this happen?
The tires don't hit anything when they reach the wheel wells, they
continue rotate. Even with the wheels up and locked in position, the
tires can still turn. Paul Mantz utilized this feature to steer the
B-17 he had been tasked with landing gear up for the movie "12 O'Clock
High" once he'd set it down. He was supposed to skid through a tent
that had been conveniantly left out beside the runway for this
purpose. He found that once he was down and skidding, he could use
left and right brake to make sure he plowed through the tent. This is
in his memoires. It was a Hollywood moment of course, no tents were
ever pitched out beside any active runway.

It would have to take one hell of a lot of inertia for something to
flip a B-17 up on it's nose after having lifted off and climbing out
under takeoff power.

In another related instance, I read of a B-17 pilot who was senior at
the air base. It was his job to test various bombers that had been
repaired. He flew one which he said lifted off at the correct speed,
but then settled down onto the runway again, momentarily, and then
lifted off again. He tested this out several times and it did it
every time. So he merely made note of it and recommended that for
this particular airplane the brakes NOT be tapped, as was normal
practice during takeoff, but to leave them revolving so that when the
bomber touched down again on the runway, there would be no screeching
of tires and possible blow out.

Next mission he was assigned that bomber. He was in the left seat
with a relatively new pilot in the right seat. He remarked that the
guy was impulsive and despite being told NOT to tap the brakes after
liftoff, to wait until the bomber had settled back down and then
lifted off again, the guy tapped them anyway after the initial liftoff
and sure enough, the airplane promptly settled back down on the runway
with juddering and screeching from the now stopped tires as they were
spun up again. Luckily, neither of the tires blew out, but the pilot
had to write up the incident so that the ground crew would replace the
tires as they were now flat spotted.

Corky Scott

"Teacherjh" wrote in message
...
One instructor told
me that you want to tap the brakes before retracting the gear to dislodge
any slush or snow so that it doesn't freeze in the wheel well

I was taught to tap the brakes to stop the wheels from spinning before
tucking
them away. (spinning tires bulge out a bit, or so I was told)

From what I've read, the reasoning is that if the wheel is still spinning,
it can still be spinning off water/slush which can accumulate and freeze
inside the wheel wells.

Paul

"Rick Durden" wrote in message
...
If you look at the gear for many of the WWII and
later large aircraft, there are red marks on the tires that line up
with red marks on the wheels so the crew can see if the tire has slide
on the wheel.

We have that on all our planes here in the UK.

It's one of the things to check on the pre-flight, that the tyre hasn't
rotated on the rim, possibly damaging the valve.

Paul