The P-38J and L in the European theater.

[drgondog]

I have seen this many times on this forum, I believe it stems first from a picture of a P-51D and an evaluation of its range, speed and altitude performance and all round handling qualities. It seems rational to conclude that it was designed to do that from the outset, but the fact is it wasn't.

The P-51B/D was the bastard stepchild of the P-51 Mustang airframe and the Packard Merlin 1650-3.

With the Allison it was a superb replacement to P-39 and P-40 in the low to middle altitude CAS, medium bomber escort role. With the Merlin it was all of those things from SL past 35,000 feet plus long range air superiority fighter.

Had the XP-51G entered serial production in Fall of 1944 it would have rivalled any piston engine interceptor and medium to long range escort fighter ever built. It would still have more range than P-38L/P-47D-25 on internal fuel alone but its combat radius would narrowly cover Berlin/Munich but not Iwo Jima/Tokyo.

 

[pbehn]

The P-51B/D was the bastard stepchild of the P-51 Mustang airframe and the Packard Merlin 1650-3.

With the Allison it was a superb replacement to P-39 and P-40 in the low to middle altitude CAS, medium bomber escort role. With the Merlin it was all of those things from SL past 35,000 feet plus long range air superiority fighter.

Had the XP-51G entered serial production in Fall of 1944 it would have rivalled any piston engine interceptor and medium to long range escort fighter ever built. It would still have more range than P-38L/P-47D-25 on internal fuel alone but its combat radius would narrowly cover Berlin/Munich but not Iwo Jima/Tokyo.

All very well dg but you must be wrong, I mean look at it, no way is that an accident of birth

Just joking, it is hard to believe though.

 

[Schweik]

Some examples of Phase Three please.

how about the first combat of the Bouton Paul Defiant

first combats of the F2A Buffalo in the Far East / CBI

first combats of the Bf 110 in Poland and France (successful!) and in the BoB (not successful and clearly needing redesign and / or a new role)

first combats of the P-38

first combats of the Ki 43

One of the things that happened a lot in phase 3 was they realized they needed to add a raft of things like more and better armor and fuel system protection, better high altitude capability (if they could figure that out) plumbing for external fuel tanks, more and better guns, more and better ammunition, better or improved radios, and etc. Sometimes they decided that the plane in question needed better turning or rolling capability and so added features like combat flaps. Sometimes they had problems which took a long time to figure out like the compressability / dive problems of the P-38.

Sometimes they figured out (often the hard way) that they needed to strengthen wings or fuselage

 

[drgondog]

I
["Schweik,]I think we are talking about two different things here, and this is kind of a big deal in aircraft development.

• Phase one is initial design and planning. Requirements issued by the government, companies come up with designs they think will match them.
• Phase two is the actual building and testing of the first few prototypes
• Phase 2.1 is evaluation and recommendation to the manufacturer for mandatory and desirable improvements
• Phase 2.5 is acknowledgment, discussion and Agreement to specific improvements
• Phase 2.7 is release of Y version meeting agreement (not always followed - NA-73 and P-47 are specific examples where production was authorized before testing improvements.
• Phase 2.8 is release of early production series to customer (ie BPC/RAF) to perform Operational Suitability Testing, which if accepted as is, leads to deployment to Training and operational units for training prior to combat
  
• Phase three is the introduction to the field and first contact with the enemy. Many aircraft never got past this stage.
• Phase 3.0 is recommendation for new mods, and/or decision that aircraft does not have a strong capability to accomplish projected role, but has value elsewhere (P-39, P-40 later models as P-38 and P-47 and P-51 are produced in numbers to gradually replace the operational aircraft and return the obsolete aircraft to lower threat environment (P-40K/N assigned to Air Training Command, P-39 also assigned to train units in States, P-63 deployed to ATC and Russia)
  
• Phase four is initial series production, teething, subsequent redesigns and improvements - this is when a given aircraft either becomes viable or gets cancelled. The aircraft is in production and gets used but may not yet be ideally suited for any job.
• Phase four as you presented is actually Phase 2.8 above
  
• Phase five is when - if the design is very successful - they start large-scale production and it gets into the field in significant numbers, and becomes one of the mainstays of the war.
• During WWII in US, your Phase five was eliminated before order placed for high quantity production - examples given include P-47B, P-51B which were contracted for production before first actual prototype flight.

In the above scenario, the P-40Q was not solicited by AAF - it was an investment, originally based on upgrading wing to low drag and introducing new Allison two stage supercharger to improve high altitude cability - but use an airframe for which tooling and processes (P-40K) existed and easily placed into production following acceptance testing and Agreement for serial production -

I'm talking about phases three and four. You guys are talking about phases one and two.

I'm talking about all except end of life cycle.

The design theories are often way, way off, and have to be radically rethought after they contact the enemy.

In many examples, the Specifiers were way off and the designers did a credible job of design/fab to spec. Where many designers failed in 1937-1942 was lack of awareness of drag rise at speeds above .5M and/or low drag airfoils which reduced high speed performance estimates to crap (specifically CW and Bell and even Douglas)

For the P-38 phase four lasted a long time. Two years arguably. For the mustang it also lasted about a year (however long the Allison Engined ones were in use). Others had a shorter

From Contract to 1st Operational combat sortie:
P-38 6-23-37 to 4-42
P-39 10-7-37 to 10-9-41
P-40 4-26-38 to 9-1940 (Russia)
P-47 9-6-1940 to 4-8-1943 (8th AF)
P-51 4-12-1940 to 5-10-1942 (RAF)
P-51B 8-25-1942 to 12-1-1943 (9th AF)

So, Schweik - you disagreed with my insertions and/or comments above to this postulation of your five phases of Design through serial production? What did you disagree with?

 

[GrauGeist]

There is also plenty of examples of aircraft that were designed and funded in house by an aircraft manufacturer with the hopes of landing a contract. Some were accepted outright, some were adapted/modified to meet a proposal and some fell short.

A few examples:
Lockheed's XP-58
Heinkel's He100
Curtiss' P-36 (Hawk 75)
Hawker's Typhoon
Seversky's SEV-3/P-35 (predecessor to the P-47)
Heinkel's He280
Focke-Wulf's Fw187

And so on...

 

[Schweik]

• Phase 2.7 is release of Y version meeting agreement (not always followed - NA-73 and P-47 are specific examples where production was authorized before testing improvements.
• Phase 2.8 is release of early production series to customer (ie BPC/RAF) to perform Operational Suitability Testing, which if accepted as is, leads to deployment to Training and operational units for training prior to combat

This is a confused muddle of specific US and RAF processes all of which fall under 'phase two'

(P-40K/N assigned to Air Training Command, P-39 also assigned to train units in States, P-63 deployed to ATC and Russia)

P-40K was one of the most successful P-40 variants and in wide / heavy combat use with the RAF, RAAF, Soviets, US 57th FG in the MTO, and 23rd, 51st, and 80th FG in the CBI. There were more aces flying the P-40K than P-38E or F for example.

P-63 was designed for the Russians with direct Russian involvement. It was changed after early combat experiences per their request.

Phase four as you presented is actually Phase 2.8 above

Actually no, you completely missed the point - very often aircraft made it through all the testing and acceptance phases, got into combat and were found to be extremely unsuitable for the intended mission when faced with actual enemy aircraft. Example I cited above such as the Defiant, the F2A and Me 110 were either quickly phased out or given a new mission (Me 110 converted to night fighter) or like the Ki-43, they were 'sent back to the drawing board' with fairly significant changes made.

During WWII in US, your Phase five was eliminated before order placed for high quantity production - examples given include P-47B, P-51B which were contracted for production before first actual prototype flight.

Yes and quite often production orders were immediately cancelled or drastically reduced as soon as the aircraft got into combat. For example the USAAF ordered 80 P-43s, but as soon as early models did poorly in Europe they cancelled the order and Seversky went back to the drawing board, ultimately leading to the P-47.

Perhaps a more salient example, the Luftwaffe put in an order for 1,000 Me 210 before they were even flown. But all the numerous problems led to a drastic reduction in that order and only 90 were made. Ultimately they kept modifying them until they came up with the Me 410 (a bit too late)

In many examples, the Specifiers were way off and the designers did a credible job of design/fab to spec. Where many designers

Ultimately it was kind of irrelevant if the problems were with the specs or the actual design or both (usually it was both). Corporate and military bureaucracy rarely predicted or implemented the design for the the actual needs well, let alone perfectly.

P-40 4-26-38 to 9-1940 (Russia)
P-47 9-6-1940 to 4-8-1943 (8th AF)
P-51 4-12-1940 to 5-10-1942 (RAF)
P-51B 8-25-1942 to 12-1-1943 (9th AF)

P-40 flew in combat in 1940? That's news to me. I think it would be a neat trick considering the first ones arrived in Russia in August and September 1941 (from English and US sources respectively) according to this article

Allison P-51 continued to be 'modded' long after may 1942

P-47 had a particularly long teething as mentioned re: the P-43 above.

S

 

[Schweik]

So, Schweik - you disagreed with my insertions and/or comments above to this postulation of your five phases of Design through serial production? What did you disagree with?

I think you are talking much more about the official design and acceptance process, where I'm talking more about what happens after the design encounters reality and the scramble to change it sufficiently to survive combat (often requiring they find some other role for it).

Fairy Fulmar made it through design and acceptance trials and then faced combat, where they quickly realized it was more suitable for recon than actual fighting. I think it was basically the same for the P-51A (also used as a dive bomber).

Also, to me it makes no difference to me if it was a private venture by the company, a side deal for some foreign government, or part of a formal proposal by their own government. Thats all part of the design and acceptance phase to me.

 

[pbehn]

Regardless of the design the engine had to gain an average of 200BHP per year from 1940 to 45 ending at 2000+. Similar improvements had to be made in drag reduction, armament protection drag reduction etc. Some base designs could be modified some couldnt

 

[Milosh]

For example the USAAF ordered 80 P-43s, but as soon as early models did poorly in Europe they cancelled the order

The P-43 was sent to Europe?

 

[Schweik]

Regardless of the design the engine had to gain an average of 200BHP per year from 1940 to 45 ending at 2000+. Similar improvements had to be made in drag reduction, armament protection drag reduction etc. Some base designs could be modified some couldnt

Sure but if it was as simple as putting more horsepower in the Fairey Firefly and the Helldiver would have been great planes, and the Fairey Spearfish and the Douglas Skypirate would have been legends...

S

 

[P-39 Expert]

Sure but if it was as simple as putting more horsepower in the Fairey Firefly and the Helldiver would have been great planes, and the Fairey Spearfish and the Douglas Skypirate would have been legends...

S

Enough horsepower and you will definitely become a legend.

 

[Schweik]

The P-43 was sent to Europe?

Sorry typo - should have said CBI

 

[Schweik]

Speaking of legendary amounts of horsepower, can somebody explain why they didn't use the F7F in WW2? 4200 hp is pretty sweet. nice looking design too unlike a lot of others late-war one-offs.

They had them in 1944 right? Climb rate is phenomenal. Celing 40,000 ft. Even wing loading is pretty good for a twin engined fighter.


Grumman F7F Tigercat - Wikipedia

 

[pbehn]

Sure but if it was as simple as putting more horsepower in the Fairey Firefly and the Helldiver would have been great planes, and the Fairey Spearfish and the Douglas Skypirate would have been legends...

S

They wouldn't because the war was over when the Spearfish first flew, they certainly would if they were in service in 1941.

 

[Schweik]

They wouldn't because the war was over when the Spearfish first flew, they certainly would if they were in service in 1941.

Ok I got to admit, I'm a little disappointed you didn't follow that. Well let me put it this way. Which aircraft do you think got more victories against Axis aircraft:

Fairey Firefly (1,730 hp)
Hawker Typhoon (2,180 hp)
Yak 3 (1,300 hp)

Also Spearfish first flight July 1945 end of war Sept 1945. I know that isn't long enough to get into combat but your literal statement was wrong breh.

 

[pbehn]

Ok I got to admit, I'm a little disappointed you didn't follow that. Well let me put it this way. Which aircraft do you think got more victories against Axis aircraft:

Fairey Firefly (1,730 hp)
Hawker Typhoon (2,180 hp)
Yak 3 (1,300 hp)

Also Spearfish first flight July 1945 end of war Sept 1945. I know that isn't long enough to get into combat but your literal statement was wrong breh.

Which had the most victories in 1939/40 Hurricane or P-51?

 

[pbehn]

Speaking of legendary amounts of horsepower, can somebody explain why they didn't use the F7F in WW2? 4200 hp is pretty sweet. nice looking design too unlike a lot of others late-war one-offs.

View attachment 500544

View attachment 500545

They had them in 1944 right? Climb rate is phenomenal. Celing 40,000 ft. Even wing loading is pretty good for a twin engined fighter.


Grumman F7F Tigercat - Wikipedia

Read the link you provided.

 

[GrauGeist]

Yes and quite often production orders were immediately cancelled or drastically reduced as soon as the aircraft got into combat. For example the USAAF ordered 80 P-43s, but as soon as early models did poorly in Europe they cancelled the order and Seversky went back to the drawing board, ultimately leading to the P-47.

It only performed poorly in the hands of Chinese pilots.
Pilots of the AVG wanted to retain their P-43s after newer types were becoming available.
The USAAC liked the performance of the P-43, but felt it was overall obsolete BUT ended up placing an order for the P-43 to keep Republic's assembly line going until the P-47 became available (which was under development and nearing acceptance). The aircraft purchased were intended to be trainers from the start.

Also, the P-43 was one of the few Allied types that could climb fast enough and high enough to intercept and dow the KI-46.

 

[fubar57]

The F7F design contained several flaws (including heavy weight and high landing speed) that prevented the Navy from accepting the plane for carrier use. I guess being a Navy aircraft they wanted to work out the bugs first. It went to Marine units instead but the war ended before it's use

 

[Milosh]

Sorry typo - should have said CBI

That is a brain fart. A typo would be "P-40 4-26-38 to 9-1940 (Russia)" where 1940 should be 1941.