By Joe Baugher
First major production version for the USAAF was the P-38E (Model 222-62-09). It differed from the D-version in having a 37mm cannon with the 15round magazine replaced by a 20mm with 150 rounds. It also had a revised nose section with double the ammunition capacity of earlier versions, improved instrumentation and a revised hydraulic and electrical systems, and a SCR-274N radio. In the middle of 1941, Hamilton Standard Hydromatic propellers with hollow steel blades were replaced on the production line by Curtiss Electric props with dural blades.
With its turbo-supercharged Allison V-1710-27/-29s top speed was 395 mph at 25,000' and 20,000' could be reached in 8 minutes. Weights were 11,880# empty, 14,424# gross, and 15,482# max take-off.
Early in its life the P-38 earned a reputation as a pilot killer; a terminal velocity dive was believed by many pilots to be a fatal maneuver. It was possible in a high-speed dive to overstress the plane during pull-out, and a number of P-38s lost empennages, usually with fatal results. It was later determined that those problems were the result of the effects of compressibility and that ALL aircraft had problems in those speed ranges, but P-38 was a pioneer in high-speed flight and thus got a bad reputation.
The most obvious effect of high speeds was the tail flutter, at first believed to be caused by turbulence from the wing. The eventual correction worked out by Kelley Johnson was a change of incidence of the entire empennage and the addition of fillets at the fuselage-wing junction.
The P-38E was still not considered combat-ready and most were redesignated RP-38E, while others were used for various experiments. [41-1983] tested several features that ended up being used in the P-38J and P-38K. Others were modified by Lockheed to test drop tanks as developed for the P-38F.
One modified P-38E deserves special note. During the spring of 1942 the rapidity of the Japanese advance caught everyone by surprise, and the AAF became concerned about shipping its aircraft to the far reaches of the Southwest Pacific. One suggestion was to equip P-38s with twin floats under the nacelle. The wheeled retractable gear would be retained and the floats removed before combat operations. However, a way to keep the tailplane free from sea-spray was needed, so, as an experiment, [41-1986] was fitted with lengthened tail booms, its fins and rudders were recontoured and its tailplane raised nearly three feet. In addition an engineer-observer's seat was installed aft of the cockpit in place of some of the radio equipment. It was only flown as a landplane, the proposed twin floats never being fitted, but such conversions proved to be unnecessary when, by the end of 1942, the Navy was able to provide adequate shipping of aircraft and materiel to the Pacific islands.
[41-2048] was converted in 1942 as a two-seater, with an elongated central nacelle extending aft of the wing trailing edge, intended as a research vehicle to find ways of reducing drag, and was the only P-38 to have have a full dual set of flight controls. Later it was modified with enlarged laminar-flow wing sections outboard of the engine booms, complete with slots and boundary layer control by means of exhaust bleed air.
One P-38E was used at Orlando in 1942 to demonstrate the feasibility of towing one CG-4A glider, but a proposal to modify Lightnings to tow "trains" of up to three troop-carrying gliders was rejected.
POP: 210 P-38E [41-1983/2097, 2100/2120, 2172, 2219, 2221/2292].
Some aircraft originally ordered as P-38Es were completed as F-4-1 (Model 222-62-13) unarmed photo-recons. They were powered by 1150hp V-1710-21/-29s and carried four K-17 cameras in a modified nose. In service, they carried a pair of 150-/165-gal drop-tanks. Most were retained for training and their restricted-use status was reflected in their redesignation as RF-4-1.
POP: 99 F-4 [41-2098/2099, 2121/2156, 2158/2171, 2173/2218, 2220].
The P-38F of late 1942 was the first Lightning to be considered fully combat-ready. It included 377 US-ordered aircraft, plus 150 planes that had originally been ordered under British and French contracts. It was powered by 1325hp turbo-supercharged Allison V-1710-49/-53s and had the same armament as the E-version. Weights were significantly higher: 12,264# empty, 15,900# gross, and 18,000# max take-off. Maximum speed was 395 mph at 25,000' and 20,000 feet could be reached in 8.8 minutes.
There were five separate production batches of the P-38F, differing from one other mainly in internal equipment. First was P-38F (Model 222-60-09). Next was P-38F-1 (Model 222-60-15), which was modified after delivery to carry a pair of drop-tanks or a pair of 1000# bombs under the wing center sections. Each rack could also carry a Smoke Curtain Installation or a 22" torpedo. Radio was SCR-522 and -525. P-38F-5 (Model 222-60-12) was built from the onset with provision for drop-tanks, had revised landing lights, desert equipment, identification lights, and various other minor improvements.
P-38F-13 and P-38F-15 were ex-British contract aircraft (Model 322-60-19s). The P-38F-13 had modified instruments meeting British Approved Specification 2338. The P-38F-15 introduced combat flaps that could be rapidly extended to 8° during maneuvers to tighten a turning radius. Twenty P-38F-1 airframes with 1325hp V-1710-49/-53 were completed as F-4A-1 (Model 222-60-13) unarmed photo-recons with four K-17 cameras in a modified nose.
POP: 128 P-38F [41-2293/2321, 2233/2358, 2382/2386, 2388/2392, 7486/7496, 7498/7513, 7516/7524, 7526/7530, 7532/7534, 7536/7538, 7542/7543,7545/7547, 7551]
POP: 149 P-38F-1 [2322, 2359/2361, 2387, 7484/7485, 7497, 7514/7515, 7525, 7531, 7535, 7539/7541, 7544, 7548/7550, 7552/7680]
POP: 100 P-38F-5 [42-12567/12666]
POP: 29 P-38F-13 [43-2035/2063]
POP: 212 P-38F-15 [43-2064/2184]
POP: 20 F-4A-1 [41-2362/2381]
P-38Gs began to roll off the production lines in June 1942, basically similar to P-38F apart from a change to the1325hp Allison V-1710-51/55 (F10) engine with increased boost ratings; however, the engine was limited to 1150hp at 27,000' because of inadequate cooling. In addition, the P-38G carried a SCR-274N radio and A-9 oxygen equipment.
Production was divided across six blocks. There were 708 US-ordered Model 222-68-12 aircraftP-38G-1 was generally similar to the P-38F-15 but with the new engines, improved oxygen equipment and more reliable radios, P-38G-3 had B-13 superchargers, P-38G-5 had revised instrumentation, P-38G-10 combined the improvements introduced in the two previous blocks with winterization equipment, provision for carrying 1600# bombs underneath the wing center section or a triple cluster of 4.5" rocket launchers on each side of the central nacelle. The 374 Model 322-68-19s (174 P-38G-13s, equivalent to the P-38G-3 and 200 P-38G-15, corresponding to the P-38G-5) came from the cancelled British contract for Lightning IIs which was taken up by AAF.
Unarmed photo-recon versions of the P-38G were produced as F-5A. A single F-5A-2 (Model 222-62-16) was completed by modifying P-38E airframe [41-2157] with V-1719-21/-29 engines. All other F-5As (Model 222-68-16) had P-38G airframes and 1325hp V-1710-51/-55s. F-5A-1, -3, and -10 had the same modifications as P-38G variants with corresponding block numbers and came off the production line in parallel with their fighter counterparts. All were unarmed and carried five cameras.
One F-5A-10 was modified as experimental two-seat recon XF-5D. The camera operator was located in a glazed nose compartment with two forward-firing .50 guns. Three K-17 cameras were installed, one underneath the nose and one in each tail boom.
[42-12866] was used as a test-bed for the proposed XP-49 armament (two 20mm cannon and four .50 guns). AAF at Wright Field also undertook preliminary design for a proposed derivative of the P-38G with a 75mm cannon in a revised and enlarged central nacelle, but that never got past the initial design stage.
The P-38G had a loaded weight some 200# less than the P-38F and was the most widely-built version of the early Lightnings. 1,082 P-38Gs were delivered by March 1943, with 181 completed as F-5A and another 200 as F-5B with camera installations similar to F-5A-10, but with engines and airframe identical to those of the later P-38J-5.
POP: 20 F-5A-1 [42-12667/12686]
POP: 1 F-5A-2 (mod) [41-2157]
POP: 20 F-5A-3 [42-12767/12786]
POP: 140 F-5A-10 [42-12967/12986, 13067/13126, 13267/13326]
POP: 1 XF-5D (mod) [42-12975]
POP: 12 P-38G-3 [42-12787/12798]
POP: 68 P-38G-5 [42-12799/12866]
POP: 548 P-38G-10 [42-12870/12966, 12987/13066, 13127/13266, 13327/13557]
POP: 80 P-38G-13 [43-2185/2358]
POP: 80 P-38G-15 [43-2359/2558]
The P-38H (Model 222-81-20) differed from earlier versions in being powered by 1425hp Allison V-1710-89/-91s and with automatic oil radiator flaps solve a chronic engine overheating problem and enable military power above 25,000' increased from 1150 to 1240hp. An M-2C cannon took the place of the M-1 and the bomb capacity for each underwing rack was raised to 1600#. In most other respects, it was identical to the P-38G-10. The first P-38H-1s went into service in May 1943. The P-38H-5s were fitted with B-33 turbos for improved high-altitude performance instead of B-13s
Weights were 12,380# empty, 19,500# normal loaded, 20,300# maximum loaded. Top speed was 402mph at 25,000' with 20,000' attained in 6.5 minutes. Service ceiling was 40,000'. Normal range was 350 miles, maximum range with external tanks was 2,400 miles.
POP: 226 P-38H-1 [42-13559, 66502/66726]
POP: 375 P-38H-5 [42-66727/67101]
Now comes the Lockheed P-38J and follow-ons.
SOURCES as previous.