Control input during loop

[MLenoch]

I must admit, for years I have been doing such but never asked why. Why do I
need to use left rudder to keep the nose straight during a loop? I have a US
airplane, with normal prop rotation. If I do not use left rudder, the nose
will yaw to the right. This is not due to P-factor?
Thx in advance.
VL

[Roger Tracy]

Because of the speed? Is this occuring at faster than normal cruise? I
don't do aerobatics .. but will notice the ball slipping a little to the
left on my Tiger if I get the speed way up over cruise in a descent.
How much angle is built into the vertical stabilizer?

"MLenoch" > wrote in message
...
> I must admit, for years I have been doing such but never asked why. Why
do I
> need to use left rudder to keep the nose straight during a loop? I have a
US
> airplane, with normal prop rotation. If I do not use left rudder, the
nose
> will yaw to the right. This is not due to P-factor?
> Thx in advance.
> VL

[MLenoch]

>"Roger Tracy"

>Because of the speed? Is this occuring at faster than normal cruise? I
>don't do aerobatics .. but will notice the ball slipping a little to the
>left on my Tiger if I get the speed way up over cruise in a descent.
>How much angle is built into the vertical stabilizer?
>

Cruise is 220 kts and loop entry is at 270 kts. The left rudder is required
only when G-pull is initiated, but not during the dive. The vertical stab has
a few degrees, not sure of the exact number.
VL

[Roger Tracy]

Fuel load balanced?


"MLenoch" > wrote in message
...
> >"Roger Tracy"
>
> >Because of the speed? Is this occuring at faster than normal cruise? I
> >don't do aerobatics .. but will notice the ball slipping a little to the
> >left on my Tiger if I get the speed way up over cruise in a descent.
> >How much angle is built into the vertical stabilizer?
> >
>
> Cruise is 220 kts and loop entry is at 270 kts. The left rudder is
required
> only when G-pull is initiated, but not during the dive. The vertical stab
has
> a few degrees, not sure of the exact number.
> VL

[Greg Esres]

<<The left rudder is required only when G-pull is initiated, but not
during the dive.>>

Gyroscopic precession is my guess. Pulling the nose up causes a yaw
to the right.

[EDR]

In article >, Greg Esres
> wrote:

> <<The left rudder is required only when G-pull is initiated, but not
> during the dive.>>
>
> Gyroscopic precession is my guess. Pulling the nose up causes a yaw
> to the right.

Correct.

[ShawnD2112]

220 and 270?!?! Criminy, what are you flying? The only thing I can think
of is what one person said about being past the trimmed airspeed of the
rudder, which is probably trimmed for no yaw at 220 or thereabouts. I don't
think it's to do with prop effects as this is backwards from what your prop
would do. How many Gs do you pull to start your loop?

Shawn
Pitts S-1D G-BKVP
"MLenoch" > wrote in message
...
> >"Roger Tracy"
>
> >Because of the speed? Is this occuring at faster than normal cruise? I
> >don't do aerobatics .. but will notice the ball slipping a little to the
> >left on my Tiger if I get the speed way up over cruise in a descent.
> >How much angle is built into the vertical stabilizer?
> >
>
> Cruise is 220 kts and loop entry is at 270 kts. The left rudder is
required
> only when G-pull is initiated, but not during the dive. The vertical stab
has
> a few degrees, not sure of the exact number.
> VL

[Dale]

In article >,
"ShawnD2112" > wrote:

> 220 and 270?!?! Criminy, what are you flying? The only thing I can think
> of is what one person said about being past the trimmed airspeed of the
> rudder, which is probably trimmed for no yaw at 220 or thereabouts. I don't
> think it's to do with prop effects as this is backwards from what your prop
> would do. How many Gs do you pull to start your loop?

You pitch down you yaw left, just like raising the tail during takeoff,
a pitch up should give some yaw to the right due to precession.

--
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

[Jay Honeck]

> 220 and 270?!?! Criminy, what are you flying?

Not sure what he's flying now, but the last time I saw Mr. Lenoch fly, he
was in a P-51D Mustang.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[ShawnD2112]

Wouldn't he kinda know what the inputs for a loop were if he were flying a
Mustang? Or at least have a more qualified contact to ask than a random
shot in a newsgroup?

"Jay Honeck" > wrote in message
news:kzumb.24688$Tr4.49151@attbi_s03...
> > 220 and 270?!?! Criminy, what are you flying?
>
> Not sure what he's flying now, but the last time I saw Mr. Lenoch fly, he
> was in a P-51D Mustang.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>

[Jay Honeck]

> Wouldn't he kinda know what the inputs for a loop were if he were flying a
> Mustang? Or at least have a more qualified contact to ask than a random
> shot in a newsgroup?

Hey -- who you callin' "random"?

We's experts here, doncha know? :-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Peter Duniho]

"ShawnD2112" > wrote in message
...
> Wouldn't he kinda know what the inputs for a loop were if he were flying a
> Mustang?

You need to read more closely. He knows what the inputs are. He's asking
WHY he needs to use them.

> Or at least have a more qualified contact to ask than a random
> shot in a newsgroup?

That applies to pretty much every question ever posed here. What's your
point?

Pete

[MLenoch]

.. He knows what the inputs are. He's asking
>WHY he needs to use them.
>

Thanks Peter.................You'd think after over 2000 hours in the bird, I'd
know............but then ask my wife, she knows better than myself sometimes
(rimshot!).
VL

[Big John]

Let me throw a dog in this fight :o)

For example in the P-51. You are trimmed up for cruise and decide to
do a loop. You drop the nose and pick up air speed. If you were
trimmed for straight an level flight then as you pick up A/S you need
to put in left rudder to keep the ball centered.

As you pull up and airspeed bleeds off, you then relax the left rudder
and put in right rudder to counteract the engine torque at the lower
A/S keeping the ball centered.

This normally is an automatic use of rudders and you don't have to
think right or left rudder, just use the rudders to keep the ball
centered.

The amount of rudder used in a P-51 with the long nose and high power,
is more than you would use in a Cessna or Piper of course but same use
of controls is required.

In the "Spam Can", always flew the bird in a coordinated manner where
I wanted it to go and never thought about the control position needed
to make it do what I wanted.

If you let the ball get out of center and pulled high "G's", then the
bird would snap pretty easy (and quick).

And a nice day to all

Big John


On Sat, 25 Oct 2003 20:02:17 +0100, "ShawnD2112"
> wrote:

>Wouldn't he kinda know what the inputs for a loop were if he were flying a
>Mustang? Or at least have a more qualified contact to ask than a random
>shot in a newsgroup?
>
>"Jay Honeck" > wrote in message
>news:kzumb.24688$Tr4.49151@attbi_s03...
>> > 220 and 270?!?! Criminy, what are you flying?
>>
>> Not sure what he's flying now, but the last time I saw Mr. Lenoch fly, he
>> was in a P-51D Mustang.
>> --
>> Jay Honeck
>> Iowa City, IA
>> Pathfinder N56993
>> www.AlexisParkInn.com
>> "Your Aviation Destination"
>>
>>
>

[ShawnD2112]

Right. Sorry. My mistake. I need to read more closely next time. In the
Pitts, I can comment. I'm totally out of my depth with a Mustang. :-)

Shawn
"MLenoch" > wrote in message
...
> . He knows what the inputs are. He's asking
> >WHY he needs to use them.
> >
>
> Thanks Peter.................You'd think after over 2000 hours in the
bird, I'd
> know............but then ask my wife, she knows better than myself
sometimes
> (rimshot!).
> VL

[EDR]

In article >, Big John
> wrote:

> For example in the P-51. You are trimmed up for cruise and decide to
> do a loop. You drop the nose and pick up air speed.

John, are you saying a stripped down civilian P-51 cannot pull up from
level flight into a vertical loop without first diving for additional
airspeed?

[MLenoch]

>John, are you saying a stripped down civilian P-51 cannot pull up from
>level flight into a vertical loop without first diving for additional
>airspeed?
>
>

Yes........cruise speed in a Mustang is 240 mph and a loop is flown at 300 mph.
You can try it, but you'll be very ragged at the top. You might even fall
out!!
VL

[EDR]

In article >, MLenoch
> wrote:

> >John, are you saying a stripped down civilian P-51 cannot pull up from
> >level flight into a vertical loop without first diving for additional
> >airspeed?

> Yes........cruise speed in a Mustang is 240 mph and a loop is flown at 300
> mph.
> You can try it, but you'll be very ragged at the top. You might even fall
> out!!

How many G pull is that?
Do you maintain a steady g throughout the pull?

[MLenoch]

It flies best with an initial pull of 4 G. G is not constant during the loop.
It may be half a G at the top. On cooler days, I can fly the loop at 3 Gs for
the initial pull; it is easier on the 50+ year old wing. But, when not doing
low level airshow loops, 3 G loops are always OK at higher altitudes. The
problem is getting too slow at the top, which is uncomfortable during an
airshow display.
VL

[Big John]

mlenoch

Sounds like you are current in bird. Just took my shoes off to count
and last flew the bird 54 years ago at Miho Japan (35 Ftr Sq, 8th Ftr
Gp) :o)

Flew D10 to D30's and K's. Had guns and full load of ammo and armor
plate behind pilot. This additonal weight required a little more speed
as I remember (maybe 325-350???)

Slow on top and G's causes the laminer flow wing to stall (and bird
snap) as sounds like you have found out :o) Inverted spins took some
altitude to recover.

During WWII birds were red lined at 505 mph. We got a directive about
1947 that reduced the red line to 450 mph to put less wear and tear on
the birds. Are you still using the 450?

We used 61-3000 and 145 octane fuel for take off and were told that
that power was needed to keep the engine clean?

Talking to a jock at Ellington some years ago, he said the 51's now
were using 45-50 inches for T/O (easier on engines)? Or may be the
lower octane fuel available now???

I enjoyed my 650 hours in the bird.

Big John

On 27 Oct 2003 02:53:33 GMT, (MLenoch) wrote:

>It flies best with an initial pull of 4 G. G is not constant during the loop.
>It may be half a G at the top. On cooler days, I can fly the loop at 3 Gs for
>the initial pull; it is easier on the 50+ year old wing. But, when not doing
>low level airshow loops, 3 G loops are always OK at higher altitudes. The
>problem is getting too slow at the top, which is uncomfortable during an
>airshow display.
>VL

[EDR]

In article >, MLenoch
> wrote:

> It flies best with an initial pull of 4 G. G is not constant during the
> loop.
> It may be half a G at the top. On cooler days, I can fly the loop at 3 Gs for
> the initial pull; it is easier on the 50+ year old wing. But, when not doing
> low level airshow loops, 3 G loops are always OK at higher altitudes. The
> problem is getting too slow at the top, which is uncomfortable during an
> airshow display.

Two more question, if I may...
What has the airspeed at the top of the loop decayed to with 4G pull?
With 3 G?

[MLenoch]

100LL fuel limits the engine to 55" on takeoff to prevent detonation. The
current owners today (non-racers) seldom get above 400 mph. Most of them seldom
do aerobatics and thus likely never get above 350 mph. The commonly know speed
limit is still at 500mph. There are about 120 airframes flying in the US, with
about 300+ still in existance worldwide. Cruise is flown at 35" which produces
220kts/240mph approximately......depending on ambient, bomb rack installed,
antennas, etc. That's about 55% power. Like John said, it needs speed to get
over the top of a loop, otherwise it can stall and depart.
VL

[MLenoch]

>Two more question, if I may...
>What has the airspeed at the top of the loop decayed to with 4G pull?
>With 3 G?

At 4G......110 kts is OK and preferrable. At 3G, you can get it to float over
at 80 to 90 kts. Also, just depends on how long the G pull is sustained during
the ride up, as well.
VL

[Jay Honeck]

> At 4G......110 kts is OK and preferrable. At 3G, you can get it to float
over
> at 80 to 90 kts. Also, just depends on how long the G pull is sustained
during
> the ride up, as well.

At OSH each year, where you get to see a variety of WWII fighters doing
fly-bys during the Warbird show, I've noticed that some Mustang pilots are
considerably less aggressive on the pull-up and wing-over than others. I've
often wondered if this is a limitation of that particular aircraft, or if
that particular pilot is simply taking it a bit easier on himself and the
bird.

The most aggressive pull-ups I've seen are with that red Corsair racer and
the Bearcats. Their vertical penetration (and ability to sustain the climb
through the top of the half-loop) is most impressive.

I always kinda feel sorry for the occasional P-40 and early naval fighters
that participate, since they obviously can't keep up with you guys... :-)

As always, I (for one) appreciate you discussing this on-line with us Spam
canners...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Rick Durden]

Vlado,

Rudder? Rudder? I thought you only used that thing on the ground
<g>.

My understanding is gyroscopic precession. When the tail comes up on
takeoff on clockwise rotating props the force applied to the rotating
prop is forward at the top, aft at the bottom, so it reacts 90 degrees
around the plane of rotation, and thus causes a left turning tendency.
On the pull up for a loop, the effect is reversed, requiring some
left rudder. Seems to be the case on the Citabria and Decathlon as
well.

You going to park it for the winter as you used to do in AZO?

Warmest regards,
Rick

(MLenoch) wrote in message >...
> I must admit, for years I have been doing such but never asked why. Why do I
> need to use left rudder to keep the nose straight during a loop? I have a US
> airplane, with normal prop rotation. If I do not use left rudder, the nose
> will yaw to the right. This is not due to P-factor?
> Thx in advance.
> VL

[MLenoch]

>As always, I (for one) appreciate you discussing this on-line with us Spam
>canners...

Very much enjoy sharing........after, that's where I started too!


>I've
>often wondered if this is a limitation of that particular aircraft, or if
>that particular pilot is simply taking it a bit easier on himself and the
>bird.

Some pilots are a little less "current" than others. In others words, they
don't fly as much and don't know how hard to pull up or are a bit scared &
unfamiliar at the same time. Just everyone's nature is different.

VL

[MLenoch]

>You going to park it for the winter as you used to do in AZO?
>
>Warmest regards,
>Rick

Warm regard - winter............Its a joke right!!

(Yes, I'll be at AZO.)
Thx,
VL