I received this from a pilot buddy and thought it would interest several here.
The attached pics are at
http://www.flickr.com/photos/6774349...7627592884885/
If that doesn't work let me know a better way/site to post them at.
Art


----- Original Message -----

Thought you may be interested in seeing this. My senior partner is David Price Sr.
who raced in the Reno gold and silver classes in a P-51 for 6-7 years. He had two
P-51s, a hot modified racer with one seat, (he has since sold that as he does not
race due to age) and the second a two seater, basically stock exterior but with a hot
motor, that he still flies. He owned the company Supermarine (a aircraft fuel and
lease company) and currently owns American Airports which manages public airports
across the US and some Pacific Island. He also is the benefactor and owner of Museum
of Flying here in Santa Monica.
This version of what happened is probably what happened, mechanical failure,
tremendous & violent yaw causing death or unconsciousness immediately, and the crash.
Gary


From another friend that has known Jimmy and Erik for many years, below you can see
what he learned today, when he spoke to Erik, the crew chief of Jimmy Leeward's
flight crew




HI Dave;

My response was on my Iphone and a few mis spelling...pretty tough break..my guess
that is the end of the reno air races.....

Erik Hokuff who is Jimmys crew chief and I had a short chat yesterday , and he
confirmed the tail wheel was deployed from massive G load and tab effect as follows.

Similar event happened to Voodoo Mustang years ago...Bob Hannah was flying and was
put to sleep for a bit..woke up with head forward of control stick and hands by
feet...sat up and had several hundred feet to recover..

Everything changes when the angle of incidence is modified both tail plane and
wing....and probably didn't help that Jimmy was mid seventies regarding G-LOC....my
guess is he could well have snapped his neck on a 12 to 15G instantaneous pull like
that....you can see in the pic below that Jim is nowhere to be seen..my guess is he
was out cold for the whole event starting at trim tab separation...I believe his
mayday was from flutter response as he was passing Stu in the Rare Bear just prior to
tab departure.

Jeff

pic 1-3 moved to above link



On Sep 18, 2011, at 8:43 AM, DK Gorrell wrote:

....DkG


Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

On 9/20/2011 8:11 PM, Artemus wrote:


Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.


2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

On Sep 20, 10:48*pm, Richard wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. *Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. *Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48*pm, Richard wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. *Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. *Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid. & this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW

On 9/21/2011 8:58 AM, Sunworshipper wrote:
On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48 pm, wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid.& this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW


It's just not possible for aircraft with such large speed ranges.
(And yes, that includes the airliners as well. They work the same way)

Maneuverability and stability are opposite ends of the same string.
A really stable aircraft will not be very maneuverable.
A maneuverable aircraft will not be very stable.
That is, of course, without modern fly-by-wire control systems.
But even then, the basic aerodynamics are that way.



This is a good synopsis, if you are really interested.
soliton.ae.gatech.edu/people/lsankar/AE1350/Lecture.11.ppt

Or if you really have the balls for it...
http://ocw.mit.edu/courses/aeronauti...rse-materials/

Take particular note of Static and dynamic stability, static margin, and
the effects of increasing or decreasing stability margins.

On Tue, 20 Sep 2011 21:48:33 -0500, Richard
wrote:

On 9/20/2011 8:11 PM, Artemus wrote:


Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.


2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.
The plane hit 15 G's before impact. That makes the pilot's head
weigh something in excess of 400 lbs, which could very well have
instantly fractured the pilot's neck.

On Wed, 21 Sep 2011 12:04:04 -0500, Richard
wrote:

On 9/21/2011 8:58 AM, Sunworshipper wrote:
On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48 pm, wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid.& this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW


It's just not possible for aircraft with such large speed ranges.
(And yes, that includes the airliners as well. They work the same way)

Maneuverability and stability are opposite ends of the same string.
A really stable aircraft will not be very maneuverable.
A maneuverable aircraft will not be very stable.
That is, of course, without modern fly-by-wire control systems.
But even then, the basic aerodynamics are that way.



This is a good synopsis, if you are really interested.
soliton.ae.gatech.edu/people/lsankar/AE1350/Lecture.11.ppt

?



Or if you really have the balls for it...
http://ocw.mit.edu/courses/aeronauti...rse-materials/


This is interesting, one can take courses for free?


Take particular note of Static and dynamic stability, static margin, and
the effects of increasing or decreasing stability margins.


Sounds good and all, but I don't believe it. Loosing a trim tab
shouldn't cause multiple G forces.


SW

On Wed, 21 Sep 2011 17:59:08 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

On Wed, 21 Sep 2011 12:04:04 -0500, Richard
wrote:

On 9/21/2011 8:58 AM, Sunworshipper wrote:
On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48 pm, wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid.& this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW


It's just not possible for aircraft with such large speed ranges.
(And yes, that includes the airliners as well. They work the same way)

Maneuverability and stability are opposite ends of the same string.
A really stable aircraft will not be very maneuverable.
A maneuverable aircraft will not be very stable.
That is, of course, without modern fly-by-wire control systems.
But even then, the basic aerodynamics are that way.



This is a good synopsis, if you are really interested.
soliton.ae.gatech.edu/people/lsankar/AE1350/Lecture.11.ppt

?



Or if you really have the balls for it...
http://ocw.mit.edu/courses/aeronauti...rse-materials/


This is interesting, one can take courses for free?


Take particular note of Static and dynamic stability, static margin, and
the effects of increasing or decreasing stability margins.


Sounds good and all, but I don't believe it. Loosing a trim tab
shouldn't cause multiple G forces.


SW
Believe it or not - at that speed it WILL.

In article , SW@GWNTUNDRA
says...

On Wed, 21 Sep 2011 12:04:04 -0500, Richard
wrote:

On 9/21/2011 8:58 AM, Sunworshipper wrote:
On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48 pm, wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid.& this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW


It's just not possible for aircraft with such large speed ranges.
(And yes, that includes the airliners as well. They work the same way)

Maneuverability and stability are opposite ends of the same string.
A really stable aircraft will not be very maneuverable.
A maneuverable aircraft will not be very stable.
That is, of course, without modern fly-by-wire control systems.
But even then, the basic aerodynamics are that way.



This is a good synopsis, if you are really interested.
soliton.ae.gatech.edu/people/lsankar/AE1350/Lecture.11.ppt

?



Or if you really have the balls for it...
http://ocw.mit.edu/courses/aeronauti...rse-materials/


This is interesting, one can take courses for free?

No, you can download some of the course materials, in some cases
including the classroom lectures. You don't get one-on-one with the
prof nor do you get your assignments graded.

Take particular note of Static and dynamic stability, static margin, and
the effects of increasing or decreasing stability margins.


Sounds good and all, but I don't believe it. Loosing a trim tab
shouldn't cause multiple G forces.


SW

On Wed, 21 Sep 2011 08:58:58 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48*pm, Richard wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. *Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. *Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid. & this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW

You are overlooking the fact that as speed changes then so does lift
and drag and torque, in a propeller driven airplane, and center of
gravity changes dependent on load. There has to be some mechanism to
balance these forces.

These changes are rather large - air pressure at, say 500 mph, is
approximately 25 times that at 100 MPH. A control surface that is
adequate at take off( say 100 MPH) would be 25 times too large at 500
MPH. Or to put it another way, a control surface that was adequate at
500 MPH would be 25 times too large at 100 MPH.

Cheers,

John B.

On Thu, 22 Sep 2011 09:03:31 +0700, john B.
wrote:

On Wed, 21 Sep 2011 08:58:58 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

On Wed, 21 Sep 2011 05:40:36 -0700 (PDT), Dave__67
wrote:

On Sep 20, 10:48*pm, Richard wrote:
On 9/20/2011 8:11 PM, Artemus wrote:



Subject: Two Questions
We have all seen the pictures of this tragedy at Reno, but I have two questions.

1. *Would losing the trim tab on one side of the elevator really cause this type of
loss of control?

Yes.

As an airplane travels faster the wing makes more lift.
To keep from climbing the nose is pushed down.

While the trim tab looks tiny compared to the rest of the aircraft, it
is really all that is holding the nose down.

Trailing edge of the tab would be up which forces the trailing edge of
the elevator down, thus pushing the the nose down.

Sudden loss of that tab means a sudden nose up - and at those speeds
if would be exceptionally violent pitch up.

2. *Why is the tail wheel extended in this photo, on a plane where everything is done
to reduce drag and increase speed?

The up lock broke - due to the violent pitch up.

Same thing happened to Bob Hannah, but happened while "all" that
resulted was a quick 10G climb and a short blackout.
And, he quit after that.


Dave

I've been thinking about this situation. A trim shouldn't EVER be
holding back a violent tendency for a plane veer off! If you've
modified a plane that wants to pull a certain way FIX the problem
don't lean it all the way on the band aid. & this has happened
before?

Cock the vertical stabilizer like is a given for the vertical. If you
still have to trim it, do it for the lower speeds. Its an unlimited
race plane, make it fly like **** slow and straight fast.

Having the stick yanked out of your hand cause of a trim tab is crazy.


SW

You are overlooking the fact that as speed changes then so does lift
and drag and torque, in a propeller driven airplane, and center of
gravity changes dependent on load. There has to be some mechanism to
balance these forces.

These changes are rather large - air pressure at, say 500 mph, is
approximately 25 times that at 100 MPH. A control surface that is
adequate at take off( say 100 MPH) would be 25 times too large at 500
MPH. Or to put it another way, a control surface that was adequate at
500 MPH would be 25 times too large at 100 MPH.

Cheers,

John B.

Correction: "Or to put it another way, a control surface that was
adequate at 500 MPH would be 25 times too SMALL at 100 MPH.
Cheers,

John B.

On 9/21/2011 5:59 PM, Sunworshipper wrote:

Sounds good and all, but I don't believe it. Loosing a trim tab
shouldn't cause multiple G forces.


SW


Doesn't matter if you believe it or not.
That's how it happens to work.

The forces involved are tremendous.

And that tiny little tab is what makes it all happen.

Think of it as the base of a transistor?
A tiny amount of current controlling a larger current.

They are, after all, just air currents!

On 9/22/2011 7:17 AM, john B. wrote:

Correction: "Or to put it another way, a control surface that was
adequate at 500 MPH would be 25 times too SMALL at 100 MPH.
Cheers,

John B.


Better

Richard fired this volley in
m:

On 9/21/2011 5:59 PM, Sunworshipper wrote:

Sounds good and all, but I don't believe it. Loosing a trim tab
shouldn't cause multiple G forces.


SW


Doesn't matter if you believe it or not.
That's how it happens to work.

The forces involved are tremendous.

And that tiny little tab is what makes it all happen.

Think of it as the base of a transistor?
A tiny amount of current controlling a larger current.

They are, after all, just air currents!


Perhaps he doesn't understand what a trim tab does. It does NOT act as
an elevator. What it does is deflect the elevator, and the elevator's
movement would cause the aircraft to pitch.

But even if he doesn't understand that, I also don't believe it. I'm a
pilot. There is NO excursion of a trim tab one cannot properly correct
for with the stick. And one that's broken loose, so it's hanging by one
corner of one end would not act to effectively deflect the elevator
surface. You would get some "flutter", but not any severe deflection one
way or the other.

One thing that sometimes breaks trim tabs is too forceful a throw of the
stick (below or at maneuvering speed). Trim tabs are delicate. Elevator
shafts or hinges are not.

If he'd been above maneuvering speed (which is damned high on a Mustang)
when such a deflection occurred, he'd have torn off a wing at the root,
instead of a trim tab.

I don't know if the Mustang had lever controls or cables -- likely cables
to the elevator. A broken or disconnected elevator cable (it would use a
pull-pull system of two cables) would cause a rapid deflection to the
neutral position (it's most streamlined position) unless a lot of force
was being applied to the still-good half of the cable pair. THAT
wouldn't happen, because the remaining cable would act to move the
elevator in the wrong direction from that in which you wished it to go.

You can do a lot of maneuvers without a rudder, or without ailerons with
enough dihedral in the wings, and even do some pretty fancy airspeed-
controlled rate-of-descent tricks with a stuck elevator, so long as it's
stuck slightly up or neutral. But you can't control the aircraft at all
with an elevator that's just flopping around loose. And with only
'down' control, you can change the trajectory, but you cannot avoid a
crash.

I had a friend who took a newly-annual'd MU2 for its shakedown, and
forgot to check aileron throw before he rolled out. They were reversed,
and he'd already rotated and retracted the gear when he finally noticed.
He got it around the field and landed it on sheer nerve and a damn-lot
more skill than I could muster in that situation. But they were
reversed, not broken.

However, I believe those racing planes have redundant cabling to all the
control surfaces to protect against the likelihood of one letting go. So
more likely, I think he busted an elevator control horn, which would act
just like a broken cable, and he couldn't correct in the desired
direction. So he used the opposite throw to try to guide his up-scaled
lawn dart away from as many people as possible. Which, if it's proven,
would make him a hero.

LLoyd

What do you fly, Lloyd?
What it the stall speed to max speed ratio?
When it get's up to 5 forces get seriously strong.

And note, the photos DO show the trim tab failure.

From Coleen
Sport Class Race 8 Crew

*Subject: : Galloping Ghost crash
*
Ok... here's the skinny on the accident.... A P-51 normally has two trim
tabs.. one on each elevator... this one had one and other one was fixed
in place.. He was warned about the forces being put on that one tab. It
failed.. He had at least a 10G load when the plane pitched up from the
loss of the trim tab and he went "nighty night" and probably never woke
up.

Here's the “theory” of the crash from experienced racers.
*In 1989 this type of thing happened to another pilot but he lived to
tell the story*. *When flying a P-51 at 450+mph you need to have full
nose down trim to keep the plane level.* The *elevator trim tab broke
off and the aircraft im ediately went in to a 10G climb, confirmed by
the G-meter.

*The *pilot came to, from the sudden blackout and realized he had
slipped through the shoulder harness and was looking at the floor of the
airplane*. He was able to reach the throttle and pull it back to slow
down and was able to recover and land.

*Photo one is the airplane taxiing, note the pilots head in the canopy*.

*Fast forward to 2011 Photo two is typical oil canning as a result of
the tremendous torque these engines put out at high power*.

*Photo three* is a *photo of GG upside down with a missing elevator trim
tab. Note all you see is the back of the pilots head indicating he is
being forced down in the cockpit*.

*Photo four* is a *view of the left side nose down with the tail wheel
extended and no view of the pilot*. The *tail wheel is held up by
hydraulics only with no mechanical uplock, thus indicating a high
G-force causing it to extend*.

*Photos five and six* are *from the left side prior to impact*, note *no
view of the pilot *and the *tail wheel extended*.

*Photo seven is the debris just after the crash*. *To the right of
center above the crowd it appears to be the wing with the leading edge down.

*A friend of mine was supposed to be there but didn't go and he has
several friends in the hospital right now. The*people were mostly hit by
chunks of concrete, asphalt and aircraft debris*. They were *also hurt
by the trampling of people getting out of the way*.

Lloyd E. Sponenburgh wrote:

I had a friend who took a newly-annual'd MU2 for its shakedown, and
forgot to check aileron throw before he rolled out.

The MU2 has no aileroms, it uses spoilers.

They were reversed,
and he'd already rotated and retracted the gear when he finally noticed.

I doubt the spoilers are visible from the cockpit. Maybe not a
pre-takeoff checklist item.

more likely, I think he busted an elevator control horn, which would act
just like a broken cable, and he couldn't correct in the desired
direction. So he used the opposite throw to try to guide his up-scaled
lawn dart away from as many people as possible. Which, if it's proven,
would make him a hero.

Knife-edge, he could have used the rudder for pitch control.

Beryl fired this volley in news:j5jp91$cfr$1
@speranza.aioe.org:

Knife-edge, he could have used the rudder for pitch control.

I don't think it can be done in that aircraft -- at least not held
indefinitely. That's a maneuver for a Sukhoy.

The P-51 has a generous rudder, but not big enough to hold a knife edge
landing.

Richard fired this volley in
news
And note, the photos DO show the trim tab failure.

You don't read posts before you answer them, do you?

Check back on what I said. I realize the trim tab failed. I can also see
the mode of failure. Duh.

Lloyd

Richard fired this volley in
m:

*When flying a P-51 at 450+mph you need to have full
nose down trim to keep the plane level.* The *elevator trim tab broke
off and the aircraft im ediately went in to a 10G climb, confirmed by
the G-meter.


I didn't know you had to maintain full down trim at speed, but a LACK of
any trim shouldn't result in a 10G climb, no.

Who is the source of this opinion?
Normally, even on performance aircraft, the elevator is always going to
move to the most aerodynamically "balanced" position -- and that is not
"full up", which required considerable control input force to do.

LLoyd

On Fri, 23 Sep 2011 20:36:57 -0500, Richard
wrote:


From Coleen
Sport Class Race 8 Crew

*Subject: : Galloping Ghost crash
*
Ok... here's the skinny on the accident.... A P-51 normally has two trim
tabs.. one on each elevator... this one had one and other one was fixed
in place.. He was warned about the forces being put on that one tab. It
failed.. He had at least a 10G load when the plane pitched up from the
loss of the trim tab and he went "nighty night" and probably never woke
up.

Here's the “theory” of the crash from experienced racers.
*In 1989 this type of thing happened to another pilot but he lived to
tell the story*. *When flying a P-51 at 450+mph you need to have full
nose down trim to keep the plane level.* The *elevator trim tab broke
off and the aircraft im ediately went in to a 10G climb, confirmed by
the G-meter.

*The *pilot came to, from the sudden blackout and realized he had
slipped through the shoulder harness and was looking at the floor of the
airplane*. He was able to reach the throttle and pull it back to slow
down and was able to recover and land.

*Photo one is the airplane taxiing, note the pilots head in the canopy*.

*Fast forward to 2011 Photo two is typical oil canning as a result of
the tremendous torque these engines put out at high power*.

*Photo three* is a *photo of GG upside down with a missing elevator trim
tab. Note all you see is the back of the pilots head indicating he is
being forced down in the cockpit*.

*Photo four* is a *view of the left side nose down with the tail wheel
extended and no view of the pilot*. The *tail wheel is held up by
hydraulics only with no mechanical uplock, thus indicating a high
G-force causing it to extend*.

*Photos five and six* are *from the left side prior to impact*, note *no
view of the pilot *and the *tail wheel extended*.

*Photo seven is the debris just after the crash*. *To the right of
center above the crowd it appears to be the wing with the leading edge down.

*A friend of mine was supposed to be there but didn't go and he has
several friends in the hospital right now. The*people were mostly hit by
chunks of concrete, asphalt and aircraft debris*. They were *also hurt
by the trampling of people getting out of the way*.


I give. I've flown

Ercoupe
Tri-Pacer
J-3
Luscombe
Stinson 108
150 Aerobat
152
172
182
207
Grumman Tiger
Aztec
Queen Air
King Air
Beech- 18
DC-3

Lived on three airports.
Soloed on 16th birthday.
VIP pass for CAF
And have heard countless flying stories from;

WW-l
Barnstorming
Small home built race pilots
WW-ll
Korea
Nam
Crop dusting
Fire fighting
Smuggler Pilots

We use to modify aircraft including

Painting
crash repair
long range
high loads
gear conversions
Speed
Navigation
Camera pods

& I've use to grind cranks for a FAA repair station.

Also have flown in bad weather, fogged in, running on fumes and lost
(Dad was cheap and used road maps or just water tower names.),
aerobatics (day & night), flown under power lines, engine failure, and
even snuck-in to an international airport at night without radio,
instrument panel lights, or navigation lights (electrical failure and
runway light down at our airport (typical).).


So, most if not all planes have a metal tab on each control surface
that is bent so that the controls are neutral in flight. Some aircraft
have adjustable trim controls in the cockpit which are adjusted for
load, prop settings, RPM, navigation, weather, ect. The most I've ever
seen is in a Staggerwing Beech. The trim is used mainly to get the
plane to fly straight without any input from the controls, because all
airplanes pull to some direction due to imperfections in construction
or modifications down to as simple as new antennas to unlimited race
plane mods.

I tryed to back out of this conversation cause I just don't know the
P-51 and the over powering of one. Matter of fact I don't think I've
ever seen the cockpit of one, I'm guessing it has a yoke instead of a
stick. Anyhow, you quote that the plane was (jacked-up my terminology)
trimmed, one permanent and one adjustable for the elevator and the
adjustable took a flight.

In my experience all simi-stable aircraft should fly straight and not
trimmed so hard that it causes black-out G-forces if a tab takes off.
Also, this type of plane took 20mm hits in the war. I would venture a
speculation (after your info.) that all the planes in the race are
trimmed hard so that during the straightaways the stick is pushed hard
forward, because it is easier to push against the back of the seat
than to stand on the rudder and pull back around the pylons and thus
the plane would be in the controls neutral position in the turns.

I'm also not sure if the unstableness of loosing that part would
exponentially increase or it got jerked out of his hands or the cable
for that trim could have broke in the cockpit and the cable got
violently stripped through the fuselage and by all the cables for the
control surfaces...

BTW, prop wash from these planes must be very violent.


SW

On 9/24/2011 6:01 AM, Lloyd E. Sponenburgh wrote:
fired this volley in
news
And note, the photos DO show the trim tab failure.

You don't read posts before you answer them, do you?

Check back on what I said. I realize the trim tab failed. I can also see
the mode of failure. Duh.

Lloyd

Yes Lloyd, I read it.

If we are going to be huffy maybe I could reply that you don't know much
about aerodynamics and didn't bother to find out before you posted.

But I generally don't go into that kind of reply.
IT just leads to a ****ing match and a lot of hard feelings.

So, instead, let me offer the following...
Understand that this is very simplified approach to calculations of
aerodynamic forces, but it valid in subsonic flight.

Equation:
Lift = .001188 * (Coefficient of Lift) * (Velocity Squared) *
(Wing Area)

.001188 constant allows:
Sea level density altitude
Velocity in MPH
Wing Area in Square feet

And, of course, the equation can be rearranged to solve for any of the
included terms.

So...

Take off performance:
(given)
Stall Speed = 100 MPH
Wing Area = 235 SqFt

CL calculates to 1.66

Max Speed performance:
(given)
Velocity = 500 mph
Wing Area 235 sq ft

CL calculates to .0066 (!)

If, at high speed, the nose pitched up to the take-off angle of attack
(thus providing the take-off Coefficient of Lift)
(given)
Velocity = 500 mph
Wing Area = 235 sq ft

Lift calculates to 249,340 pounds.
For the 10,000 pound weight that means 24 Gs possible load factor.

Like I said earlier, the forces are tremendous!
The thing that modulates the wing's lift is the tail.
The long arm from wing to tail allows smaller forces to control the
pitch of the wing.

The trim tab in question is located at the very aft edge of the control
surface (elevator, aileron, whatever). The distance between the hinge
points (elevator hinge and trim tab hinge) define the trim arm.
That's how the small trim tab can deflect the much larger elevator, and
the elevator control the pitch of the much larger wing.

Now, yes, there are other approaches that can be taken.
Tailless (flying wing), tandem wing, and canards.
But they all have to face the same issues.

Tailless types have very short tail arms and are thus very limited in
their pitch authority. That usually means higher take off speeds.

Canards are kind of in the same category. The forward control surface
(the canard?) is designed to stall before the wing stalls. Has to be
this way to avoid the serious problems of a deep stall - where the wing
stalls before the canard - with an uncontrollable pitch up resulting.
Again that usually means higher take off speeds.

So the design of modern aircraft has evolved to the aft-tail arrangement
because it offers the widest range of performance.

Conclusion:
Directly related to the question at hand, this configuration also
offers higher speed potential since it can provide higher pitch down
forces at high speed.

I hope that perhaps this helps illustrate the "why" behind "this is how
it's done".

On 9/24/2011 6:04 AM, Lloyd E. Sponenburgh wrote:
fired this volley in
m:

*When flying a P-51 at 450+mph you need to have full
nose down trim to keep the plane level.* The *elevator trim tab broke
off and the aircraft im ediately went in to a 10G climb, confirmed by
the G-meter.


I didn't know you had to maintain full down trim at speed, but a LACK of
any trim shouldn't result in a 10G climb, no.

Who is the source of this opinion?
Normally, even on performance aircraft, the elevator is always going to
move to the most aerodynamically "balanced" position -- and that is not
"full up", which required considerable control input force to do.

LLoyd



The pitching moment of the main wing airfoil itself is the source of the
pitch-up force. Not the tail.

On 9/24/2011 8:40 AM, Sunworshipper wrote:

I'm also not sure if the unstableness of loosing that part would
exponentially increase or it got jerked out of his hands or the cable
for that trim could have broke in the cockpit and the cable got
violently stripped through the fuselage and by all the cables for the
control surfaces...

BTW, prop wash from these planes must be very violent.


SW


You know your stuff alright.

But, for a moment, imagine what it would be like to fly any airplane
without a trim system.

The aircraft will be naturally trimmed to fly hands-off at ONE GIVEN SPEED.

So at any other speed, the pilot has to provide the control force to
maintain attitude (and thus airspeed)

Assuming we are trimmed for cruise - approach and landing are going to
be "interesting"...

Lloyd E. Sponenburgh wrote:
Beryl fired this volley in news:j5jp91$cfr$1
@speranza.aioe.org:

Knife-edge, he could have used the rudder for pitch control.

I don't think it can be done in that aircraft -- at least not held
indefinitely. That's a maneuver for a Sukhoy.

The P-51 has a generous rudder, but not big enough to hold a knife edge
landing.

I don't think this P-51 pilot had time to be a hero, but I'm imagining
what he might have accomplished given a few seconds to think it through.
The knife edge idea was along the lines of steering away from the crowd,
and cartwheeling elsewhere.

I once read about a quick-thinking pilot making an inverted approach,
then rolling it over just in time for touchdown.

Also, a test pilot unable to break a stall crawled out of the cockpit
out onto the nose to force it down.

Richard fired this volley in
m:

The pitching moment of the main wing airfoil itself is the source of the
pitch-up force. Not the tail.

I guess I can only answer, "No, duh!". You don't get a _high_ positive
angle of attack on the wing with a loosely trailing elevator. The elevator
will more-or-less follow a neutral angle of attack with the wings. It's
the elementary aerodynamics of an empenage-equipped aircraft.

LLoyd

Beryl fired this volley in news:j5l6q1$qg$1
@speranza.aioe.org:

I once read about a quick-thinking pilot making an inverted approach,
then rolling it over just in time for touchdown

Then there's the aerobatic pilot who landed on one wing. Anything (almost)
is possible if you have large enough control surfaces, and enough power.
For the one-wing guy, if it had been the _other_ wing, he'd have died,
because P-torque was part of what he used to save himself.

LLoyd

In article , "Lloyd
E. Sponenburgh" says...

Beryl fired this volley in news:j5l6q1$qg$1
@speranza.aioe.org:

I once read about a quick-thinking pilot making an inverted approach,
then rolling it over just in time for touchdown

Then there's the aerobatic pilot who landed on one wing. Anything (almost)
is possible if you have large enough control surfaces, and enough power.
For the one-wing guy, if it had been the _other_ wing, he'd have died,
because P-torque was part of what he used to save himself.

Then there was this guy http://www.youtube.com/watch?v=-_EXtBEaBbs.

On Sat, 24 Sep 2011 06:04:57 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Richard fired this volley in
om:

*When flying a P-51 at 450+mph you need to have full
nose down trim to keep the plane level.* The *elevator trim tab broke
off and the aircraft im ediately went in to a 10G climb, confirmed by
the G-meter.


I didn't know you had to maintain full down trim at speed, but a LACK of
any trim shouldn't result in a 10G climb, no.

Who is the source of this opinion?
Normally, even on performance aircraft, the elevator is always going to
move to the most aerodynamically "balanced" position -- and that is not
"full up", which required considerable control input force to do.

LLoyd

A document named "Flight test of P-51H Airplane", dated 14 October
1945, is available on the Web and states in part that:

Elevator trim for take off is 1 degree Nose Heavy, i.e., nose down.

It goes on to state that "at high manifold pressures approaching 90
Hg, where water injection is required, the elevator trim is inadequate
and excessive forward pressure on the control stick is necessary to
maintain level flight."

So, it appears that even at low (take off) speed the P-51H required
some nose down trim and at high power settings the elevator trim was
inadequate to maintain level flight and the pilot had to hold forward
pressure on the stick.

When operating at high power settings it is obvious that full nose
down trim plus additional stick force will be required. If while
flying in this condition the elevator trim tab were to separate from
the aircraft it is logical to assume that extremely violent nose up
forces would occur.


Cheers,

John B.

"J. Clarke" fired this volley in
n.local:

Then there was this guy http://www.youtube.com/watch?v=-_EXtBEaBbs.

I've had two in-flight emergencies, and neither compromised the flight
controls.

It takes one more thing, besides what we'd mentioned, to bring in a plane
with a missing wing --- BALLS!

G

LLoyd

On Sat, 24 Sep 2011 19:31:47 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"J. Clarke" fired this volley in
in.local:

Then there was this guy http://www.youtube.com/watch?v=-_EXtBEaBbs.

I've had two in-flight emergencies, and neither compromised the flight
controls.

It takes one more thing, besides what we'd mentioned, to bring in a plane
with a missing wing --- BALLS!

Sorry, sir, but balls have -much- less lift than an airfoil profile.
Hanging your balls out will not replace a missing wing, and your legs
will create considerable drag. The Bernoulli principle ensures that
you'll have blue balls from the effort, though, with all that cool air
flowing over 'em so quickly.

--
If you're trying to take a roomful of people by
surprise, it's a lot easier to hit your targets
if you don't yell going through the door.
-- Lois McMaster Bujold

Larry Jaques fired this volley in
:

The Bernoulli principle ensures that
you'll have blue balls from the effort, though, with all that cool air
flowing over 'em so quickl

Larry, just landing that successfully, and then seeing the wing missing
would have given me blue balls! G

I've had one cockpit electrical fire in the air, and one high-speed
malfunction deployment of my landing gear at about 60 knots over the
maximum allowable speed at which to deploy the gear. Neither caused me
any injury -- only a few very tense moments. (Well, in the case of the
gear emergency, it took a half-hour, and three low passes over the tower
in Sarasota to ensure I had everything down and locked. I only had two
lights!)

Both were simple, non-fatal, not-control-surface, not-engine-failure
emergencies that scared the Sh*T out of me. I handled them, sure --
that's only training. But I can't even imagine how scary it must be to
survive a mid-air, and still retain control!

LLoyd

john B. wrote:

A document named "Flight test of P-51H Airplane", dated 14 October
1945, is available on the Web and states in part that:

Elevator trim for take off is 1 degree Nose Heavy, i.e., nose down.

It goes on to state that "at high manifold pressures approaching 90
Hg, where water injection is required, the elevator trim is inadequate
and excessive forward pressure on the control stick is necessary to
maintain level flight."

Maybe that "Flight test... " document was about a particular airplane
that needed some re-rigging. The words "inadequate" and "excessive" say
unsatisfactory.

The stock P-51 was made to be handled by twenty-something-year-old
pilots with little experience. The vertical fin on the stocker is turned
to offset P-Factor, relieving some of the need for the pilot to hold
rudder at high power and low speed.
The Reno racers are rigged differently. They have their fins set
straight, they want to minimize trim drag.

So, it appears that even at low (take off) speed the P-51H required
some nose down trim and at high power settings the elevator trim was
inadequate to maintain level flight and the pilot had to hold forward
pressure on the stick.

And that would be draggy at 400+ mph.

When operating at high power settings it is obvious that full nose
down trim plus additional stick force will be required. If while
flying in this condition the elevator trim tab were to separate from
the aircraft it is logical to assume that extremely violent nose up
forces would occur.

All depends on the horizontal stab incidence. I think the trim tab
should be doing very little at high speed.



Cheers,

John B.

On Sat, 24 Sep 2011 20:51:28 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Larry Jaques fired this volley in
:

The Bernoulli principle ensures that
you'll have blue balls from the effort, though, with all that cool air
flowing over 'em so quickl

Larry, just landing that successfully, and then seeing the wing missing
would have given me blue balls! G

I see no reason why it wouldn't.


I've had one cockpit electrical fire in the air, and one high-speed
malfunction deployment of my landing gear at about 60 knots over the
maximum allowable speed at which to deploy the gear. Neither caused me
any injury -- only a few very tense moments. (Well, in the case of the
gear emergency, it took a half-hour, and three low passes over the tower
in Sarasota to ensure I had everything down and locked. I only had two
lights!)

Yeah, tense. Too bad it couldn't have been a few high-speed buzz runs
past the tower, with all parts in working order, eh?

Dad and I were on an Aero Mexico flight from LaPaz to TJ (our
boys-only vacation one year) and they were out of beer. The way the
pilot flew, I was certain that he alone had drank it all. In TJ, he
nearly overshot the runway, put her down on one wheel, and I could
have sworn he was going to take us into the sand at the end of the
runway. I swear the nose of the plane was hanging over the end when he
pirouetted it in place far enough to get us rolling. That nose wheel
was at 90 degrees from normal all that time. Dad was Air Force and he
disagreed with my estimation of the landing. I gave it 1 point out of
10, he gave it a 3. His reasoning: the plane still had all its parts.


Both were simple, non-fatal, not-control-surface, not-engine-failure
emergencies that scared the Sh*T out of me. I handled them, sure --
that's only training. But I can't even imagine how scary it must be to
survive a mid-air, and still retain control!

Oh, no kidding!

--
If you're trying to take a roomful of people by
surprise, it's a lot easier to hit your targets
if you don't yell going through the door.
-- Lois McMaster Bujold

Beryl fired this volley in news:j5mafu$okn$1
@speranza.aioe.org:


All depends on the horizontal stab incidence. I think the trim tab
should be doing very little at high speed.

Yep, and the stabilizer is going to have its incidence angle set to produce
_minimumum_ drag at the desired racing speed.

Therefore, one can almost completely rule out the possibility that losing
the trim tab would have immediately resulted in full-up elevator.

LLoyd

On Sat, 24 Sep 2011 20:51:28 -0500, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:

[...]

I've had one cockpit electrical fire in the air, and one
high-speed malfunction deployment of my landing gear at about 60
knots over the maximum allowable speed at which to deploy the
gear. Neither caused me any injury -- only a few very tense
moments. (Well, in the case of the gear emergency, it took a
half-hour, and three low passes over the tower in Sarasota to
ensure I had everything down and locked. I only had two lights!)

Lloyd,

Speaking on behalf of college students adjoining the Sarasota
Airport, I'd like to express my appreciation for your not
overshooting the runway and taking out (say) the Circus Hall of Fame
or the NatSci Lab. grin!


Frank McKenney
--
...[A]n adventure is, by its nature, a thing that comes to us. It
is a thing that chooses us, not a thing we choose. ... The supreme
adventure is being born. There we do walk suddenly into a splendid
and startling trap. ... When we step into the family, by the act
of being born, we do step into a world which is incalculable, into
a world which has its own strange laws, into a world that could do
without us, into a world we have not made. In other words, when we
step into the family we step into a fairy-tale.
-- G.K. Chesterton: On the Institution of the Family (1905)
--
Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney aatt mindspring ddoott com

On Sun, 25 Sep 2011 04:29:31 -0700, Larry Jaques
wrote:

On Sat, 24 Sep 2011 20:51:28 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Larry Jaques fired this volley in
m:

The Bernoulli principle ensures that
you'll have blue balls from the effort, though, with all that cool air
flowing over 'em so quickl

Larry, just landing that successfully, and then seeing the wing missing
would have given me blue balls! G

I see no reason why it wouldn't.


I've had one cockpit electrical fire in the air, and one high-speed
malfunction deployment of my landing gear at about 60 knots over the
maximum allowable speed at which to deploy the gear. Neither caused me
any injury -- only a few very tense moments. (Well, in the case of the
gear emergency, it took a half-hour, and three low passes over the tower
in Sarasota to ensure I had everything down and locked. I only had two
lights!)

Yeah, tense. Too bad it couldn't have been a few high-speed buzz runs
past the tower, with all parts in working order, eh?

Dad and I were on an Aero Mexico flight from LaPaz to TJ (our
boys-only vacation one year) and they were out of beer. The way the
pilot flew, I was certain that he alone had drank it all. In TJ, he
nearly overshot the runway, put her down on one wheel, and I could
have sworn he was going to take us into the sand at the end of the
runway. I swear the nose of the plane was hanging over the end when he
pirouetted it in place far enough to get us rolling. That nose wheel
was at 90 degrees from normal all that time. Dad was Air Force and he
disagreed with my estimation of the landing. I gave it 1 point out of
10, he gave it a 3. His reasoning: the plane still had all its parts.


LOL, the air force must instill that type of humor. One time my dad
and I took a commercial flight and when the lady said we can use our
seat cushion as a flotation device my dad turned to me and said ' When
the water comes in I'm going to scoop it up in my hands and inhale,
cause I'm not going back in the sea."

One time I was flying back to Vegas and the pilot must have had to
wait and then get in line, like they missed the first opportunity.
Anyhow, while meandering around lake mead the plane was banking and
pulling up and up and up till I started to worry, then the plane
slipped a bit to the left and then it was corrected like someone
wasn't paying attention. I looked around like someone else might have
noticed that, while I was thinking "Better not stall this thing over
the lake or anywhere else !" As I got off I noticed the pilot was a
short chick at about 30 and shook my head.


Both were simple, non-fatal, not-control-surface, not-engine-failure
emergencies that scared the Sh*T out of me. I handled them, sure --
that's only training. But I can't even imagine how scary it must be to
survive a mid-air, and still retain control!

Oh, no kidding!

On Sat, 24 Sep 2011 21:27:31 -0700, Beryl wrote:

john B. wrote:

A document named "Flight test of P-51H Airplane", dated 14 October
1945, is available on the Web and states in part that:

Elevator trim for take off is 1 degree Nose Heavy, i.e., nose down.

It goes on to state that "at high manifold pressures approaching 90
Hg, where water injection is required, the elevator trim is inadequate
and excessive forward pressure on the control stick is necessary to
maintain level flight."

Maybe that "Flight test... " document was about a particular airplane
that needed some re-rigging. The words "inadequate" and "excessive" say
unsatisfactory.

The stock P-51 was made to be handled by twenty-something-year-old
pilots with little experience. The vertical fin on the stocker is turned
to offset P-Factor, relieving some of the need for the pilot to hold
rudder at high power and low speed.
The Reno racers are rigged differently. They have their fins set
straight, they want to minimize trim drag.

You are wrong Sir. The P-51 was designed to meet the specifications
set out by the British Purchasing Commission and the prototype was
rolled out 102 days after contract sighing and was first flown on 26
October 1940. They were first used by the Royal Air Force and from
late 1943, were used by the USAAF's Eighth Air Force to escort bombers
in raids over Germany,

I can find no evidence that the Vertical fin was offset in any manner
and I do know that the late model fuselages and canopies required
addition of a dorsal fin to increase lateral stability.

The report I quoted was prepared by the AAF Flight Test Division at
the request of the Production Section, Procurement division, to verify
the supplier's figures.

The stated conclusion was that "control and handling characteristics
of the P-51H are good under conditions tested with the exception of a
tendency to hunt directionally at indicated speeds above 400 MPH.

(this by the way is typical of a plane with a marginal amount of
vertical stabilizer)

As for 20 year olds, I know of no military airplane that performance
was dummied down to meet the abilities of inexperienced pilots. Quite
the opposite in fact, they are designed to meet a need specified by
the Military and in quite a few cases that results in aircraft that
are distinctly "Twitchy". The F-100A, for example, officially entered
USAF service on 27 September 1954 with 479th Fighter Wing at George
AFB, CA. By 10 November 1954, the F-100As suffered six major accidents
due to flight instability, structural failures, and hydraulic system
failures, prompting the Air Force to ground the entire fleet until
February 1955. Does that sound like an airplane designed to be flown
by novices?

So, it appears that even at low (take off) speed the P-51H required
some nose down trim and at high power settings the elevator trim was
inadequate to maintain level flight and the pilot had to hold forward
pressure on the stick.

And that would be draggy at 400+ mph.

When operating at high power settings it is obvious that full nose
down trim plus additional stick force will be required. If while
flying in this condition the elevator trim tab were to separate from
the aircraft it is logical to assume that extremely violent nose up
forces would occur.

All depends on the horizontal stab incidence. I think the trim tab
should be doing very little at high speed.

The F-51 did not have a movable horizontal stab. A trim tab will
generate more force as air speed increases.



Cheers,

John B.
Cheers,

John B.

Then there's the aerobatic pilot who landed on one wing.

I saw a video of that, and there were six or eight things that were
different in the video, and video of the plane on the ground. An obvious
photoshop job. Not to say that planes have never landed with one wing, just
that one of them was a hoax, and not too good a hoax at that.

Steve

On 9/25/2011 3:29 AM, Larry Jaques wrote:

I gave it 1 point out of 10, he gave it a 3. His reasoning: the plane
still had all its parts.

A good landing is any landing you can walk away from.
A great landing is any landing in which you can still use the airplane.

(quoted as best I can recall from a cartoon I saw)


Jon