On Sun, 25 Sep 2011 09:00:58 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

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
:

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

He said he'd been in 1 and 2-grade landings before, where tails fell
off and landing gear collapsed. As an IFR instructor in Anchorage, AK,
he'd seen guys forget to drop the landing gear, too. One of his jokes
as instructor was to get the new pilot confused, then head him due
north. When asked if there was anything in his way, the pilot would
say "No." About that time, Dad would pull the pilot's hood off and
he'd be looking straight ahead (and up, 20k') at Mount McKinley.
Mean! chuckle But he taught pilots to pay close attention to the
potential hazards in their flight paths.


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."

I guess you had to be there.


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.

And blonde, no doubt?

--
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

On Sun, 25 Sep 2011 21:27:20 +0700, john B.
wrote:

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,

It should be noted that the original P-51s (A/B) bought by the RAF had
underpowered, non supercharged Allison engines in them and were used
solely for ground attack.

It wasnt until hummm...late 1941 was the supercharged Merlin installed,
at which point the P51 (C/D) became the awesome aircraft that its known
for today.



"In the history of mankind, there have always been men and women who's goal
in life is to take down nations. We have just elected such a man to run our
country." - David Lloyyd (2008)

(Edward A. Falk) fired this volley in news:j5no0n$son$1
@blue-new.rahul.net:

Ever since I heard of that incident, I've made it a point to periodically
check that the ailerons were moving in the right direction (which might
be a bit silly since I don't think you can rig a Mooney backwards.)

Yeah, well, since I'm not an A&P mechanic, and don't really know how my
aircraft is rigged internally, I always check. I have to do a mental
double-take to remember that ailerons UP means wing DOWN G.

LLoyd

john B. wrote:
...
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 Reno P-51s, at least one that AOPA Pilot magazine carried an article
about, have the vertical fin re-aligned as I described. The article
specifically said that the stock airplane was tamed so as not to kill
new pilots, and the Reno P-51s are re-rigged for less drag and maximum
speed.

I think the same article also says that the racing engines remain
basically stock. They already can produce more power than their metal is
capable of containing.

Do I need to find that magazine? I really don't want to search through a
4-foot tall stack of magazines.

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.

It's an old report.

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 need wasn't top speed. They were designed to perform as well at 200
mph as at 400 mph. Pilots racing them today don't care about much of that.

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

All horizontal stabilizers are movable! Take out rivets, cut, bend, and
put it back on in a new position. Even the famous air scoop under the
P-51s belly is movable. The Galloping Ghost's was moved somewhere, I
can't see it in any pictures.

Beryl fired this volley in news:j5o6as$jfg$1
@speranza.aioe.org:

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

All horizontal stabilizers are movable!

Yeah, again, although he protested loudly about it, he didn't read the
post he responded to.

Nobody SAID the stab was "movable", only that its incidence angle was
set; set by modification, not by "articulation".

Any aircraft can have modifications. I wonder if he thinks the incidence
angle of the stab (or wings, for that matter) was just accidental?

I helped a friend modify a DC3 for export (he did one about every seven
months). I'm not an A&P, but I'm an aircraft "groupy" and always willing
to throw in some grunt labor on an interesting project.

Before we were done, we'd changed a whole lot of how the airframe worked,
including re-bracing and re-framing the starboard side of the fuse,
carving a 10' wide cargo door in the side, and moving numerous
components, including electrical and hydraulic systems. We didn't move
the vertical or horizontal stabilizers, but it's pretty apparent how one
would go about it.

I also helped another friend rebuild an SNJ (got to fly it, too! G).
That project was almost a complete un-skin job. There was all kinds of
corrosion in load-bearing structures. It took a while. And while he was
at it, he made mods... G Any aircraft can be modified, even some of
those "glass slippers" like GlassAirs or Rutans.

LLoyd

On Sun, 25 Sep 2011 12:27:49 -0700, Larry Jaques
wrote:

On Sun, 25 Sep 2011 09:00:58 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

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

He said he'd been in 1 and 2-grade landings before, where tails fell
off and landing gear collapsed. As an IFR instructor in Anchorage, AK,
he'd seen guys forget to drop the landing gear, too. One of his jokes
as instructor was to get the new pilot confused, then head him due
north. When asked if there was anything in his way, the pilot would
say "No." About that time, Dad would pull the pilot's hood off and
he'd be looking straight ahead (and up, 20k') at Mount McKinley.
Mean! chuckle But he taught pilots to pay close attention to the
potential hazards in their flight paths.

Yeap, teach them the first rule of flying, don't hit anything with the
plane.

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."

I guess you had to be there.

Or know he did 3 days after ditching in the ocean.

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.

And blonde, no doubt?

Nope, short haired brunette.


SW

On Sun, 25 Sep 2011 12:27:49 -0700, Larry Jaques
wrote:

On Sun, 25 Sep 2011 09:00:58 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

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

He said he'd been in 1 and 2-grade landings before, where tails fell
off and landing gear collapsed. As an IFR instructor in Anchorage, AK,
he'd seen guys forget to drop the landing gear, too. One of his jokes
as instructor was to get the new pilot confused, then head him due
north. When asked if there was anything in his way, the pilot would
say "No." About that time, Dad would pull the pilot's hood off and
he'd be looking straight ahead (and up, 20k') at Mount McKinley.
Mean! chuckle But he taught pilots to pay close attention to the
potential hazards in their flight paths.


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."

I guess you had to be there.


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.

And blonde, no doubt?
Sounds like a classic side slip - pull the nose up to peal off speed,
then drop one wing and let it slide a few hundred Or thousand) feet,
drop the nose to catch back a few knots, and hit the runway, instead
of doing another 2 circuits around lake meade to get down.

On Sun, 25 Sep 2011 07:57:26 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Beryl fired this volley in news:j5mafu$okn$1
:


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
Not according to race pilots I've spoken to. They all say any quick
change in trim can put in excess of 8 Gs load on the plane - and 8 Gs
will turn out the lights just like THAT. Telemetry showed over 12 Gs,
apparently, on the Ghost.

On Sun, 25 Sep 2011 16:38:44 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Beryl fired this volley in news:j5o6as$jfg$1
:

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

All horizontal stabilizers are movable!

Yeah, again, although he protested loudly about it, he didn't read the
post he responded to.

Nobody SAID the stab was "movable", only that its incidence angle was
set; set by modification, not by "articulation".

Any aircraft can have modifications. I wonder if he thinks the incidence
angle of the stab (or wings, for that matter) was just accidental?

I helped a friend modify a DC3 for export (he did one about every seven
months). I'm not an A&P, but I'm an aircraft "groupy" and always willing
to throw in some grunt labor on an interesting project.

Before we were done, we'd changed a whole lot of how the airframe worked,
including re-bracing and re-framing the starboard side of the fuse,
carving a 10' wide cargo door in the side, and moving numerous
components, including electrical and hydraulic systems. We didn't move
the vertical or horizontal stabilizers, but it's pretty apparent how one
would go about it.

I also helped another friend rebuild an SNJ (got to fly it, too! G).
That project was almost a complete un-skin job. There was all kinds of
corrosion in load-bearing structures. It took a while. And while he was
at it, he made mods... G Any aircraft can be modified, even some of
those "glass slippers" like GlassAirs or Rutans.

LLoyd
And EVERY modification, unless in Unlimited experimental class,
requires [aterwork up the yazoo - and on certified planes it requires
a "supplimental type certificate" for EVERY modification.

If exporting to the third world, one MIGHT get away without.

fired this volley in
:

Sounds like a classic side slip - pull the nose up to peal off speed,
then drop one wing and let it slide a few hundred Or thousand) feet,
drop the nose to catch back a few knots, and hit the runway, instead
of doing another 2 circuits around lake meade to get down.

It was standard approach practice for the Aussie pilots flying Caribous
in 'Nam. They wanted to avoid ground fire, so they'd do what amounts to
a side-slipping stall right above the threshold, and drop in like a rock,
recovering just enough airspeed to flare near the end.

On 1100' PSP runways, that actually looks like an attractive way to make
an approach!

LLoyd

fired this volley in
:

And EVERY modification, unless in Unlimited experimental class,
requires [aterwork up the yazoo - and on certified planes it requires
a "supplimental type certificate" for EVERY modification.

If exporting to the third world, one MIGHT get away without.

No... even with the market, one had to STC every change, because the
aircraft had to be flown "commercially" (that is, in pursuit of being
sold) in US airspace.

Dick had all the approvals. The inspectors would glide by about twice a
week, just give a cursory look, and sign off. Remember, Dick did this
for a living, and had all the mods pre-approved. So it wasn't like doing
"custom" mods.

LLoyd

On Sun, 25 Sep 2011 17:34:18 -0500, Sunworshipper SW@GWNTUNDRA
wrote:

On Sun, 25 Sep 2011 12:27:49 -0700, Larry Jaques
wrote:
He said he'd been in 1 and 2-grade landings before, where tails fell
off and landing gear collapsed. As an IFR instructor in Anchorage, AK,
he'd seen guys forget to drop the landing gear, too. One of his jokes
as instructor was to get the new pilot confused, then head him due
north. When asked if there was anything in his way, the pilot would
say "No." About that time, Dad would pull the pilot's hood off and
he'd be looking straight ahead (and up, 20k') at Mount McKinley.
Mean! chuckle But he taught pilots to pay close attention to the
potential hazards in their flight paths.

Yeap, teach them the first rule of flying, don't hit anything with the
plane.

Good rule!


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."

I guess you had to be there.

Or know he did 3 days after ditching in the ocean.

Yeah, that could certainly make a difference in an attitude.

--
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

On Sun, 25 Sep 2011 13:27:41 -0700, Gunner Asch
wrote:

On Sun, 25 Sep 2011 21:27:20 +0700, john B.
wrote:

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,

It should be noted that the original P-51s (A/B) bought by the RAF had
underpowered, non supercharged Allison engines in them and were used
solely for ground attack.

Correct, the British specified the Alison V-1710 ( 1475 H.P. @ 3,000
RPM) and "was first flown operationally by the Royal Air Force (RAF)
as a tactical-reconnaissance aircraft and fighter-bomber".

It wasnt until hummm...late 1941 was the supercharged Merlin installed,
at which point the P51 (C/D) became the awesome aircraft that its known
for today.

Not correct. Both the Allison and Packard-Merlin engines were
supercharged. The most powerful version of the Packard-Merlin V-1650-9
was actually of a lower horsepower (1380H.P. versus 1475H.P.) then the
earlier Allison. The difference was that the Packard-Merlin had a two
speed supercharger which allowed better performance at altitude then
the Allison.

The first airplane fitted with the Merlin engine was an RAF test craft
and first flown on 30 April 1942.

Cheers,

John B.

On Sun, 25 Sep 2011 14:28:57 -0700, Beryl wrote:

john B. wrote:
...
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 Reno P-51s, at least one that AOPA Pilot magazine carried an article
about, have the vertical fin re-aligned as I described. The article
specifically said that the stock airplane was tamed so as not to kill
new pilots, and the Reno P-51s are re-rigged for less drag and maximum
speed.


Not to argue but here is what I can find about the P-51's dorsal fin,
which was not fitted to the earlier aircraft.

Despite these modifications, the P-51Bs and P-51Cs, and the newer
P-51Ds and P-51Ks, experienced low-speed handling problems that could
result in an involuntary "snap-roll" under certain conditions of air
speed, angle of attack, gross weight, and center of gravity. Several
crash reports tell of P-51Bs and P-51Cs crashing because horizontal
stabilizers were torn off during maneuvering. As a result of these
problems, a modification kit consisting of a dorsal fin was
manufactured. One report stated: "Unless a dorsal fin is installed on
the P-51B, P-51C and P-51D airplanes, a snap roll may result when
attempting a slow roll. The horizontal stabilizer will not withstand
the effects of a snap roll. To prevent recurrence, the stabilizer
should be reinforced in accordance with T.O. 01-60J-18 dated 8 April
1944 and a dorsal fin should be installed. Dorsal fin kits are being
made available to overseas activities"

One specification that was part of the cockpit canopy modification was
" Because the new structure slid backwards on runners it could be slid
open in flight. The aerial mast behind the canopy was replaced by a
"whip" aerial which was mounted further aft and offset to the right."

I think the same article also says that the racing engines remain
basically stock. They already can produce more power than their metal is
capable of containing.

Do I need to find that magazine? I really don't want to search through a
4-foot tall stack of magazines.

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.

It's an old report.

True, but it is the report that the AAF produced at the time the P-51H
was accepted by the AAF.

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 need wasn't top speed. They were designed to perform as well at 200
mph as at 400 mph. Pilots racing them today don't care about much of that.

Actually most of the modifications of the P-51 were to improve high
altitude performance or to allow better visibility. The original
Allison engines were actually more powerful then the later fitted
Packard-Merlin however the Packard-Merlin with their two speed
supercharger were faster at altitude.

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

All horizontal stabilizers are movable! Take out rivets, cut, bend, and
put it back on in a new position. Even the famous air scoop under the
P-51s belly is movable. The Galloping Ghost's was moved somewhere, I
can't see it in any pictures.

Certainly one can butcher anything but it is a bit more complicated
then taking out rivets and bending. The horizontal stabilizer is a
major control surface and on these airplanes a fixed structure. The
cooling scoop is not movable, again it is a fixed structure. What you
are referring to was, I believe, the total removal of the cooling
scoop done to the Ghost as part of converting the cooling system to a
totally different type - the "boil off cooling system".
Cheers,

John B.

On Sun, 25 Sep 2011 16:38:44 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Beryl fired this volley in news:j5o6as$jfg$1
:

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

All horizontal stabilizers are movable!

Yeah, again, although he protested loudly about it, he didn't read the
post he responded to.

Nobody SAID the stab was "movable", only that its incidence angle was
set; set by modification, not by "articulation".

Any aircraft can have modifications. I wonder if he thinks the incidence
angle of the stab (or wings, for that matter) was just accidental?

I helped a friend modify a DC3 for export (he did one about every seven
months). I'm not an A&P, but I'm an aircraft "groupy" and always willing
to throw in some grunt labor on an interesting project.

Before we were done, we'd changed a whole lot of how the airframe worked,
including re-bracing and re-framing the starboard side of the fuse,
carving a 10' wide cargo door in the side, and moving numerous
components, including electrical and hydraulic systems. We didn't move
the vertical or horizontal stabilizers, but it's pretty apparent how one
would go about it.

I also helped another friend rebuild an SNJ (got to fly it, too! G).
That project was almost a complete un-skin job. There was all kinds of
corrosion in load-bearing structures. It took a while. And while he was
at it, he made mods... G Any aircraft can be modified, even some of
those "glass slippers" like GlassAirs or Rutans.

LLoyd

So what? We once manufactured and installed the entire aft fuselage on
a U-10 that had been run into by a truck at Nha Trang. We removed the
floor from the cargo compartment of a C-47 gunship and replaced all
the supporting structure after the crew complained about the mini-guns
"wiggling".

But this is not to say that we arbitrarily changed the incidence of
either the wing or stabilizers.

Cheers,

John B.

On Sun, 25 Sep 2011 18:56:56 -0400, wrote:

On Sun, 25 Sep 2011 07:57:26 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Beryl fired this volley in news:j5mafu$okn$1
:


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
Not according to race pilots I've spoken to. They all say any quick
change in trim can put in excess of 8 Gs load on the plane - and 8 Gs
will turn out the lights just like THAT. Telemetry showed over 12 Gs,
apparently, on the Ghost.


There was also a reference to a named pilot who experienced the same
difficulty - loss of trim tab at high speed. the result was immediate
and violent pitch up and black-out. In that case the airplane
apparently climbed to several thousand feet and the pilot regained
consciousness and landed.

Cheers,

John B.

john B. wrote:
...
There was also a reference to a named pilot who experienced the same
difficulty - loss of trim tab at high speed. the result was immediate
and violent pitch up and black-out. In that case the airplane
apparently climbed to several thousand feet and the pilot regained
consciousness and landed.

If it settled into a climb like that, instead of continuing to loop, G
forces quickly went right back to 1. The horizontal stab held it at
whatever pitch attitude it took, the elevator and trim tab needed to do
nothing.

On 9/25/2011 8:53 PM, Beryl wrote:
john B. wrote:
...
There was also a reference to a named pilot who experienced the same
difficulty - loss of trim tab at high speed. the result was immediate
and violent pitch up and black-out. In that case the airplane
apparently climbed to several thousand feet and the pilot regained
consciousness and landed.

If it settled into a climb like that, instead of continuing to loop, G
forces quickly went right back to 1. The horizontal stab held it at
whatever pitch attitude it took, the elevator and trim tab needed to do
nothing.

Not exactly....

I would expect it to decelerate in the climb.
Rapidly, in fact.

Richard wrote:
On 9/25/2011 8:53 PM, Beryl wrote:
john B. wrote:
...
There was also a reference to a named pilot who experienced the same
difficulty - loss of trim tab at high speed. the result was immediate
and violent pitch up and black-out. In that case the airplane
apparently climbed to several thousand feet and the pilot regained
consciousness and landed.

If it settled into a climb like that, instead of continuing to loop, G
forces quickly went right back to 1. The horizontal stab held it at
whatever pitch attitude it took, the elevator and trim tab needed to do
nothing.

Not exactly....

I would expect it to decelerate in the climb.
Rapidly, in fact.

OK, a quick 10 G, then less than 1 G when things stabilized. But the
trim tab was gone, and the unconscious pilot wasn't pushing or pulling
the stick.

john B. fired this volley in
:

But this is not to say that we arbitrarily changed the incidence of
either the wing or stabilizers.

And that's not to say that they "arbitrarily" changed anything, either.
But they could -- relatively easily, considering the scope of a complete
re-build.

And I'll bet they did, because almost any aircraft can benefit from some
tweaking. But certainly not "arbitrarily". There's a boatload of
empirical data on how to make the P-51 a better racer. They've been
flying them in pylon circuits for a lot of years.

LLoyd

On 9/25/2011 11:16 PM, Beryl wrote:
Richard wrote:
On 9/25/2011 8:53 PM, Beryl wrote:
john B. wrote:
...
There was also a reference to a named pilot who experienced the same
difficulty - loss of trim tab at high speed. the result was immediate
and violent pitch up and black-out. In that case the airplane
apparently climbed to several thousand feet and the pilot regained
consciousness and landed.

If it settled into a climb like that, instead of continuing to loop, G
forces quickly went right back to 1. The horizontal stab held it at
whatever pitch attitude it took, the elevator and trim tab needed to do
nothing.

Not exactly....

I would expect it to decelerate in the climb.
Rapidly, in fact.

OK, a quick 10 G, then less than 1 G when things stabilized. But the
trim tab was gone, and the unconscious pilot wasn't pushing or pulling
the stick.


Beryl, how do you know what was happening in the cockpit?

The guy wasn't visible in the canopy.
If he slipped down between the straps he very well could have been
pushing the stick forward.

From what happened, it seems most likely.

Richard wrote:
On 9/25/2011 11:16 PM, Beryl wrote:
Richard wrote:
On 9/25/2011 8:53 PM, Beryl wrote:
john B. wrote:
...
There was also a reference to a named pilot who experienced the same
difficulty - loss of trim tab at high speed. the result was immediate
and violent pitch up and black-out. In that case the airplane
apparently climbed to several thousand feet and the pilot regained
consciousness and landed.

If it settled into a climb like that, instead of continuing to loop, G
forces quickly went right back to 1. The horizontal stab held it at
whatever pitch attitude it took, the elevator and trim tab needed to do
nothing.

Not exactly....

I would expect it to decelerate in the climb.
Rapidly, in fact.

OK, a quick 10 G, then less than 1 G when things stabilized. But the
trim tab was gone, and the unconscious pilot wasn't pushing or pulling
the stick.


Beryl, how do you know what was happening in the cockpit?

The guy wasn't visible in the canopy.

I'm referring to the named pilot who experienced the same difficulty and
apparently climbed until regaining consciousness.

If he slipped down between the straps he very well could have been
pushing the stick forward.

From what happened, it seems most likely.

Does it seem likely that full nose down trim and forward stick pressure
are used all the time? Lots of drag with that kind setup, exactly what
isn't wanted in a race. Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?

Beryl fired this volley in news:j5qc6r$5c5$1
@speranza.aioe.org:

Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


That would create parasitic drag, which is just as bad.

There's no way these guys are flying deliberatly "dirty". Hanging all that
pitched up/down crap out in the wind is just another form of air brake.

LLoyd

Lloyd E. Sponenburgh wrote:
Beryl fired this volley in news:j5qc6r$5c5$1
@speranza.aioe.org:

Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


That would create parasitic drag, which is just as bad.

But somehow the Avanti is the fastest turboprop.

There's no way these guys are flying deliberatly "dirty". Hanging all that
pitched up/down crap out in the wind is just another form of air brake.

LLoyd

That sums it up nicely.


January 2007 Air & Space Smithsonian magazine has an article titled The
Physics of Winning.

Author George C. Larson writes -
"Most try to relax the airplanes static pitch stability by moving the
center of gravity as far aft as possible without making the airplane
unsafe in slow flight. This reduces the work the horizontal tail has to
do to keep the airplane balanced in turns, and reducing the workload of
the tail reduces drag."

Larson says about P-51 Strega pilot Bill Destefani -
"His team went to great efforts to remove every last bit of trim
pressure that would be exerted at top speed. Even a small surface like a
trim tab or a tiny control deflection adds drag."

Quoted from Destefani himself -
"The Mustang was a compromise. The engine is set in there with a thrust
line of 1 or 1.5 degree upwards. We had to change that. The Mustang also
had 1.5-degree kick right on the vertical tail. We make it zero. The
stock Mustang at 400 mph will take 6 degrees of left rudder trim to fly
straight, and they tweaked the rudder to help those 18-year-old pilots.
You take it out so there's no rudder trim, no wing trying to raise, no
aileron trying to rise. We clipped the wings 30 inches, so you have to
land it faster. You have less drag, but it's speedier on landing and
takeoff."

In article , says...

Lloyd E. Sponenburgh wrote:
Beryl fired this volley in news:j5qc6r$5c5$1
@speranza.aioe.org:

Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


That would create parasitic drag, which is just as bad.

But somehow the Avanti is the fastest turboprop.

That would be news to Tupolev.

J. Clarke wrote:
In article , says...
Lloyd E. Sponenburgh wrote:
Beryl fired this volley in news:j5qc6r$5c5$1
@speranza.aioe.org:

Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?

That would create parasitic drag, which is just as bad.
But somehow the Avanti is the fastest turboprop.

That would be news to Tupolev.

What, the Bear bomber, or whatever it's called? I recall that's a speedy
one alright.

J. Clarke wrote:
In article , says...
Lloyd E. Sponenburgh wrote:
Beryl fired this volley in news:j5qc6r$5c5$1
@speranza.aioe.org:

Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?

That would create parasitic drag, which is just as bad.
But somehow the Avanti is the fastest turboprop.

That would be news to Tupolev.

http://en.wikipedia.org/wiki/Tupolev_Tu-95

Specifications (Tu-95MS)
Maximum speed: 920 km/h (510 knots, 575 mph)

In article , says...

J. Clarke wrote:
In article , says...
Lloyd E. Sponenburgh wrote:
Beryl fired this volley in news:j5qc6r$5c5$1
@speranza.aioe.org:

Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?

That would create parasitic drag, which is just as bad.
But somehow the Avanti is the fastest turboprop.

That would be news to Tupolev.

What, the Bear bomber, or whatever it's called? I recall that's a speedy
one alright.

Actually the airliner derived from it. 541.45 mph over a 1000km closed
course, 532.6 over 5000 km.

The military versions are supposed to be faster.

On 9/26/2011 12:21 PM, Beryl wrote:

Does it seem likely that full nose down trim and forward stick pressure
are used all the time? Lots of drag with that kind setup, exactly what
isn't wanted in a race. Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


At 500 MPH?
Of course it need nose down trim.

I'm guessing you kind of skipped over the numbers.

I'm also convinced you are not a flyer.

Richard wrote:
On 9/26/2011 12:21 PM, Beryl wrote:

Does it seem likely that full nose down trim and forward stick pressure
are used all the time? Lots of drag with that kind setup, exactly what
isn't wanted in a race. Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


At 500 MPH?
Of course it need nose down trim.

I'm guessing you kind of skipped over the numbers.

I'm also convinced you are not a flyer.




One little tidbit of information is that with most aircraft you can get
a couple of extra knots of speed if you trim the plane up ( the trim tab
is set in the neutral position for least drag) and then you apply
forward pressure to the yoke. The drag of the trim tab to force the
elevator down is eliminated picking up a little more speed. I found
that out by playing with the trim on the many long boring flights I've
taken.

John

On Mon, 26 Sep 2011 22:29:49 -0400, John
wrote:

Richard wrote:
On 9/26/2011 12:21 PM, Beryl wrote:

Does it seem likely that full nose down trim and forward stick pressure
are used all the time? Lots of drag with that kind setup, exactly what
isn't wanted in a race. Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


At 500 MPH?
Of course it need nose down trim.

I'm guessing you kind of skipped over the numbers.

I'm also convinced you are not a flyer.




One little tidbit of information is that with most aircraft you can get
a couple of extra knots of speed if you trim the plane up ( the trim tab
is set in the neutral position for least drag) and then you apply
forward pressure to the yoke. The drag of the trim tab to force the
elevator down is eliminated picking up a little more speed. I found
that out by playing with the trim on the many long boring flights I've
taken.

John
Or reflex your flaps.

Richard wrote:
On 9/26/2011 12:21 PM, Beryl wrote:

Does it seem likely that full nose down trim and forward stick pressure
are used all the time? Lots of drag with that kind setup, exactly what
isn't wanted in a race. Or maybe the P-51 is tail heavy and the
horizontal stabilizer is a lifting surface, like with the P.180 Avanti?


At 500 MPH?
Of course it need nose down trim.

Nose down trim relative to what? Cruise?

The Unlimited class racers are optimized for best performance = least
drag at ~500 mph. If they need nose down at that speed, the streamlined
horizontal stabilizer will provide it. Not some angular pitched up/down
crap hanging out in the wind, as Lloyd aptly describes it.
So, when optimized for 500 mph, of *course* it needs nose up trim at 200
mph! And it's also draggier than it needs to be at 200 mph, with all the
pitched up/down crap hanging out in the wind.

I'm guessing you kind of skipped over the numbers.

I don't see where any numbers were discussed. Provide some numbers where
you feel they're missing.

I'm also convinced you are not a flyer.

I am crushed. Read what I posted from the Air & Space Smithsonian
article. Pilot Bill Destefani doesn't agree with your understanding of
how his P-51 Strega works.

Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?

What's the tradeoff?

Richard wrote:
Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?

I assume you mean stabilizer, not elevator.
You'd have zero induced drag from the trim tab or elevator. And if you
put the Center of Gravity right at the Center of Lift, none from the
stabilizer either.
Bill Destefani likes all of that, but it's not very safe.


Tell me where you disagree.

1) The airplane is always nose-heavy, of course, even at 500 mph, but as
little as Bill feels is necessary for safety.

2) The tail surfaces need to produce some down force to keep the nose
up, even at 500 mph.

3) Why are you pushing the stick forward to hold the nose down at 500
mph? Only because the elevator is properly trimmed for 200 mph.

4) Trim the elevator for 500 mph and you won't have to push the stick.

5) Rig the stabilizer for 500 mph and you won't have to push the stick,
AND you won't have the elevator or trim tab jutting out into the
airstream. Everything is lined up nicely.

What's the tradeoff?

Less efficiency at the speeds where most airplanes spend most of their
time, cruising along at ~70% power.

On 9/27/2011 12:13 AM, Beryl wrote:
Richard wrote:
Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?

I assume you mean stabilizer, not elevator.
You'd have zero induced drag from the trim tab or elevator. And if you
put the Center of Gravity right at the Center of Lift, none from the
stabilizer either.
Bill Destefani likes all of that, but it's not very safe.


Tell me where you disagree.

1) The airplane is always nose-heavy, of course, even at 500 mph, but as
little as Bill feels is necessary for safety.

2) The tail surfaces need to produce some down force to keep the nose
up, even at 500 mph.

3) Why are you pushing the stick forward to hold the nose down at 500
mph? Only because the elevator is properly trimmed for 200 mph.

4) Trim the elevator for 500 mph and you won't have to push the stick.

5) Rig the stabilizer for 500 mph and you won't have to push the stick,
AND you won't have the elevator or trim tab jutting out into the
airstream. Everything is lined up nicely.

What's the tradeoff?

Less efficiency at the speeds where most airplanes spend most of their
time, cruising along at ~70% power.


How about a 200 MPH landing speed?

Richard fired this volley in
m:

Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?

What's the tradeoff?

Yeah... do you? Although I have lots of hour PIC, I've never flown a
full-scale pylon racer. But (just like the guy in a Holiday Inn Express
commercial) I've flown model pylon racers. Real (not scale) speeds of
200+ mph. They are not "toy" airplanes, they're real airplanes made
smaller. They behave to aerodynamics just like big ones (although they
tend to leave less wake turbulenceG).

We trim 'em out for max speed. Then we honk on the stick pretty hard at
low speeds, just to keep the nose up. So what?

The ONLY reason these full-scale racing guys want to land for, at all, is
so they can gas up and do it again! So long as the aircraft handling is
survivably safe at landing and takeoff speeds, all they're concerned with
is how clean they can make it at full speed.

Since one _can_ adjust one's approach speed, there need not be any
compromises.

LLoyd

John B. wrote:
On Mon, 26 Sep 2011 22:13:16 -0700, Beryl wrote:

Richard wrote:
Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?
I assume you mean stabilizer, not elevator.
You'd have zero induced drag from the trim tab or elevator. And if you
put the Center of Gravity right at the Center of Lift, none from the
stabilizer either.
Bill Destefani likes all of that, but it's not very safe.


Tell me where you disagree.

1) The airplane is always nose-heavy, of course, even at 500 mph, but as
little as Bill feels is necessary for safety.

Do you have any idea of the flight characteristics of a wing with the
CG and CL in the same spot?

Yes, that's why I said said it's always nose heavy.
I'm attempting to point out that always pushing the nose down on an
airplane that's already nose heavy is nonsensical... except I've read
that the Blue Angels do trim their jets that way. It helps them keep a
steady hand.

If the plane is nose heavy at 500 MPH what do you think it is going to
be like at 100 MPH and the much lower lift you have there.

Still nose heavy, and trimming the nose up would be a good idea.

2) The tail surfaces need to produce some down force to keep the nose
up, even at 500 mph.


3) Why are you pushing the stick forward to hold the nose down at 500
mph? Only because the elevator is properly trimmed for 200 mph.

4) Trim the elevator for 500 mph and you won't have to push the stick.
t
5) Rig the stabilizer for 500 mph and you won't have to push the stick,
AND you won't have the elevator or trim tab jutting out into the
airstream. Everything is lined up nicely.

What's the tradeoff?
Less efficiency at the speeds where most airplanes spend most of their
time, cruising along at ~70% power.

With the CG and CL at the same point you have an extremely unstable
aircraft. I thing that the original P-51% figures were in the 20% of
cord neighborhood and it had a reputation for being very "twitchy".

One of the basic reasons for having the CG ahead of the CL is so that
if you stall the airplane the nose will drop which hopefully, will
allow you to recover.

I know that. Even before you stall, the nose lowers. This is what's
behind the whole reason that pitch controls airspeed, and power controls
altitude (another interesting argument).

If you trim an aircraft for hands off level flight at 500 mph you are
going to be extremely nose heavy at take off and landing speeds and it
is going to be very difficult to control the aircraft, if you lose
the power at low speed the nose is going to drop very, very quickly.

I know that.

AS Richard pointed out the lift generated by a wing varies
considerably with changes in the air speed and consequently the trim,
the tendency to dive or climb, must also change.

Of course trim needs chsnge. Richard apparently believes that some
nose-down is ALWAYS needed, and only the /amount/ of nose-down changes
as speed changes.

Richard wrote:
On 9/27/2011 12:13 AM, Beryl wrote:
Richard wrote:
Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?
...
What's the tradeoff?

Less efficiency at the speeds where most airplanes spend most of their
time, cruising along at ~70% power.


How about a 200 MPH landing speed?

X-15? What lands at 200 mph?

Are you saying that the Galloping Ghost, or Strega, couldn't be rigged
for minimum drag at 500 mph because they'd then have to land at 200?

Note that I never said the Stabilizer produces no nose-down force at 500
mph. I'm only doubting that the Trim Tab/Elevator are doing much work
there, at all. Set the Stabilizer to do the work, and lift (downward)
comes by way of Angle of Attack. But set the Trim Tab and Elevator to do
the work, and lift (downward) comes by way of Camber. And not even a
good camber, it's all zig-zagged and creased.

Beryl,

One last try and then I'll go away and leave you alone.


Forget "nose heavy".

Think "pitch", aka deck angle, or preferably, angle of attack.


Within limits of course, angle of attack directly controls the amount of
lift generated by the wing. Yes, other parameters are also involved
but this angle is what the pilot has control of via the stick.

For straight and level unaccelerated flight, lift equals weight.
(thrust equals drag too, but that's another story)

As speed increases _so will lift_, unless something is done to keep that
from happening. THAT trick is simply pushing the nose down.

(Airliners often pump fuel forward(!) but that's a bit over the top for
light aircraft)

By lowering the nose, the angle of attack is decreased, thereby
decreasing the coefficient of lift, and, if done right, maintaining
a constant altitude (the level part of straight and level)

Ok?

That's the whole of it.


So...

Quote
Of course trim needs chsnge. Richard apparently believes that
some nose-down is ALWAYS needed, and only the /amount/ of nose-down
changes as speed changes.

So for the discussion of a racer at 500 MPH, Yeah, True, Si, Da...

When landing, no.

On Tue, 27 Sep 2011 19:54:59 -0700, Beryl wrote:

Richard wrote:
On 9/27/2011 12:13 AM, Beryl wrote:
Richard wrote:
Do you know what would happen if the elevator were rigged for zero
trim at 500 mph?
...
What's the tradeoff?

Less efficiency at the speeds where most airplanes spend most of their
time, cruising along at ~70% power.


How about a 200 MPH landing speed?

X-15? What lands at 200 mph?

Are you saying that the Galloping Ghost, or Strega, couldn't be rigged
for minimum drag at 500 mph because they'd then have to land at 200?

Note that I never said the Stabilizer produces no nose-down force at 500
mph. I'm only doubting that the Trim Tab/Elevator are doing much work
there, at all. Set the Stabilizer to do the work, and lift (downward)
comes by way of Angle of Attack. But set the Trim Tab and Elevator to do
the work, and lift (downward) comes by way of Camber. And not even a
good camber, it's all zig-zagged and creased.


The elevator - and the trim tab - do a LOT of work on a race plane at
500mph. And a lot at 200 too.