Author Topic: Fw 190A vs P-47D diving from 25,000 ft to deck.  (Read 13618 times)

Offline BlauK

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #45 on: April 27, 2007, 10:50:49 AM »
:)


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Offline TimRas

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #46 on: April 27, 2007, 11:07:05 AM »
Just to clarify.
It is quite possible that Mr. Brown is wrong in this particular topic. When you hear enough pilots testimonials of about any plane, you will find that they cannot probably agree about anything. The "Joint Fighter Conference" -report is a good example.

But starting to sling insults at these respectable veterans because of this is pretty low, IMO.

Offline Viking

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #47 on: April 27, 2007, 11:21:54 AM »
Inexcusable is the word I would choose. I had a lot of respect for Widewing’s opinions; they seemed levelheaded and fairly well researched, and always polite. None of that matters now. He has shown his true nature.

Offline Widewing

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #48 on: April 27, 2007, 12:23:02 PM »
Quote
Originally posted by BlauK
Quite arrogant of you to post such insults of an older gentleman on a public board.


I must agree that I have been harsh. For that I apologize. However, Brown has made repeated statements over the years that have been disputed as not being true or accurate. I'll say it again, he is not held in wide regard within the Flight Test Community. He is regarded highly by aviation buffs who often believe everything they read in print.

Brown's opinions are often not supported by any documentation. If fact, the documentation often shows that his opinion is just that, an opinion, purely anecdotal in nature.

When challenged, as he was by former Flying Tiger and Republic test pilot Ken Jernstedt over his published assertions against the P-47, Brown replied that he (Jernstedt) was entitled to his opinion. Jernstedt was lead test pilot on the P-47N and XP-72 programs... Ken Jernstedt logged thousands of flight hours testing and wringing out P-47s. If I wanted an opinion on the P-47, I would have gone to Jernstedt, certainly not Brown.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline Widewing

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #49 on: April 27, 2007, 12:34:45 PM »
Quote
Originally posted by TimRas
From Wikipedia:

C
On December 3, 1945, Brown made the world's first landing of a jet aircraft on an aircraft carrier. He landed a de Havilland Sea Vampire on the Royal Navy carrier HMS Ocean.



As we can all see he must have been a complete idiot (and British, a damn foreigner at that).



TimRas, using wikipedia as a source is not a good idea.

Brown was not the first man to land a jet powered fighter on a carrier...

On November 6, 1945, Marine Lt. J.C. West made the first carrier landing in an aircraft powered only by a jet engine. His Ryan FR-1 suffered a failure of the R-1820 radial. He feathered the propeller and proceeded to fly to and land the Ryan aboard the USS Wake Island flying only on its GE J31 turbojet. This is common knowledge and undisputed fact.

Ryans were often flown on jet power only.




If Eric Brown claims he was first, he does so in the face of the truth.

My regards,

Widewing
« Last Edit: April 27, 2007, 12:42:20 PM by Widewing »
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline BlauK

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #50 on: April 27, 2007, 12:48:25 PM »
:aok Ww.

I certainly know not to trust any single source alone. Actually Mr. Brown's testflights with a captured Bf109G (with wing cannons) have e.g. been the source for a commonly repeated (in several "average" books) misquote of the max speed of any 109G. Not likely his fault (the misquotes), but I did not know that when I first heard of the man, and built a prejudice pretty much on wrong assumptions.

I have not yet read his latest book, Wings on my Sleeve, and cannot therefore have much of an opinion of his opinions. However, I met him in Duxford last summer, and found him a very friendly and polite gentleman.
« Last Edit: April 27, 2007, 12:58:23 PM by BlauK »


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Offline gripen

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #51 on: April 27, 2007, 01:36:03 PM »
Generally the RAE results on dive testing of the P-47 are quite similar as tested by Republic. There is minor differences in the mach number values (probably due to measurement errors) but the phenomena and the effects are pretty much the same.

BTW I do think that we don't need name calling etc. here.

Offline Knegel

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #52 on: April 27, 2007, 02:42:55 PM »
Quote
Originally posted by Viking
It was very much wing compression related. When the plane approached compression speeds the wing would lose lift due to the forming of supersonic shockwaves at the leading edge. This loss of lift resulted in an uncontrolled nose down into a vertical dive. Before the installation of new ailerons and dive flaps with the D-30 model the only thing the pilots could do was throttle back and ride it out. Those that survived managed to pull out at very low altitudes. They were beaten and bruised by the heavy buffeting, and the control stick had beaten their legs black and blue. Early B and C model P-47s could also simply disintegrate in mid air.


Hi,

afaik the P47 could get recovered as long as it got trimmed up. The main problem imho was the to heavy forces.

Of course all normal wings got compression related problems around mach 0.75, but if i look to the max dive speeds of the P47 i only can conclude that the wing compressions wasnt the main problem, rather the not very effective elevator at this speed.
Thats rather similar to the 109, if it was trimmed for level flight and the trim system got frozzen, the pilot also couldnt recover, on the other side, if the 109G pilot raised the trim with power at highspeed, the g forces could rip of the wing.

Steep dives around mach 0,75 was dangerus for every WWII plane, but not many got to this speed by easy.

After all reading i got the conclusion that the P47´s dive acceleration at higher speeds in combination with the needed missing pilot experience was the cause of the P47 crashs, not the in general absolut dangerus plane. Same count for the 109!

Actually i still doubt the RAE results on the Spitfire, thats abosut again the war experiences, where the 109´s and FW190´s could leave the Spits behind by easy. I still think they had bad measurement mistakes, what was rather normal at that time.

btw, was the pilot able to trim the P47 at highspeed, like the 109 and 190 pilot could(as long as the trim wasnt frozen due to wrong lubricant)??  

Ww, to call a pilot like Brown a idiot in a public forum is not very honourable!! Many pilots tend to overstate and dont have a good sence for scientific work, but it looks to me thats in the nature of many fighter pilots.
Carson made even more bad statements, specialy regarding the 109, and that in a attempt to proof the bad design of the 109 in a "scientific" layout. Such articels are way more bad than the obvious opinion like statements of Mr. Brown.

Greetings,

Knegel

Offline Widewing

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #53 on: April 27, 2007, 06:03:53 PM »
Quote
Originally posted by Knegel

Ww, to call a pilot like Brown a idiot in a public forum is not very honourable!! Many pilots tend to overstate and dont have a good sence for scientific work, but it looks to me thats in the nature of many fighter pilots.
Carson made even more bad statements, specialy regarding the 109, and that in a attempt to proof the bad design of the 109 in a "scientific" layout. Such articels are way more bad than the obvious opinion like statements of Mr. Brown.

Greetings,

Knegel


I agree... I should have simply bitten my tongue. Brown is certainly not an idiot.

He is in my opinion, however, a shameless self-promoter. In that regard, he reminds me of Thomas Lanphier and his obsession with his claim of shooting down Yamamato. To this day, many still repeat this as the gospel truth, despite the fact that it was known from the day it happened that Lanphier's claim was false, as was his claim of shooting down a Zero as well.

Brown insinuates that he was the impetus to the installation of dive recovery flaps on the P-47. Naturally, he ignores the fact that NACA was working on this years before his test flight in the P-47.

In point of fact, NACA suggested the solution to Lockheed in the autumn of 1942. Lockheed developed the flaps in their own wind tunnel and was flying a P-38G fitted with dive recovery flaps in February of 1943. That was a full year before Brown flew the P-47. The AAF told Lockheed to share their data with all manufacturers. In January of 1944, a modified P-47D-22-RE was flown with Republic's dive recovery flaps installed. This was STILL before Brown had flown the P-47.

It is things like this that cause me to take many of Brown's comments with a grain of salt. It also irritates me when people accept what he says as the holy grail without question.

Thus, my over-reaction....

My regards,

Widewing
« Last Edit: April 27, 2007, 06:06:33 PM by Widewing »
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline bozon

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #54 on: April 27, 2007, 07:04:50 PM »
viking, non of these quotes really say that P47 were breaking in mid air. The only place something such as this is mention is in the line:
"P-47’s and P-38’s were being flown straight into the ground, or even breaking up in flight."
It is not even clear if this relates to P38 or P47 and if this was a one-case or a common phenomenon. It is also not clear whether they were being flown into the ground because compressibility was a "new phenomenon" and pilots did not know how to respond (or were careless), or because it was impossible to recover. If the critical mach was 0.9 and they could reach it, would have they not compressed and crashed? The quote clearly relates to the period when these planes were being introduced into service.
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Offline Viking

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #55 on: April 28, 2007, 03:15:54 AM »
Quote
Originally posted by Knegel
Hi,

afaik the P47 could get recovered as long as it got trimmed up. The main problem imho was the to heavy forces.


No the P-47 could not be trimmed out of a compressibility dive. The controls and trim tabs were completely ineffective until the Mach number was reduced to less than 0.73. Trying to trim out of dives killed many pilots by overloading the airframe when the controls became responsive again.


Quote
Originally posted by Knegel
Of course all normal wings got compression related problems around mach 0.75, but if i look to the max dive speeds of the P47 i only can conclude that the wing compressions wasnt the main problem, rather the not very effective elevator at this speed.
Thats rather similar to the 109, if it was trimmed for level flight and the trim system got frozzen, the pilot also couldnt recover, on the other side, if the 109G pilot raised the trim with power at highspeed, the g forces could rip of the wing.
 


It is completely different than the 109. The 109 had a “flying tail” trim before the term was even invented. The whole tail plane would move with trim and thus remained effective at any and all speeds (theoretically even supersonic speeds). Trimming too much would of course overload the airframe.  The P-47 had trim tabs that were totally ineffective during compressibility dives. Losing control of the aircraft at Mach 0.73 and having no option than “riding it out” down to less than 10,000 feet where control was reestablished is totally unacceptable in a high-speed high-altitude fighter as Brown and the RAE found out. The problem was not as bad as with the P-38s that often lost their tail section in dives, but bad enough.

Offline Viking

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #56 on: April 28, 2007, 03:17:43 AM »
Quote
Originally posted by bozon
viking, non of these quotes really say that P47 were breaking in mid air. The only place something such as this is mention is in the line:
"P-47’s and P-38’s were being flown straight into the ground, or even breaking up in flight."
It is not even clear if this relates to P38 or P47 and if this was a one-case or a common phenomenon. It is also not clear whether they were being flown into the ground because compressibility was a "new phenomenon" and pilots did not know how to respond (or were careless), or because it was impossible to recover. If the critical mach was 0.9 and they could reach it, would have they not compressed and crashed? The quote clearly relates to the period when these planes were being introduced into service.



The early P-47s (B series and perhaps the very early C series) had fabric covered control surfaces. These would often fly apart during compressibility dives dooming the plane and pilot. Also before a recovery procedure was worked out pilots would try to trim out of the dive resulting in overloading the airframe when the plane reached lower altitudes where the controls became effective again. Or in the words of Warren Bodie (a man I believe Widewing respects greatly): “Pilots were running up against compressibility and they were dying.”

Eric Brown test flew the P-47 with a Mach meter installed and found that the speed at where control was lost was Mach 0.73. This is INDISPUTABLE, and totally unacceptable in a high-speed high-altitude fighter. And I’ll take the word of an accomplished test pilot like Eric Brown who actually test flew the plane in question over some armature internet historian who’s peeved that his pet warbird got a bad rep.

Offline bozon

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #57 on: April 28, 2007, 05:14:06 AM »
Quote
Originally posted by Viking
The early P-47s (B series and perhaps the very early C series) had fabric covered control surfaces. These would often fly apart during compressibility dives dooming the plane and pilot.

As far as I remember, B series never saw combat and C was replaced by D very early on.
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Offline Stoney74

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #58 on: April 28, 2007, 06:53:30 AM »
Quote
Originally posted by Viking
Eric Brown test flew the P-47 with a Mach meter installed and found that the speed at where control was lost was Mach 0.73. This is INDISPUTABLE, and totally unacceptable in a high-speed high-altitude fighter.


The C model had metal covered control surfaces as a result of the flaws found in the B model, which as Bozon said, never saw combat.  And, for you to say that Mach .73 was where the P-47 lost control is indisputable, is well...disputable, as there are many other credible sources in the aviation history world that counter it.  

Personally, I don't understand why you're so dug in on this one--unless you've got some sort of agenda.

Offline Shuckins

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Fw 190A vs P-47D diving from 25,000 ft to deck.
« Reply #59 on: April 28, 2007, 07:13:24 AM »
The B-series, indeed, did NOT see combat....being mainly test aircraft.  One of the early dog-ships in this series shed its tail during a test dive.  This was at a time when the effects of compressibility were first being encountered and engineers in nearly every company producing modern fighters for the military were at a loss as to its causes.

Corky Meyer flew one of these early P-47Bs in 1943, and was cautioned by Republics people to not exceed the dive limit speed.  That the Jug was capable of getting rid of an appalling amount of altitude in a short amount of time was evidenced in the warning not to attempt a split-s at less than 15,000 feet of altitude.

The Jugs tail structure was strengthened, and the aircraft went into combat.  Statements made previously that suggest the P-47 pilots routinely dove their aircraft past their German foes and into the ground are gross exaggeration.

While I admire Capt. Eric Brown and have enjoyed reading "Duels in the Sky" and some of his aviation articles, I take some of his statements with a grain of salt.  While he has flown literally hundreds of aircraft his time in some of them is not extensive. The statements of test and combat pilots who were intimately familiar with the aircraft and all of its foibles should have more weight.

Corky Meyer flew a P-47M in 1944.  Republic's engineers told him that test pilot Parker Dupouy had dived the Jug vertically to its maximum Mach number of .868 and made a very successful dive recovery-flap pullout.  This was 61mph faster than the P-47s compressibility entry Mach number.  Corky took the P-47M to 30,000 feet and pushed over into a 60-degree dive and ran the combined Mach number/airspeed indicator up to .80 - well past its compressibility limit Mach number.  He extended the dive recovery flaps which provided a stick-free 4G pullout that brought the fighter back below its airspeed limit within a "few easy seconds."

Macky Steinhoff has stated that German pilots feared the Thunderbolt because of its "extraordinary ability to attack in a nose dive."  Robert Johnson and every pilot who went to war in the Jug states the same thing.

If a Jug was close to a Luftwaffe fighter, neither pilot would give a fig for its chances of escaping the Thunderbolt in a dive.
« Last Edit: April 28, 2007, 07:22:49 AM by Shuckins »