Winter flying with retractable gear?

[Paul Tomblin]

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?

--
Paul Tomblin > http://xcski.com/blogs/pt/
The biggest problem with democracy is that it is, in effect, the rule
by the whim of the moment.
-- Keith Glass

[john smith]

I do both on the Arrow I fly.
Some will argue that leaving the gear down longer just freezed the slush
faster. To me the most important is to blow it out of the brakes.

Paul Tomblin wrote:
> 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?
>

[john smith]

I do both on the Arrow I fly.
Some will argue that leaving the gear down longer just freezed the slush
faster. To me the most important is to blow it out of the brakes.

Paul Tomblin wrote:
> 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?
>

[Ben Jackson]

In article >,
Paul Tomblin > wrote:
>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.

My understanding is that you don't want the gear to freeze in the gear
well, so you leave it down after takeoff to ensure that anything that's
going to freeze will, and then if the gear is going to get stuck it's
stuck down, not up.

--
Ben Jackson
>
http://www.ben.com/

[Ben Jackson]

In article >,
Paul Tomblin > wrote:
>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.

My understanding is that you don't want the gear to freeze in the gear
well, so you leave it down after takeoff to ensure that anything that's
going to freeze will, and then if the gear is going to get stuck it's
stuck down, not up.

--
Ben Jackson
>
http://www.ben.com/

[Teacherjh]

> 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) I confess I've
never actually looked down (sometimes I fly a cutlass) to see how long it takes
them to stop on their own.

I'm not sure how tapping the brakes dislodges any snow. There's very little
shoe travel.

Jose

--
(for Email, make the obvious changes in my address)

[Teacherjh]

> 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) I confess I've
never actually looked down (sometimes I fly a cutlass) to see how long it takes
them to stop on their own.

I'm not sure how tapping the brakes dislodges any snow. There's very little
shoe travel.

Jose

--
(for Email, make the obvious changes in my address)

[AJW]

>
>My understanding is that you don't want the gear to freeze in the gear
>well, so you leave it down after takeoff to ensure that anything that's
>going to freeze will, and then if the gear is going to get stuck it's
>stuck down, not up.
>
>--
>Ben Jackson
>
>http://www.ben.com/
>
That's called fixed gear, down and welded.

I spent lots of hours in a Mooney in the northeast, winter and night, never
took special precautions with the gear when on an inch of snow or slush. I
don't remember a runway being sluch covered, but taxiways had been, and I'm
guessing the takeoff run was enough to remove whatever slush might have
accumulated. It may also be people who live in colder areas than Massachusetts
have to do things differently. There's nothing in the approved manual that
says anything about special care (that I remember, at least)

[AJW]

>
>My understanding is that you don't want the gear to freeze in the gear
>well, so you leave it down after takeoff to ensure that anything that's
>going to freeze will, and then if the gear is going to get stuck it's
>stuck down, not up.
>
>--
>Ben Jackson
>
>http://www.ben.com/
>
That's called fixed gear, down and welded.

I spent lots of hours in a Mooney in the northeast, winter and night, never
took special precautions with the gear when on an inch of snow or slush. I
don't remember a runway being sluch covered, but taxiways had been, and I'm
guessing the takeoff run was enough to remove whatever slush might have
accumulated. It may also be people who live in colder areas than Massachusetts
have to do things differently. There's nothing in the approved manual that
says anything about special care (that I remember, at least)

[Michelle P]

Paul,
Tapping brakes stops the rotation before entering the wheel well. You do
not want them spinning into the gear well.
Leaving them down blows off excess slush and snow as well as freezes any
thin residue that may be left. having it freeze in the wheel well can
make it stick into the well.
Michelle

Paul Tomblin wrote:

>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?
>
>
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

[Michelle P]

Paul,
Tapping brakes stops the rotation before entering the wheel well. You do
not want them spinning into the gear well.
Leaving them down blows off excess slush and snow as well as freezes any
thin residue that may be left. having it freeze in the wheel well can
make it stick into the well.
Michelle

Paul Tomblin wrote:

>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?
>
>
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

[Rick Durden]

Paul,

Tapping the brakes prior to retraction is one of aviation's old wives
tales that just hangs in there. The gear wells are large enough to
hold the tires even if they have some bulge from spinning (which isn't
much anyway on our slow little bugsmashers). There are some
transports in which the manual calls for tapping the brakes and some
in which it specifically says not to as the sudden stop on large tires
and wheels can cause the tire to slide on the rim.

Check the manual for your airplane for winter operations. Some
suggest to delay gear retraction for a bit to help blow off
snow/slush/water. The inertia from the spinning tire usually tosses
off most of the contamination (allowing it to freeze to the underside
of the wing <g>) and waiting a bit to suck the gear up allows the
airflow to take it off the brake discs and other, stationary, portions
of the gear. Having the gear freeze up is pretty rare. More common
will be that you'll taxi through some snow that gets on the brakes, it
melts on the discs and then freezes one or both of the brakes after
takeoff. Just land on centerline to give yourself room for a swerve
as it takes a moment or two of sliding tire(s) before the brake
unfreezes and you have rolling control. Naturally, it occurs when you
make one of those lucky, smooth touchdowns and you hear the squeal of
a tire sliding, then the pop as the ice lets go and things go back to
normal. Not usually a big deal, but folks have gone into the
snowbanks adjacent to the runway due to not reacting quickly enough.

All the best,
Rick

(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?

[Rick Durden]

Paul,

Tapping the brakes prior to retraction is one of aviation's old wives
tales that just hangs in there. The gear wells are large enough to
hold the tires even if they have some bulge from spinning (which isn't
much anyway on our slow little bugsmashers). There are some
transports in which the manual calls for tapping the brakes and some
in which it specifically says not to as the sudden stop on large tires
and wheels can cause the tire to slide on the rim.

Check the manual for your airplane for winter operations. Some
suggest to delay gear retraction for a bit to help blow off
snow/slush/water. The inertia from the spinning tire usually tosses
off most of the contamination (allowing it to freeze to the underside
of the wing <g>) and waiting a bit to suck the gear up allows the
airflow to take it off the brake discs and other, stationary, portions
of the gear. Having the gear freeze up is pretty rare. More common
will be that you'll taxi through some snow that gets on the brakes, it
melts on the discs and then freezes one or both of the brakes after
takeoff. Just land on centerline to give yourself room for a swerve
as it takes a moment or two of sliding tire(s) before the brake
unfreezes and you have rolling control. Naturally, it occurs when you
make one of those lucky, smooth touchdowns and you hear the squeal of
a tire sliding, then the pop as the ice lets go and things go back to
normal. Not usually a big deal, but folks have gone into the
snowbanks adjacent to the runway due to not reacting quickly enough.

All the best,
Rick

(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?

[Ron Natalie]

Teacherjh wrote:

>
> 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) I confess I've
> never actually looked down (sometimes I fly a cutlass) to see how long it takes
> them to stop on their own.

At the rate it takes the Cessna single mains to retract, it's probably
stopped :-)
>
> I'm not sure how tapping the brakes dislodges any snow. There's very little
> shoe travel.

Correct, if you've got disks there's not much clearance there to begin
with. For other forms of brakes, it's not even going to do anything.

Of course all this stuff neglects the nose gear.

[Ron Natalie]

Teacherjh wrote:

>
> 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) I confess I've
> never actually looked down (sometimes I fly a cutlass) to see how long it takes
> them to stop on their own.

At the rate it takes the Cessna single mains to retract, it's probably
stopped :-)
>
> I'm not sure how tapping the brakes dislodges any snow. There's very little
> shoe travel.

Correct, if you've got disks there's not much clearance there to begin
with. For other forms of brakes, it's not even going to do anything.

Of course all this stuff neglects the nose gear.

[Ron Natalie]

Michelle P wrote:
> Paul,
> Tapping brakes stops the rotation before entering the wheel well. You do
> not want them spinning into the gear well.
>
What do you do about the nose gear?

I can tell you what happens in the Navion. If you yank that gear up as
soon as you brake ground, the nose gear hits a rubber snubber to stop
it's rotation. Smells bad too. If you let it hang out a little
longer, the rotation isn't has bad.

[Ron Natalie]

Michelle P wrote:
> Paul,
> Tapping brakes stops the rotation before entering the wheel well. You do
> not want them spinning into the gear well.
>
What do you do about the nose gear?

I can tell you what happens in the Navion. If you yank that gear up as
soon as you brake ground, the nose gear hits a rubber snubber to stop
it's rotation. Smells bad too. If you let it hang out a little
longer, the rotation isn't has bad.

[Robert M. Gary]

(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

[Robert M. Gary]

(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

[Ron Natalie]

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).

Myth.

First, the wheels are NOT that big compared to the weight of the aircraft.

Second, the B-17 wheels are retracted along their plane of rotation.
They swing forward nestling in the inboard engine nacells. If you
land one gear up, it will roll on the retracted wheels (with other parts
of the aircraft scraping, however).

[Ron Natalie]

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).

Myth.

First, the wheels are NOT that big compared to the weight of the aircraft.

Second, the B-17 wheels are retracted along their plane of rotation.
They swing forward nestling in the inboard engine nacells. If you
land one gear up, it will roll on the retracted wheels (with other parts
of the aircraft scraping, however).

[Roger Halstead]

On Tue, 12 Oct 2004 10:00:16 -0400, Ron Natalie >
wrote:

>Teacherjh wrote:
>
>>
>> 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) I confess I've
>> never actually looked down (sometimes I fly a cutlass) to see how long it takes
>> them to stop on their own.
>

To me that sounds like a good way to have the brakes freeze.
I have never tapped the brakes yet. OTOH I did land with the brakes
locked one time. Interesting experience.


>At the rate it takes the Cessna single mains to retract, it's probably
>stopped :-)

In the Deb it takes 10 to 12 seconds. POH says not to retract until a
safe altitude has been reached.

>>
>> I'm not sure how tapping the brakes dislodges any snow. There's very little
>> shoe travel.

If they've been used the disks are warm to hot. tapping the brakes
could cause water to collect.

>
>Correct, if you've got disks there's not much clearance there to begin
>with. For other forms of brakes, it's not even going to do anything.
>
>Of course all this stuff neglects the nose gear.

It doesn't have any brakes to freeze either.

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

[Roger Halstead]

On Tue, 12 Oct 2004 10:00:16 -0400, Ron Natalie >
wrote:

>Teacherjh wrote:
>
>>
>> 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) I confess I've
>> never actually looked down (sometimes I fly a cutlass) to see how long it takes
>> them to stop on their own.
>

To me that sounds like a good way to have the brakes freeze.
I have never tapped the brakes yet. OTOH I did land with the brakes
locked one time. Interesting experience.


>At the rate it takes the Cessna single mains to retract, it's probably
>stopped :-)

In the Deb it takes 10 to 12 seconds. POH says not to retract until a
safe altitude has been reached.

>>
>> I'm not sure how tapping the brakes dislodges any snow. There's very little
>> shoe travel.

If they've been used the disks are warm to hot. tapping the brakes
could cause water to collect.

>
>Correct, if you've got disks there's not much clearance there to begin
>with. For other forms of brakes, it's not even going to do anything.
>
>Of course all this stuff neglects the nose gear.

It doesn't have any brakes to freeze either.

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

[David Rind]

Rick Durden wrote:
> Paul,
>
> Tapping the brakes prior to retraction is one of aviation's old wives
> tales that just hangs in there. The gear wells are large enough to
> hold the tires even if they have some bulge from spinning (which isn't
> much anyway on our slow little bugsmashers). There are some
> transports in which the manual calls for tapping the brakes and some
> in which it specifically says not to as the sudden stop on large tires
> and wheels can cause the tire to slide on the rim.

The POH on my Trinidad (1986 TB21) calls for applying the brakes before
retracting the gear. Is there really no reason for this?

--
David Rind

[David Rind]

Rick Durden wrote:
> Paul,
>
> Tapping the brakes prior to retraction is one of aviation's old wives
> tales that just hangs in there. The gear wells are large enough to
> hold the tires even if they have some bulge from spinning (which isn't
> much anyway on our slow little bugsmashers). There are some
> transports in which the manual calls for tapping the brakes and some
> in which it specifically says not to as the sudden stop on large tires
> and wheels can cause the tire to slide on the rim.

The POH on my Trinidad (1986 TB21) calls for applying the brakes before
retracting the gear. Is there really no reason for this?

--
David Rind

[Rick Durden]

David,

Tapping the brakes was apparently started on larger airplanes because
on some there was a concern about the rotating tires in the wheel
wells; then the habit pattern passed on to little airplanes, despite
it not being necessary. Next time you can, observe a gear swing on
the airplane in the shop and see that the tire clears the sides of the
wells nicely. Even if there is some question of clearance on a little
airplane, the only thing that happens is that the tire rubs on the
well and comes to a stop. It isn't going to jam in there because it
was rotating and the tire was bulged out a little bit.

There is also a tendency for the folks who write POHs to put in a few
things because "we've always done it that way" rather than to spend
the time and money to check to see if it's needed. That being said,
if the manufacturer calls for a procedure, I would suggest following
it unless I've got good evidence it is counter productive, so on your
airplane, tap the brakes. In winter I don't touch the brakes at all
on a retractable gear airplane because I want the inertia from the
spinning tire to toss all of the moisture possible and second, if I
touch the brakes I heat up the brake shoe and disc, which will melt
any snow on it, but having stopped the rotation, I don't get rid of
the water. Then, because it's cold, the water freezes and I have a
frozen brake that leads to sliding one or both tires on landing,
something that has a certain level of discomfort.

All the best,
Rick

David Rind > wrote in message >...
> Rick Durden wrote:
> > Paul,
> >
> > Tapping the brakes prior to retraction is one of aviation's old wives
> > tales that just hangs in there. The gear wells are large enough to
> > hold the tires even if they have some bulge from spinning (which isn't
> > much anyway on our slow little bugsmashers). There are some
> > transports in which the manual calls for tapping the brakes and some
> > in which it specifically says not to as the sudden stop on large tires
> > and wheels can cause the tire to slide on the rim.
>
> The POH on my Trinidad (1986 TB21) calls for applying the brakes before
> retracting the gear. Is there really no reason for this?

[Robert M. Gary]

Ron Natalie > wrote in message >...
> 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).
>
> Myth.
>
> First, the wheels are NOT that big compared to the weight of the aircraft.
>
> Second, the B-17 wheels are retracted along their plane of rotation.
> They swing forward nestling in the inboard engine nacells. If you
> land one gear up, it will roll on the retracted wheels (with other parts
> of the aircraft scraping, however).

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.

-Robert

[Orval Fairbairn]

In article >,
David Rind > wrote:

> Rick Durden wrote:
> > Paul,
> >
> > Tapping the brakes prior to retraction is one of aviation's old wives
> > tales that just hangs in there. The gear wells are large enough to
> > hold the tires even if they have some bulge from spinning (which isn't
> > much anyway on our slow little bugsmashers). There are some
> > transports in which the manual calls for tapping the brakes and some
> > in which it specifically says not to as the sudden stop on large tires
> > and wheels can cause the tire to slide on the rim.
>
> The POH on my Trinidad (1986 TB21) calls for applying the brakes before
> retracting the gear. Is there really no reason for this?



IIRC, the Trinidad gear retracts inward. Stopping wheel rotation
eliminates inertial coupling between the wheels and the gear pinoins.
You really don't want to make the wheel change its plane of rotation.

[Ron Natalie]

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.

[Bob Moore]

(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).
> 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.

First.... why would I want to believe anything that ANY Flight
Instructor or Designated Examiner has to say about anything?
I've worked with them for too long and know better.

Second... I can easily see how this story has become corrupted.
If the pilot DOES apply the brakes on a B-17 with spinning tires,
then there WILL be a pitching moment applied to the airframe.
On a barely flying B-17, this could be a problem.

But, you can be forgiven Robert. From many years of experience
in de-briefing new private pilots after their practical test, I
found that very few could recall accurately the problem areas that
they had encountered and in discussing these with the DE, I would
receive an entirely different story. :-)

BTW, most Boeing jetliners have automatic wheel stopping brakes
that are applied with reduced pressure during retraction. The nose
wheels were stopped by wooden rub strips in the nose wheelwell.
Pilots were cautioned to not apply the brakes due to the sudden
stoppage breaking the tire bead to wheel seal.

Bob Moore

[Rick Durden]

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 >...
> (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

[Roger]

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

[G.R. Patterson III]

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.

[Ron Natalie]

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.

[Rick Durden]

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 >...
> 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.

[Corky Scott]

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

[Paul Sengupta]

"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

[Paul Sengupta]

"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