An Allison V-1710 with a two-speed supercharger in 1942 (4 Viewers)

[drgondog]

Been away from this conversation for a while mainly because the discussion here made me try once again to find some more original source materials online and I hit something of a jackpot when I found a website with a large number of US Air Force Historical Research Agency (AFHRA) files in PDF format (https://www.generalstaff.org/DRA/DRA.htm). I've been downloaded quite a few and have gone through several thousand pages already (obviously, not reading them all since not all were relevant) and found some very interesting stuff. For instance, I was able to find much of what I asked about in this thread earlier: documentation regarding Arnold's aircraft range extension program of February 1942. Bottom line, whatever the original intent it quickly transformed (apparently under the influence of everyone's favorite AAF general, Echols) into an initiative focused on increasing the ferry range of US fighters, not their combat range. Yes, there was a mad scramble to address that later in 1943, but in the intervening time period little was accomplished.

You have succinctly stated what I spent significant ink to explain in my forthcoming book about the 'translation; from Arnold's Fighter Conference in Feb 42 and his TO 1016 of March 2 to "Extend Range of ALL Tactical Aircraft', which then was translated By General Carroll Chief, Engineering Mat Cmd. as 'increase Ferry range". I could amplify this but not enough time at the moment.

In your link above, take the time to download A2069 and extract the droppable tank and FAREP sections for the primary source material for Boylon's Study 136 History of the Long Range Escort Fighter.

Anyways, since one of my main themes is the unacknowledged importance of fighter range apart from heavy bomber escort and since that is not really the theme of this thread, I won't continue too much more right here on that. I will add that I found a doc from May 1943 in which Doolittle praises the Allison Mustang's "long range, excellent fire power, and outstanding performance" that he maintains would be useful to his command, though he also adds that with a "two speed, two stage or other high performance supercharger" (emphasis added) it could "escort heavies". The foreshadowing aside, what else could he have been talking about with "other high performance supercharger" than the original subject of this thread?

Doolittle was responding to Arnold's reach to both theater commanders and Mil.Requirements and Wright Field for an 'actionable recommendation for Long Range Escort choice following letters from both Eaker and Robt. Lovett Asst Secy War-Air begging for long range escort in ETO in June 1943. Doolittle replied that P-38 was doing fine job of escort but suggested that theP-51 was also a candidate. (parphrased). He was referring to the role of A-36 in escort role to B-25 and A-20s which had the same range on internal fuel as the later P-51B with only main wing tank internal fuel. He was also up to speed on the RAF experiment and recent flight tests of the first P-51B-1.

I congratulate you for getting this at least half right (more than I can say for most), numerically the Jagdwaffe was not seriously written down in the months preceding D-Day (actually higher available SE fighters in GAF on 31 May 1944 than 20 Feb 1944, just before Big Week). This is what I intend to make the subject of Part II of my study and I base it on figures I got from the German military archives in Freiburg. I will have something to say on the qualitative dimension as well, which I have considerable evidence there was no dramatic drop off in that either (the Allies just overwhelmed them with large numbers of good fighters with good pilots).

This true, but I would offer that the distribution of LW day fighter squadrons began draining from SUD and OST to Germany summer 1943 through May 1944. It is also a fact that production for fighters went way up at the expense of bombers and transport. Also important was the forced attention to recruit and re-assign bomber and transport pilots to fighters to balance woeful flight school planning to sustain attrition in 1944.

All the more reason to build more Allison Mustangs rather than Allison P-40s (the production of which continued well into 1944) or P-39s, both of which could have been largely phased out in 1943 (excluding, of course, P-39s for the Soviets, which came to 192 in 1942 and 2,627 in 1943, though that probably does not count those passed on by the British). The NAA Inglewood P-51 line was working at 1/3 capacity in 1941, 1942 and early 1943 at which point they were preparing for simultaneous production of the Allison and Merlin Mustangs (up to a combined 20/day, much higher than what actually resulted in 1943), the output of which was going to be limited for many months by the Packard Merlins anyways. NAA had a pretty good track record in WWII for performing so if they thought they could do simultaneous production (which was what Curtiss was doing, I believe, with the P-40) it seems reasonable to believe they could have pulled it off.

There were many moving parts in early 1942 through mid 1942. First, the production of the 'last' Mustang on order from RAF was expected to end in October - with no back orders. There were serious turf battles between Wright Field and Military Req. over the A-36. Eaker had highly recommended the P-51 after flying it Dec 1941, to both Spaatz and Arnold who then visited Inglewood in January 1942. B-25 production was ramping up and threatening existing production line space for future P-51s. The RAF R-R experiment was unfolding and NAA was enthusiastic about the prospect in May 1942. Arnold returned from his critical visit to UK to fight for securing part of the commitments to RAF and Coastal command of badly needed aircraft for USAAF training and combat projections. After a briefing by RAF, with Amb. Winant and attache Hitcock, Winant sent a letter to both Lovett and Arnold stressing the importance of the Merlin Mustang as high priority. At the same time the contracts for A-36 were let, the XP-51B agreement was let after Arnold's return, and RAF agreed to give up two of their share of the future Packard 1650-3 for the experimental Mustang.

At the same time Echols 'put his foot down' and said no more Mustangs, convert line to B-25s. He was crushed again by Mil.Req. and the P-51A contract was let with proviso that it could be converted to P-51B. The influx of orders enabled Kindelberger to secure funding for expansion of Inglewood, construction of Kansas City B-25 plant.

The P-40 question is complicated because it was a.) a pretty good fighter, and b.) was necessary for supplying both US and Commonwealth orders in 1942, leading to FY 43 orders as well as spare engines for 1650-1 production for FY 44 for P-40F and L.

in late 1942 with the success of the RAF experiment and pending XP-51B testing and plant expansion proceeding apace, the first of the A-36s were completed, the P-51A designs complete and production started in parallel and P-51B design complete along with new tooling and started in Dec 1942 - concurrently successful test flights of XP-51B. The P-51A contracts were truncated with decision to replace with P-51B. NAA IMO Could have secured more orders for the P-51 or possibly even the A-36 but both would impinge on the priorities assigned by WPB for the P-51B and 1650-3. NAA needed all available space save the AT-6 lines for both the P-51B and also P-51C. At Dallas the B-24 contract was terminated and tooling for P-51B/C dispatched for Dallas along with temporary transfer of key Inglewood production supervisors to train Dallas. It was a major effort and notable the first production P-51C-1 was not delivered until august 1943.

I agree with your general comments about Echols, and would ramp up criticism from your base. IMO, the root of Echols repeated examples of animosity toward the P-51 arose when Kindelberger/Atwood rejected his 'offer' offload P-40 from Curtiss to NAA to supply them to RAF. He was focused on the disastrous P-46, then attempted recovery with the XP-60, and later rejecting suggestions to purchase the P-51 in lieu of future P-40 orders. It wasn't until the Operational Suitability testing at Eglin with the glowing reports on the P-51-2 that his suppression of vocal support for the Mustang was finally exposed.

I have a lot more to say about Echols, much already stated in my last book and equally supported in Ludwig's P-51 Mustang book.

The P-51A was, I believe, lighter than the Merlin P-51. In any event all sources I am familiar with, incl. the RAF relative airspeed chart I posted earlier, put the low altitude speed of the P-51A (and even the Mustang I at increased manifold pressure) significantly higher than the P-51B. If you're lighter and moving faster with a nearly identical air frame, it's hard to see how the takeoff run would be longer.

It is but 'significantly higher' is perhaps overstated. The point is taken however that the P-51A at full internal gross weight compared to P-51B at comparable fuel (184 vs 180-gal for P-51A) and same MP is faster up to 10000+ feet altitude. Major factor was lower Induced drag due to lower wing loading for the same wing. Takeoff run about the same because T.O Power with 100/130 fuel was 1200 for P-51A vs 1380 for P-51B with P-51B getting the nod.

I have never seen that Churchill got involved. That would be interesting. Do you have a source for that?

I have seen that, circa Nov 1942, when he supported idea proposed by Withold Freeman to assemble P-51B airframes with Merlin variations in UK. I have to dig.

I am not here shouting "conspiracy!" or "treachery!" or even "corruption!". At best what you have is favoritism (aka "a bank of goodwill") that influenced decisions in the wrong way.

In any event, in my written study I tread very lightly on such nefarious possibilities, because it is not really central to my overall themes.

Certainly many sources point to Echols favoritism to 'big box' and 'proven' contractors. The P-46 and P-60 and XP-75 ventures seem to prove the speculation.

So have a Congressional investigation to root it out (or give the current governing party a fig leaf to hide behind). Oh wait, they did! And one of its major findings was that Curtiss was given contracts to produce an inferior fighter to the (Allison) Mustang. So it's not at all critical to my major point, and maybe it was just about publicity for the man heading the inquiry (paid off pretty big, didn't it?) but it is still interesting, IMO. Again, I'm not going to live or die on the "corruption!" hill, but I think it's pretty clear there was favoritism (sorry, "a bank of goodwill") involved, the result being the procurement of an inferior warplane at the expense of a better one. But if I had to discuss corruption I would mention that one of Gen. Echols's main subordinates at Wright Field, Gen. Meyers, was apparently convicted postwar of 3 counts of suborning perjury in an investigation of his own corrupt practices during the war related to AAF a/c procurement. I believe it even made Time magazine. Again, I'm not going to spend more time on this side issue, but to dismiss the possibility that there was significant corruption going on in the US with military contracts during WWII because lots of families had loved ones fighting in it is a bit of a reach. The very fact that the Truman Commission got the attention it did was that many Americans at the time assumed that not everything was on the up and up.

Yes and yes.

 

[tomo pauk]

Anyways, since one of my main themes is the unacknowledged importance of fighter range apart from heavy bomber escort and since that is not really the theme of this thread, I won't continue too much more right here on that. I will add that I found a doc from May 1943 in which Doolittle praises the Allison Mustang's "long range, excellent fire power, and outstanding performance" that he maintains would be useful to his command, though he also adds that with a "two speed, two stage or other high performance supercharger" (emphasis added) it could "escort heavies". The foreshadowing aside, what else could he have been talking about with "other high performance supercharger" than the original subject of this thread?

The 'other hign performance supercharger' might've referred to the bigger supercharger, ie. the one with a bigger impeller? Americans were probably briefed about the big S/C on the Merlin 46/47, but already something like a the 10.25 in impeller on the Merlin 45 is a major improvement over the legacy impeller on the V-1710.
Another thing that might've caught the eye of the planners - the supercharger by the TEC company (a.ka. Birmann) with the 10.25in impeller and the 2-speed drive? That S/C is mentioned several times in the 'Vee's for victory' book.

 

[Shortround6]

Ouch. Another case where the old Squadron/Signal books got it wrong. The fixation that if it was an early Mustang it was a P-51A that persists to this day.

I welcome the correction and plead quick grab from the internet for illustration.

As you and Mr. Marshall point out there were a lot of differences between the Allison Mustangs and the Merlin versions and a simple look at a few data points can overlook things.

 

[Steamed_Banana]

Anyways, since one of my main themes is the unacknowledged importance of fighter range apart from heavy bomber escort

I just want to QFT this one. I think this is so often ignored, it was so important. During the crucial period of 1942-43, the US and UK had a major issue with fighters (especially their best or most widely available types) lacking the range to escort light, dive, and medium bombers to the targets they could reach, as well as things like transports or flying fighter sweeps and CAP for ships and ground installations (as range is also endurance). The US had the P-38 but as we know, it wasn't quite up to snuff initially and took a while to iron out problems, especially for Mediterranean or European Theater. It was also available in small numbers and production only slowly ramped up.

Right. I have been saying the same for a long time, though I think your formulation there is more succinct than the way I have been putting it. My point (and evidently this is where Steamed_Banana is coming from too) is that for much of the war, and (for me at least) especially for 1942 through at least early 1943, low to medium altitude is more important because there are multiple ground campaigns going on and also very important naval actions taking place (of course, we can always pick out exceptional cases where there was high altitude flying going on, but as others have already pointed out, how significant were their impact really?). Things worked out well enough in the Pacific (though a long-range fighter like the original P-51 should have been very helpful and potentially could have secured some significantly better results for the USN in certain situations), but not quite as well in the Med. (about which more below).

I do agree with this, and I think the (early / Allison) P-51 could have been very helpful in the Pacific in a number of roles, but more on that in a sec

Agreed, but more than that they needed long-range fighters to get the fuel there to get those fighters off the ground to begin with. It did not necessarily need to be Mustangs (though they were def. more suited to recon - yet another vital role often glossed over - than the PR Spits that were favored but which there never was enough of on the island), the RAF could have just gotten more Spitfire drop-tanks to Malta than they did otherwise (basically the only ones there from what I can tell are the ones the Spitfires flew in with). The results of Op Harpoon showed this pretty clearly, but the RAF ignored it and nothing was done to bolster that key capability for Pedestal.

Agree here as well, the success the British seem to have had with the Mustang as a recon plane doesn't get enough press, IMO. Recon was very important and tended to be very dangerous, and they were flying F4 / P-38s, Spit IV, and worst of all Hurricanes on these TacR flights, which were often a death sentence in many Theaters. Anecdotally looking at the operational histories all of these types were getting slaughtered pretty routinely. Reconnaissance was very important, it's really often the first mission of military aircraft (at least until our era of satellites and drones) and gets ignored far too often.

The Japanese in particular had good recon planes, the often overlooked Mitsubishi Ki-15 ('Babs' to the Allies), a very fast for it's time 1930s design (300 mph with a 640 hp engine and fixed landing gear!) with 1,500 mile range, was replaced by the much more famous, small and elegant Mitsubishi Ki-46 (known as 'Dinah' in Allied terminology)

which made 375 mph on two 1,000 hp engines at 20,000 ft with a similar 1,500 mile range, and proved difficult to shoot down (though certainly not impossible)

and then eventually (a little too late) the zippy Nakajima C6N Saiun which made 380 mph.

The British had the superb Mosquito, but seemingly never quite enough of them. The Germans had the Arado 234 (excellent but too few and arriving too late) and various fighters (which also seem to have gotten shot down a lot). For the US the best wartime recon was the F-5 recon version of the P-38 and ... the F6 Mustang. Only the Mustang really had the needed speed though, arguably. And the British figured that out in 1942

So have a Congressional investigation to root it out (or give the current governing party a fig leaf to hide behind). Oh wait, they did! And one of its major findings was that Curtiss was given contracts to produce an inferior fighter to the (Allison) Mustang.

I think the bigger problem was Bell producing far too many P-39s. I agree production was needed for the Soviets, but they were not very useful in the Pacific or the MTO. The P-40s were useful in the stop-gap period, and I think they would have been very well complimented by some more (Allison) P-51s notably due to the latter's greater range and better climb. P-40s seemed to have better outcomes against German, Italian and Japanese fighters in particular, and were definitely needed by many of our Allies - British, Australian, New Zealand, South African, and yes Soviet air forces actually relied on P-40s quite a bit in 1942-1943 (and to some extent well into 1944).

Unless you could produce vastly larger number of (Allison) P-51 in 1942-43 you are still going to need another Army fighter, it seems to me the logical place to take the capacity from is whatever went into Bell producing so many P-39s. Curtiss had extra resources squandered on a series of P-40 replacements which were never going anywhere, so many take some from that as well. By mid 1943 or 1944 switch them over to (Merlin) Mustangs by all means, assuming there is enough supervision to assure they are doing a better job with them than with the P-47s they built.

So it's not at all critical to my major point, and maybe it was just about publicity for the man heading the inquiry (paid off pretty big, didn't it?) but it is still interesting, IMO. Again, I'm not going to live or die on the "corruption!" hill, but I think it's pretty clear there was favoritism (sorry, "a bank of goodwill") involved, the result being the procurement of an inferior warplane at the expense of a better one. But if I had to discuss corruption I would mention that one of Gen. Echols's main subordinates at Wright Field, Gen. Meyers, was apparently convicted postwar of 3 counts of suborning perjury in an investigation of his own corrupt practices during the war related to AAF a/c procurement. I believe it even made Time magazine. Again, I'm not going to spend more time on this side issue, but to dismiss the possibility that there was significant corruption going on in the US with military contracts during WWII because lots of families had loved ones fighting in it is a bit of a reach. The very fact that the Truman Commission got the attention it did was that many Americans at the time assumed that not everything was on the up and up.

I also do wholeheartedly agree the US had a corruption problem and Curtiss wasn't the only epicenter of it. I've brought this up here several times (against a strong headwind!)

 

[Geoffrey Sinclair]

Something omitted from previous altitude notes. For sorties reporting altitude, 15th Air Force effective sorties average attacking height, B-17 23,080 feet, B-24 21,090 feet, some reports give an altitude range, this uses the lower limit of any such range.

Everyone here knows what happened with the Blenheim, and why it was left out of the fight while the Boston, Maryland, and Baltimore continued. What is to be learned by posting data that most people here already have available?

They know because I posted the data, the promise was a refutation of that data. Instead, like here, ignored.

Presumably a few hundred far better MC 205, Fiat G 55 and Re 2005 could have helped the German war-effort. At the very least it would have meant less German fighters had to be committed to the defense of Italy.

A few hundred is German monthly fighter production 1943/44, Bf109 or Fw190. Italy capitulated in early September 1943, by which stage the Luftwaffe was pulling out of the Mediterranean, so how many Luftwaffe fighters stayed?

Ground fighting (Kursk, Dnieper, Kharkov, Guadalcanal, Tunisia, Sicily) was having a major impact on the outcome of the war in 1943, in various Theaters other than England.

Air combat in those Theaters was therefore more consequential.

Again, the allied air forces in Britain were generating a high percentage of western allied air activity, which matters to the air forces, this topic is about improving altitude performance, giving examples where low altitude performance is preferred does not help the case. The Soviets made it clear they really liked the P-39 and wanted lots more, the USAAF had the opposite opinion. The Soviets were sent some P-51 for evaluation but do not seem to have asked for any more, then again there were not a lot on offer.

For those who are interested in allied fighter performance improvements, altitude or otherwise, consider where the western allies could encounter the benchmark for 1941/42/43 fighters, the Fw190A, or on average the better Bf109F and G.

The Soviets actually had far more to do with the destruction of the Nazi war machine than the UK or the US did. How is that for disturbing news?

Sorry you took the news so badly. Are you still shook up by the way it warped Luftwaffe operations in the east 1942 onwards?

not getting into a sumo wrestling match with some cranky old man about nothing.

Sumo? Are you that much overweight? By the way how old am I? You must know. Also what amount of time being cranky constitutes the level to which cranky can be used for all a person's behaviour.

Besides Steamed Banana likes the messages, keeps handing out funnies, so obviously encouraging more.

Arnold's aircraft range extension program of February 1942. Bottom line, whatever the original intent it quickly transformed (apparently under the influence of everyone's favorite AAF general, Echols) into an initiative focused on increasing the ferry range of US fighters, not their combat range. Yes, there was a mad scramble to address that later in 1943, but in the intervening time period little was accomplished.

Ferry range solved or tried to solve the big problems the US had in getting its aircraft to the front lines, even ports in the US, flying ferry routes and so on, add the 1942 ideas about self defending bombers, issues like the problems of a lone pilot navigating themselves and unsurprisingly the idea of a large combat radius came second, debates about whether combat tanks should be self sealing. P-38 and P-51 were fitted with the relevant racks in 1942.

a doc from May 1943 in which Doolittle praises the Allison Mustang

Doolittle was in Tunisia and he was reacting like just about everyone to what the Mustang had and could promise. The word was spreading.

for 1942 through at least early 1943, low to medium altitude is more important because there are multiple ground campaigns going on and also very important naval actions taking place

Combined arms does that. After the initial landings how many days of combat did the US forces on Guadalcanal face where at least a regiment was involved? For the desert war in 1942 at least a division? What were the relevant air force sortie rates? Supply issues dictated forces in and around Britain would generate a way disproportionate amount of allied air activity, it was also generating data on what it was going to be like taking on the main Luftwaffe, not expeditionary forces even more supply constrained than allied ones.

The significance of the higher altitude operations in 1942 were more learning, for both sides, about what was to come in 1943, as the turbo equipped USAAF finally deployed its modern types in numbers.

In terms of numbers of lower level sorties in 1943, how do you think they compare with 1st and 2nd TAF and 9th Air force June 1944 onwards?

(Things worked out well enough in the Pacific (though a long-range fighter like the original P-51 should have been very helpful and potentially could have secured some significantly better results for the USN in certain situations),

The P-51 was unlikely to become carrier capable, so how exactly does this work?

[Malta]

they needed long-range fighters to get the fuel there to get those fighters off the ground to begin with. It did not necessarily need to be Mustangs (though they were def. more suited to recon - yet another vital role often glossed over - than the PR Spits that were favored but which there never was enough of on the island),

There is a certain chicken and egg to this, pre war planning was abandoning Malta as an RN base if Italy entered the war, 95 square miles of land with around 240,000 people does not leave a lot of room for airfields, food supplies constrained how big any defence force could be. The number of airfields made the air force vulnerable, many aircraft were destroyed on the ground. Sicily could provide space for a much bigger air force than Malta.

The RAF used Beaufighters as the long range fighter type, a dedicated navigator really helps over ocean sorties. PR Spitfires in the Mediterranean normally did high altitude sorties.

If you pump up your air power on Malta, which what was done really accomplished little more than to keep it from starving out (the contributions of Malta based air in the anti-shipping operations post Op Pedestal, though certainly not non-existent, have often been exaggerated), by increasing your long-range fighter capability and keeping a decent sized anti-shipping strike force (there was an unfortunate tendency for the RAF to disperse those to less critical and even quiescent areas and not so long after Pedestal avgas on Malta ran low again) you have an excellent chance of forcing the Luftwaffe to engage in a long-term attritional battle which would not be good for them at that time (much less capability to replace losses in 1942 than later in the war) or risk having DAK even more starved for supplies than historically. There's a very good chance both could happen as would take place around Tunisia the following spring.

A lot to unpack there. The British in the Middle East spent about the first half of 1941 shuffling forces across multiple fronts on shoestring supply lines, end 1941 saw losses and diversion of planned reinforcements to India. The Beaufort battled engine problems into 1941, the Wellington was considered too vulnerable to attack by day. The RN provided Swordfish and Albacore squadrons.

So how many aircraft would be based at Malta, given that will dictate how much commitment the Luftwaffe has to make? Does it include fast climbing fighters for defence? How many anti shipping sorties and therefore what sort of resupply rate will be required? How are losses on he ground avoided?

The axis did not lose any cargo on the Africa run until December 1940, when 10.65% was lost, percentage losses all causes for 1941 were 2.81, 1.46, 8.89, 8.04, 8.01, 6.19, 19.13, 12.56, 28.27, 20.37, 62.32, 18.01.

The Luftwaffe engaged in systematic suppression of Malta in early 1942, losses on the Libya run by month for the year.
0.07, 0.85, 17.30, 0.78, 7.24, 22.14, 6.45, 33.03, 20.00, 44.20, 25.86, 52.62, 68.79, but December had little cargo shipped.

Tunisia run, November 1942 to April 1943, loss rate 0.00, 28.52, 21.07, 22.81, 35.71, 41.23.

Pedestal was in August 1942.

Italian merchant fleet losses to aircraft 1940 to 1942, ships/GRT, 15/35,904, 58/161,589, 71/144,238 Germany in the Mediterranean, none in 1940 then 5/16,639, 10/28,871

cargo deliveries to Libya by recipient organisation, grand total 1,929,955 tonnes

Nation	Italian	Italian	Italian	Italian	Germans
Service	Army	Navy	Air force	Civilians	All
6 to 12/40	226,343​	12,291​	8,042​	50,799​	0​
1941​	362,189​	39,781​	48,728​	127,583​	274,912​
1/42 to 1/43	354,166​	31,974​	36,935​	76,239​	279,973​
Total	942,698​	84,046​	93,705​	254,621​	554,885​

To concentrate in the Med., where your main ground operations were taking place and where you were trying to score a strategic win by opening it back up to save shipping resources (the main bottleneck for the Western Allies) just makes good sense.

Not until end 1941 and confidence the USSR would stay in the war, at a cost of sending it large number of aircraft and other supplies. Then comes putting the forces into the supply lines leaving Britain and actually delivering them.

I congratulate you for getting this at least half right (more than I can say for most), numerically the Jagdwaffe was not seriously written down in the months preceding D-Day (actually higher available SE fighters in GAF on 31 May 1944 than 20 Feb 1944, just before Big Week). This is what I intend to make the subject of Part II of my study and I base it on figures I got from the German military archives in Freiburg. I will have something to say on the qualitative dimension as well, which I have considerable evidence there was no dramatic drop off in that either

Williamson Murray notes 31 December 1943 the Luftwaffe day fighter force had 2,395 pilots, 1,491 fully operational, then took 2,262 killed wounded, missing by end May 1944, this excludes the twin engine force. We know the Luftwaffe cut training hours in 1943 so how did the Luftwaffe maintain pilot quality in early 1944?

A fundamental problem with using two dates is it misses out what happened in between, Luftwaffe single engine fighter force.

date	Strength	serviceable
10-Jan-44​	1,554​	1,043​
20-Jan-44​	1,545​	1,121​
31-Jan-44​	1,670​	1,008​
10-Feb-44​	1,763​	1,180​
20-Feb-44​	1,791​	1,216​
29-Feb-44​	1,747​	1,220​
10-Mar-44​	1,743​	1,141​
20-Mar-44​	1,704​	1,118​
31-Mar-44​	1,696​	1,188​
10-Apr-44​	1,801​	1,224​
20-Apr-44​	1,663​	1,163​
30-Apr-44​	1,648​	1,114​
10-May-44​	1,748​	1,250​
20-May-44​	1,749​	1,224​
31-May-44​	1,683​	1,111​

In this date period a peak in strength in April 1944 while generally holding 1,100 to 1,200 serviceable across the 5 months.

(the Allies just overwhelmed them with large numbers of good fighters with good pilots).

Yet the Luftwaffe by falling back to Germany maintained nominal parity in numbers with the allied fighters able to fly to Germany well into 1944. The overwhelming numbers in the west in 1944 came into play in June. For big week the 8th Air force had 2 P-38, 9 P-37 and 1 P-51 group operational, the 9th Air Force could add 2 P-47 and 1 P-51 groups.by end May it was 33 USAAF fighter groups operational.

P-39s for the Soviets, which came to 192 in 1942 and 2,627 in 1943, though that probably does not count those passed on by the British).

The British on shipped some P-39 sent to them, apart from that there was Britain for Russia deliveries in the US, so in 1942, 420 BFR and 181 direct, 1943 1,509 BFR and 1,138 direct.

The NAA Inglewood P-51 line was working at 1/3 capacity in 1941, 1942 and early 1943 at which point they were preparing for simultaneous production of the Allison and Merlin Mustangs (up to a combined 20/day, much higher than what actually resulted in 1943),

NAA Inglewood had around 5,000 employees in early 1940, 8,244 end December, 15,637 in December 1941, then 24,352 in December 1942, peak at 25,098 in November 1943, down to 17,651 including Los Angeles in December 1944. In 1940 production was 1,245 trainers and lighter types, in 1942 1,843 including 1,524 trainers, in 1942 it was 1,904 almost all combat types including 1,119 B-25, in 1943 it was 3,145, almost all the increase due to P-51, in 1944 it was 5,033 including 4,368 P-51.

Dallas first employees in December 1940, maximum over 37,000 late 1943, Kansas City in September 1941, maximum 25,156 November 1943.

Inglewood achieved close to its wartime maximum employment end 1942, so how is capacity measured to give a 1/3 figure? You can see how output per worker went up in 1943/44 thanks to experience and concentration on a relatively stable P-51 design. The US did studies showing how much more efficient things became on long production runs and how costly set up was.

Factory acceptances in 1942 of US fighters with the Allison = 7,015 of which 1,265 were P-38, so just under 8,300 total engines in completed a/c.

I make it 8,324 Allison fighters, 1,265 P-39, 1,973 P-38, 4,454 P-40, 632 P-51 requiring 10,300 engines,

[EDIT/Correction, As per message 289, Correction time, the P-38 and P-39 figures were flipped, far more importantly while the XP-51B were the P-40F were not removed, Allison users, 1,265 P-38, 1,973 P-39, 3,169 (out of 4,454) P-40, 632 P-51, total 7,039, needing 8,304 new engines.]

add a 20% reserve for them plus shipments for aircraft already in service and stocks for 1943 production you largely account for all 15,000 Allison production in 1942. (The Canadians asked for 20% spare engines for their Hurricanes, the USAAF early was specifying higher reserves, places like the desert and tropics tended to reduce service life before talking combat and greater flying hours)

No substantial increase in P-51 production in 1942 without finding a new engine source, plus North American hiring more people.

your figures illustrate the main reason the AAF should have been interested in pushing for the development of a single-stage/two-speed s/c for the Allison: you are going to be producing lots of them regardless so why not make a "medium tech" upgrade to extend their usefulness further into the war?

The first point is whether the altitude upgrade comes at the expense of low level performance. The second point is it was asking yet more of Allison at time when it was struggling to meet demand. Finally the way the Allison was designed made supercharger changes harder.

Could you pleas let me know where I can find the "War production Report" or "CAA" reports you refer to?

CAA report US National Archives.

World War II Operational Documents will allow you to download the US War Production Board report or read online.

The P-51A was, I believe, lighter than the Merlin P-51. In any event all sources I am familiar with, incl. the RAF relative airspeed chart I posted earlier, put the low altitude speed of the P-51A (and even the Mustang I at increased manifold pressure) significantly higher than the P-51B. If you're lighter and moving faster with a nearly identical air frame, it's hard to see how the takeoff run would be longer.

I gave the figures including the source, you need to find take off distance figures, not low altitude airspeed.

I have never seen that Churchill got involved. That would be interesting. Do you have a source for that?

Many Mustang stories mention it, I do not have a specific archive reference at the moment.

I am not here shouting "conspiracy!" or "treachery!" or even "corruption!". At best what you have is favoritism (aka "a bank of goodwill") that influenced decisions in the wrong way.

Think of how many fighter prototypes Curtiss turned out compared with other companies

In any event, in my written study I tread very lightly on such nefarious possibilities, because it is not really central to my overall themes.

So have a Congressional investigation to root it out (or give the current governing party a fig leaf to hide behind). Oh wait, they did!

That sort of language indicates a conspiracy to cover up corruption.

And one of its major findings was that Curtiss was given contracts to produce an inferior fighter to the (Allison) Mustang.

Overall inferior but available much earlier in numbers, then came judgements on how the war would go and when replacements could be built and units converted.

I think it's pretty clear there was favoritism (sorry, "a bank of goodwill") involved, the result being the procurement of an inferior warplane at the expense of a better one.

While others note the timings and the problems and costs of switching to new types. Of ramping up production and so on.

But if I had to discuss corruption I would mention that one of Gen. Echols's main subordinates at Wright Field, Gen. Meyers, was apparently convicted postwar of 3 counts of suborning perjury in an investigation of his own corrupt practices during the war related to AAF a/c procurement.

Major General Benny Meyers - Success and Corruption at Wright Field in the Second World War

Wright Field in the Second World War As the Second World War began President Roosevelt challenged the nation to produce 50,000 (later 60,000) airplanes per year, and the staff at Dayton’s Wright Field was remarkably successful in meeting and even exceeding this procurement goal. Despite the...

continuingeducation.udayton.edu

On the basis one corrupt individual makes for a corrupt system everything is corrupt.

The very fact that the Truman Commission got the attention it did was that many Americans at the time assumed that not everything was on the up and up.

If you want to bury corruption keep the publicity down. No human organisation is totally honest, starting with the people who claim to be working when not.

 

[Frog]

The most complete information I found on (former) Major General Myers frauds :

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://grokipedia.com/page/bennett_meyers&ved=2ahUKEwjHzMevodyTAxU0T6QEHSvULgkQFnoECB0QAQ&usg=AOvVaw3O2fcQV_Qy_ZXiBIAAopNy

 

[Shortround6]

The P-40 question is complicated because it was a.) a pretty good fighter, and b.) was necessary for supplying both US and Commonwealth orders in 1942, leading to FY 43 orders as well as spare engines for 1650-1 production for FY 44 for P-40F and L.

It was a good fighter, just on a power to weight ratio it was in well in the medium range for speed (drag). Mustang was in a class of it's own.
But fighters need to a do a number of things and for some, like climb, weight is the enemy as you know.

P-40 was good, even if not great, it was available while most "better" X planes were not. The US did not know how fast German and Japanese and Italian aircraft were going to get better.

US fighter development was more complicated than anybody else and the US made more mistakes than anybody else.
From May of 1939 (order for 13 YP-43) to Oct 1942 (order for two XP-75) is just about 3 1/2 years and the US Army considered 28 (?) different fighter designs or at least assigned that many numbers. I am not at all sure what the overriding philosophy was as they went from small under 4000lbs planes to monsters like the XP-58 (twin turbo Allison V-3420 engines)
Some might say they just threw a bunch of stuff at the walls (and ceiling) and saw what stuck.
Some did not like the P-40 because it was not advanced enough and in 1940-41-42 they were looking to the future. Unfortunately for Curtiss and a lot of US fighter designs a lot of the future fighters crashed a burned taking millions of dollars and tens of thousands of man hours with them. Curtiss alone saw the XP-46 flop. Then they tried with the XP-53, a big laminar flow wing on a P-40 fuselage with the Air Corp's fair haired child engine, the Continental V-1430 instead of the Allison. Turned into the XP-60 when there were no flyable Continental V-1430 engines. Then Curtiss built the XP-55 with a canard wing, but built a small low powered version which delayed things. Also engine selection problems. XP-60 went through 4-5 different engine combinations while they kept churning out P-40s hoping that something would stick to wall, or at least only slide slowly to the floor.
The US was really in a jam as the P-47 was running late. The P-39 was fast down low but it was slightly worse at altitude than the P-40 and it didn't do much of anything better than the P-40 and had shorter range. P-38 was having problems and it was complicated to build.
Allison P-51s could not do some of things the US wanted (like high altitude) with existing engine/s, or likely ones.
The Continental V-1430 took a lot of prototype aircraft down not even counting the ones it actually set fire to.
There was supposed to be at least two versions (out of 13) that used a single stage, two speed supercharger that was supposed to give 1600hp at 15,000ft. Used a 10.5in diameter impeller. Why didn't the US Army "give" that supercharger design to Allison? Most of the rest of the Continental V-1430 versions used turbos. Some of the ones they tried to fly with set fire to the aircraft.
What the generals at the front wanted may have been different than what the generals at the rear (Washington) wanted and what the generals that were planning future strategy wanted was different than what the generals in the next hallway (procurement and industrial management) wanted.

Many of the men were trying to juggle building planes for use 2-3 years down the road vs what they could make right now. Some officers wanted to skip over improving existing designs for the 'potentially' better ones. And often they were looking for 50-100mph increases in speed rather than 20-40mph increases. US aircraft industry was roughly tripling in size every year from 1939-44 and figuring out which companies could actually deliver (or close) as promised vs running months late also hard to figure out.

Going from the Xp-43 to the XP-52 five aircraft out of 10 were supposed to use turbos. One was just a short-term designation for the P-39C.
The US army doesn't appear to be interested in either two speed superchargers or mechanical two stage in 1939-40. The XP-53 was supposed to use a two speed supercharger on the I-1430 engine but that engine was still very much in the test house stage at this time. Demanding good two speed superchargers in 1942 when they hadn't done the ground work wasn't going to work well.

P-40 was never going to be a P-51 but perhaps, if Curtiss had not been busy with so many other projects, a true "light weight" P-40 could have been built and perhaps Allison could have come up with an Engine roughly equal to the Merlin XX or later versions.
Army was planning on high altitude fighting happing with orders for huge fighters.

XP-62, contract signed April 29th 1941. Project start was in Jan 1941. A turbo charged Wright R-3350 engine, contra rotating propeller, pressure cabin. Desired top speed of 468mph at 27,000ft
Eight 20mm cannon (or twelve .50s). 420 sq ft wing.
If this was what the Air Corp wanted why fool around very much with warmed over P-40s?
In 1942 they did get contract for 100 aircraft but that was cancelled to avoid conflict with Curtiss production of P-47Gs, which was running behind schedule.

The Army was looking for really big steps or leaps. Not just a fast but steady pace. For the most part, they got neither.

 

[Shortround6]

Personnel numbers (employees) are important, what is often unknown is the size (square footage) of the factories and the amount of machinery needed in the factories.
Many factories expanded or bult new buildings. Structural steel and cement were regulated so at times, production was not as rapid as was desired (or somebody else's factory was slowed down). Even transportation of workers had to considered. Or nearby housing.
Southern California was favored because they could work on planes outdoors, most of the time. Then the middle of country was favored, Working outdoors in a Kansas winter was not going to fun (or productive) but it was much harder to bomb factories from airplanes launched by submarines or enemy aircraft carriers or an enemy base in Mexico.
US built around 400-500 120mm AA guns, around four went to Europe and one battalion went to the Philippines in 1945.
A resounding success, only one Axis plane bombed the Continental US during the entire war

There were a lot of things the US could have done differently. How much was really corruption and how much was just poor judgement or trying to cross all the T's and dot all the I's?
Try to guess in 1941 the chances of an Enemy air attack on either coast? Now try in Jan 1942, try again in July 1942. Try again in Jan 1943.

I just want to QFT this one. I think this is so often ignored, it was so important. The US and UK had a major issue with fighters (especially their best or most widely available types) lacking the range to escort light, dive, and medium bombers to the targets they could reach, as well as things like transports or flying fighter sweeps and CAP for ships and ground installations (as range is also endurance).

For at least the US Navy the difference in range was not that great until after Midway. Actual range of a SBD carrying a 1000lb bomb was not great. Or range of a Devastator carrying a torpedo. The book ranges do not include either circling while forming up or the time spent circling waiting to take turn landing. Once the TBFs show up there is a disparity in range.
The other thing, that I have harped on for years, is that what was technically possible in 1943 (or after) was not technically possible in 1938-39-40-41, mostly.
The aircraft designers of the 1930s (and various air ministry's) were not totally corrupt or stupid. Ok maybe the British ministers were getting pay offs from the Greater Sherwood Woodworks Guild for the continued production of wooden propellers

there is only so much you can do with a single 700-1100hp engine and the power changed with every year. Not all countries improved at the same rate and improvements were not an even slope but rather plateaus and slopes. The Object of an escort fighter is to fight at or near the end of the bombing mission with some hope of winning.
A fighter only has a certain percentage of payload available (drop tanks excepted) and you have to count the pilot and gear, the radio/navigation equipment, the fuel/oil and the guns and ammo. You can swap somethings around, like less guns for more fuel but most fighters are designed with nearly the same pay load for a roughly equal engine power.
Now in the 1930s and the first few years of the 1940s the radios used in the fighters were not long ranged. Fighter that got lost was probably doomed.
Even if you could fit in a longer ranged radio (heavier) and operate it you just lost something else, speed or climb or turn or 10 gal of gas, or two 7.7mm machine guns + ammo.
You don't have 1942 flaps in 19388-39.
You have to get your escort fighters out of the exisitng airfeilds. British may have had more problems with this, but they were increasing the size of the airfields every year.

Most Air ministry's thought they needed a twin-engine fighter for escort work, to handle the extra fuel and the radio and navigation chores. Radios made faster progress than some airframe designs. Some engines made good progress with much improved power at not much weight increase over early engines. British finally decided to use better propellers and could lift larger loads out of the same size airfield. Now they had to decide how to use the improved payload. More fuel? better protection? Better radios (and IFF)? more firepower?

A Spitfire I with a wooden prop, early radio, no protection was not going to be a good escort fighter in 1938 even if you hung a 90 imp gal tank underneath.
Now when the Spitfire could have been used as an escort fighter is a discussion. Which mark with which engine and what state of accessories (radios. etc). But just saying they did in it in 1944 and that means they could have done it in 1940 (two pitch props) ignores reality.
The 109 is in the same boat but some of the reasons are different.
If you use a heavy fighter (lots of fuel) you may be able to keep the speed up, but you have worse climb, less acceleration and a larger turning radius than your opposing interceptor fighters. Unless you sacrifice something else, radios, armor, protected tanks and so on.

 

[ggiumarra]

Hopefully I can address more of this post of yours soon (it's quite wide-ranging). But just wanted to answer two parts of it real quick...

World War II Operational Documents will allow you to download the US War Production Board report or read online.

Since it seems we seem to be crossing swords more than once (I hope in a friendly manner), I just wanted to make sure to thank you for this first. I have downloaded many documents from CARL over the years, but did not know of this one, so I am grateful to get this data from what looks like an authoritative source. I've already cross-checked my M4 Sherman production, as well at LST and LCT numbers, all of which seem to tie out, and now I can confirm what I had rattling around in my head for some time about DE production as well, and on and on. Brilliant stuff.

I make it 8,324 Allison fighters, 1,265 P-39, 1,973 P-38, 4,454 P-40, 632 P-51 requiring 10,300 engines, add a 20% reserve for them plus shipments for aircraft already in service and stocks for 1943 production you largely account for all 15,000 Allison production in 1942. (The Canadians asked for 20% spare engines for their Hurricanes, the USAAF early was specifying higher reserves, places like the desert and tropics tended to reduce service life before talking combat and greater flying hours)

No substantial increase in P-51 production in 1942 without finding a new engine source, plus North American hiring more people.

Looks like you are using the AAF Statistical Digest, WWII, table 76, p. 118, just like I am but you have the P-39 and P-38 figures mixed up, thus overstating the twin-engined Lightning. Also, you have the same number of P-40s as I do, but as you know a significant quantity of those were produced with Packard Merlins, so those need to be deducted from the 4,454. From other sources I have the Merlin P-40s at just over 1,300. Don't worry, I almost made the same mistake myself in the post you responded to (not subtracting the Merlin P-40s). My math says just under 8,300 engines. It's a long way from there to 14,900, so maybe I have a point this time (I don't pretend to be inerrant, however).

On the other hand... If I compare the AAF Statistical Digest with the War Production Board report the numbers tie out almost exactly for P-40, P-39, and P-51, but they have a 1,478 for the P-38, so that would add 426 Allison engines to my 8,300 and take it closer to 9,000 engines for 1942. I still think you should be able to get another 500 - 1,000 SE engine fighters in the next 5,900 Allisons (but who's counting? Lol).

And, yeah, NAA would hire more people.

 

[tomo pauk]

<snip>

Just wanted to thank you for the friendly and well-informed conduct here.
Cheers, mate.

 

[SaparotRob]

…


I also do wholeheartedly agree the US had a corruption problem and Curtiss wasn't the only epicenter of it. I've brought this up here several times (against a strong headwind!)

Just mention Brewster and Fisher. You should be cool.

 

[ggiumarra]

I is in editing now at P&S. Their POV is that it will be released in July.

If anything I am more champing at the bit than before! (And after "Bastard Stepchild" I'd probably buy anything by these authors, even if it was the "Secret Sex Life of the P-51 Mustang" haha)

The first segment is a detailed examination of the history of developing the long-range-escort-fighter from just pre-AWPD-1 in which the 'escort fighter' is described as a long range, fast, agile multi engine escort with crew served weapons.

Through 1943, the parallel development of the history of droppable tanks,

the Fighter Aircraft Range Extension Program

false starts (YB-40/XP-75) combined with

increasing high losses of 8th AF - all leading to:
Failure of Republic to deliver long range escort capable P-47 until mid-1944. Why?
Relentless pressure by AAF to increase internal fuel on P-38, P-47 and P-51B.
Political forces which stripped the P-38 from 8th AF inventory to support Torch. Why and who
The failure of AAF (and Germany and RAF) to deliver a single engine long range escort. Why and extensive range discussions?
Discussion and rebuttal of 'bomber mafia conspiracy'.

I have my own opinions on some (but not all) of these so I definitely will hold back Part I of my study (which actually I don't intend to attempt to publish anyways, at least in its current form, but do want to circulate to certain historians to get their feedback) until I get a chance to consult your findings and conclusions, though as you might imagine, it doesn't guarantee I will agree with all of them.

The second segment is...

Segments 2-4 are not as topical for me, but they do sound interesting and I'm sure looking forward to reading and studying them as well.

The Appendices presents:
Detailed range tables AAF FAREP, Table for Actual Ranges attained for combat victory credits by fuel load and a/c type vs AAF tables.
Maps FAREP vs Actual.
Technical Section including drag comparison, model variation weight and balances, NAA range calcs for both ferry and combat radius, Engine horsepower, Total Victory credits by theater and quarter (ETO only)

You know you've got a good book coming when even the appendices are alluring!

 

[drgondog]

If anything I am more champing at the bit than before! (And after "Bastard Stepchild" I'd probably buy anything by these authors, even if it was the "Secret Sex Life of the P-51 Mustang" haha)

Unfortunately, Lowell Ford passed away in late 2024 and Bob Gruenhagen in Jan 2025. Bastard Stepchild could not have been done without them. Significant source material for the XP-51F and other Lightweights came from their original NAA sources.

I have my own opinions on some (but not all) of these so I definitely will hold back Part I of my study (which actually I don't intend to attempt to publish anyways, at least in its current form, but do want to circulate to certain historians to get their feedback) until I get a chance to consult your findings and conclusions, though as you might imagine, it doesn't guarantee I will agree with all of them.

Segments 2-4 are not as topical for me, but they do sound interesting and I'm sure looking forward to reading and studying them as well.

You know you've got a good book coming when even the appendices are alluring!

That is what research is all about - and several on this forum as well as past members including Geoffrey Sinclair, Colin Ford and Calum Douglas are contributors to the new book. The Chapter 1 depends heavily on NARA and USAFHRC. Make sure you extract Case History of Droppable Tanks and Case History of FAREP from Reel A2069 before finalizing your conclusions.

If you do not have Ludwig's "P-51 Mustang, Development of the Long Range Escort Fighter", I recommend it. I carefully checked on several of his source documents that are relative to the animosity he portrayed by Echols and Stratemeyer and Saville against the purchase of the Mustang and found them valid. He, like I, draws conclusions based on fact and opinions based on fact. In some cases opinions dominated.

I think that an author touching on the politics of the Mustang must look very deeply into multiple histories of the USAAF pre-WWII and all the way through to at least the run-up to Overlord to view the very complicated moving political parts.

As to Echols, Arnold, Spaatz, Eaker, Lovett, Winant roles in development of long-range-fighter-escort not only the case histories named above are (IMO) important but also the various bios written by many are important to read, because many are contradicting on core discussions, such as the 'bomber mafia', etc.

I draw conclusions based on an assembly of perspectives and chase facts to the best of my ability, but - it is My lens that you see the narrations.

 

[drgondog]

And, yeah, NAA would hire more people.

NAA should have gotten the Mustang orders to match the AT-6 and B-25 orders. They were able to make a case with WP Board for investment in the Dallas operation, but it took time to assemble the same quality infrastructure in Dallas, then repeat later in Kansas City.

Had NAA received orders for the P-51 in mid-1941 the plant capacity in floorspace, tooling and trained production personnel would have ramped to meet the combinations of commitments of all produced aircraft from Inglewood and Dallas in 1943. Both Dallas and Kansas City experienced challenges while being cloned with Inglewood supervisors to generate the standards of quality.

In a perfect world in which the P-51B could have been delivered with the Packard 1650-1;

1. The Mustang had to be looked upon favorably (factually and politically) by Echols as better than the P-40 (and P-46) as early as May -July 1941 after first production release and first test flights RAF and by Wright Field test Pilot Lee.
2. Kindelberger had to be successful at swaying GMC to agree to abandon Allison in favor of Packard (as replacement following conclusion of NA-83 and NA-91 for RAF) at the same time.
3. Echols had to choose NAA over Curtiss for Priority 1-A allocation of AAF share (vs RAF) of the Packard production of 1650-1. Conversely, the P-40F never lives as Merlin powered and all P-40s remain Allison powered.
4. The production agreements for P-51B had to be planned and agreed based on Inglewood short term and Inglewood/Dallas mid term.
5. Planning to move B-25 (and investment in plant) to KC, along with a staffing plan which shared Inglewood personnel and reproduce and set up tooling.
6. Likely several political forces would further pull NAA, including RAF desire to order the P-51B with proviso that airframes could be completed and shipped engineless to UK for assembly and use of Merlin types. Significant pulls on NAA to meet both AAF and RAF demands for production, while maintaining quality, would severely strain NAA Production and Service/Liaison teams.
7. Field Services for NAA to support both Allison and Merlin versions would require highly intense training for additional staffing.
8. NAA would need to closely align with R-R both in US and UK as well as Packard to be early in the devlopment cycle for the Merlin 60 series/1650-3 development to maintain design requirements for greater cooling infrastructure in the Mustang high-altitude version.
9. There had to be a clear vision between AAF Plans - Military Requirements for the roles of the P-51B and P-51B+ relative to battlefield superiority vs long range escort.

In that perfect world:
The arrival date for the first P-51B+ (Packard 1650-3 equipped) is entirely dependent on Packard delivery of production quality V-1650-3 and not going on strike in June 1943 is perhaps October 1, maybe in time for Schweinfurt II on October 14th.

IMO the difference between 'when it arrived to begin combat ops on December 1, 1943' vs 'earliest possible date for combat ops in ETO' is perhaps 60 days -due to lost production by Packard of the 1650-3s due to the strike.

The arrival dates for the P-51B w/1650-1 would parallel the P-40F.

 

[Geoffrey Sinclair]

Looks like you are using the AAF Statistical Digest, WWII, table 76, p. 118, just like I am but you have the P-39 and P-38 figures mixed up, thus overstating the twin-engined Lightning. Also, you have the same number of P-40s as I do, but as you know a significant quantity of those were produced with Packard Merlins, so those need to be deducted from the 4,454. From other sources I have the Merlin P-40s at just over 1,300. Don't worry, I almost made the same mistake myself in the post you responded to (not subtracting the Merlin P-40s). My math says just under 8,300 engines. It's a long way from there to 14,900, so maybe I have a point this time (I don't pretend to be inerrant, however).

Correct, except I am using more detailed reports, changes made to my original message. What is really required is the number of engines in stock including in the repair and overhaul system. Given a time between overhauls of 300 hours there were plenty of engines needing work. The 9h Air Force in the ETO says its units flew 1,080,904 hours on operations (excluding transport and liaison aircraft), and 820,117 hours on training. Using credit sorties, not total sorties, the average P-38 was in the air for 2.51 hours, P-47 2.41 hours, P-51 2.96 hours, P-61 2.26 hours. The bombers between 3 and 4 hours. The average P-38 flew 17.3 sorties per month, the P-47 18.9, the P-51 16.8, the P-61 13.6

If I compare the AAF Statistical Digest with the War Production Board report the numbers tie out almost exactly for P-40, P-39, and P-51, but they have a 1,478 for the P-38,

Recommend a double check, the WPB says 1,264 P-38 in 1942.

so that would add 426 Allison engines to my 8,300 and take it closer to 9,000 engines for 1942. I still think you should be able to get another 500 - 1,000 SE engine fighters in the next 5,900 Allisons (but who's counting? Lol).

Again, you need the US engine stocks available, if the US followed the British practice they usually had engines in hand well before airframes were built, airframes take up a lot of storage area for a start. If you want P-51 then North American Inglewood built 1,904 aircraft in 1942, requiring a 25 to 50% increase in output.

Investment in North American run factories, dollars, total, public, private, note

Grand Prairie	35,654,000​	34,507,000​	1,147,000​	AT-6, P-51, B-24
Inglewood	13,757,000​	10,413,000​	3,344,000​	B-25, P-51, P-82
Kansas City	30,359,000​	30,359,000​		B-25 (U.S. Government Assembly Plant #2)
Kansas City	3,951,000​	3,951,000​		Modification, B-25, P-51 (U.S. Government modification centre #4)
Los Angeles	793,000​	0​	793,000​	B-25
Pasadena	292,000​	0​	292,000​	Aircraft testing
Waco	94,000​	0​	94,000​	Aircraft

The US ceased openly publishing US military aircraft production for the US in the second half of 1938, many sources use the partial year figures, 858, for the full year

Year	Total	USN	USAAF	Note
1935​	318​	296​	22​	USN plus 1 Airship, includes 15 a/c for USCG
1936​	850​	332​	518​	USN plus 1 Caudron Le Simoun/C-620, includes 1 a/c for USCG
1937​	846​	438​	408​	USN plus 1 Bf108 and 3 Balloons (27 BT-9B under army for navy)
1938​	1253​	571​	682​	USN plus 4 lighter than air and 1 S.A.I S-2 (Italian). 13 BT-9B/NJ-1 and 7 UC-43/GB-1 under army for navy.
1939​	863​	303​	560​	USAAF includes 64 a/c for National Guard, also plus 1 Bf108/C-44

The 5 year total of 4,130 compares with July 1942 output of 4,097. Somehow the US military needed to cope with the increase in all aspects, including figuring out the better types while trying to forecast what was needed 1 or 2 years in the future. Same for the people doing the actual production, it is really easy to succeed so well you go out of business. And it was not just the assembly plants, supplying Ford at Willow Run were 965 subcontractors located in 287 cities in 38 states.

For those who think the US did really well in WWII aircraft production consider Ford Willow run never operated at full capacity thanks to a lack of workers, the limit Halley (Buying Aircraft) uses is about 600 B-24 a month. Ford was aiming for 1 an hour. Which is probably the source of the incorrect claim that some factories actually managed this.

Next is while "everyone" had reliable enough 1,000 HP class engines in the second half of the 1930's and then stepped up to 1,500 HP class without major problems, "everyone" had their 2,000 HP class engine horror stories. Engines took longer, the two allied fighters that started design mid war and made it into production in some numbers in WWII used an engine already in production, matched to a new airframe. Another effect was the efficiency of propellers near the speed of sound put limits on useable engine power for top speeds.

From WWI the air forces knew they needed a development line, on drawing board, test flying, entering production, in full production, leaving production and that the time from start to numbers had increased from the months it took in WWI, but surely not the years in the 1930's as peace time collided with economic crisis. For fighters came the unwelcome incursion into the transonic zone where the old rules ceased applying.

We all know the story of the big company that suppressed better methods, or the big company grabbing better methods and driving the inventors out of business. The small firm that knew it needed a big improvement to break into the market and delivering or the small company that lacked the resources to build that better product.

Pre and during WWII lots of funds were made available for research and development, so how to allocate that amongst the big and small players and their always looking good on paper ideas? Knowing one could be a major advantage and most would not or worse. In the end the majority of US aircraft output in WWII was by the small number of "big" pre war aviation companies.

In 1939/40 the US had the EP-1/P-35A, CW-21, P-37, FM-1, XP-41 and YP-43. Wartime programs that actually saw flying, XP-49, XP-50, XP-54, XP-55, XP-56, XP-60, XP-62, XP-67, XP-72, XP-77, XP-79, plus some small production runs like the P-75. The USN in 1939/40 had its F2A, F3F and F4F, wartime XF13C, XF14C, XF15C, XF5F, XFL along with the FR, it was more experimental at the dawn of the jet age.

On the engineless P-51 airframes to Britain, to end 1942 Britain had built 75 Merlin 60, 673 Merlin 61, 95 Merlin 62 and 40 Merlin 63, while in 1943 built 1,328 Spitfire V when they would have preferred Spitfire IX. Britain did have plenty of Merlin XX etc.

 

[Steamed_Banana]

There were a lot of things the US could have done differently. How much was really corruption and how much was just poor judgement or trying to cross all the T's and dot all the I's?
Try to guess in 1941 the chances of an Enemy air attack on either coast? Now try in Jan 1942, try again in July 1942. Try again in Jan 1943.

You've brought this up many times and I get it now, it's a very good point. The degree to which the people running these firms (and their associates in the military / government) had to be an oracle and predict the future accurately is really quite daunting.

or at least the US Navy the difference in range was not that great until after Midway. Actual range of a SBD carrying a 1000lb bomb was not great. Or range of a Devastator carrying a torpedo. The book ranges do not include either circling while forming up or the time spent circling waiting to take turn landing. Once the TBFs show up there is a disparity in range.

That's fair, though the SBD did seem to outrange the F4F even with bombs (I guess the light bombs in scout mode). But the bigger issue here is that Wildcats didn't just work for the Navy. Especially in USMC service they would often be flying on missions with land based Army bombers like B-25s and A-20s and B-26s etc., even the heavy bombers sometimes. So you needed the range for that. Better range was almost always helpful I think. And then third of course range is (more or less) also endurance, and a Wildcat needs to be able to fly CAP for a long time, might get into multiple combats on a given mission.

The other thing, that I have harped on for years, is that what was technically possible in 1943 (or after) was not technically possible in 1938-39-40-41, mostly.
The aircraft designers of the 1930s (and various air ministry's) were not totally corrupt or stupid. Ok maybe the British ministers were getting pay offs from the Greater Sherwood Woodworks Guild for the continued production of wooden propellers

there is only so much you can do with a single 700-1100hp engine and the power changed with every year. Not all countries improved at the same rate and improvements were not an even slope but rather plateaus and slopes. The Object of an escort fighter is to fight at or near the end of the bombing mission with some hope of winning.

Or really, to put a finer point on it, at least some hope of protecting the bombers from being shot down without being shot down themselves. More on this a bit later when i start my P-39 thread.

A fighter only has a certain percentage of payload available (drop tanks excepted) and you have to count the pilot and gear, the radio/navigation equipment, the fuel/oil and the guns and ammo. You can swap somethings around, like less guns for more fuel but most fighters are designed with nearly the same pay load for a roughly equal engine power.
Now in the 1930s and the first few years of the 1940s the radios used in the fighters were not long ranged. Fighter that got lost was probably doomed.
Even if you could fit in a longer ranged radio (heavier) and operate it you just lost something else, speed or climb or turn or 10 gal of gas, or two 7.7mm machine guns + ammo.
You don't have 1942 flaps in 19388-39.
You have to get your escort fighters out of the exisitng airfeilds. British may have had more problems with this, but they were increasing the size of the airfields every year.

I would say all true but it's quite remarkable the vast differences in range from one aircraft to another with basically the same size / power engine.

Most Air ministry's thought they needed a twin-engine fighter for escort work, to handle the extra fuel and the radio and navigation chores. Radios made faster progress than some airframe designs. Some engines made good progress with much improved power at not much weight increase over early engines. British finally decided to use better propellers and could lift larger loads out of the same size airfield. Now they had to decide how to use the improved payload. More fuel? better protection? Better radios (and IFF)? more firepower?

...bombs? External fuel tanks? But I don't think all those items on your grocery list weigh precisely the same.

A Spitfire I with a wooden prop, early radio, no protection was not going to be a good escort fighter in 1938 even if you hung a 90 imp gal tank underneath.
Now when the Spitfire could have been used as an escort fighter is a discussion. Which mark with which engine and what state of accessories (radios. etc). But just saying they did in it in 1944 and that means they could have done it in 1940 (two pitch props) ignores reality.

I hear a lot about the abandoned Spitfire Mk III project. which maybe shouldn't have been abandoned. If you had something like a Mk VIII but a year or two earlier, that could have helped a lot.

The 109 is in the same boat but some of the reasons are different.
If you use a heavy fighter (lots of fuel) you may be able to keep the speed up, but you have worse climb, less acceleration and a larger turning radius than your opposing interceptor fighters. Unless you sacrifice something else, radios, armor, protected tanks and so on.

And worse roll, inevitably, which is one of the overlooked but probably most crucial elements for air combat.

 

[ggiumarra]

So I am not going to reply to all of your post, since some were not directed at me, a couple I already addressed and some are not very important in this particular discussion (like the take off distance question).

Ferry range solved or tried to solve the big problems the US had in getting its aircraft to the front lines, even ports in the US, flying ferry routes and so on, add the 1942 ideas about self defending bombers, issues like the problems of a lone pilot navigating themselves and unsurprisingly the idea of a large combat radius came second, debates about whether combat tanks should be self sealing.

The implication is that I do not appreciate that. One of the first subjects I wrote about in my study was the importance of ferry range for fighter a/c, especially in 1942, citing Harold Larson, The Army's Cargo Fleet In World War II and other sources. There would not be "lone pilots navigating themselves" because it was pretty much a standard method to have fighters accompany bombers that have navigators on them when on long flights over water. This is how the Spitfires navigated from carriers in the Med. to Malta (the guide plane departing Gib. and rendezvousing over the carrier), and the P-38s made it from Gander to Scotland (N Atlantic Ferry Route) later in the year. Already at the end of January, 1942 the plan was to send all B-26s for Australia from Hawaii via the So Pacific Ferry Route which had a max hop of 1200 miles (again, the original P-51 could go 1750 miles with its internal auxiliary tanks, a capability verified by one of the AFRHA docs I recently found).

But combat range is also very important and my point was merely that it appeared that that capability, instead of being primary, equal to, or a close second to the first (ferry range), was apparently, for good reason or ill, sidetracked by Materials. Basically nothing was done for the P-39 or P-40 and the P-38's ferry tanks, which I believe came into being on the initiative of Lockheed even before February 1942, and the famous 200 gal. belly tank for the P-47.

P-38 and P-51 were fitted with the relevant racks in 1942.

I do not believe any of the P-51s manufactured in 1942 came from the factory with bomb or drop tank racks, though I know the British successfully fitted one or more with both on an experimental basis (as many other fighter types were as well, even out in the field), suggesting that it would be an easy modification to add that feature on the production line, if an order came down to do so.

Doolittle was in Tunisia and he was reacting like just about everyone to what the Mustang had and could promise. The word was spreading.

From what drgondog said in a previous post it sounds much more specific than that and if you read the document itself it does sound like Doolittle was basing his evaluation on more than "what everyone was saying".

Combined arms does that. After the initial landings how many days of combat did the US forces on Guadalcanal face where at least a regiment was involved? For the desert war in 1942 at least a division? What were the relevant air force sortie rates?
.
.
.
In terms of numbers of lower level sorties in 1943, how do you think they compare with 1st and 2nd TAF and 9th Air force June 1944 onwards?

If I was talking about CAS or other direct support of ground troops (which, so I am not again misunderstood, I do believe is important) then perhaps these comments would be more relevant, though the importance of long range for a fighter, which is what I have been emphasizing, would be quite a bit less. I am mostly talking about how the original P-51 could have played a very useful role in friendly convoy protection and also as escort for anti shipping strike forces as well as reconnaissance for both of those types of missions and also, possibly, in support of naval surface forces, including carriers. I probably should have been more clear about what I was talking about earlier, but always have the impression that my posts are on the long side (plus they are a major time suck!)

...forces in and around Britain would generate a way disproportionate amount of allied air activity, it was also generating data on what it was going to be like taking on the main Luftwaffe...

I have no problem with that statement as far as it goes, but I am talking about other important ongoing fighter tasks and missions which had a good chance of making a bigger impact on the war sooner.

The significance of the higher altitude operations in 1942 were more learning, for both sides, about what was to come in 1943, as the turbo equipped USAAF finally deployed its modern types in numbers.

Well, I have to say that generally speaking the "it may look like we are wasting our time, but we are gaining valuable experience that will pay off handsomely in the future" line is all too often trotted out to defend unsound operations that reflect poorly on someone's favorite leader, military branch or sub-branch (like FC, BC or 8th AF/15th AF) or piece of military hardware. Perhaps what you are referring to does not fall in that category, however.

The P-51 was unlikely to become carrier capable, so how exactly does this work?

"Unlikely" is putting it conservatively. AAF a/c did operate from Midway (not during the battle, but some P-40s were sent immediately afterwards on the Saratoga - there was no real opportunity to get them there earlier) and on Guadalcanal both during the fight to drive off the Japanese and afterwards. The original Mustang, however, with their original internal auxiliary tanks, could have flown direct to Midway from Hawaii and via the South Pacific Air Route to just about anywhere in the South or SW Pacific (see? I do acknowledge the importance of ferry range capability).

...end 1941 saw losses and diversion of planned reinforcements to India. The Beaufort battled engine problems into 1941, the Wellington was considered too vulnerable to attack by day. The RN provided Swordfish and Albacore squadrons.

I am dealing with the 1942 time frame, which the fact I referred to Julius (Harpoon/Vigorous) and Pedestal (do you really think I didn't know it was in August?) points to the fact I am not even talking about early 1942, so we are talking about the Beaufort at first to possibly be replaced by torpedo Beaufighters later on (there is def. already talk of using them in that role by late summer, but they don't seem to have been used like that until later).

The RAF used Beaufighters as the long range fighter type, a dedicated navigator really helps over ocean sorties.

You guide the fighters towards the convoys and back over your land air base using IFF with your fighter controllers on either end - the Harpoon convoy had a special FC with VHF radios on HMS Cairo that worked brilliantly with Spitfires that also had VHF, but, unfortunately, someone forgot to inform the RN officers who setup the FC on Cairo that the day Beaufighters, had HF radios (night Beaufighters had VHF) on them so they could not be vectored to intercept the inbound Axis bombers seen inbound on radar at a critical moment of the operation. Note that Mustangs or more LR Spitfires (meaning just Spits that had available drop tanks, all the Spits on Malta could use drop tanks) would be used instead of day Beaufighters which were dog meat for Axis SE fighters (losses were very heavy during Op Julius), were only available in small quantities to begin with and, due to their twin engines, almost invariably came under friendly fire from the very convoys they were supposed to be protecting (this was not unknown for SE fighters, but seems to be far less frequent).

With strike forces, the Mustang or Spit would just rely on the navigation of the bombers they were escorting.

So how many aircraft would be based at Malta, given that will dictate how much commitment the Luftwaffe has to make? Does it include fast climbing fighters for defence? How many anti shipping sorties and therefore what sort of resupply rate will be required?

I do believe that I have already answered the "climbing fighters" question at least twice. Of course, they have to keep Spitfires there to satisfy this requirement and in any scenario they would outnumber Mustangs considerably. In fact (as I believe I have already stated), there may be no need for Mustangs if enough 90 gal drop tanks (or a combo of 90 and 30 gal) are supplied, although for naval recon (which are not typically flown at high altitude, btw) the additional drop tanks would be the best choice. To get them in (over and above the 90-gal tank brought in by every Spitfire sent to Malta) you have the possibility of bringing some in on cargo a/c or on a ultra-fast RN minesweeper that made periodic trips to Malta, or you just include them as cargo on the merchant ships being convoyed in, relying on a surge of Mustangs brought in at the last moment, as they did with the Beaufighter, to supplement the Spitfires for which there already was a supply of drop tanks (the Beaufighter was good a/c for many types of missions, but as Vigorous showed to no one's surprise, dead meat for SE enemy fighters). Mustangs flying from near Tobruk would also have been very helpful for Vigorous, bc the Kittyhawks from there for convoy protection during Vigorous were very effective it's only that their shorter loiter capability meant there was at least one gap in coverage that led to a merchantman loss. In the case of the Spitfires covering the Harpoon convoy as well as the Kittyhawks covering Vigorous there seems there were no losses while SE fighters were overhead.

As far as the number of a/c required the problem would be basing and supply. One source puts the number of shelters on Malta at this time as over 300, but original sources show they were straining to accommodate half that. There will def. need to be an increase from that, probably about 50% more (so around 200-225) or perhaps a bit less arguably would have been sufficient (I won't go into a breakdown for now, but certainly 90-100 Spits and a large number of torpedo bombers), but nothing like the increase in capacity involved for Husky, so, yes, there will have to be greater success for Julius to bring in especially food (starving workers don't build very many a/c shelters) as well as avgas (I will take the opportunity here to dispel the myth that the tanker Ohio carried aviation fuel; avgas came packaged, mostly in barrels on the reg. merchantmen while the Ohio transported kerosene, diesel and naval fuel), or, at the latest, Pedestal, which is what the increased long-range fighter capability would be designed to facilitate. This is getting long, so I will leave it at that for now.

How are losses on he ground avoided?

The same way they did historically. In the time frame I am talking about, ground losses were not nearly as severe as earlier in the war.

The axis did not lose any cargo on the Africa run until December 1940, when 10.65% was lost, percentage losses all causes for 1941 were 2.81, 1.46, 8.89, 8.04, 8.01, 6.19, 19.13, 12.56, 28.27, 20.37, 62.32, 18.01.

The Luftwaffe engaged in systematic suppression of Malta in early 1942, losses on the Libya run by month for the year.
0.07, 0.85, 17.30, 0.78, 7.24, 22.14, 6.45, 33.03, 20.00, 44.20, 25.86, 52.62, 68.79, but December had little cargo shipped.

Tunisia run, November 1942 to April 1943, loss rate 0.00, 28.52, 21.07, 22.81, 35.71, 41.23.

Italian merchant fleet losses to aircraft 1940 to 1942, ships/GRT, 15/35,904, 58/161,589, 71/144,238 Germany in the Mediterranean, none in 1940 then 5/16,639, 10/28,871

What your stats show is that some months there were light losses, while at other times there were heavy losses (it's a mistake to attribute all to Malta, however, since probably the majority came from a/c and subs not based on the island, at least post-Pedestal). Of course, the ultimate goal would be to drive the loss rate significantly higher and also hopefully start taking a big toll on the Italian escorts as well. (Note: it does look like you have 13 figures for 1942 for the Libya run by month for 1942)

I was hoping to answer another post at this point but won't yet bc I'm having trouble staying awake - hopefully that has not affected too negatively the quality of this response.

UPDATE (made a couple of clarification and typo changes now that I am semi-awake, though undoubtedly I still missed some): What does a "Bacon" reaction mean?

 

[Steamed_Banana]

That's a real good point about Mustangs as a compliment / part time alternative to Beaufighters.

Beaufighters can transition to the torpedo / rocket carrying role a bit earilier, they did very well in general (I am a big fan of the Beau) but as you note, when they had to tangle with single-engined fighters they sometimes got into serious trouble. Beaufighters with Allison Mustangs operating together by say late 1942 or early 1943 seem like a very strong option both for the Med and the Pacific, as well as for Burma and the North Sea to protect those Arctic convoys. Long range Mustangs will definitely be better for convoy protection and for bomber escort / bomber interception IMO. The Germans and Italians in particular lack any long range fighters and were relying heavily on often antiquated or barely suitable types (He 111, He 115, SM.79) for anti-shipping attacks out at long range. The Japanese did the same sometimes with G3Ms and G4Ms, who got wrecked when they ran into single engined fighters.

Just got to fit an RDF loop on those Mustangs (which most longer-ranged Allied fighters were getting in 1943), and give the pilots as much navigation training as possible and the best maps available. The issue of these guys having to fly and navigate long distances came up regardless with the Merlin Mustangs.

If you fix the ailerons and put a two speed supercharger in them a bit earlier you have a serious threat!

 

[Shortround6]

few points.

That's fair, though the SBD did seem to outrange the F4F even with bombs (I guess the light bombs in scout mode). But the bigger issue here is that Wildcats didn't just work for the Navy. Especially in USMC service they would often be flying on missions with land based Army bombers like B-25s and A-20s and B-26s etc., even the heavy bombers sometimes. So you needed the range for that. Better range was almost always helpful I think. And then third of course range is (more or less) also endurance, and a Wildcat needs to be able to fly CAP for a long time, might get into multiple combats on a given mission.

upload pilots handbook for sbd-3 dauntless

Hi All, uploaded pilots handbook for sbd-3 dauntless cheers Jerry

ww2aircraft.net

This is a 1942 manual and they later increased the max gross weight. I don't know how, beefed up a few things, fitted better tires, accepted increased airframe fatigue or???
This also shows the difference between early design (unprotected) and later protected loads and fuel capacities/ranges. By late 42 or 43 and operating at higher weights they could carry a large bomb and get over the visual horizon from the carrier (sarcasm). Later SBDs with 20% more power for take-off could do a lot more combinations of bombs and fuel/range. The SBD-5 was introduced in early 1943, how fast the SBD-3&4 left front line squadron service?
During 1939, 1940 and 1941 the Navy thought that escorting Army bombers was the Army's problem. Things in war rarely went according to plan. But in 1942it is too late to rewind the clock back to 1939 and ask for more range from the F4F, in case the Marines had to escort Army bombers.
Tactics also changed during the war. Putzing around at around 160mph at low altitude gave the F4F a fair amount of endurance. Did not mean they could actually intercept enemy attackers though.

Or really, to put a finer point on it, at least some hope of protecting the bombers from being shot down without being shot down themselves. More on this a bit later when i start my P-39 thread.

The US was building some of the longest-range fighters in the world (only the Japanese did any better) in the late 30s. But this was more for deployment than combat range.
From the P-35 though the early P-43s the US army was asking for between 164 US gal (620 liters) and 200 US gal (755 liters) for their single engine fighters. But this was built in ferry fuel (no drop tanks) and with unsafe for combat maneuver CG.
Problem was that even the B-18

could carry over 2000lbs of bombs around 1000 miles (maybe more) The B-18A got slightly better engines. Douglas beat the B-17 because they were cheap, 1/2 the price of the B-17s (even without turbos). 1937-38 was also when just about everybody thought that "the bombers will always get through" and the only solution to bombers was being able to out bomb you enemy. RAF had a number of policy and budget battles over that one.
Germans, even with their expeince in Spain.

Thought that three 7.9mm machine guns were good enough for the start of the BoB. Soon changed.
We know now that they were all wrong. But expecting escort fighters to match the ranges of bombers in the late 30s or 1940-41 was asking an awful lot.

I would say all true but it's quite remarkable the vast differences in range from one aircraft to another with basically the same size / power engine.

Well, a lot depends on the payload.
A P-36 carried a useful load of around 1100lbs, that includes the fuel, oil, pilot, guns/ammo and 'extras' like radio and oxygen?
Of course the P-36 was carrying one .50 cal and one .30 cal and the .50 cal gun was 73lbs compared to the 27lbs of the .30 cal gun. 109 could carry four 7.9mm guns for about the same weight. Somebody else might carry two 7.7mm guns and trade armament for fuel.
You could put another 366lbs of fuel and oil into the P-36 (it had the tanks), but you were not supposed to fight at that weight.

And worse roll, inevitably, which is one of the overlooked but probably most crucial elements for air combat.

Roll was not understood early on. Some designers did better than others. Sometimes minor changes could have large results.
Sometimes just re-rigging.
Sometimes changing to metal covered ailerons, fabric covered worked at lower speeds but then the aerodynamic forces made the fabric covering balloon and ruined the shape and airflow.
Short wings helped. Ailerons that went all the way to the wing tips help.
weight distribution helped, at least with roll acceleration even if not peak roll.
But being too twitchy could also hurt.
Getting a good balance was important.

 

[ggiumarra]

Unfortunately, Lowell Ford passed away in late 2024 and Bob Gruenhagen in Jan 2025. Bastard Stepchild could not have been done without them.

Sad to hear that. If I ever produce anything half as good as you all did on that book, I will be proud.

Significant source material for the XP-51F and other Lightweights came from their original NAA sources.

If memory serves, Ford was the one with the original NAA docs. Do you still have access to them? Two things I found in Michael O'Leary's "Production Line to Frontline" book on the P-51 I would feel a whole lot better if I could confirm and get fuller context from original docs (or from someone with extensive knowledge on the subject such as yourself):

1. "During December 1941, North American was building 3 1/2 Mustangs per day to fulfill the British order, but Kindelberger felt that he could raise production to...ten fighters per day within three weeks of a substantial Army order" (p. 43; this may be sandwiching Col. Sanders's of the 51st FG recollections from mid-1942 back into December, which I guess is when he flew the Mustang in So Cal, but we are relying on his memory from months later as to what K. actually said, so I would like to get this straight. I recall seeing this same representation - triple production within 3 weeks - as being a K. message for Arnold also from Dec 41, but I cannot find it and so am wondering if I got it wrong.)

2. "North American officials seriously considered the implications of mass-producing the new B-model alongside the huge order for 1200 P-51As, and, accordingly a simple and efficient production line was designed and implemented that could accommodate the delivery of 20 Mustangs per day." Later NAA reconfigured Ingelewood to build -Bs only when the -As were cancelled. (p. 74)

Make sure you extract Case History of Droppable Tanks and Case History of FAREP from Reel A2069 before finalizing your conclusions.

Yes, you mentioned that in a previous post, but I already poured over both 10 days ago or so and what I found there was the basis of many of my comments of the last several days.

I can't tell you how elated I was to find those two case histories. It did hit me towards the end of my first pass at them, however, that they are a curated set of documents. I am not charging deliberate bias here or anything, but it struck me that the 1945 introduction to the FAREP case history states "Initiated to insure continuous fighter cover for bombardment aircraft." While that is perhaps a fair statement of what it became later on, for 1942 and early 1943 that seems highly misleading at best. More to the point, though another summary of the FAREP study in that collection refers to the conference in Arnold's office on 20 Feb 1942, there is nothing more about what actually was said there, and what Arnold's actual directive was, which, for one thing, would clue me in as to whether Materials did truly push Arnold's original in a different direction. I would also like to know some more about the actual content of the "several cablegrams from the various theaters of operation" which "in almost all cases expressed a demand for increased range in pursuit". Now it is conceivable some or all of these related to ferry range, but it seems more likely they had more concerns about combat range.

As an aside, around this same time Wavell from his ABDA command sends a flaming message back to London (paraphrasing) "why do the bloody Japanese fighters have so much more range than ours? It is a MAJOR problem that is a HUGE factor in us getting our arses whipped!!" This starts a back and forth between Churchill and Portal on the subject of fighter range, drop tanks, etc. I deal with that in Part I of my study, but don't want to go off too much more on that tangent here other than to add the ironic thing was that the Dutch gov't in exile was asking the Brits in mid-1941 to get an allocation of Mustang Is, undoubtedly for use in the NEI! I'm sure Wavell would have been quite happy to get those (to close the range gap somewhat) if that had actually taken place in time (the delay in Mustang production in 1941 prob. - I think due to lack of Allison allocations, but it's also possible due to working out problems with the a/c itself or the assembly line, I wish I were more certain - made that impossible).

Hey, if your answer to this or any of my other questions is "it's in the book" I can certainly wait since I know replying to these messages can take up a lot of time maybe best devoted to "real" work.

If you do not have Ludwig's "P-51 Mustang, Development of the Long Range Escort Fighter", I recommend it. I carefully checked on several of his source documents that are relative to the animosity he portrayed by Echols and Stratemeyer and Saville against the purchase of the Mustang and found them valid. He, like I, draws conclusions based on fact and opinions based on fact. In some cases opinions dominated.

I most certainly do! I've had it for several years. I do find it benefits from a LOT of good research, but it could have used a better editor since it jumps around a lot IMO. Yeah, while the Echols narrative in there seems to be based on fairly solid, I was interested to see that the take in "Bastard" (also manifestly a well-researched work - though it didn't keep me from verifying the drop-in fuel tanks thing with my own two eyes when I was last at the British National Archives and had access to the Mustang I's pilot manuals) was similar.

The funny thing is that looking back into Ludwig recently (prompted by the discussion here) I found two significant things in that book that I failed to note before:

1. On p. 74 you see not only an AAF officer in March 42 referring to the "competing" B-25 production question when it came to shutting down the Mustang, but also the claim that "no [Allison] engines are immediately available due to the planned increase in production of Bell P-39s to 600 a month." I am thinking Bell's extra allocation of Allisons is related to the recent cancellation of the P-60A (something I found in the AFHRA docs), though since the P-60A wasn't due start production until Sept. maybe it wasn't since the quote states "immediate", but regardless, there is a potential source of extra engines for the Mustang without cutting anything in already approved programs. I might add that P-39 output averaged 200/mo the last half of 1942 (avg. is less if you include earlier months) and peaked for the year at 302 in December. Overall peak was 511 the following April, so it never got that close to 600/mo.

I really think the nearly 15,000 Allisons produced in 1942, despite all the padding another contributor to this thread wants to throw in there, gives plenty of room for a substantial (at least 1,000) additional "Mustang I" production in 1942 (it also appears that the P-51A could have started production earlier as well). There were only 2812 AAF fighter a/c arrivals overseas anyways, and some of those were P-38s, and front line fighter forces at that time were not super big, so even that amount could have meant a lot compared to the force actually deployed.

2. Perhaps even more to the point, on pp. 75-6 you have Gen. Fairchild directing in April 1942 that more P-51s be produced as "dive bombers" even before the mods to put the dive brakes on have been completed, which that interim production could "be used as fighters". So this relates to what I posted before that I don't completely subscribe to the "they only had budget remaining for dive bombers" argument as to why more Mustang fighters could not have been procured in 1942. I have thought for a long time "just put some bomb shackles on and call them a dive-bombers" so I was pleased to discover that someone in authority (Fairchild was the superior to Echols when it came to procurement at least, according to Ludwig) at the time had already come to the same solution. There are at least 2 other ways it (meaning, getting around the supposed 1942 limit) could have been done that I can think of. And now we see how far Allison production exceeded fighter production that year. The only thing objectively limiting Mustang production in 1942 IMO was ink on a contract and the true capacity of the Inglewood assembly line, so it is not out of the question that up to 2600 could have been made that year. Even well under that number could have provided ample numbers to make real contributions that year that might have had an outsized impact on the war, when you consider the relatively small number of fighter a/c on which a number of important operations turned. Really, a few hundred more on top of RAF allocations might have had a real impact if used correctly at the right place and time.

...all the way through to at least the run-up to Overlord...

I want to take the opportunity to clarify a statement I made in an earlier post, which, upon reflection, was really misleading. What I meant about the Allies overwhelming the GAF with lots of good pilots and planes was over France in support of Overlord, not previous to that. I also do NOT mean to suggest that fighter escort, specifically Mustang escort of AAF heavies over Germany was a waste of time or did not accomplish anything significant. I am only pushing back against the idea that it "destroyed" the Luftwaffe and the like. Lacking the Mustang in early 1944 GAF fighter losses probably are significantly less, etc. so the air war over Normandy would have been more involved and costly, but I don't see a chance the GAF could ever have been strong enough to make a major difference during a cross-Channel attack either in mid-1944, even without as big of an air campaign deep into Germany as what took place (there's really no chance of 8th and 15th AFs standing down completely) or even back in 1943 or 1942. That's a major theme of Part II of my study. In fact the record from German sources is clear - the best way to attrit their fighter forces is to mount major ground operations with support from fighters and AA (the accomplishment of early 1944 was truly doing it the hard way - though given all the existing factors it still was overall the best use of AAF forces there during that time period). The Merlin Mustang, however, also undoubtedly saved a lot of AAF bomber crews - so I have no problem with the concept reflected in the subtitle "The Bastard Stepchild that Saved the Eighth Air Force" despite the impression my earlier post might have given.

As to Echols, Arnold, Spaatz, Eaker, Lovett, Winant roles in development of long-range-fighter-escort not only the case histories named above are (IMO) important but also the various bios written by many are important to read, because many are contradicting on core discussions, such as the 'bomber mafia', etc.

I will be very interested to read about those.