XP-40Q: what was it able to do when?

[GregP]

I reserve the right to pass on what I hear about aircraft, companies, and the war from the people who were there. I will endeavor to make it clear that is what what was heard, not what I espouse. Hopefully that will suffice.

However, I don't think like Drgondog or Shortround ... I think like me. Nothing whatsoever wrong with the way they think at all ... insinuated or implied... and no insult intended, I simply think like me. Asking either to change their style of positing to match my own would doubtless have little result. The converse is likely, too and I don't lament that since their posts are usually enjoyable.

And no, General Davey Allison was not invloved in the design of either the P-40 or the P-51, but he was intimately invloved with demonstrating the P-40 and was very close to Curtiss aircraft management. Those were his own words, not mine ... and I have not researched him or his words. Just heard him say it over a pleasant lunch.

Posts like this from the Aviation Enthusiast Corner make me still wonder though:

"My Grandfather Walter Tydon who designed the P-40 wrote a book that I wish to publish. Hum, why is it that the P-40Q looks a lot like the Mustang or is it why does the Mustang look a lot like the P-40Q. Is the Mustang actually the XP-40 and the XP-40Q combined ?
Mark Lane
05/16/2006 @ 08:05 [ref: 13293]"

Came from Aircraft: Curtiss XP-40Q Warhawk

Haven't seen his book yet, but am still interested, though I am doing no active research on it at this time. I believe the XP-40Q, at least one or more, did have a laminar flow wing (at least I have seen this in print), but the subject is not very well covered in my references or in what I can find on the internet, and the details of the airfoil are not seemingly available as yet to me. If anyone knows the laminar airfoil used on the XP-4Q please post at least the airfoil number. Just becuase the XP-4Q had a laminar flow wing, it doesn't mean it was the same as the P-51 airfoil, as stated above in a couple of posts.

I don't claim it was the same since I have no data on it from the Curtiss side other than the engines used and the basic design details.

This stuff is interesting to me, but not overly so and I do not wish to argue about it any further. If the subject surfaces again, at least from me,it will be because some new information has come to light. You never know ... we even have a member who claims to have unearthed new information about the Ta-152 ... but it hasn't come to light yet either. So it is not inconceivable that new information about the connection or lack thereof might surface sometime.

Cheers.

 

[Shortround6]

Did the P-40 design go as far as it could go? Or was there any meat left for it go into production 1945?

The Army only bought the P-40 in the first place because it could be put into production and service quicker than another design ( by about a full year), being a re-engined P-36 it certainly didn't represent the latest and best thinking of 1939. By some point 1943 US Army training manuals were telling student Pilots that the P-40 was a good trainer/transition aircraft but that NO new squadrons or groups would be formed using P-40s. It was supplied to allied forces after this date and some planes were sent out to units as replacements even as many units as possible were re-equipped with other aircraft. The Continued production into 1944 was part of the Trumann Committee investigation into waste and fraud in WW II. Many of the last few hundred P-40s built went directly from the factory to the scrap yards.

 

[GregP]

The P-40 in the Doug Champlin Collection (noe defunct) was one that was flown from the assmbly line to storage. In 1989, the total time was only just over 40 flight hours.

 

[The Basket]

Instantly scrapped? Whole lotta nothing.

 

[GregP]

More like "surplus to war needs at the time." I believe the one Doug had was one of the last few off the line. At least that's what they said in their program. Either way, it was in rather pristine shape.

They're worth more than Mustangs these days because there are fewer available.

 

[wuzak]

I believe some Typhoons went to scrap from the production lines late in the war.

As for storage, sometimes the history of an individual Mosquito will read something like, "built by xxxxx, transferred to nn OTU then to storage then 1 year later allocated to NNN Squadron".

Also, if teh P-40Q design was done in 1940 why did they bother with P-40D, P40E, P-40F, P-40G, P-40K, P-40L, P-40M and P-40N?

 

[GregP]

Hi Wayne,

I don't maintain it WAS done in 1940.

I heard it was, and it never got management approval for development due to no government funds for it and no company funds for it would be allocated. The resulting XP-40Q was supposed to have used a lot of the original design elements adapted to the latest P-40 coming down the line.

Except for two people (Gen. Davey Allison and the grandson of the P-40 designer), I have never heard that anywhere else.

If true, then we COULD have had a better fighter much sooner. If not true, then it at leasts makes for interesting speculation that has been brought up by a man involved on P-40 display and with P-40 management and the grandson of the designer. Their pedigree makes me wonder pretty hard, especially after what was done to Jack Northrop after WWII by Defense Secretary Symington.

All Jack did was to refuse to sell his company to Consolidated and his government contracts were cancelled. If they could do that to a successful company, I believe that, during the war, anything went if it was deemed necessary to the war effort.

 

[drgondog]

I reserve the right to pass on what I hear about aircraft, companies, and the war from the people who were there. I will endeavor to make it clear that is what what was heard, not what I espouse. Hopefully that will suffice.

Nobody questions your 'Right'.

However, I don't think like Drgondog or Shortround ... I think like me. Nothing whatsoever wrong with the way they think at all ... insinuated or implied... and no insult intended, I simply think like me. Asking either to change their style of positing to match my own would doubtless have little result. The converse is likely, too and I don't lament that since their posts are usually enjoyable.

Thank you.

And no, General Davey Allison was not invloved in the design of either the P-40 or the P-51, but he was intimately invloved with demonstrating the P-40 and was very close to Curtiss aircraft management. Those were his own words, not mine ... and I have not researched him or his words. Just heard him say it over a pleasant lunch.

Define 'very close' and what that means to his intimate knowledge of the development of the XP-40Q or the data Curtiss sold to NAA? As a quoted source he could shed light on such questions - why don't you ask him?

Posts like this from the Aviation Enthusiast Corner make me still wonder though:

"My Grandfather Walter Tydon who designed the P-40 wrote a book that I wish to publish. Hum, why is it that the P-40Q looks a lot like the Mustang or is it why does the Mustang look a lot like the P-40Q. Is the Mustang actually the XP-40 and the XP-40Q combined ?
Mark Lane
05/16/2006 @ 08:05 [ref: 13293]"

Came from Aircraft: Curtiss XP-40Q Warhawk

Speculation? One possible reason is that Curtiss engineers did what good engineers do - namely imitate the best features or a superior competitive design, if possible. Having said that, it is possible that the design and implementation of the bubble canopy for the XP-40Q preceeded the modification of the P-51B to P-51D. The XP-51F started in Januray 1943 with bubble canopy design, the 10th P-51B-1 42-12102 per change order NA-106 dated May 1, 1943 to install a bubble canopy. The two P-51Bs 42-106539 and 540 were contracted for the bubble canopy plus six 50 cal modification in February, 1943. Conceptually, given the allocation of airframes, the XP-40Q, the XP-51F and XP-51D canopy design all started in about the same timeframe, but the first XP-40Q was the P-40K pulled around December 1942 to January 1943.

Of note is that the XP-40Q speed, despite being tested at weights below the Basic Weight of the P-51B/D (IIRC-memory, not fact) was stll slower significantly than the Mustang. Drag is cruel.

Haven't seen his book yet, but am still interested, though I am doing no active research on it at this time. I believe the XP-40Q, at least one or more, did have a laminar flow wing (at least I have seen this in print), but the subject is not very well covered in my references or in what I can find on the internet, and the details of the airfoil are not seemingly available as yet to me. If anyone knows the laminar airfoil used on the XP-4Q please post at least the airfoil number. Just becuase the XP-4Q had a laminar flow wing, it doesn't mean it was the same as the P-51 airfoil, as stated above in a couple of posts.

The P-51 laminar flow airfoil was NAA proprietary modification of 45-100. It was modified in part by first selecting pressure distribution they wanted with the airfoil thickness of choice, then iterating to get the leading edge design best suited to the laminar flow wing. GALCIT Report 284 "A cComparative Wind Tunnel Test of Two Airfoils for the North American NA-73X", September 20, 1940. The two airfoils tested were NACA 2300 series and the NAA 45-100.

Long story short, Curtiss should have attempted to copy the NAA 45-100 but the 65-000 series was published by 1943.

I don't claim it was the same since I have no data on it from the Curtiss side other than the engines used and the basic design details.

Good on ya - because there appears to be zero source data from Curtiss referncing the specific airfoil.

This stuff is interesting to me, but not overly so and I do not wish to argue about it any further. If the subject surfaces again, at least from me,it will be because some new information has come to light. You never know ... we even have a member who claims to have unearthed new information about the Ta-152 ... but it hasn't come to light yet either. So it is not inconceivable that new information about the connection or lack thereof might surface sometime.

Cheers.

Greg - the dispute was not your thinking style, which is beyond criticism. It was about facts in evidence and conclusions drawn anecdotally versus logically based on assembled facts long published and available for compliation.

EDIT http://www.wwiiaircraftperformance.org/P-40/P-40Q_42-9987_Eng-47-1660-A.pdf

The Gross weight at takeoff was 8203, implying that the 400mph stated in the report was after a climb to the critical altitude. If so, the run could have been made at ~ 8150 pounds with about 140 gallons of fuel. The report mentions neither guns nor ammo for the tests.

The P-51D at that weight would be the pilot, 94 pounds of oil, no ammo and about 30 gallons of fuel but full compliment of 6x 50 cal..

 

[GregP]

Hi Drgondog,

I was aware the P-51 wing was a 45-100 series but was not aware that it was a modified 45-100 since I have not researched the Mustang wing section. I appreciate the information. It may well be that there are no surviving data on the XP-4Q that are useful, but I'll keep my eyes open on the subject since I am interested.

To me, the P-40 was one of the fastest-rolling airframes in US WWII manufacture. The turning circle was decent if not great, and I believe that the XP-40Q markedly improved the basic P-40 and closely approached the P-51 for speed while probably still out-rolling it significantly. I have no data on turning circles and none on diving speed, flight test climb graphs, or other things that would allow a meaningful comparison with the P-51D, so I can't say what it was like to fly from anything other than speculation.

But historically, if the P-40 could make 420 mph and still retain its characteristics or maybe get better at turning and service celiling, it would have been a good thing ... at least for the P-40 fliers. I already stated that we probably made the right desision doing what we did, but I still believe the XP-40Q could have made a decent fighter, if 15 mph slower than the P-51 at the P-51's best altitude. I cannot say if the XP-40Q was slower than a P-51 at the XP-40Q's best altitude because I don' have the data to say it. All I have a a top speed of 422 mph without an altitude or power setting.

I would ask General Davey Allison if he were still alive. Alas, he passed away shortly after his visit to our shop. We toook pics and have one on the wall. His own words were that he often visited the Curtiss factory and knew most of the management quite well, and that they often had lunch when he was there. I have no method of checking his recollections and, while interested, am not interested enough to try to feret out any inconsistencies since there was so little detailed information passed along. He was pretty sure the preliminary XP-40Q innovations were on paper and shown to NAA, but did not elaborate as to why he thought that or what his source was.

His main subject at lunch was his demonstration to Chenault of the P-40B, He used greatly elevated manifold pressure to get sparkling performance out of it. Chennault reportedly told him hat he got more out of a P-40 than anbody else. If he used 75" of manifold pressure on an Allison C-15 engine as he said, that might explain why Chennault obtained P-40's. It was well over the approved boost level and would have made a good show.

Meanwhile, I have no proof of his claims, but appreciated hearing them over lunch.

Just for fun, here's my own side view of the XP-40Q:

View attachment 224440

 

[Deuelly]

NAA Received information from Curtiss about early P-40 developement testing not specifically the "Q" model. The NA-73 was based off of this information. Below are some documents that NAA received from Curtiss.

 

[drgondog]

NAA Received information from Curtiss about early P-40 developement testing not specifically the "Q" model. The NA-73 was based off of this information. Below are some documents that NAA received from Curtiss.
View attachment 224636
View attachment 224637

There is no evidence that any part of the NA-73X was derived from any data received from Curtiss. The data purchased from Curtiss was a.) purchased after May 1, and b.) approximately 30 days after Edgard Schmued completed the 3D, performance estimates and weights/balances package was in Dutch Kindleberger's hands by the end of March, 1940 when He took them to Britain to make his pitch with Sir Henry Self.

Just looking at the XP-46 gives you insight to the total divergence of NA-71X from any derivative of P-40 line until early to spring 1943 when the XP-40Q started with a P-40K airframe

 

[tomo pauk]

No doubt that I'd would like to see all of the remaining stuff

The plane at the picture looks more like a sibling of XP-37, with pilot seated so far aft. The fuel is to be between the engine and pilot? The vertical tail looks it would need more height surface in order to look like NAA fighter. Of course, the drawings of the wing (esp side elevation of the ribs, and spar fuel tank layout) and radiator installation. The main UC - fully or partially covered? The wing tips and tips of empenage parts are not 'square cut', a difference vs. NA-73.
The front part seems to house the C series (featuring the internal spur reduction gear) V-1710, not the F series (= external spur reduction gear, giving higher thrust line). The NA-73 was featuring F series engine.

 

[GregP]

Hi Duelly,

What information do you have that indicate the drawings you posted were used in the design of the NA-73 and what is the source?

I am of the opinion that they used the Curtiss data including the early drawings for what turned into the XP-40Q, but I have no concrete data to prove it ... just supposition that, rightfully, has been called into question by some members. So ... if you have some proof, please offer it or at least say why you posted what you did.

While Drgondog and I may disagree, his questions are spot on and should be supported or the thesis abandoned, at least in public, until such support documents are forthcoming. Stories can be believed or not, but documents that can be corroborated are hard to ignore. Can you help out here?

Thanks!

 

[Deuelly]

Sorry guys I'm new to this thread posting thing and may have let my opinion get in the way of fact. I'm working on a book, kind of a P-40Q in detail thing. I'm using the original P-40Q prints to redraw major structures of the aircraft as 3D models so I can use them for detail pictures. I'm concentrating on the structure aspect of it and not necessarily the would have could have part of it. Anyway, the pictures I posted are from my set of prints I use. From the Curtiss documents I've read though it seems that the information NAA receive wasn't a specific design but airfoil, drag, and structural layout data. Not really for any specific aircraft but things they may have been planning to incorperate into a future project or a P-40 change possibly. Sorry again guys for trying to inject my opinion without any real proof.

Just so you know I have the P-40Q prints I talked about here are a couple scans I've done.

 

[FLYBOYJ]

Just an observation...

There are many times that a "common" or "standard" part or assembly may be used on several different aircraft from the same manufacturer. I see the drawing scanned shows XP-40Q in the NHA/ model block (highlighted). The entries below that seem to show "P-40N" in the model block. If a manufacturer took the time to put together a "drawing tree" one might be able to see common parts and assemblies between two models of aircraft and how they relate to each other and may give an indication when the drawing was first developed. When I worked at Lockheed I used to see this all the time between the "Model 188 Electra" and the "Model 185/ 285" better known as the P-3. I also came across "standard parts" like a ICS foot switch that was common between the P-2 and P-3.

 

[drgondog]

Also Joe, one might note that the signature block (s) on the Drawing are 1943..

 

[FLYBOYJ]

Also Joe, one might note that the signature block (s) on the Drawing are 1943..

Yep - saw that too! I think that further validates your point Bill, at least looking at this very small example.

 

[FLYBOYJ]

I came across this earlier...

As early as 1938 Kindelberger had made numerous trips to Europe seeking orders for his company, and he had the opportunity to see up close some of the airplanes that would be in combat in the war that almost everyone believed would soon be coming. Once hostilities broke out, Kindelberger eagerly sought out combat reports from both sides and developed some ideas of his own.

Although Kindelberger had no experience with fighters, he collaborated with Atwood to formulate an outline for a fighter project. A project team was formed at NAA, made up of such people as Raymond H Rice, Edgar Schmued, Larry Waite, and Ed Horkey. (A sort-of urban legend had grown up about Edgar Schmued that claimed he had once worked for Willy Messerschmitt, and that the Mustang was heavily influenced by the Bf.109.)

Following the outbreak of war in Europe, the British Purchasing Commission, headed by Sir Henry Self, was posted to New York to determine if American combat aircraft could be of any use to the Royal Air Force. Bell P-39s and Curtiss P-40s were ordered in substantial numbers even though they were not up to the performance standards of the latest British and German fighters.

One of the corporations that Self had contacted was NAA, who had already been building NA-16 trainers for the RAF as the Harvard. In April of 1940 Kindelberger was requested to manufacture Curtiss P-40Ds under license for the RAF. He responded that NAA could do that, but countered that his company could build a better fighter than the P-40 and that they could design a REAL fighter in the same time that it would take to put the P-40 into production. The British commission felt that they could take Kindelberger at his word and, on Apr 10, 1940, accepted his proposal on the condition that the first prototype be ready in 120 days. The design was assigned the company project name of Model NA-73.

At that time, the USAAC reserved for itself the right to block any foreign aircraft sales that it regarded as not in the Army's interest for whatever reason. On May 4, 1940, the US Army reluctantly agreed not to block the British sale, but added a condition—two examples of the initial British NA-73 lot were to be transferred to the AAC for testing. free of charge.

The NA-73X prototype contract was signed on May 23, 1940. The British insisted that a heavy eight-gun armament be fitted. NAA had actually been quietly working on such a fighter project since the summer of 1939 and had already completed much of the detail design. On May 29 a provisional RAF procurement was issued for 320 aircraft, contingent on satisfactory testing of the prototype. NAA agreed to start deliveries in January 1941. RAF s/ns were issued [AG345/664] and the aircraft given the name Mustang I for RAF service.

Another urban legend surrounding the Mustang is that it owed a great deal to the Curtiss XP-46 and, in fact, stole numerous design features from that fighter. It is true that the British had insisted that since NAA had no fighter experience they should secure all current data from Curtiss about both the P-40 and XP-46. Although NAA did pay $56,000 to Curtiss for technical aerodynamic data for the XP-46, there was only a very broad resemblance between it and the NA-73X. The Curtiss shared only a similar radiator/oil-cooler configuration and did not have laminar-flow wings. In fact, development of XP-46 lagged behind that of NA-73X, with prototypes not ready for flight until Feb 1941.

As well, preliminary design of the NA-73X was completed before NAA gained access to the Curtiss material. It could even be argued that the XP-46 data was most useful to NAA in guiding them in what not to do. The NA-73X appears to owe virtually nothing to any previous fighter design. Nevertheless, despite convincing denials from both Edgar Schmued and aerodynamicist Horkey, the full magnitude of the contribution of Curtiss to the NA-73X design remains controversial to this day.

North American NA-73

 

[FLYBOYJ]

And caught this on "Wiki" for what it's worth...

A myth surrounding the origins of the P-51 Mustang is linked to the North American Aviation (NAA) purchase of test data on the P-40 and P-46. NAA paid $56,000 to Curtiss for technical aerodynamic data on the XP-46 and although there are certain design similarities in the radiator/oil-cooler configuration, the new NA-73X (the company designation for the future P-51) even in preliminary design had already progressed beyond the XP-46.[1] In addition, after the war, NAA engineers revealed that they had learned of a European study (before the US entry into World War II) which indicated the value of a well-designed embedded radiator, and were eager to apply that knowledge to a new design.

[1] Baugher, Joe. "North American NA-73." USAAC/USAAF/USAF Fighter and Pursuit Aircraft: North American P-51 Mustang, 29 August 1999. Retrieved: 10 August 2010.

 

[drgondog]

The absolute 'smoking gun' was that NAA, specifically Edgar Schmued, head of the NA-73X/Mustang Program did a detailed set of three view drawings, made weight and performance estimates and packaged them for Kindleberger before he went to the UK to present the 'new fighter' to Sir Henry Self. Ergo, the preliminary design was complete no later than March 31st, 1940.

The data (and whatever that means) purchased by NAA from Curtiss was bought in the first week of May, 1940 and there is no definitive date of arrival at NAA...

Summary -

1.) design outlines including 'Meridith concept' radiator, trapezoidal wing and tail, Allison 1710, inward folding landing gear had been analyzed and put to Vellum at least 30 days before anybody went to Curtiss to purchase any data in the Hands of Curtiss. The decision to put a laminar flow wing was close to fruition in May 1940. None of the P-40's or any data that could have been included in the May 1940 'package' could have Any Laminar flow data for any P-40 design to date. It is so far not even conclusive that the XP-40Q had a Laminar Flow wing.

2.) the NA-73X and future Mustang looks nothing like the P-40, or P-46, or even the XP-40Q except for the bubble canopy. Notably the NA-73X, P-51, P-51A, A-36 and P-51B/C did Not have a bubble canopy, so there certainly was no indication that the XP-40Q canopy concepts were used for nearly three years. History shows that the first prototype P-51D Mustang canopy design were in parallel to the XP-40Q design - so one might ask - "who was copying whom"?

3.) the XP-40Q, which did not start modification process from P-40K until February 1943, does not look like the P-51 in either radiator design (under wings a la Spitfire and Bf 109), landing gear design, tail design or planform for wing and horizontal stabilizer. On the other hand, the wing and tail of the XP-40Q looks like the P-40 and P-46 and all other Curtiss derivative single engine fighter.

If there is any connection remotely between the P-51 and the XP-40Q, one must presume that somehow NAA had a glimpse more than three years in the future, took the bubble canopy, and sat on it for three years.

Remember last of all. The airframe per se did not get significantly 'cleaned up' for the XP-40Q when they used the P-40K for the bones to perform the conversion... result - the airframe of the P-40Q, extremely light in flight test, with a much more powerful engine was ~13 mph faster than a P-51A with full combat load...