1944, wow
It took sooo long to resolve something that should have/could have been resolved so much sooner.
That was how I remember it being discussed on a programme about Lindbergh, everyone was worried about running for long periods with a very lean mixture boost levels and RPM wernt mentioned but TV programmes tend to dumb down a bit.
I Wonder if the problem would have been recognized and addressed any sooner if the Lightning had been adopted (and more exhaustively tested) by the RAF.
The Allison engined aircraft they did recieve seemed to get fairly exhaustive testing with some notes beyond that the USAAC/AAF was doing, or at least beyond that the US was forwarding to standard squadron training. (the extreme range figures for the P-40B in testing seem to point to rather careful use of low RPM and full manual lean mixture control)
British reports remarked on the Allison's ability to operate smoothly at considerably lower RPM and somewhat leaner mixture than the merlin. I'm not sure if this resulted in such practices being used for long-range cruise in RAF/Commonwealth service, though.
Plus a somewhat different context given the more variable boost pressures possible on a turbocharged aircraft. (and relatively little power lost to the turbocharger through exhaust backpressure and the integral superchargers of P-38 Allisons -compared to the 8.8 or 9.6 supercharger gearing on P-40s and P-39s)
At least a few hundred hours of twin time was needed to fully master the P-38. The ETO brass did not like the aircraft.
The engines were government furnished. Any modifications had to be run through the government and Allison for approval, so changes weren't always quickly forthcoming.
There were many things that Kelly Johnson wanted to do to the P-38 but wasn't able to because of war demands. I remember Tony mentioning that Johnson wanted to put a stick in the P-38 and get rid of the yoke.
I've read about the yolk vs stick issue several times before and it does seem rather unfortunate even from a paractical standpoint alone. (aside from being easier for fighter pilots to transition to, a stick clutters the cockpit much less, giving easier view to the complex array of instruments lining the P-38 dashboard and a stick might have given more leverage to operate the heavy ailerons on early non-boosted models)
Aside from that, the mention of political issues and UTO brass disliking the P-38 in general might be relevant to question I posed in the RAF day bombing thread, but is probably more relevant here:
From:
http://www.ww2aircraft.net/forum/av...ng-campaign-results-42824-11.html#post1191095
Hmm ... shifting the topic a bit, but still somewhat relvant: in terms of similar manufacturing cost/resources, would ordering more early model P-38s (or modified turbo-less ones) have been more useful than similar resources going into P-39 and/or P-40 production? (this includes potential use as a medium altitude escort fighter)
In terms of sheer logistics would the P-38 have made more sense to produce in quantity (with or without turbos) in place of the P-40 and P-39 in roughly half the numbers? (maybe slightly more than that if outsourced production had transitioned efficiently enough and allowed relatively streamlined production of a single type -or variants of a single airframe -including changes required for an actually practical non-turbocharged variant, unless engine production becomes the bottleneck in which case it'd be exactly half)
The P-38 had the capacity for 2 to 4 times the bomb load of the contemporary P-40 and P-39 along with considerably longer range at the same time throughout its production. (more than double the bomb load and double the range -with load- in some configurations) On top of that it had a heavy, tough airframe and twin engines making for better survivability. Then the generally superior armament to either of those single engined contemporaries (be it guns used, concentration of fire, rate of fire, or ammunition capacity, there's a list of advantages -not to mention configuring the 20 mm cannon with a cocking mechanism allowing jams to be cleared by the pilot in-flight)
With similar ram intake and short exhaust stacks optimized on the P-40 and P-51, low/medium altitude turbo-less P-38s likely would have been generally more capable aircraft than similarly powered P-40s and P-39s (and better fighter-bombers than allison P-51s). Possibly better low-altitude performers than their turbocharged counterparts (at least early on) and potentially able to be equipped with the wing tanks in place of the intercoolers. (or at very least saving weight from the removal of turbos, intercoolers, and related exhaust and induction ducting) On top of that, the early P-38's problems were considerably less pronounced in low/middle altitudes and those ranges were far more often flown in the PTO and (especially) MTO as it was.
With the P-38s historically costing around double that of P-40s and P-39s (perhaps a bit less for turbo-less models), it seems like they'd still be more valuable engine per engine and pound per pound than their single engine counterparts. The performance on top of the sheer versitility of the arcraft to accomplish nearly anything the P-40 or P-39 could do ... or often what it might take two of them to achive, in addition to long range work totally impossible for either of the others to accomplish, it just seems a more valuable overall aircraft.
The only other logistical problem comes down to pilot training. You'd only need to train around half the pilots, but each pilot would need a considerably greater investment made in their training compared to the P-39, P-40 or the other single engine US fighters. (P-40 more so than P-39 given the handling characteristics) Granted, omitting turbo controls would simplify matters somewhat and simplify some aspects of training compared to the P-47 (plus lack of need to compensate for engine torq in normal operation), but twin-engine training in general would be the major hurtle.
That still may have been logistically less costly than training double the number of single engine pilots but leaves less room for error in questionable training. On the other hand, average P-38 pilot competency than happened historically may have been better if such emphasis was put on twin engine training.
Anything along this line would also likely be in exception to the P-40/A/B (and Tomahawks) but possibly supplanting P-39D and P-40D production depending how fast the transition to P-38 production actually took place. (the P-38 would have to be a surefire design before distributed/expanded priority production even made sense, lest they have delays that lead to having too few servicable aircraft early-war)
With the P-40's earlier initial production, friendlier handling, longer range, generally better reputation among pilots and crew, and older, proven airframe, keeping that aircraft as the main early 'backup' fighter would have made sense to keep production up until the P-38 was really proven. (and before the Mustang reached mass production) While cancelling the P-39 outright (export orders notwithstanding) in favor of second-sourced P-38 production seems somewhat viable, political issues with Lockheed-Bell cooperation notwithstanding. That and the P-40F and L wouldn't be competing with P-38 engine production either. (aside from the separate topic of those engines being more valuable if mated to P-51 airframes)
Delays in the P-38 testing program with the crash of the original prototype along with the unfortunately lacking modifications made for the non-turbocharged Lightning I hamper the viability for this to have happened. A better performing Lighting I (or at least an improved follow-on) along with more aggressive early testing to work out the major bugs in the initial P-38 design would have all made its merits more clear as a domestic and export aircraft. (to the point the British may have seen it as genuinely worthwhile over purchasing double the P-40s and P-39s)