Why didn't the army develop the P-51?

[Balljoint]

Just my take from a number of sources that I can't document, but I believe the P-51's slow acceptance was a lack of mission. Specifically, the bomber generals, particularly Arnold, were of the Mitchell, Douhet school that the bombers would get through and self-defend. They resisted the concept of a long-range escort plane on the basis that it was an impossible objective for an interceptor fighter plane and it would divert resources from bomber building. Only after the Big Week debacle, pressure from Eisenhower and fresh thinking in view of the bloody and failing strategic bombing campaign was the need for a long-range escort plane recognized whereupon the ugly duckling P-51 rather quickly came into its own.

Any other mission for the P-51 would not have been nearly as compelling. Arnold did take the blame for the delayed development.

 

[oldcrowcv63]

I believe the P-51's slow acceptance was a lack of mission. "...failing strategic bombing campaign was the need for a long-range escort plane recognized whereupon the ugly duckling P-51 rather quickly came into its own."

Any other mission for the P-51 would not have been nearly as compelling. Arnold did take the blame for the delayed development.

My interest in the early history of the type stemmed from the Mustang I's unrealized potential as an interceptor in the PTO (see Midway P-51 thread on this topic). The application of the P-40E to the interceptor mission, was already discredited by the USAAF pilots and their commanders. They had first hand knowledge of its inadequacy but apparently, being in the field, little awareness of possible alternatives. Realistically (and there is little realism in this line of thought), I can't see Colonel Harold George sending a telegram to Hap Arnold saying "Send us as many of the NAA Mustang I as you can and in exchange, give the RAF all the P-40s you plan to send us." By all accounts, no one would have appreciated the attributes of the Mustang I more than he.

The P-38 was evolving too slowly to meet the immediate need for nearly a year. I am not sure of the status of the P-47 in December 1941 but the Mustang I was being produced in numbers at the right time. The main issue delaying its PTO use was resolving the issue of national ownership and then subsequent unit training. In the most optimistic circumstances (obviously not the most realistic, just "what if...") the realization of the need to acquire the aircraft contracted by the RAF didn't arise until late December, 1941 at the earliest. By the time a unit was trained in late Spring, 1942, those who might benefit most had either surrendered or retired to Australia to struggle on with the P-40E without the immediate threat of invasion. They were evidently able to achieve a bit more success in the interceptor role, overcoming the limitations of the Curtiss fighter by methods that are as yet a bit unclear. Within a couple of months the F4F-4 and P-38s had arrived and the crisis was abating.

I am curious about your post that Arnold took the blame. Do you happen to have a reference. That should make interesting reading.

 

[davebender]

Without the benefit of hindsight 1941 U.S. Army Air Corps have no way to know P-51 development would have far fewer problems then P-38. We bet on the high altitude aircraft which looked best at the time and lost.

 

[Shortround6]

Republic had submitted the "idea" for the XP-47B in June of 1940. Army was impressed enough that over 700 were ordered "off the drawing board" Sept 13 1940. 1st prototype flew on May 6th 1941. 2nd Prototype/first production plane flew Dec 21 1941. Next four 'production planes rolled out In March of 1942, but the "B" model was used either entirely in the US for training or only a handful went over seas. Accounts vary. Last of the 171 "B"S was delivered in Sept 1942. an awful lot of early problems with the early ones.

 

[Balljoint]

My interest in the early history of the type stemmed from the Mustang I's unrealized potential as an interceptor in the PTO (see Midway P-51 thread on this topic). The application of the P-40E to the interceptor mission, was already discredited by the USAAF pilots and their commanders. They had first hand knowledge of its inadequacy but apparently, being in the field, little awareness of possible alternatives. Realistically (and there is little realism in this line of thought), I can't see Colonel Harold George sending a telegram to Hap Arnold saying "Send us as many of the NAA Mustang I as you can and in exchange, give the RAF all the P-40s you plan to send us." By all accounts, no one would have appreciated the attributes of the Mustang I more than he.

The P-38 was evolving too slowly to meet the immediate need for nearly a year. I am not sure of the status of the P-47 in December 1941 but the Mustang I was being produced in numbers at the right time. The main issue delaying its PTO use was resolving the issue of national ownership and then subsequent unit training. In the most optimistic circumstances (obviously not the most realistic, just "what if...") the realization of the need to acquire the aircraft contracted by the RAF didn't arise until late December, 1941 at the earliest. By the time a unit was trained in late Spring, 1942, those who might benefit most had either surrendered or retired to Australia to struggle on with the P-40E without the immediate threat of invasion. They were evidently able to achieve a bit more success in the interceptor role, overcoming the limitations of the Curtiss fighter by methods that are as yet a bit unclear. Within a couple of months the F4F-4 and P-38s had arrived and the crisis was abating.



I am curious about your post that Arnold took the blame. Do you happen to have a reference. That should make interesting reading.

Again in generalities –hopefully generally sound-, the PTO was second fiddle under the US and British strategic planning. The USN was the primary rather feeble shield against the real threat of invasion of Australia. Rather miraculously, Coral Sea, Midway and Guadalcanal blunted the invasion threat and, I believe, gets to the question of interceptor aircraft to ward off the Japanese bombing of Australian cities.

To my mind there were two problems. There was little early warning of the raids. And the Japanese bomber and escort flew at very high altitudes. Not only were the P-40s ineffective, but the quintessential interceptor, the Spitfire, was also rather useless while in a hard climb with the Zeros having the vertical advantage. Other than perhaps having somewhat better dive performance to disengage, I don't see that the P-51A would have matched the Spitfire performance.

As to Arnold, Eaker realized the need for long range escort about mid-1943. However, Arnold stayed old school and blamed the bombing groups for lack of aggressiveness. Eaker was replaced and, finally under Eisenhower's demands, the P-51B was brought to bear. While I think that Arnold publicly recognized the rather substantial losses the delay caused, all I can find is Arnold's statement that it "…was the Air Force's own fault…" that the P-51 wasn't developed as a long-range escort earlier. This statement can be found in Arnold's Google write up and in Donald R. Miller's Masters of the Air. Perhaps the more direct apology is my mental addendum of what he should have said.

 

[oldcrowcv63]

Again ...the PTO was second fiddle under the US and British strategic planning.

Historically, this seems to be the most commonly presented theme. However I think the real evidence of that prioritization comes a bit later like late 1942 starting with Torch. My understanding is that from December 1941 thru October 1942 (a bit longer than the time period with which I am most concerned and addressing), US troops and sailors were primarily engaged (fighting and dying in the greatest numbers) in the PTO. Moreover, PTO was the theater where the nation had the war forced upon its citizens. So there was an emotional dimension to a political reality. Strategically, the prioritization was European victory first. Politically, there is a fair amount of evidence that both the military and civil leadership were pandering to the public and acting in ways to present the PTO as the primary theater. Its a tangled period, but I think you are responding in the stratosphere (looking at the big picture) and I am down in the weeds. (looking at very local and very time specific events).

The USN was the primary rather feeble shield against the real threat of invasion of Australia. Rather miraculously, Coral Sea, Midway and Guadalcanal blunted the invasion threat and, I believe, gets to the question of interceptor aircraft to ward off the Japanese bombing of Australian cities.

Pretty much historically true, although I believe the reality of the invasion threat is debated by historians. I think there was some IJA consideration given to occupying the northern reaches of Oz, but ultimately dismissed as beyond the capability of the army to support and not a part of their original Phase 1 plan. I'd defer here to someone who has spent a lot more time reading and thinking about the Australia invasion threat. They inhabit the forum and, if we are lucky, one may weigh in.

However, it was the P-40Es of the FEAF defending the PI and those of 17th PPS in Java and the 49th Fighter Group's three squadrons that were dedicated to the defense of Darwin during the IJ raids from early December 1941 through September, 1942 that are the focus of my interest. During that period, the USAAF P-40Es fought their own isolated war against the raiding IJ aerial forces. From about February 1942 on, the USN was essentially guarding the Australian Eastern flank during the Spring and then later caught up in the Watchtower offensive.

To my mind there were two problems. There was little early warning of the raids. And the Japanese bomber and escort flew at very high altitudes. Not only were the P-40s ineffective, but the quintessential interceptor, the Spitfire, was also rather useless while in a hard climb with the Zeros having the vertical advantage. Other than perhaps having somewhat better dive performance to disengage, I don't see that the P-51A would have matched the Spitfire performance.

I think your second point is the most important. I won't address the problems the Spitfires had with the A6Ms over Darwin in 1943. that was much later and I expect that was not related to early warning, operational ceiling or time to climb to interception altitude.

The US built SCR-270 Radar station 31 operated by the RAAF at Dripstone Cliff north of Darwin was installed in march 1942 and was the same type used at PH, On Luzon, and on Midway. It typically provided about 100 miles of early warning of a high altitude aerial raid. that's about a half hour warning IIRC, even on Java, where the warning was by a sophisticated spotter system, the advance warning was about 30 minutes. A half hour is about the time it took for an alert P-40E to climb to its highest, but sadly insufficient altitude under optimal circumstances. Hoping to improve its interception capability the fighter group took to operating standing CAP patrols over Darwin. However, the best the P-40E could do in the tropics was ~27k'. I believe the evidence suggests the amount of warning time was not the key issue but maximum ceiling was.

The F4F-4 not only had the ceiling, it had both the SCR-270 on Guadalcanal and the outlying coast watchers to provide more than 30 minutes warning. The F4F-4 took awhile to get there but it could reach altitudes in excess of 30,000 ft. The Mustang I (XP-51, NOT the P-51A) was simply better than the P-40. had a higher ceiling, faster climb rate and generally faster in level flight. Of course the P-38 was a true high altitude, high-performance interceptor.

As to Arnold, Eaker realized the need for long range escort about mid-1943. However, Arnold stayed old school and blamed the bombing groups for lack of aggressiveness. Eaker was replaced and, finally under Eisenhower's demands, the P-51B was brought to bear. While I think that Arnold publicly recognized the rather substantial losses the delay caused, all I can find is Arnold's statement that it "… was the Air Force's own fault…" that the P-51 wasn't developed as a long-range escort earlier. This statement can be found in Arnold's Google write up and in Donald R. Miller's Masters of the Air. Perhaps the more direct apology is my mental addendum of what he should have said.

I would characterize it as Air force leadership at fault, but then other air force leadership also saved it and brought it to fruition so I guess it evens out.

 

[nuuumannn]

I wonder whether this early comment by RAF test pilots is correctly dated? In the previous post, tests at Boscombe Down commenced in January 1942.

The date of the test is correct; it was done at Liverpool Speke where the Mustangs were assembled and readied for service after arrival in the UK. From there the first were allocated to 26 Sqn in January 1942.

the realization of the need to acquire the aircraft contracted by the RAF didn't arise until late December, 1941 at the earliest.

This is the crux of the matter regarding the British; they were at war and there was definite need for more aeroplanes. Since the Mustang was being built for the British at the time, I'm not sure that too many diversions from the original contract would have been tolerated, even though some were diverted to the USAAF.

Part of the issue with asking why the Mustang wasn't taken up by the uSAAC/F sooner than it was is that in the early days (early - mid 1941), we have to know what was actually known about the aircraft and by whom within the USAAF. As most of us know, in peacetime military, the left hand doesn't always know what the right hand is doing. You're right Oldcrow, there probably was a bit of lobbying going on, but the fact that the Mustang was a 'British' machine would have been something of an obstacle to any acquring of the type. Even later on once the first Mustangs got to the UK, information on its performance and capabilities by the squadrons that operated them would have gone through the British Air Attache in Washington, from which the information would have been further distributed.

I'm inclined to agree with the suggestion that things moved as fast as they could in peacetime, because once the evidence began piling up that a Merlin powered Mustang was going to be a winner, things on both sides of the Atlantic clipped along, particularly with NAA, Packard and RR, pretty swiftly also as a result of entry into the war; although the USAAF was going a little slower, as we know.

 

[Conslaw]

OldCrow, I suspect your hypothesis is correct that the Army could have and should have moved faster in evaluating the initial prototype NA-73 that they received. Another issue would be whether North American Aviation had the capability of ramping up another large scale production operation in 1940-1941. North American was a rather new company at that time, and it was already knee deep in ramping up the AT-6/SNJ and the B-25. Arguably, the AT-6 was the most important plane In the Army Air Force in 1941 due to the need to train huge quantities of pilots.

 

[oldcrowcv63]

OldCrow, I suspect your hypothesis is correct that the Army could have and should have moved faster in evaluating the initial prototype NA-73 that they received. Another issue would be whether North American Aviation had the capability of ramping up another large scale production operation in 1940-1941. North American was a rather new company at that time, and it was already knee deep in ramping up the AT-6/SNJ and the B-25. Arguably, the AT-6 was the most important plane In the Army Air Force in 1941 due to the need to train huge quantities of pilots.

I agree, opening another production line for the USAAF was probably out of the question for NAA. As drgondog indicated, that's why the order of 500 units for the USAAF was so important to subsequent events by giving the means whereby NAA could grow into a USAAF production line.

The date of the test is correct; it was done at Liverpool Speke where the Mustangs were assembled and readied for service after arrival in the UK. From there the first were allocated to 26 Sqn in January 1942.

This is the crux of the matter regarding the British; they were at war and there was definite need for more aeroplanes Since the Mustang was being built for the British at the time, I'm not sure that too many diversions from the original contract would have been tolerated, even though some were diverted to the USAAF.

Part of the issue with asking why the Mustang wasn't taken up by the uSAAC/F sooner than it was is that in the early days (early - mid 1941), we have to know what was actually known about the aircraft and by whom within the USAAF. As most of us know, in peacetime military, the left hand doesn't always know what the right hand is doing. You're right Oldcrow, there probably was a bit of lobbying going on, but the fact that the Mustang was a 'British' machine would have been something of an obstacle to any acquring of the type. Even later on once the first Mustangs got to the UK, information on its performance and capabilities by the squadrons that operated them would have gone through the British Air Attache in Washington, from which the information would have been further distributed.

I'm inclined to agree with the suggestion that things moved as fast as they could in peacetime, because once the evidence began piling up that a Merlin powered Mustang was going to be a winner, things on both sides of the Atlantic clipped along, particularly with NAA, Packard and RR, pretty swiftly also as a result of entry into the war; although the USAAF was going a little slower, as we know.

Considering how pilots love to talk about their airplanes, I'd guess that word spread more quickly in back channels and the brass was behind the power curve on knowledge of the Mustang I's performance.

With respect to the issue of national ownership, I expect everyone weighing in on this aspect has a good point but consider: The USAAF was ultimately defending Darwin, Australia and to some extent doing its best to protect Commonwealth interests in the Pacific whether intentionally or otherwise. I can see a case to be made that the order could have been filled by exchanging P-40Es for Mustang Is, or more realistically, sending RAF trained Mustang I units to protect Oz, or alternatively; train an RAAF Mustang I unit and send it. Wait! Those are probably the least realistic options! Ouch! I may have poured salt on old wounds.

Did RAF Mustang I units every deploy overseas to commonwealth countries? CBI?

 

[Shortround6]

It takes time to ship aircraft and units, time to train units.
While the First Mustangs arrive in Britain in the fall of 1941 (5 by Nov 11) it is not until April that #2 squadron gets it's Mustangs (assembly, testing, writing manuals, both flight and service/maintenance take a lot of time for the first squadron) First combat op is May 10th, a flight just across the Channel. July 27th sees 16 Mustangs form #2 squadron do a fighter sweep over the Ruhr.

Now how long will it take to send #2 squadron to Australia? Get the planes ready for travel by ship, get them to Australia, re-erect them, flight test and deploy to Air fields?

Send pilots and key ground personnel by air and send NEW planes for US to Australia?

Issue Mustangs to a US unit in the Spring of 1942, train, write manuals, deploy to Australia?

Granted the P-47 had a lot more teething problems than the Mustang but the 56th fighter group got it's first P-47s in June of 1942, it was not declared operational (in the US) until Nov. The Personnel sail for England on the Queen Mary Jan 6 1943, they will get new planes in England. In Jan 1943 the plan is to have the 4th fighter group, converting from Spitfires, operational by March 1st. The 56th fighter group operational 2 weeks later and the 78th fighter group, converted from P-38s ( with all it's planes and most pilots having been sent to North Africa) operational by the end of March.

The Mustang had a lot fewer teething problems but it takes time to go from factory door to an 'operational' combat squadron.

No matter what you do you are not going to get an operational squadron/group of Mustangs into the Pacific until mid summer or fall of 1942. It would be highly unlikely than a full group of Mustangs could have been available to meet the June 16th Darwin raid even with the best of efforts. Planning for a such a deployment would have had to been started in Jan/Feb.

 

[drgondog]

Only after the Big Week debacle, pressure from Eisenhower and fresh thinking in view of the bloody and failing strategic bombing campaign was the need for a long-range escort plane recognized whereupon the ugly duckling P-51 rather quickly came into its own.

Any other mission for the P-51 would not have been nearly as compelling. Arnold did take the blame for the delayed development.

During Big Week two P-51B equipped fighter groups (354 and 357) were in the thick of it. They destroyed 64.5 in the air compared to 10 (P-38 55, and 20), and 78 (4,56,78,352,353,355,356,358,359,361,362 FG) P-47

Eaker was well aware of the need for long range escort in 1942, and already had the 1st, 14th, 78th and 82nd FG equipped with P-38s arriving in England July -October, 1942. All but the 78th were transferred to Africa and the 78th lost all their P-38s to Africa also.

When reading the various biographies of Eaker, Spaatz and Arnold it is clear that while the mantra "the bombers can get through" of the Bomber Mafia existed, it is equally true that they knew by early 1943 that the need for long range escort was there in the ETO but equally, they also knew the PTO and MTO had the existing pipeline for P-38s.

Tommy Hitchcock had serious connections in the AAF inner circles and through him the promise of the RAF experiments surfaced to Arnold in spring 1942. I have yet to find the precise time that Arnold was truly 'aware' of the P-51 but believe he understood the early RAF acceptance testing results in July-August 1941 in the States indicating a 'good fighter'. Having said that nothing in particular separated it from the P-47 or P-38 or any of the avalanche of fighter designs flooding Wright Pat in late 1941.

The combination of Hitchcock, the RAF mods with the Merlin, the first thorough test results for the Allison XP-51 at Wright Pat - all entered his zone at about the same time and he finally initiated a series of actions ranging from finding money in the dive bomber program for the A-36, which in turn funded a full blown tooling and production line at Inglewood for the P-51, and helped NAA with the P-51B acceleration.

Colonel (soon to be General) Wolfe was directed to step up the P-51 testing. Wolfe can be somewhat excused as he was dominantly focused on the B-29 program and would soon be promoted and dispatched to CBI to command the first B-29 force.

As to OldCrow comments about possible political interference? I don't have a strong opinion one way or the other. I lean to the theory of a.) too many balls in the air as far as new ships (P-38, P-47) and many new prototypes in process, b.) NAA underfunded to invest in the P-51 other than to fulfill the RAF contract, c.) the timing of the arrival of the XP-51 which was the second XP-51. The first was damaged and took time to repair. Had the first one been delivered in say, July 1941 when the RAF acceptance flights were scheduled then who knows what might have happened relative to priority and command muscle assigned to flight test.

IMO, the REAL fire was lit due to two lines of circumstance. First, the RAF commitment and preliminary estimates of performance for the Merlin P-51. Second, Colonel Tommy Hitchcock's personal excitement and interest in the project to the extent that he drew upon all his many political connections to 'Take a look at This' in the spring of 1942.

As a sideline, one of the things that Probably got Eaker 'promoted' to the MTO was his disagreement over basic philosophy of 'close escort' versus 'aggressive escort' in the pursuit of the Luftwaffe. Monk Hunter was of similar philosophy and 'promoted to Wright Pat', to be replaced by Kepner as head of 8th FC. Nobody believed POINTBLANK objectives to destroy the Luftwaffe prior to the Invasion was going to happen with tethered fighters.

 

[Balljoint]

However, it was the P-40Es of the FEAF defending the PI and those of 17th PPS in Java and the 49th Fighter Group's three squadrons that were dedicated to the defense of Darwin during the IJ raids from early December 1941 through September, 1942 that are the focus of my interest. During that period, the USAAF P-40Es fought their own isolated war against the raiding IJ aerial forces. From about February 1942 on, the USN was essentially guarding the Australian Eastern flank during the Spring and then later caught up in the Watchtower offensive.



I think your second point is the most important. I won't address the problems the Spitfires had with the A6Ms over Darwin in 1943. that was much later and I expect that was not related to early warning, operational ceiling or time to climb to interception altitude.

The US built SCR-270 Radar station 31 operated by the RAAF at Dripstone Cliff north of Darwin was installed in march 1942 and was the same type used at PH, On Luzon, and on Midway. It typically provided about 100 miles of early warning of a high altitude aerial raid. that's about a half hour warning IIRC, even on Java, where the warning was by a sophisticated spotter system, the advance warning was about 30 minutes. A half hour is about the time it took for an alert P-40E to climb to its highest, but sadly insufficient altitude under optimal circumstances. Hoping to improve its interception capability the fighter group took to operating standing CAP patrols over Darwin. However, the best the P-40E could do in the tropics was ~27k'. I believe the evidence suggests the amount of warning time was not the key issue but maximum ceiling was.

The F4F-4 not only had the ceiling, it had both the SCR-270 on Guadalcanal and the outlying coast watchers to provide more than 30 minutes warning. The F4F-4 took awhile to get there but it could reach altitudes in excess of 30,000 ft. The Mustang I (XP-51, NOT the P-51A) was simply better than the P-40. had a higher ceiling, faster climb rate and generally faster in level flight. Of course the P-38 was a true high altitude, high-performance interceptor.

I agree that the P-40s were not the optimal choice as a high altitude interceptor. However, there were better choices for this role than the "Mustang" in my opinion. I cited the P-51A as the most likely to be available during December, 1941 and September 1942. The XP-51 was clearly a superior plane, but it had the advantage of a Merlin 61 which only became available about March of 1942. Even in 1943 the Spitfire VCs in Australia were using the less desirable, with regard to altitude, Merlin 45. Actually, in terms of high-altitude interceptor performance, I would cite Merlin development as the pacing item. And with regard to airframes, the lighter Spitfire with its better RoC wing would be the better interceptor for a given Merlin relative to the generic Mustang.

During the subject time span, neither the US nor Britain had the capacity to supply airframes other than at the expense of some other airframe choice. And both with regard to volume and evolution the Merlin was a challenge. In this environment, mating a high-altitude Merlin to a Mustang airframe during early 1942 makes as much sense as configuring the aerodynamically advanced Mustang with its liquid cooled engine as a CAS iteration. But at least the V-1710s were available.

 

[pinsog]

I agree that the P-40s were not the optimal choice as a high altitude interceptor. However, there were better choices for this role than the "Mustang" in my opinion. I cited the P-51A as the most likely to be available during December, 1941 and September 1942. The XP-51 was clearly a superior plane, but it had the advantage of a Merlin 61 which only became available about March of 1942. Even in 1943 the Spitfire VCs in Australia were using the less desirable, with regard to altitude, Merlin 45. Actually, in terms of high-altitude interceptor performance, I would cite Merlin development as the pacing item. And with regard to airframes, the lighter Spitfire with its better RoC wing would be the better interceptor for a given Merlin relative to the generic Mustang.

During the subject time span, neither the US nor Britain had the capacity to supply airframes other than at the expense of some other airframe choice. And both with regard to volume and evolution the Merlin was a challenge. In this environment, mating a high-altitude Merlin to a Mustang airframe during early 1942 makes as much sense as configuring the aerodynamically advanced Mustang with its liquid cooled engine as a CAS iteration. But at least the V-1710s were available.

RoC shouldn't have been an issue in this particular role, the Mustang should have had plenty of time to climb up to that altitude and once it is at or above the enemy's altitude, its speed advantage would have been its trump card. Zoom and Boom, never slow down, never turn, just dive, hit the bombers, zoom climb back up and do it again.

 

[VBF-13]

I don't know about engines or any of that. But I think this is a good question and I think the P51s could have been put to good use in the PTO had we had the mind to it.

 

[oldcrowcv63]

There are few things more disconcerting in this forum than getting a reality check from Shortround6. Yes, there are certainly others here who have equal insight into the realities of the winged world and can singe the tail feathers of the most exuberant, highest flying conceptual fowl. But his inevitably carry the weight of detail and solid reference-validated research that can only be respected and absorbed.

When faced with such a learned and detailed critique, I submit there is only one suitable response: "Shortround6, I reject your reality and substitute my own."

In the spirit of davparl's post #53 in the thread: "Could the P51A been made available for the Battle of Midway?". If the stars were perfectly aligned and the most efficacious, enabling decisions were made at every calendar-page turn (circumstances that virtually never happen in the real world), might an operational unit have been in Australia sometime around the June/July/August 1942 time frame.

I am NOT saying it was a blunder on the part of any military leadership that such an event DIDN'T happen. I am resigned to the perspective that events worked out about as well as they could, all things considered. After all, we do live in "the best of all possible worlds"....

It takes time to ship aircraft and units, time to train units.

Absolutely!

While the First Mustangs arrive in Britain in the fall of 1941 (5 by Nov 11) it is not until April that #2 squadron gets it's Mustangs (assembly, testing, writing manuals, both flight and service/maintenance take a lot of time for the first squadron) First combat op is May 10th, a flight just across the Channel. July 27th sees 16 Mustangs form #2 squadron do a fighter sweep over the Ruhr.

Rather than defer to your example of the P-47 time line which may indeed be closer to the norm, I'll take the one you generously provided for RAF #2 Squadron: Initial Mustang Is arrive in Britain in late 1941, tested in early 42 and by May 10, 1942 they are flying combat missions. That's basically 5 months from trials to combat. Admittedly, this is far faster than the norm, but in my alternate reality, more perfect world, I'll take it as the standard for the proposed scenario.

Now how long will it take to send #2 squadron to Australia? Get the planes ready for travel by ship, get them to Australia, re-erect them, flight test and deploy to Air fields?

Send pilots and key ground personnel by air and send NEW planes for US to Australia?

Issue Mustangs to a US unit in the Spring of 1942, train, write manuals, deploy to Australia?

There are a couple of option-scenarios here:

option 1. The US piloted and owned scenario only works if you choose the earliest possible dates with the most perfect, earliest intercession by authority to expedite the events: In this hypothetical scenario, guided by extraordinary quantities of hindsight:

The USAAF FEAF pilots and pursuit commanders realize (as they historically did) that the P-40E is not an effective interceptor by about November 17, 1942 when pilots of the 20th Pursuit squadron in their higher flying P-40B's are barely able to successfully intercept a flight of B-17s approaching Clark AB at 25,000'. Re-attacks on the Army flight fail due to the aircraft speed differential at that attitude. The B-17s are faster than the P-40Bs which are faster at that altitude than the P-40Es. An urgent flash message is sent to Hap Arnold describing the exercise and begging for P-38s or any aircraft with superior high altitude performance to replace the P-40Es. This initiates a search for a solution to the FEAF problem. Examining possible options, it becomes apparent that recent tests on the Allison powered NA-73/Mustang I/XP-51 show it better than the P-40E in virtually all performance requirements. It's not a perfect solution, but it is a 'better' one. The RAF is approached with a request to relinquish a portion of their Mustang I/NA-73/XP-51 purchase to the USAAF in exchange for P-40Es. Terms are reached and aircraft are obtained to equip a Group of three pursuit squadrons of 25 aircraft each; just over half the 1941 RAF-bound production. Squadron training commences shortly thereafter and is in full swing by January or February, 1942. By the end of May, the USAAF Group is deploying to Australia. Much of the prepositioned infrastructure organizational and depot level maintenance to support P-40E operations in Oz is suitable to maintain the NA-73 with the same Allison engine. the trip to Australia is ~3.5 weeks. As an analog example, 24 P-40Es arrived in Manilla on November 25, 1941. By December 6, 20 of the 24 P-40Es had been assembled, delivered to the 21st Pursuit Squadron and apparently flown. This seems to suggest an operational USAAF Mustang I squadron could have been conceivably (but not historically) in place in Australia by early July.

An alternate solution involving more effective use of crystal balls and hindsight is one in which an RAF or RAAF squadron is trained at facilities made available in the USA and sent directly to Australia. This may be completely out of historical context as a solution but seems doable under extreme pressure of a perceived crisis and may come in a few days earlier than the USAAF option.

No matter what you do you are not going to get an operational squadron/group of Mustangs into the Pacific until mid summer or fall of 1942. It would be highly unlikely than a full group of Mustangs could have been available to meet the June 16th Darwin raid even with the best of efforts. Planning for a such a deployment would have had to been started in Jan/Feb.

So, after all that, your original premise was essentially confirmed. Why did I bother; just to shave a few weeks off?

 

[oldcrowcv63]

RoC shouldn't have been an issue in this particular role, the Mustang should have had plenty of time to climb up to that altitude and once it is at or above the enemy's altitude, its speed advantage would have been its trump card. Zoom and Boom, never slow down, never turn, just dive, hit the bombers, zoom climb back up and do it again.

NA-73/Mustang I/XP-51 time to 25,000' ~17 minutes or about 2+ minutes faster than the P-40E and possessing a altitude-speed advantage of probably something like 50 mph. I expect someone here can cite more accurate values. The thing is, given adequate warning, the Mustang I could probably reach 30,000' in the tropics while that altitude was beyond the reach of the P-40E. I'd expect that deleting the 4 x 0.30" MGs, leaving the 4 x 0.50" guns, would probably improve all performance margins. I don't think there was every "plenty of time". I think it was always pretty close under the best of circumstances with the P-40E and would have only been a bit better time to climb with an XP-51/NA-73, but with whatever time it had the NA-73/XP-51 could have climbed higher beyond the P-40E's ceiling while retaining some decent speed at altitude. The Mustang I's Allison was still a single-staged supercharged engine like the P-40E and so capability limited above 20-25,000'.

The NA-73 doesn't seem to me to be a great interceptor, just better than the P-40E in some critical performance parameters for the PTO.

 

[Shortround6]

Thank you (I think?)

 

[Shortround6]

NA-73/Mustang I/XP-51 time to 25,000' ~17 minutes or about 2+ minutes faster than the P-40E and possessing a altitude-speed advantage of probably something like 50 mph. I expect someone here can cite more accurate values. The thing is, given adequate warning, the Mustang I could probably reach 30,000' in the tropics while that altitude was beyond the reach of the P-40E. I'd expect that deleting the 4 x 0.30" MGs, leaving the 4 x 0.50" guns, would probably improve all performance margins. I don't think there was every "plenty of time". I think it was always pretty close under the best of circumstances with the P-40E and would have only been a bit better time to climb with an XP-51/NA-73, but with whatever time it had the NA-73/XP-51 could have climbed higher beyond the P-40E's ceiling while retaining some decent speed at altitude. The Mustang I's Allison was still a single-staged supercharged engine like the P-40E and so capability limited above 20-25,000'.

The NA-73 doesn't seem to me to be a great interceptor, just better than the P-40E in some critical performance parameters for the PTO.

You might be better off ditching the fuselage .50 cal guns. Their rate of fire is rather low, around 8 bullets a second each compared to the 36-40 bullets a second from the pair of .30 cal guns in the wing.

 

[GregP]

Yah but, according to people like Bf 109 ace Erich Hartmann, one in the fuselage is worth two in the wings. So we have the opinion of the guy that shot down the most enemy aircraft in history that kind of contradicts that.

He might be right or wrong, but has a VERY good track record of success with fuselage guns. Not that WE didn't, we did OK with wing guns. But the BEST EVER used mainly fuselage guns to achieve the top spot.

I tend to believe him since he was head and shoulders bove the rest except for Barkhorn and Rall who ALSO used mainly fuselage guns in the Bf 109. Among them they shot down almost 1,000 aircraft, so their methods are at LEAST worthy of study, if not definitive.

 

[Shortround6]

The luftwaffe guns and set ups were a bit different. If they are talking about a fuselage cannon (through the prop) there is NO difference in rate of fire from a wing gun. If they are talking about cowl mounted mgs then the German MG 17 suffered maybe a 10% loss in rate of fire. Since the Germans hardly ever ( or maybe never) stuck the MG 131 in the wings it is a little hard to draw a comparison there.

The Browning .50 didn't like being synchronized. While the USAAF doesn't seem to give out the figures in British tests the synchronized .50 fired at 400-500rpm instead of the 750-850rpm of an un-synchronized gun. So our fuselage mounted mounted .50 has about 56-60% of the rate of fire of the wing mounted gun. Even if we agree with Hartman the fuselage placement is almost nullified by the change in rate of fire.

If we were talking about keeping two .30 cal wing guns instead of a .50 cal wing gun it might be different but IF the British tests are correct then the pair of cowl/fuselage guns good for 14-16 (420/480rpm) rounds per second for the pair compared to 12.5-41.1 rounds per second for a single wing mounted .50 and 73-80 rounds per second for four .30s in the wing.