Most Overrated aircraft of WWII.....?

[KiwiBiggles]

Funnily enough, Gilruth doesn't appear in that document.

It's all part of the ongoing plan to prove that the Spitfire and Merlin were really American, so all becomes right with the world again.

 

[Navalwarrior]

It's all part of the ongoing plan to prove that the Spitfire and Merlin were really American, so all becomes right with the world again.

Resp:
The Spitfire was a British development. Period! If there is a culprit, it is not Robert R. Gilruth. I could find no other source, other than what Kraft wrote in 2000, and later 2001. I could understand descrepencies if his two stories were decades apart, but Kraft seems to have mis-spoke (exaggerated) about Gilruth's contributions, in stating 'Spitifre' in lieu of general aircraft.
I do remember reading of Joint Fighter Meets held during WWII (two at Elgin Field, Florida) where British aircraft were also present; the first in mid 1943. Pilots from all services could fly each other's planes, once they were given instruction on its idiosyncrasies. Representatives and aircraft from the RCAF were present.

 

[DerAdlerIstGelandet]

What other designs would be comparable? I'd guess the P-38 with dive-recovery flaps and P-47N?

I probably should have phrased that better...

My beef with the 51, has nothing to do with it's ability. It was an amazing aircraft. I consider it overrated because so many people forget there were so many other aircraft that contributed to winning the war. It's P-51 this, P-51 that.

You won't see that so much here, or on other forums with knowledgable people though.

 

[Navalwarrior]

I probably should have phrased that better...

My beef with the 51, has nothing to do with it's ability. It was an amazing aircraft. I consider it overrated because so many people forget there were so many other aircraft that contributed to winning the war. It's P-51 this, P-51 that.

You won't see that so much here, or on other forums with knowledgable people though.

Resp:
I agree. The P-51 (Merlin) didn't really play much of a role until around the Feb/Mar 1944 timeframe. Other fighters (1939-1943) bore the brunt of the air war. From what I read, the Hurricane shot down more enemy aircraft during the Battle of Brittan. However, most cite the Spitfire as the aircraft that won the battle.

 

[Navalwarrior]

Probably not much as it isn't mentioned in his NASA bio...
https://history.nasa.gov/naca/bio.html
A large bio
https://www.aem.umn.edu/info/history/gilruth-robert.pdf
Or the all important Wiki
Robert R. Gilruth - Wikipedia

Resp:
Spitfire reported dated Dec 1942, Characteristics Exhaust Stacks of Spitfire, Langley Field, VA, dtic.mil

 

[fubar57]

Resp:

​

Oops...forgot the quote....

Resp:
Spitfire reported dated Dec 1942, Flying Characteristics of Spitfire, Langley Field, VA, www.dtic.mil

 

[Navalwarrior]

Zactly

Guess you need book number 83! Just kidding.

 

[wuzak]

Resp:

View attachment 509938
​

Oops...forgot the quote....

Upd:
http://www.dtic.mil/dtic/tr/fulltext/u2/a800911.pdf

by L. Richard Turner and Maurice D. White.

Tests done on a Mk V airframe in late 1942, published December 1942.

6mph gain at +psi boost, ~21,000ft - 22,000ft.

Hard to tell from the picture, but it doesn't look like the Spitfire ever used those ejector exhausts.

The 2 stage Merlin Spitfires also did not use the same ejector exhausts as the V.

So to say they "fixed" anything is a stretch. If Supermarine/Rolls-Royce adopted the exhaust stacks it would be a performance improvement, not a fix.

 

[Shortround6]

MK IX shouldn't use the same stacks as a MK V in any case.
You have a different mass flow on the two stage engine.

Even on P-40s with Allison the exhaust stacks had to be modified when WEP was approved as the original stacks were optimised for a mass flow for a an 1150hp (net) engine and not a 1500hp engine.
Exhaust stacks work best at one altitude and one speed. anything other than that altitude or speed is a compromise.

 

[XBe02Drvr]

Upd:
http://www.dtic.mil/dtic/tr/fulltext/u2/a800911.pdf

by L. Richard Turner and Maurice D. White.

Tests done on a Mk V airframe in late 1942, published December 1942.

6mph gain at +psi boost, ~21,000ft - 22,000ft.

Hard to tell from the picture, but it doesn't look like the Spitfire ever used those ejector exhausts.

The 2 stage Merlin Spitfires also did not use the same ejector exhausts as the V.

So to say they "fixed" anything is a stretch. If Supermarine/Rolls-Royce adopted the exhaust stacks it would be a performance improvement, not a fix.

I think there's a little confusion here. There are TWO NACA reports on Spit Vs in Dec 1942, one a quantification of handling qualities, and the other an investigation of thrust enhancement through exhaust ejector design. They seem to be getting confused here.
Search: Flying Characteristics of Spitfire, Langley Field, VA
This one is right up Gilruth's alley, although he doesn't seem to be named. It relies heavily on Gilruth's pet concept of stick force gradient in its analysis of the Spit's maneuvering performance. It describes, among other things, making a high G turn with the wing partially stalled while retaining full control through sensitive handling of the stick. Sounds like one of those tricks that could keep you alive....if you could live long enough to learn it.
Also it appears that stick force gradient with elevator mass balances installed (for high speed flutter protection) was so light as to encourage overstressing the airframe. I can't imagine trying to make stick pressure modulations measured in ounces while under 5 or 6 Gs loading. (Glad I'm not an F-16 or F-18 pilot!)
The concept of stick force gradient as a quantitative parameter was apparently a new thing in the US with Gilruth, but I'd be surprised if Mitchell, Camm, and company didn't already have some concept of it.
Cheers,
Wes

 

[GrauGeist]

I was actually trying to find an image of the Spitfire being tested at Langley and ran across this document.
Fascinating read for those who are into the technical aspect of the aerodynamics of the Spitfire (and Mustang).

http://naca.central.cranfield.ac.uk/reports/arc/rm/2535.pdf

 

[wuzak]

Certainly tests between the Spitfire I, Hurricane and Bf 109E noted stick forces to achieve roll and turn performance.

As for the report, is there any evidence that anything on the Spitfire was changed as a result?

 

[XBe02Drvr]

As for the report, is there any evidence that anything on the Spitfire was changed as a result?

I didn't read all 53 pages down to the finest detail, but it seems to be an investigative report, not an experimental one.
Cheers,
Wes

 

[Navalwarrior]

Upd:
http://www.dtic.mil/dtic/tr/fulltext/u2/a800911.pdf

by L. Richard Turner and Maurice D. White.

Tests done on a Mk V airframe in late 1942, published December 1942.

6mph gain at +psi boost, ~21,000ft - 22,000ft.

Hard to tell from the picture, but it doesn't look like the Spitfire ever used those ejector exhausts.

The 2 stage Merlin Spitfires also did not use the same ejector exhausts as the V.

So to say they "fixed" anything is a stretch. If Supermarine/Rolls-Royce adopted the exhaust stacks it would be a performance improvement, not a fix.

Resp:
Kraft likely sinned when he didn't furnish his sources via footnotes. I suspect that Gilruth simply put aircraft assessments/evaluations/recommendations in a folder, likely with a 'form' cover sheet . . . for the purpose of sharing what his engineers learned with the RAF. I also suspect he did it with all aircraft if he thought it could help in other aircraft refinement. It is how engineers think.
I try to look at things with an open mind. My dad was an engineer, so every time I 'listed' the pros to why I wanted something, he would automatically make me list the 'cons.' It took me years as a kid to understand how he thought.
The document does show:
1. That an early Mk Spitifre did make it 'across the pond' early in the war,
2. That NACA did evaluate it,
3. That the report likely was furnished to the RAF (via Canada or directly ? ?)
So I will accepted 3 out ot 4 correct is not bad, but I suspect you hardliners will continue to disagree. I didn't post on this subject to elevate America's involvement with the Spitfire. It was merely interesting to see something I had not heard before. Shame on me!

 

[Kevin J]

Resp:
Kraft likely sinned when he didn't furnish his sources via footnotes. I suspect that Gilruth simply put aircraft assessments/evaluations/recommendations in a folder, likely with a 'form' cover sheet . . . for the purpose of sharing what his engineers learned with the RAF. I also suspect he did it with all aircraft if he thought it could help in other aircraft refinement. It is how engineers think.
I try to look at things with an open mind. My dad was an engineer, so every time I 'listed' the pros to why I wanted something, he would automatically make me list the 'cons.' It took me years as a kid to understand how he thought.
The document does show:
1. That an early Mk Spitifre did make it 'across the pond' early in the war,
2. That NACA did evaluate it,
3. That the report likely was furnished to the RAF (via Canada or directly ? ?)
So I will accepted 3 out ot 4 correct is not bad, but I suspect you hardliners will continue to disagree. I didn't post on this subject to elevate America's involvement with the Spitfire. It was merely interesting to see something I had not heard before. Shame on me!

The Seafire III series certainly introduced individual exhausts and a host of other mods that recovered the speed lost because of the addition of wing folding, catapult spools and an arrestor hook. This was about a 20 mph loss in total. The Seafire III was produced in 1943/44 and was as fast as the Spitfire Vc which it was based on. Produced by Westland and Cunliffe-Owen, the latter a smaller company that also introduced flush riveting. Production was about 1300. So its possible that the changes identified were applied to them, but again by small companies with 'more skilled' workers? The main production Spitfires VII, VIII, IX and XVI totalling about 8400 machines probably didn't have these mods as their speed would have been adequate to combat the FW 190A and Bf 109G and they were mass produced. Also perhaps the Spitfire IX floatplane fighter that only lost 30 mph in top speed as opposed to the earlier Spitfire Vb variant that lost 50 mph in speed.

 

[wuzak]

The Spitfire IX was using individual ejector exhausts 6 months before that report.

Rolls-Royce were evolving them over time.

Edit:
The Seafire III's exhausts look a lot like the Spitfire IX's

Flying Legends aircraft

https://upload.wikimedia.org/wikipe...re_Mk_IX_-Indianapolis_Air_Show-24Aug2008.jpg

 

[wuzak]

Resp:
Kraft likely sinned when he didn't furnish his sources via footnotes.

Who is Kraft, and what report did he write?

I suspect that Gilruth simply put aircraft assessments/evaluations/recommendations in a folder, likely with a 'form' cover sheet . . . for the purpose of sharing what his engineers learned with the RAF.

That's some sort of assumption.

This report by Phillips and Vensel issued in September 1942 referenced Gilruth, Requirements for Satisfactory Flying Qualities of Airplanes and Gilruth and Turner, Lateral Control Required for Satisfactory Flying Qualities Based on Flight Tests of Numerous Airpanes. Bot these reports predate testing of the Spitfire by NACA (which occurred between December 29, 1941 and January 31, 1942).

Conclusions were drawn on the Spitfire's flying qualities based on desired properties set forth in those documents, and others.

Is there any evidence that Gilruth was involved directly with Spitfire testing?

I also suspect he did it with all aircraft if he thought it could help in other aircraft refinement. It is how engineers think.

That is a complete guess.

If he was involved in the testing process and providing notes it is likely he would have been listed as an author.

The document does show:
1. That an early Mk Spitifre did make it 'across the pond' early in the war,
2. That NACA did evaluate it,

It is not surprising that a Spitfire was sent to the US for evaluation.

It is likely this was part of the process of evolving requirements for new fighter type aircraft.

3. That the report likely was furnished to the RAF (via Canada or directly ? ?)

The report would have been sent to the Air Ministry directly, or to the Aeroplane and Armament Experimental Establishment (A&AEE). Not to the RAF or Canada.

The A&AEE did much the same stuff as NACA did in the US.

The A&AEE also tested captured aircraft, such as the Bf 109E.

I didn't post on this subject to elevate America's involvement with the Spitfire.

It seems to me that you did precisely that:

Resp:
I just read that an NACA employee named Robert Gilruth found and fixed some flaws in early Mark Spitfire's. And from that point the British assigned a team to him for the rest of the war. Each time Gilruth made a discovery or developed an innovation, it was forwarded back to Briain where it was incorporated into aircraft built there.

 

[Navalwarrior]

Who is Kraft, and what report did he write?




That's some sort of assumption.

This report by Phillips and Vensel issued in September 1942 referenced Gilruth, Requirements for Satisfactory Flying Qualities of Airplanes and Gilruth and Turner, Lateral Control Required for Satisfactory Flying Qualities Based on Flight Tests of Numerous Airpanes. Bot these reports predate testing of the Spitfire by NACA (which occurred between December 29, 1941 and January 31, 1942).

Conclusions were drawn on the Spitfire's flying qualities based on desired properties set forth in those documents, and others.

Is there any evidence that Gilruth was involved directly with Spitfire testing?




That is a complete guess.

If he was involved in the testing process and providing notes it is likely he would have been listed as an author.




It is not surprising that a Spitfire was sent to the US for evaluation.

It is likely this was part of the process of evolving requirements for new fighter type aircraft.




The report would have been sent to the Air Ministry directly, or to the Aeroplane and Armament Experimental Establishment (A&AEE). Not to the RAF or Canada.

The A&AEE did much the same stuff as NACA did in the US.

The A&AEE also tested captured aircraft, such as the Bf 109E.




It seems to me that you did precisely that:

Resp:
The info was taken from book: Flight, My Life in Mission Control, by Chris Kraft. My three listed statements were challenged earlier by a blogger. I produced a document that pretty much confirms 1 - 3. An assumption was in the 4th only.

 

[XBe02Drvr]

Who is Kraft, and what report did he write?

Most everybody in my generation remembers "Chris Kraft, the voice of Mission Control", the narrator of dozens of televised NASA rocket launches in the 60s and 70s.
Cheers,
Wes

 

[Navalwarrior]

Most everybody in my generation remembers "Chris Kraft, the voice of Mission Control", the narrator of dozens of televised NASA rocket launches in the 60s and 70s.
Cheers,
Wes

Resp:
Wes, it is a good read. There are many interesting points.

Most everybody in my generation remembers "Chris Kraft, the voice of Mission Control", the narrator of dozens of televised NASA rocket launches in the 60s and 70s.
Cheers,
Wes

Most everybody in my generation remembers "Chris Kraft, the voice of Mission Control", the narrator of dozens of televised NASA rocket launches in the 60s and 70s.
Cheers,
Resp:
Wes, the book 'Flight, My Life In Mission Control' is a very good read. Kraft had a lot 'on his plate.' NASA had a very diverse group of engineers. As an example, around 1959-1960 the Canadian company A.V. Roe got the contract to produce the 'Arrow' but the government dropped the project. This left English engineers w/o employment. NASA sent invitations to them for a job interview. Teewyn Roberts, James Chamberlin and John Hodge, to name a few. This chapter reminded me of the different flags on my street in late 1960s; a Union Jack on the left end of the street, a Maple Leaf in the middle on the right side, and finally a unknown S. American flag. If you read it, I just wouldn't mention Kraft's statement on the Spitifre . . .some on this blog think the War is still on-going. LOL!