P-38 Lightning
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The Lockheed P-38 Lightning was one of the most important American fighters of the Second World War. Although its operational record was somewhat mixed, in general, the P-38 was a fast, powerful and capable twin boom aircraft that performed well in a wide range of roles.
The aircraft had twin booms with the engines mounted forward and a single, central nacelle containing the pilot and armament. The engine sounds were a unique, rather quiet "whuffle," because the exhausts were muffled by the turbochargers of the twin Allison V12s. The canopy could not be opened without severe buffeting, so pilots were often too hot in the tropics. In northern Europe, the distance of the engines from the cockpit prevented effective heating of the cockpit, thus it was always either too hot or too cold. However, late variants of the P-38 received modifications that solved this problem.
Design and development
Lockheed designed the P-38 in response to a 1937 United States Army Air Corps request for a high-altitude interceptor, capable of 360 mph at altitude of 20,000 ft, (580 km/h at 6100 m). The Bell P-39 Airacobra and the Curtiss P-40 Warhawk were designed to meet the same requirements.
At that time, US piston engines could not push fighter performance to ideal limits so the Lockheed design team, under the direction of Clarence “Kelly” Johnson decided to use two turbo-supercharged 12-cylinder Allison V-1710 engines which had not been rated at even 1000 hp (746 kW). The P-38 was the first plane developed by the new Skunk Works team in Burbank, California.
Johnson's concepts covered a range of configurations, but the Lockheed team chose twin booms, seen earlier on the Fokker G.I, to accommodate the empennage and the engines with a central nacelle for the pilot and armament. The propellers rotated in opposite directions to eliminate the effect of torque. The superchargers were positioned in the booms, behind the engines. Armament comprised of four machine guns in the nose of the nacelle clustered around a cannon. The design was the first fighter to utilize tricycle undercarriage.
The prototype Lockheed Model 22, later designated XP-38, rolled out in December 1938 and first flew on 27 January 1939. It set a cross-continent speed record by flying from California to New York on 11 February 1939 in seven hours, two minutes, including two fuel stops. Unfortunately, the prototype landed short of the runway in New York and was wrecked, much to the distress of the Lockheed engineering team. They had opposed the flight, but it was done at the insistence of General Henry "Hap" Arnold, commander of the USAAC, as a publicity stunt.
Although the loss of the aircraft was a serious setback (putting the program back two years), on the basis of the record flight, the Air Corps ordered 13 YP-38s in April 1939. If the XP-38 had not been destroyed, orders would not have been placed until the prototype had been thoroughly evaluated.
P-38 flying over California.
However, manufacture of the YP-38s proved troublesome, and the first example didn't roll off the production line until September 1940, with the last delivered in June 1941. Although they looked much like the hand-built XP-38, they were substantially redesigned and differed greatly in detail. They were lighter, and included changes in engine fit, particularly in that propeller spin rotation was reversed, with the blades rotating outwards (away) from the cockpit at the top of their arc rather than inwards as before. This change, according to Kelly Johnson, improved the aircraft's stability as a gunnery platform.
Although weapons were not fitted in most of these aircraft, they were designed to be armed with two Browning .50 calibre (12.7 mm) machine guns with 200 rounds per gun, two .30 calibre (7.62 mm) Brownings with 500 rounds per gun, and an Oldsmobile 37 mm cannon with 15 rounds.
Orders were already in hand from France, Britain and the USAAC. The French and the British ordered a total of 667, with Model 322F for the French and Model 322B for the British. Each variant had unique modifications for their respective air arms, such as metric measurements on the flight indicators for the French aircraft, but they both shared a major change from all other P-38 variants in that turbo-superchargers were deleted and the left-handed and right-handed engine arrangement was changed to twin right-handed engines.
As turbo-superchargers were a new technology, the Anglo-French purchasing commission was concerned that turbo-superchargers might lead to delays, and being intended for medium-altitude combat, were not needed. The requirement for sole use of right-handed engines was for commonality with the large numbers of Curtiss Tomahawks both nations had on order. (Moreover, the turbocharged engines were prohibited from export by the U.S. government.) Lockheed engineers protested strongly against this decision, and privately labeled the variant the "castrated" P-38.
After the fall of France in June 1940, the British took over the entire order. They decided that only the first 143 of the order would be delivered in the unsupercharged format, as Model 322 Lightning Mk Is, with the remaining 524 to be delivered with turbo-superchargers and left and right-handed engines, as Model 322 Lightning Mk IIs.
The British never got that far. Three of the unsupercharged Lightning Is were delivered to the UK in March 1942, and were promptly given a thumbs-down. They "topped out" at 480 km/h (300 mph) and had nasty handling characteristics, so the entire order was cancelled.
The remaining 140 Lightning Is were completed for the USAAF. The rest of this batch, most refitted with counter-rotating engines but still minus turbo-superchargers, were relegated to United States Army Air Forces training units under the designation RP-322. These aircraft helped the USAAF train new pilots to fly a powerful and complex new fighter. The RP-322 was actually a fairly hot aircraft at low altitude and perfectly satisfactory in the training role.
The other positive result of this fiasco was to give the aircraft the name "Lightning." Lockheed originally dubbed the aircraft Atalanta in the company tradition of naming their planes after mythological and celestial figures, but the RAF name won out.
Thirty initial production P-38 Lightnings were delivered to the USAAF in mid-1941. Although not all these aircraft were armed, when they were, they were fitted with four .50 calibre (12.7 mm) machine guns (instead of the two .50 calibre (12.7 mm) and two .30 calibre (7.62 mm) weapons of their predecessors) but the 37 mm cannon was retained. They also had armor glass, cockpit armor and fluorescent cockpit controls. One was completed with a pressurized cabin on an experimental basis and designated XP-38A.
These 30 aircraft were part of an order for 66, but in light of USAAF feedback, the remaining 36 in the batch were fitted with various small improvements such as self-sealing tanks and enhanced armor protection to make them combat capable. For some odd reason, the USAAF specified that these 36 aircraft were to be designated P-38D. As a result, there never were any P-38Bs or P-38Cs. Early production variants of the Lightning are a confusing subject. None of these aircraft ever saw combat. Their main role in the story of the P-38 was to work out bugs and give the USAAF experience with handling the type.
Tail flutter was quickly found to be a problem. In an attempt to fix it, mass balances were attached to little booms in the middle of the elevator. This fix was derided by Kelly Johnson, who regarded the weights as useless, and, in fact, the buffeting eventually proved to be due to the straight connection of the wing root to the fuselage pod. A few aerodynamic changes, most particularly the addition of a wing-root fillet, solved the problem. Nonetheless, the external balances were a feature of every P-38 built from then on.
A more serious problem was "compressibility stall," the tendency of the controls to simply lock up in a high-speed dive, leaving the pilot no option but to bail out. The tail structure also had a nasty tendency to fall apart under such circumstances; this defect killed a YP-38 test pilot, Ralph Virden, in November 1940.
USAAC Major Signa Gilkey managed to stay with a YP-38 in a compressibility lockup, riding it out until he got to denser air, where he recovered using elevator trim. This feat led to experiments that would eventually resolve the problem.
Kelly Johnson later recalled: "I broke an ulcer over compressibility on the P-38 because we flew into a speed range where no one had ever been before, and we had difficulty convincing people that it wasn't the funny-looking airplane itself, but a fundamental physical problem. We found out what happened when the Lightning shed its tail and we worked during the whole war to get 15 more knots [28 km/h] more speed out of the P-38. We saw compressibility as a brick wall for a long time. Then we learned how to get through it."
That would not be until later, however, and the new P-38 had other defects. The most dangerous problem was that both engines were "critical" engines—losing one on takeoff, which happened often, created "critical torque," rolling the plane towards the live engine's wingtip, rather than the dead engine's. Normal reflex in pilots flying twin engine aircraft would be to push the remaining engine to full throttle when they lost an engine on takeoff, but in the P-38, the resulting critical torque would produce such an uncontrollable level of asymmetric roll that the aircraft would flip over and slam upside-down into the ground. Eventually, procedures were devised to allow a pilot to deal with the situation by reducing power on the running engine, feathering the prop on the dead engine, and then increasing power gradually until the aircraft was in stable flight.
Lightnings go to war
The first combat-capable Lightning was the P-38E, which featured improved instruments, electrical systems, and hydraulic systems; new Curtiss Electric duraluminum propellers (though early P-38E production retained the older Hamilton Standard Hydromatic hollow steel propellers) and the definitive armament configuration, featuring four 12.7 mm machine guns with 500 rounds per gun and a Hispano 20 mm cannon with 150 rounds instead of the unreliable Oldsmobile 37 mm gun.
Interestingly, while the machine guns had been arranged symmetrically in the nose on earlier variants, they were "staggered" in the P-38E and later versions, with the muzzles sticking out of the nose in the relative lengths of roughly 1:4:6:2. This was done to ensure a straight ammunition belt feed into the weapons, as the earlier arrangement had led to jamming.
The first P-38E rolled out of the factory in October 1941. 210 P-38Es were built. They were followed, starting in April 1942, by the P-38F, which incorporated racks inboard of the engines for fuel tanks or a total of 900 kg (2,000 pounds) of bombs. 527 P-38Fs were built. Over a hundred P-38Es were completed in the factory or converted in the field to a photo-reconnaissance variant, the F-4, in which the guns were replaced by four cameras. Most of these early reconnaissance Lightnings were retained stateside for training, but the F-4 was the first Lightning to see combat, beginning operations out of Australia and then New Guinea in April 1942. Three of the F-4s were operated by the Royal Australian Air Force in this theater for a short period beginning in September 1942.
By June 1942, P-38s were operating in the Aleutians as well. The fighter's long range made it well-suited to the campaign over the almost 2,000 km (1,200 mile) long island chain, and it would be flown there for the rest of the war. It was one of the most rugged environments available for testing the new aircraft under combat conditions. More Lightnings were lost due to weather and other conditions than enemy action. There were cases where Lightning pilots, mesmerized by flying for hours over gray seas under gray skies, simply flew into the water. Nonetheless, the P-38 scored successes. On 4 August 1942, two P-38Es, operating at the 1,600 km (1,000 mile) end of a long-range patrol, bounced a pair of Japanese Kawanishi H6K "Mavis" flying boats and destroyed them. They were the first of many Japanese aircraft to be shot down by the Lightning.
In the meantime, Lightnings of the 1st Fighter Group were being flown across the Atlantic via Iceland to England, though most of them made the trip on freighters. On 15 August, a P-38F and a P-40 operating out of Iceland shot down a Focke-Wulf Fw 200 Condor shipping raider over the Atlantic. This was reputedly the first Luftwaffe aircraft destroyed by the USAAF.
The Lightnings sent to England were part of the force being built up for the invasion of North Africa. The invasion took place in November 1942, and Lightning units, including a photo-reconnaissance unit under command of Colonel Elliott Roosevelt, the American president's son, then began acquiring familiarity with operating under "austere conditions" and matching their skills and aircraft against the enemy.
The Lightning proved surprisingly maneuverable at low altitudes, mostly due to very docile low-speed stall characteristics. The contra-rotating props had the benefit of eliminating the effects of engine torque, and on occasion a Lightning could even out-turn smaller fighters. However, maneuverability was not its strong suit, its major virtue in combat being a "terrific zoom climb" that would leave pursuers in the dust. Luftwaffe pilots also quickly learned not to make head-on attacks on the P-38, since its concentrated firepower ensured mutual destruction. Although not the best dogfighter, the P-38 was a formidable interceptor and attack aircraft and in the hands of a good pilot could be dangerous in air-to-air combat. The P-38 remained a force in the Mediterranean for the rest of the war.
A growing need for long-range escort fighters in Northwest Europe to protect heavy bomber operations resulted in four groups of Lightnings being deployed to the 8th Air Force in 1943-44. Although the P-38 gained a reputation with the Luftwaffe as the "fork-tailed devil," its performance at frigid high altitudes was disappointing and it proved difficult to maintain. By September 1944, all the Lightning groups in the 8th Air Force had converted to the P-51.
Four P-38s flying in formation.
However, the Lightning proved ideally suited for the Pacific theater, as it combined excellent performance with very long range. While the P-38 could not out-maneuver the Zero and most other Japanese fighters, its speed and climb gave American pilots the option of choosing to fight or run and its focused firepower was even more deadly to lightly-armored Japanese warplanes than to the Germans. Jiro Horikoshi, designer of the Zero, wrote: "The peculiar sound of the P-38's twin engines became both familiar and hated by the Japanese all across the South Pacific."
General George C. Kenney, commander of the USAAF Fifth Air Force operating in New Guinea, could not get enough P-38s, though since they were replacing serviceable but inadequate P-39s and P-40s, this might seem like guarded praise. But Lightning pilots began to compete in racking up scores against Japanese aircraft, including one of the most famous missions of the war, the interception of Admiral Isoroku Yamamoto on 17 April 1943.
Yamamoto was the architect of Japan's naval strategy in the Pacific, including the attack on Pearl Harbor. When American codebreakers found out that he was flying to Bougainville Island to conduct a front-line inspection, 16 Lightnings were sent on a long-range flight to intercept him: four to actually attack the bombers and the other 12 as top cover. The mission went off perfectly, the Lightnings met Yamamoto's Mitsubishi G4M "Betty" bomber and escorting Zero fighters just as they arrived, and the G4M was shot down over the jungle. The Admiral was killed.
(See main article: Death of Isoroku Yamamoto)
The P-38F was followed in early 1943 by the P-38G, utilizing more powerful Allisons of 1,400 hp (1,040 kW) each and equipped with a better radio. A total of 1,082 P-38Gs were built. The P-38G was followed in turn by 601 similar P-38Hs, with further uprated Allisons (1,425 hp [1,060 kW] each), an improved 20 mm cannon and a bomb capacity of 1,450 kg (3,200 pounds). These models were also field-modified into F-4B and F-5A reconnaissance aircraft.
There was never a P-38I. The USAAF didn't use the "I" designation since it looked like the numeral "1" (one).
The Lightning in maturity: P-38J, P-38L
The definitive P-38J was introduced in August 1943. The twin booms of previous Lightnings featured a sleek, art-deco streamlining, however, the turbocharger intercooler system that had been housed in the leading edges of the wings had proven vulnerable to combat damage and could explode if the wrong series of controls were mistakenly activated. Ultimately, they were inefficient, consequently, the engine and radiator configuration was rethought.
The most noticeable feature of the new fit was that the intercooler radiators were placed under the prop hub at the front of the booms, forming a "chin" that made the P-38J visibly different from its predecessors. The space left open in the wings was replaced with fuel tanks, further increasing the aircraft's long range. The revised radiator configuration made cooling much more efficient and improved both performance and reliability.
Late production P-38Js also finally ameliorated the compressibility problem through the introduction of minor aerodynamic changes, particularly the addition of a set of small dive flaps just outboard of the engines on the bottom centerline of the wings. With these improvements, a USAAF pilot reported a dive speed of almost 970 km/h (600 mph) and recovered in one piece. After World War II, it was realized that the reported air speed had to be corrected for compressibility error as well, so the actual dive speed was lower than reported.
Finally, later production of the P-38J was equipped with power-boosted flight controls, one of the first times such a system was fitted to a fighter, and did much to improve the Lightning's roll rate at high speeds and maneuverability. With a truly satisfactory Lightning in place, Lockheed ramped up production, working with subcontractors across the country to produce hundreds of Lightnings each month. Some 2,970 P-38Js were built.
The 5,000th Lightning built, a P-38J, was painted fire-engine red, and had the name "YIPPEE" painted on the underside of the wings in big letters as well as the signatures of factory workers. This aircraft was used by Lockheed test pilots Milo Burcham and Tony LeVier in remarkable flight demonstrations, performing such stunts as slow rolls at treetop level with one prop feathered to show that the P-38 was not the unmanageable beast of legend. Their exploits did much to reassure pilots that the Lightning might be a handful, but it was no "widow maker." (Burcham was killed flying a P-80 Shooting Star in October 1944.)
There were two P-38Ks developed in 1942-1943. The first was a modified P-38E with the Hamilton Standard propellers being fitted to the P-47 and the new intercoolers being developed for the P-38J, its performance led to the development on the second aircraft. A modified P-38G (re-designated P-38K-1-LO) was fitted with the propellers and a new Allison engine with 100 more bhp than even the later P-38L. In tests it was rated at 432MPH in Military Power and predicted to exceed 450MPH in War Emergency Power with a similar increase in rate of climb, load, ceiling and range. However, the War board refused the change due to the two to three-week shutdown of the Lightning production line needed to redesign the cowlings to accommodate the new engine.
The P-38L was the most numerous variant of the Lightning, with 3,923 built, 113 by Consolidated-Vultee in their Nashville plant. It entered service with the USAAF in June of 1944, just in time for close support of Allied troops who invaded occupied France on D-Day. Lockheed production of the Lighting was distinguished by a suffix consisting of a production block number followed by "LO," for example "P-38L-1-LO," while Consolidated-Vultee production was distinguished by a block number followed by "VN," for example "P-38L-5-VN."
The P-38L was the first Lightning to offer zero-length rocket launchers, at first, with seven HVARs (high velocity aircraft rockets) on pylons beneath each wing but later with ten rockets on each wing on "Christmas tree" launch racks. The P-38L also had strengthened stores pylons to allow carriage of 900 kg (2,000 pound) bombs or 1,140 liter (300 US gallon) drop tanks.
200 P-38J airframes were modified in production to become unarmed F-5B photo-reconnaissance aircraft, while hundreds of other P-38Js and P-38Ls were field-modified to become F-5Es, F-5Fs, and F-5Gs. A few P-38Ls were field-modified to become two-seat TP-38L familiarization trainers.
Late model Lightnings were delivered unpainted, as per USAAF policy established in 1944. At first, field units tried to paint them, since pilots worried about being too visible to the enemy, but it turned out the reduction in weight was a minor plus in combat.
15 P-38Js and P-38Ls were flown by the Nationalist Chinese late in the war, and, after the war, they also received a similar number of F-5Es and F-5Gs.
The new P-38 Lightning was operated by the US Army Eighth Air Force in Europe beginning in 1943 for long-range escort missions, but did not achieve great success in this role. This was partly because it was harder to fly than a single-engine aircraft and, since it had no engine in front of the pilot to keep him warm, it was an "ice-box" on high-altitude missions. Still, the main reason for the P-38's relative failure in high-altitude operations in the European Theatre was due to engine failures experienced above 20,000 feet. The reasons for frequent engine failures were due to failing spark plugs and other parts that could not use the European, rain-drenched fuel.
The P-38L-5 - the most common sub-variant of the P-38L - had a modified cockpit heating system which consisted of a plug in the cockpit in which the pilot would plug his heat suit wire, giving him more comfort. As well, P-38L's were fitted with hydraulically operated dive flaps and ailerons, giving them better handling at higher speeds. These Lightnings also received the uprated V-1710-111/113 (F30) engines, and this dramatically lowered the amount of engine failure problems experienced at high altitude. By this time, however, the earlier P-38 models had left a negative reputation in the minds of those in charge of fighter escort for USAAF bombers and had been replaced by the more fuel-efficient, agile and cheaper-to-produce P-51 Mustang.
The Eighth operated F-5 recon variants with more enthusiasm and success. They were also operated by a Free French squadron, which worked as part of the USAAF Twelfth Air Force; the French would continue to operate the type up to 1952.
Unfortunately, since F-5s operated alone, when their missions went wrong, they generally disappeared without a trace. The noted aviation pioneer and writer Antoine de Saint-Exupery vanished in an F-5 while on a reconnaissance mission over Lyon, France, on 31 July 1944. recently, a French scuba diver found the wreckage of a Lightning in the Mediterranean off the coast of Marseille in 2000, and it was confirmed in April 2004 as Saint-Exupery's.
The RAF's legendary photo-recon "ace," Wing Commander Adrian Warburton DSO DFC, was the pilot of a Lockheed F-5B borrowed from the USAAF that took off on 12 April 1944 to photograph targets in Germany. W/C Warburton failed to arrive at the rendezvous point and was never seen again. (In 2003, remains uncovered in Germany from a wrecked USAAF F-5B Lightning were found to be his aircraft.)
Despite its mixed career in Europe, the Lightning remained an outstanding success in the Pacific. Freezing cockpits were not a problem in the warm tropics. In fact, since there was no way to open a window while in flight, as it caused buffeting by setting up turbulence through the tailplane, it was often too hot, and pilots would fly stripped down to shorts, tennis shoes, and parachute.
P-38 pilots racked up big scores against the Japanese. Richard I. "Dick" Bong and Thomas J. "Tommy" McGuire of the USAAF competed for the top position, a rivalry made interesting by the contrast in personalities of the two men. Both Bong and McGuire were unbelievably aggressive and fearless in the air. After dogfights, their P-38s would be warped out of shape by overstress. On the ground, they were completely different men. Dick Bong was a modest, quiet, almost shy man, while the egotistical McGuire was "an unpleasant individual with a talent much bigger than he was," as one of his colleagues remembered him.
The famed Charles Lindbergh worked in the South Pacific for Lockheed as an operational test pilot, where he shot down at least one Japanese aircraft with his P-38. He was instrumental in extending the range of the P-38 through improved throttle settings, or engine-leaning techniques, notably by reducing engine RPM to 1600 rpm, which had prior been considered dangerous, because it was thought this would upset the fuel mixture and cause an explosion. He also shared a tent with McGuire. Visitors recalled McGuire ordering Lindbergh around, telling him to run errands as though he were a servant. Lindbergh was sent home after his kill in the P-38 because the Army did not want to risk the press of losing the famous pilot in a war he was not even supposed to be in[citation needed]. Gen. Douglas MacArthur, on the other hand, was supportive of Lindbergh's efforts and impressed with his innovations[1].
Bong was rotated back to the States as America's ace of aces, after making 40 kills. He was killed on 6 August 1945, the day the atomic bomb was dropped on Japan, when his P-80 Shooting Star jet fighter flamed out on take-off. McGuire had been killed in air combat in January 1945, over the Philippines, after racking up 38 confirmed kills, making him the second-ranking American ace. Both men were awarded the Medal of Honor.
The seventh-ranking American ace, Charles MacDonald, also flew a Lightning against the Japanese, scoring 27 kills in his famous aircraft, the "Putt Putt Maru."
The P-38 fought all around the Pacific, from the Aleutians to New Guinea to Burma and China. A P-38 piloted by Clay Tice was the first American aircraft to land in Japan after VJ-Day, when he and his wingman set down on Nitagahara because his wingman was low on fuel.
The P-38 had several aces that hailed from Alabama, one was Hoyt "Curley" Arnold Eason, who was an excellent pilot and great trainer of hundreds of pilots including Dick Bong (later to become America's all time leading ace). Eason shot down at least five himself. Eason was missing in action 3 March 1942, after the second day of the three-day Bismark Sea battle.
Lightning variants: Pathfinders, Night Fighter, XP-49, XP-58
The Lightning was modified for other roles. In addition to the F-4 and F-5 reconnaissance variants, a number of P-38Js and P-38Ls were field-modified as formation bombing "pathfinders" or "droopsnoots," fitted with a glazed nose with a Norden bombsight, or a H2X radar "bombing through overcast" nose. A pathfinder would lead a formation of other P-38s, each overloaded with two 900 kg (2,000 pound) bombs; the entire formation would release when the pathfinder did.
A number of Lightnings were modified as night fighters. There were several field or experimental modifications with different equipment fits that finally led to the "formal" P-38M night fighter, or "Night Lightning."
75 P-38Ls were modified to the Night Lightning configuration, painted flat-black with conical flash hiders on the guns, an AN/APS-6 radar pod below the nose, and a second cockpit with a raised canopy behind the pilot's canopy for the radar operator. The headroom in the back cockpit was limited, requiring radar operators who were preferably short in stature.
The additional external clutter imposed surprisingly little penalty on the P-38M's performance; it was faster than the purpose-built Northrop P-61 Black Widow night fighter. The Night Lightnings saw some combat duty in the Pacific towards the end of the war, but, verifiably, none engaged in combat.
Lockheed also built two sister designs to the P-38: the XP-49 and the XP-58 Chain Lightning.
In spring 1939, the Air Corps issued a request for an advanced twin-engine interceptor, to be derived from an existing type and fitted with advanced high-performance engines. Lockheed responded to the request with the Model 222, based on the L22 except for a pressurized cabin, to be powered by 24-cylinder inline Pratt & Whitney X-1800-SA2-G engines, then in development and expected to provide over 2,000 hp (1,500 kW). The Model 222 was to be armed with four 12.7 mm and two 20 mm guns, and a P-38G was modified to test this armament fit.
The Model 222 won the competition, the Air Corps ordering a single prototype as the XP-49 in October 1939. Lockheed proposed production P-49s be fitted with turbocharged Wright R-2160 Tornado radials with 2,300 hp (1,720 kW) each, which would give the P-49 an estimated performance of 800 km/h (500 mi/h) at altitude.
Work on the XP-49 went slowly as Lockheed was caught up in the prewar US military buildup. As development work plodded along, both the Air Corps and Lockheed began to have doubts for various reasons about the powerful engines to be fitted to the aircraft, and so the design was changed to incorporate two Continental XIV-1430-9/11 12-cylinder inverted-vee engines with 1,540 hp (1,150 kW) each for takeoff.
Engine availability further delayed development of the aircraft, and the XP-49 didn't take to the air until April 1942. The XP-49 looked much like a P-38, except for increased length and longer nacelles; the two aircraft shared about two-thirds of their parts. The aircraft was evaluated into the summer of 1943, but the Continental engines were troublesome.
Some sources claim the XP-49 had few if any performance advantages over existing P-38 production, others cite a test pilot as saying it "fly rings around the Lightning," but whatever the case, the USAAF abandoned all plans to put the XP-49 into production. The single prototype was used for occasional tests, including being dropped from a crane to simulate hard landings, and was finally scrapped in 1946.
The XP-58 actually started life in the spring of 1940 as an advanced escort fighter version of the P-38, with the development at the request of the USAAF. Single-seat and two-seat versions were considered, with the two-seat version fitted with addition turret-mounted armament.
The single-seat version was quickly abandoned, and the two-seat version went through a number of radical design changes, particularly with regards to engine fit. With the outbreak of the Pacific War in December 1941, the project was more or less put on the "back burner," with most of the staff moved to higher-priority projects.
The USAAF then began to flip-flop on their requirements, redefining the XP-58 as a ground attack aircraft, then a bomber, then an interceptor, with a bewildering variety of equipment fits considered. The single XP-58 prototype finally flew on 6 June 1944.
The XP-58 was a much more radical departure from the original P-38 design than the XP-49. While the XP-58 had the general Lightning configuration, nobody could have mistaken it for a Lightning. It was a monster, more on the scale of the Northrop P-61 Black Widow night fighter, and powered by two 24 cylinder Allison V-3420-11 inline engines with 2,100 hp (1,570 kW) each.
The XP-58 was to mount four 37 mm fixed forward-firing cannon and two remote-control barbettes, each with two 12.7 mm machine guns, mounted at the rear of the crew nacelle. An alternate forward armament of two 12.7 mm machine guns and a 75 mm cannon, for breaking up bomber formations, was also considered, but in reality no armament was ever fitted.
By the time the prototype flew, the USAAF had completely lost interest in the project, leading to a short and undistinquished flight test program. A second prototype was never completed, and the one flying example was scrapped after the war.
Lightning in twilight
Col. MacDonald and Al Nelson in the Pacific.
The end of the war left the USAAF with thousands of war-weary P-38s on their hands, rendered obsolete by the jet age. 50 late-model Lightnings were provided to Italy and operated for several years, with a dozen sold to Honduras. The others were put up for sale for US$1,200 apiece to whoever wanted one, and the rest were scrapped.
Lockheed test pilot Tony LeVier was among those who came up with the money to buy a P-38, turning it into an air racer. The Lightning was a popular contender in the air races from 1946 through 1949, with brightly colored Lightnings making screaming turns around the pylons.
F-5s were bought by aerial survey companies and used for aerial mapping. From the 1950s on, however, the use of the Lightning steadily declined, and, today, only a little more than two dozen exist, with a handful still flying. One particularly pretty example is a P-38L owned by the Lone Star Flight Museum in Galveston, Texas, painted in the colors of Charles MacDonald's Putt Putt Maru.
The P-38's final report card gave somewhat mixed grades. On the negative side, most variants were certainly harder to fly than the best single-engine fighters and in early models, pilots suffered badly from the cold in northern climates, and their twin supercharged Allisons were temperamental. A good portion of Lightnings lost during the war were brought down by engine difficulties rather than the enemy, with unscheduled engine changes common, which contributed to the plane's relatively low kill-ratio. Up until the "J-25" variant, P-38's were often sitting ducks to Luftwaffe fighters because of the problematic engines and the lack of dive flaps to counter compressibility in dives. German fighter pilots would often go into steep dives because they knew that the Lightnings would be reluctant to follow.
Early variants did not have reputations for being maneuverable aircraft, though they could be surprisingly agile at low altitudes if flown by a good pilot with specific tactics. But when the P-38F arrived, equipped with flaps called "fowler flaps," the P-38 had a much-improved turn radius. When deployed at eight degrees, these flaps could allow the P-38 to turn extremely tightly compared to any fighter, although the flaps could induce enough drag to slow down the plane significantly if left open for too long. The addition of hydraulically-operated control surfaces also improved roll rate and response in the P-38J-25. Nevertheless, the Lightning's real virtues were long range, heavy payload, high speed, fast climb and concentrated firepower.
Clustering all the armament in the nose meant that unlike most other US aircraft with wing-mounted guns, where the trajectories were set up to criss-cross at several points in a "convergence zone," Lightning pilots had to be good shots. For example, Dick Bong would fly recklessly in towards his targets to make sure he hit them, in some cases flying through the debris of his victim. However, the nose-mounted guns did not suffer from having their useful ranges limited by pattern convergence, meaning good pilots could shoot much farther. A Lightning could reliably hit targets at any range from point-blank to 1,000 yards, whereas other fighters had to pick a single convergence range between 100 and 250 yards. The clustered weapons had a "buzz-saw" effect on the receiving end, making the aircraft terrifyingly effective for strafing as well.
Over 10,000 Lightnings were manufactured in all; it was one of the few combat aircraft that had been in production at the beginning of the war that was still in production at the end. The Lightning had a major effect on other aircraft. One example is the fact that the Lightning's wing (in a scaled-up form) was used on the Model 49 Constellation.[2]
Unusual Lightning variants
There were a number of oddball experimental modifications of the Lightning:
One of the initial production P-38s had its turbochargers removed, with a secondary cockpit placed in one of the booms to examine how flightcrew would respond to such an "asymmetric" cockpit layout. One P-38E was fitted with an extended central nacelle to accommodate a tandem-seat cockpit with dual controls, and was later fitted with a laminar flow wing.
Very early in the Pacific War, a scheme was proposed to fit Lightnings with floats to allow them to make long-range ferry flights. The floats would be removed before the aircraft went into combat. There were concerns that salt spray would corrode the tailplane, and so one P-38E was modified with a raised tailplane and a rearward-facing second seat for an observer to monitor the effectiveness of the new arrangement. This P-38E was not actually fitted with floats, and the idea was quickly abandoned as the US Navy proved to have enough sealift capacity to keep up with P-38 deliveries to the South Pacific.
Still another P-38E was used in 1942 to tow a Waco troop glider as a demonstration. There proved to be plenty of other aircraft, such as C-47s, available to tow gliders, and the Lightning was spared this duty.
An F-5A was modified to an experimental two-seat reconnaissance configuration, with additional cameras in the tail booms.
To try and cure tail flutter and compressibility problems, one P-38 was modified with upswept tail booms in a "scorpion's tail" arrangement.
Standard Lightnings were even used as crew and cargo transports in the South Pacific. They were fitted with pods attached to the underwing pylons, replacing drop tanks or bombs, that could carry a single passenger in a lying-down position or cargo. This was a very uncomfortable way to fly. Some of the pods weren't even fitted with a window to let the victim see out or bring in light. One fellow who hitched a lift on a P-38 in one of these pods later said that whoever designed the damn thing should have been forced to ride in it.
Lockheed proposed a carrier-based Model 822 version of the Lightning for the United States Navy. The Model 822 would have featured folding wings, an arresting hook, and stronger undercarriage for carrier operations. The Navy wasn't interested, as they regarded the Lightning as too big for carrier operations and didn't like liquid-cooled engines anyway, and the Model 822 never went beyond the paper stage. However, the Navy did operate four land-based F-5Bs in North Africa, with these aircraft inherited from the USAAF and redesignated "FO-1."
A single P-38G was captured intact by the Italians during the war when the pilot accidentally landed at an Italian base, and this Lightning was flown in combat against Allied aircraft, but this aircraft was quickly grounded due to lack of parts. Two Lightnings that were forced to land in Lisbon, Portugal, while on a ferry flight from England to Algeria were interned and operated by the Portuguese.
A P-38J was used in experiments with an unusual scheme for mid-air refueling, in which the fighter snagged a drop tank trailed on a cable from a bomber. Astonishingly, they got this to work, but unsurprisingly decided it wasn't practical. A P-38J was also fitted with experimental retractable snow ski landing gear, but this idea never reached operational service, either.
A P-38L was modified by Hindustan Aeronautics in India as a fast VIP transport, with a comfortable seat in the nose, leather-lined walls, accommodations for "refreshments," and a glazed nose to give the passenger a spectacular view.
After the war, a P-38L was experimentally fitted with armament of three 15.2 mm (0.60 in) machine guns. This sounds like a misprint, but such guns were actually developed. The 15.2 mm cartridge had been developed early in the war for an infantry "anti-tank rifle," a type of weapon developed by a number of nations in the 1930s when tanks were lighter, but by 1942 the idea of taking on a tank with a large-caliber rifle was somewhere between "outdated" and "suicidal."
The cartridge wasn't abandoned, with the Americans designing a derivative of the German MG 151 15 mm machine gun around it and designating the weapon the "T17," but though 300 of these guns were built and over six million 15.2 mm rounds were manufactured, they never worked out all the bugs, and the T17 never saw operational service. The cartridge was "necked up" to fit 20 mm projectiles and became a standard US ammunition after the war. The T17-armed P-38L did not go beyond unsuccessful trials.
Another P-38L was modified after the war as a "super strafer," with eight 12.7 mm machine guns in the nose and a pod under each wing with two 12.7 mm guns, for a total of twelve. Nothing came of this fit, either.
Military operators
"Glacier Girl" at Oshkosh, 2005
Survivors
P-38F s/n 417630 was one of six P-38 fighters and two B-17 bombers being flown to Europe seven months after the United States entered the Second World War. When bad weather caused the eight aircraft to turn back while enroute over Greenland, the entire flight attempted to land together before they ran out of fuel. Although one P-38 overturned, the flight successfully belly-landed. The crews were rescued within a few days, but the airplanes were abandoned and over the years, they were covered by ice. A few attempts to salvage the airplanes were made but were unsuccessful.
Eventually, Roy Shoffner, a Middlesboro, Kentucky businessman, acquired the salvage rights and in 1992, 50 years and one month after the planes landed, a P-38 recovery mission was undertaken. Using photos taken by the original crews while they were awaiting rescue as well as modern seismographic equipment, the salvage workers located the buried squadron and selected the least damaged of the planes. They reached it by boring a hole using hot water through the layer of ice 268 feet thick. The airplane was transported to Middlesboro, where a 10-year restoration began. Nicknamed "Glacier Girl," the restored P-38F Lightning made its first post-restoration flight on 26 October 2002.
Specifications (P-38L)
General characteristics
Performance
- Maximum speed: 414 mph at 25,000 ft (667 km/h at 7,620 m)
- Stall speed: 105 mph (170 km/h)
- Range: 1,100 mi combat, 2,600 mi ferry (1,770 km / 3,640 km)
- Service ceiling: 44,000 ft (13,400 m)
- Rate of climb: maximum: 4,750 ft/min (1,448 m/min)
- Wing loading: 53.4 lb/ft² (260.9 kg/m²)
- Power/mass: 0.16 hp/lb (0.27 kW/kg)
Armament
- 1x Hispano M2(C) 20 mm cannon with 150 rounds (2 AP, 2 tracer and 2 HE ammo belt composition) and 4x Colt-Browning MG53-2 0.50 in (12.7 mm) machine guns with 500 rounds per gun. The rate of fire was about 650 rounds per minute for the 20x110 mm cannon round (130 g shell) at a muzzle velocity of about 880 m/s, and for the 12.7x99 mm MGs (43-48 g), about 850 rpm at 840 m/s velocity.
- 4x M10 three-tube 4.5 in (112 mm) rocket launchers or:
- 10x 5 in (127 mm) HVAR's (High Velocity Aircraft Rocket) and/or:
- either 2x 2,000 lb (908 kg) or 2x 1,000 lb (454 kg), 4x 500 lb (227 kg) or 4x 250 lb (114 kg) bombs
