Lockheed P-38 Lightning

Design and development

The Lockheed Corporation designed the P-38 in response to a February 1937 specification from the United States Army Air Corps (USAAC). Circular Proposal X-608 was a set of aircraft performance goals authored by First Lieutenants Benjamin S. Kelsey and Gordon P. Saville for a twin-engined, high-altitude "interceptor" having "the tactical mission of interception and attack of hostile aircraft at high altitude." Forty years later, Kelsey explained that Saville and he drew up the specification using the word "interceptor" as a way to bypass the inflexible Army Air Corps requirement for pursuit aircraft to carry no more than 500 lb (230 kg) of armament including ammunition, and to bypass the USAAC restriction of single-seat aircraft to one engine. Kelsey was looking for a minimum of 1,000 lb (450 kg) of armament. Kelsey and Saville aimed to get a more capable fighter, better at dog fighting and at high-altitude combat. Specifications called for a maximum airspeed of at least 360 mph (580 km/h) at altitude, and a climb to 20,000 ft (6,100 m) within six minutes, the toughest set of specifications USAAC had ever presented. The unbuilt Vultee XP1015 design was offered to fill this requirement, but was not advanced enough to merit further investigation. A similar proposal for a single-engined fighter was issued at the same time, Circular Proposal X-609, in response to which the Bell P-39 Airacobra was designed. Both proposals required liquid-cooled Allison V-1710 engines with turbosuperchargers and gave extra points for tricycle landing gear.

Lockheed formed a secretive engineering team to implement the project apart from the main factory; this approach later became known as Skunk Works. The Lockheed design team, under the direction of Hall Hibbard and Clarence "Kelly" Johnson, considered a range of twin-engined configurations, including both engines in a central fuselage with push–pull propellers.

The eventual configuration was rare in contemporary production fighter aircraft design, with the Dutch Fokker G.I heavy fighter, and the later Northrop P-61 Black Widow night fighter and Swedish SAAB 21 having a similar planform. The Lockheed team chose twin booms to accommodate the tail assembly, engines, and turbosuperchargers, with a central nacelle for the pilot and armament. The XP-38 gondola mockup was designed to mount two .50-caliber (12.7 mm) M2 Browning machine guns with 200 rounds per gun (rpg), two .30-caliber (7.62 mm) Brownings with 500 rpg, and a United States Army Ordnance Department prototype T1 23 mm (.90 in) autocannon with a rotary magazine as a substitute for the nonexistent 25 mm Hotchkiss aircraft autocannon specified by Kelsey and Saville. In the prototype YP-38s, an Army Ordnance Department T9 37 mm (1.46 in) autocannon (later designated as the M4 in production) with 15 rounds replaced the 23 mm T1. The 15 rounds were in three, five-round clips, an unsatisfactory arrangement according to Kelsey, and the T9/M4 did not perform reliably in flight. Further armament experiments from March to June 1941 resulted in the P-38E combat configuration of four M2 Browning machine guns, and one Hispano 20 mm (.79 in) autocannon with 150 rounds.

XP-38 and YP-38 prototypes

Lockheed won the competition on 23 June 1937 with its Model 22, and was contracted to build a prototype XP-38 for US$163,000, though Lockheed's own costs on the prototype would add up to $761,000. Construction began in July 1938 in an old bourbon distillery purchased by Lockheed to house expanding operations. This secure and remote site was later identified by Johnson as the first of five Lockheed Skunk Works locations. The XP-38 first flew on 27 January 1939 at the hands of Ben Kelsey.

Kelsey then proposed a speed dash to Wright Field on 11 February 1939 to relocate the aircraft for further testing. General Henry "Hap" Arnold, commander of the USAAC, approved of the record attempt and recommended a cross-country flight to New York. The flight set a speed record by flying from California to New York in seven hours and two minutes, not counting two refueling stops. Kelsey flew conservatively for most of the way, working the engines gently, even throttling back during descent to remove the associated speed advantage. Bundled up against the cold, Arnold congratulated Kelsey at Wright Field during his final refueling stop, and said, "don't spare the horses" on the next leg. After climbing out of Wright Field and reaching altitude, Kelsey pushed the XP-38 to 420 miles per hour (680 km/h). Nearing his destination, Kelsey was ordered by Mitchel Field tower (Hempstead, New York) into a slow landing pattern behind other aircraft. Carburetor icing caused it to be brought down short of the Mitchel runway, and it was wrecked. On the basis of the record flight, though, the USAAC ordered 13 YP-38s on 27 April 1939 for US$134,284 (~$2.37 million in 2024) each. (The "Y" in "YP" was the USAAC's designation for service test, i.e. small numbers of early production aircraft, while the "X" in "XP" was for experimental.) Lockheed's chief test pilot, Tony LeVier, angrily characterized the accident as an unnecessary publicity stunt, but according to Kelsey, the loss of the prototype, rather than hampering the program, sped the process by cutting short the initial test series. The success of the aircraft design contributed to Kelsey's promotion to captain in May 1939.

Manufacture of YP-38s fell behind schedule, at least partly because of changes to meet the need for mass production, making them substantially different in construction from the prototype. Another factor was the sudden required expansion of Lockheed's facility in Burbank, taking it from a specialized civilian firm dealing with small orders to a large government defense contractor making Venturas, Harpoons, Lodestars, and Hudsons, and designing the Constellation for TWA. The first YP-38 was not completed until September 1940, with its maiden flight on 17 September. The 13th and final YP-38 was delivered to the USAAC in June 1941; 12 aircraft were retained for flight testing and one for destructive stress testing. The YPs were substantially redesigned and differed greatly in detail from the hand-built XP-38. They were lighter and included changes in engine fit. The propeller rotation was reversed, with the blades spinning outward (away from the cockpit) at the top of their arc, rather than inward as before. This improved the aircraft's stability as a gunnery platform.

High-speed compressibility problems

Test flights revealed problems initially believed to be tail flutter. During high-speed flight approaching Mach 0.68, especially during dives, the aircraft's tail would begin to shake violently, and the nose would tuck under (see Mach tuck), steepening the dive. Once caught in this dive, the fighter would enter a high-speed compressibility stall and the controls would lock up, leaving the pilot no option but to bail out (if possible) or remain with the aircraft until it got down to denser air, where he might have a chance to pull out. During a test flight in May 1941, USAAC Major Signa Gilkey managed to stay with a YP-38 in a compressibility lockup, riding it out until he recovered gradually using elevator trim. Lockheed engineers were very concerned by this limitation, but first had to concentrate on filling the current order of aircraft. In late June 1941, the Army Air Corps was renamed the U.S. Army Air Forces (USAAF), and 65 Lightnings were finished for the service by September 1941, with more on the way for the USAAF, the Royal Air Force (RAF), and the Free French Air Force operating from England.

By November 1941, many of the initial assembly-line challenges had been met, which freed up time for the engineering team to tackle the problem of frozen controls in a dive. Lockheed had a few ideas for tests that would help them find an answer. The first solution tried was the fitting of spring-loaded servo tabs on the elevator trailing edge designed to aid the pilot when control yoke forces rose over 30 pounds-force (130 N), as would be expected in a high-speed dive. At that point, the tabs would begin to multiply the effort of the pilot's actions. Expert test pilot Ralph Virden was given a specific high-altitude test sequence to follow and was told to restrict his speed and fast maneuvering in denser air at low altitudes, since the new mechanism could exert tremendous leverage under those conditions. A note was taped to the instrument panel of the test craft underscoring this instruction. On 4 November 1941, Virden climbed into YP-38 #1 and completed the test sequence successfully, but 15 minutes later, was seen in a steep dive followed by a high-G pullout. The tail unit of the aircraft failed at about 3,500 ft (1,000 m) during the high-speed dive recovery; Virden was killed in the subsequent crash. The Lockheed design office was justifiably upset, but their design engineers could only conclude that servo tabs were not the solution for loss of control in a dive. Lockheed still had to find the problem; the USAAF personnel were sure it was flutter, and ordered Lockheed to look more closely at the tail.

In 1941, flutter was a familiar engineering problem related to a too-flexible tail, but the P-38's empennage was completely skinned in aluminum rather than fabric and was quite rigid. At no time did the P-38 suffer from true flutter. To prove a point, one elevator and its vertical stabilizers were skinned with metal 63% thicker than standard, but the increase in rigidity made no difference in vibration. Army Lieutenant Colonel Kenneth B. Wolfe (head of Army Production Engineering) asked Lockheed to try external mass balances above and below the elevator, although the P-38 already had large mass balances elegantly placed within each vertical stabilizer. Various configurations of external mass balances were equipped, and dangerously steep test flights were flown to document their performance. Explaining to Wolfe in Report No. 2414, Kelly Johnson wrote, "the violence of the vibration was unchanged and the diving tendency was naturally the same for all conditions." The external mass balances did not help at all. Nonetheless, at Wolfe's insistence, the additional external balances were a feature of every P-38 built from then on.

Range extension

The strategic-bombing proponents within the USAAF, nicknamed the Bomber Mafia by their ideological opponents, had established in the early 1930s a policy against research to create long-range fighters, which they thought would not be practical; this kind of research was not to compete for bomber resources. Aircraft manufacturers understood that they would not be rewarded if they installed subsystems on their fighters to enable them to carry drop tanks to provide more fuel for extended range. Lieutenant Kelsey, acting against this policy, risked his career in late 1941 when he convinced Lockheed to incorporate such subsystems in the P-38E model, without putting his request in writing. Kelsey possibly was responding to Colonel George William Goddard's observation that the US sorely needed a high-speed, long-range photo reconnaissance plane. Along with a change order specifying some P-38Es be produced with guns replaced by photoreconnaissance cameras, to be designated the F‑4‑1‑LO, Lockheed began working out the problems of drop-tank design and incorporation. After the attack on Pearl Harbor, eventually about 100 P-38Es were sent to a modification center near Dallas, Texas, or to the new Lockheed assembly plant B-6 (today the Burbank Airport), to be fitted with four K-17 aerial photography cameras. All of these aircraft were also modified to be able to carry drop tanks. P-38Fs were modified, as well. Every Lightning from the P-38G onward was capable of being fitted with drop tanks straight off the assembly line.

In March 1942, General Arnold made an off-hand comment that the US could avoid the German U-boat menace by flying fighters to the UK rather than packing them onto ships. President Roosevelt pressed the point, emphasizing his interest in the solution. Arnold was likely aware of the flying radius extension work being done on the P-38, which by this time had seen success with small drop tanks in the range of 150 to 165 US gal (570 to 620 L), the difference in capacity being the result of subcontractor production variation. Arnold ordered further tests with larger drop tanks in the range of 300 to 310 US gal (1,100 to 1,200 L); the results were reported by Kelsey as providing the P-38 with a 2,500-mile (4,000 km) ferrying range. Because of available supply, the smaller drop tanks were used to fly Lightnings to the UK, the plan called Operation Bolero.

Led by two Boeing B-17 Flying Fortresses, the first seven P-38s, each carrying two small drop tanks, left Presque Isle Army Air Field in Maine on 23 June 1942 for RAF Heathfield in Scotland. Their first refueling stop was made in far northeast Canada at Goose Bay. The second stop was a rough airstrip in Greenland called Bluie West One, and the third refueling stop was in Iceland at Keflavik. Other P-38s followed this route, with some lost in mishaps, usually due to poor weather, low visibility, radio difficulties, and navigational errors. Nearly 200 of the P-38Fs (and a few modified Es) were successfully flown across the Atlantic in July–August 1942, making the P-38 the first USAAF fighter to reach Britain and the first fighter ever to be delivered across the Atlantic under its own power. Kelsey himself piloted one of the Lightnings, landing in Scotland on 25 July.

Operational history

The first unit to receive P-38s was the 1st Fighter Group. After the attack on Pearl Harbor, the unit joined the 14th Pursuit Group in San Diego to provide West Coast defense.

Entry to the war

The first Lightning to see active service was the F‑4 version, a P‑38E in which the guns were replaced by four K17 cameras. They joined the 8th Photographic Squadron in Australia on 4 April 1942. Three F‑4s were operated by the Royal Australian Air Force in this theater for a short period beginning in September 1942.

On 29 May 1942, 25 P-38s began operating in the Aleutian Islands in Alaska. The fighter's long range made it well-suited to the campaign over the almost 1,200-mile (1,900 km)-long island chain, and it was flown there for the rest of the war. The Aleutians were some of the most rugged environments available for testing the new aircraft under combat conditions. More Lightnings were lost due to severe weather and other conditions than enemy action; cases occurred where Lightning pilots, mesmerized by flying for hours over gray seas under gray skies, simply flew into the water. On 9 August 1942, two P-38Es of the 343rd Fighter Group, 11th Air Force, at the end of a 1,000-mile (1,600 km) long-range patrol, happened upon a pair of Japanese Kawanishi H6K "Mavis" flying boats and destroyed them, making them the first Japanese aircraft to be shot down by Lightnings.

European theater

After the Battle of Midway, the USAAF began redeploying fighter groups to Britain as part of Operation Bolero, and Lightnings of the 1st Fighter Group were flown across the Atlantic via Iceland. On 14 August 1942, Second Lieutenant Elza Shahan of the 27th Fighter Squadron, and Second Lieutenant Joseph Shaffer of the 33rd Squadron operating out of Iceland shot down a Focke-Wulf Fw 200 Condor over the Atlantic. Shaffer, flying either a P-40C or a P-39, scored the first hit, causing a fire on the Condor; Shahan in his P-38F finished it off with a high-speed gunnery pass. This was the first Luftwaffe aircraft destroyed by the USAAF.

After 347 sorties with no enemy contact, the 1st and 14th Fighter Groups transferred from the UK to the 12th Air Force in North Africa as part of the force being built up for Operation Torch. The Lightning's long range allowed the pilots to fly their fighters over the Bay of Biscay, skirting neutral Spain and Portugal to refuel in Morocco. The P-38s were initially based at Tafaroui Airfield in Algeria alongside P-40 Warhawks and the rest of the 12th Air Force. P-38s were first involved in North African combat operations on 11 November 1942. The first North African P-38 kill was on 22 November, when Lieutenant Mark Shipman of the 14th downed an Italian airplane with twin engines. Shipman later made two more kills – a Messerschmitt Bf 109 fighter and a very large Me 323 Gigant transport.

Early results in the Mediterranean theater of operations were mixed. Some P-38 pilots scored multiple kills to become aces, while many others were shot down due to inexperience or tactical strictures. Overall, the P-38 suffered its highest losses in the Mediterranean theater. The primary function of the P-38 in North Africa was to escort bombers, but the fighters also targeted transport aircraft, and later in the campaign, they were sometimes given ground-attack missions. When tied to bomber-escort duties, the P-38 squadrons were vulnerable to attack from above by German fighters, which selected the most advantageous position and timing. The initial tactical doctrine of the American units was for the P-38s to fly near the bombers at all times rather than to defend aggressively or to fly ahead and clear the airspace for the bombers, and many American pilots were downed because of this limitation. Losses mounted, and all available P-38s in the UK were flown over to North Africa to restore squadron strength. After this painful experience, the American leadership changed tactics, and in February 1943, the P-38s were given free rein in their battles.

Pacific theater

The P-38 was used most extensively and successfully in the Pacific theater, where it proved more suited, combining exceptional range with the reliability of two engines for long missions over water. The P-38 was used in a variety of roles, especially escorting bombers at altitudes of 18,000–25,000 ft (5,500–7,600 m). The P-38 was credited with destroying more Japanese aircraft than any other USAAF fighter. Freezing cockpit temperatures were not a problem at low altitude in the tropics. In fact, the cockpit was often too hot, since opening a window while in flight caused buffeting by setting up turbulence through the tailplane. Pilots taking low-altitude assignments often flew stripped down to shorts, tennis shoes, and parachute. While the P-38 could not out-turn the A6M Zero and most other Japanese fighters when flying below 200 mph (320 km/h), its superior speed coupled with a good rate of climb meant that it could use energy tactics, making multiple high-speed passes at its target. In addition, its tightly grouped guns were even more deadly to lightly armored Japanese warplanes than to German aircraft. The concentrated, parallel stream of bullets allowed aerial victory at much longer distances than fighters carrying wing guns. Dick Bong, the United States' highest-scoring World War II air ace (40 victories in P-38s), flew directly at his targets to ensure he hit them, in some cases flying through the debris of his target (and on one occasion colliding with an enemy aircraft, which was claimed as a "probable" victory). The twin Allison engines performed admirably in the Pacific.

General George C. Kenney, commander of the USAAF 5th Air Force operating in New Guinea, could not get enough P-38s; they had become his favorite fighter in November 1942 when one squadron, the 39th Fighter Squadron of the 35th Fighter Group, joined his assorted P-39s and P-40s. The Lightnings established local air superiority with their first combat action on 27 December 1942. Kenney sent repeated requests to Arnold for more P-38s, and was rewarded with occasional shipments, but Europe was a higher priority in Washington. Despite their small force, Lightning pilots began to compete in racking up scores against Japanese aircraft.

On 2–4 March 1943, P-38s flew top cover for 5th Air Force and Australian bombers and attack aircraft during the Battle of the Bismarck Sea, in which eight Japanese troop transports and four escorting destroyers were sunk. Two P-38 aces from the 39th Fighter Squadron were killed on the second day of the battle: Bob Faurot and Hoyt "Curley" Eason (a veteran with five victories who had trained hundreds of pilots, including Dick Bong). In one notable engagement on 3 March 1943, P-38s escorted 13 B-17s (part of an attack including B-25 Mitchells and Beaufighters) as they bombed the Japanese convoy from a medium altitude of 7,000 ft (2,100 m), which dispersed the convoy formation and reduced their concentrated antiaircraft firepower. A B-17 was shot down and when Japanese Zero fighters machine-gunned some of the B-17 crew members who bailed out in parachutes, three P-38s promptly dived into action, claiming five Zeros.

Service record

The P-38's service record shows mixed results, which may reflect more on its employment than on flaws with the aircraft. The P-38's engine troubles at high altitudes only occurred with the Eighth Air Force. One reason for this was the inadequate cooling systems of the G and H models; the improved P-38 J and L had tremendous success flying out of Italy into Germany at all altitudes. Until the -J-25 variant, P-38s were easily avoided by German fighters because of the lack of dive flaps to counter compressibility in dives. German fighter pilots not wishing to fight would perform the first half of a Split S and continue into steep dives because they knew the Lightnings would be reluctant to follow.

On the positive side, having two engines was a built-in insurance policy. Many pilots arrived safely back to base after having an engine failure en route or in combat. On 3 March 1944, the first Allied fighters reached Berlin on a frustrated escort mission. Lieutenant Colonel Jack Jenkins of 55th Fighter Group led the group of P-38H pilots, arriving with only half his force after flak damage and engine trouble took their toll. On the way into Berlin, Jenkins reported one rough-running engine, causing him to wonder if he would ever make it back. The B-17s he was supposed to escort never showed up, having turned back at Hamburg. Jenkins and his wingman were able to drop tanks and outrun enemy fighters to return home with three good engines between them.

In the European theater, P-38s made 130,000 sorties with a loss of 1.3% overall. P-51s posted a 1.1% loss, though appearing later in the war, they benefited from greater numerical superiority and more mature tactics. Lieutenant Colonel Mark Hubbard, a vocal critic of the aircraft, rated it the third-best Allied fighter in Europe. The Lightning's greatest virtues were long range, heavy payload, high speed, fast climb, and concentrated firepower.

In the Pacific Theater, the P-38 downed over 1,800 Japanese aircraft, with more than 100 pilots becoming aces by downing five or more enemy aircraft. American fuel supplies contributed to a better engine performance and maintenance record, and range was increased with leaner mixtures. In the second half of 1944, the P-38L pilots out of Dutch New Guinea were flying 950 mi (1,530 km), fighting for 15 minutes and returning to base. Such long legs were invaluable until the P-47N and P-51D entered service.

Postwar operations

The end of the war left the USAAF with thousands of P-38s rendered obsolete by the jet age. Orders for 1,887 more were cancelled. The last P-38s in service with the United States Air Force were retired in 1949. One-hundred late-model P‑38L and F‑5 Lightnings were acquired by Italy through an agreement dated April 1946. Delivered, after refurbishing, at the rate of one per month, they finally were all sent to the Aeronautica Militare by 1952. The Lightnings served in the 4° Stormo and other units including 3° Stormo, flying reconnaissance over the Balkans, ground attack, naval cooperation, and air-superiority missions. Due to old engines, pilot errors, and lack of experience in operations, large numbers of P‑38s were lost in at least 30 accidents, many of them fatal. Despite this, many Italian pilots liked the P‑38 because of its excellent visibility on the ground and stability on takeoff. The Italian P‑38s were phased out in 1956; none survived the scrapyard.

Surplus P-38s were also used by other foreign air forces, with 12 sold to Honduras and 15 retained by China. Six F‑5s and two unarmed black two-seater P‑38s were operated by the Dominican Air Force based in San Isidro Airbase, Dominican Republic, in 1947. Most of the wartime Lightnings present in the continental U.S. at the end of the war were put up for sale for US$1,200 apiece; the rest were scrapped. P‑38s in distant theaters of war were bulldozed into piles and abandoned or scrapped; very few avoided that fate.

The CIA "Liberation Air Force" flew one P-38M to support the 1954 Guatemalan coup d'etat. On 27 June 1954, this aircraft dropped napalm bombs that destroyed the British cargo ship SS Springfjord, which was loading Guatemalan cotton and coffee for Grace Line in Puerto San José. In 1957, five Honduran P-38s bombed and strafed a village occupied by Nicaraguan forces during a border dispute between these two countries concerning part of Gracias a Dios Department.

P-38s were popular contenders in the air races from 1946 through 1949, with brightly colored Lightnings making screaming turns around the pylons at Reno and Cleveland. Lockheed test pilot Tony LeVier was among those who bought a Lightning, choosing a P‑38J model and painting it red to make it stand out as an air racer and stunt flyer. Lefty Gardner, former B‑24 and B‑17 pilot and associate of the Confederate Air Force, bought a mid-1944 P‑38L‑1‑LO that had been modified into an F‑5G. Gardner painted it white with red and blue trim and named it White Lightnin'; he reworked its turbo systems and intercoolers for optimum low-altitude performance and gave it P‑38F–style air intakes for better streamlining. White Lightnin' was severely damaged in a crash landing following an engine fire on a transit flight, and was bought and restored with a brilliant polished-aluminum finish by the company that owns Red Bull. The aircraft is now located in Austria.

Production

Over 10,000 Lightnings were manufactured, becoming the only U.S. combat aircraft that remained in continuous production throughout the duration of American participation in World War II. The Lightning had a major effect on other aircraft; its wing, in a scaled-up form, was used on the Lockheed Constellation.

P-38D and P-38Es

Delivered and accepted Lightning production variants began with the P-38D model. The few "handmade" YP-38s initially contracted were used as trainers and test aircraft. No Bs or Cs were delivered to the government as the USAAF allocated the 'D' suffix to all aircraft with self-sealing fuel tanks and armor. Many secondary but still initial teething tests were conducted using the earliest D variants.

The first combat-capable Lightning was the P-38E (and its photo-recon variant the F‑4) which featured improved instruments, electrical, and hydraulic systems. Part-way through production, the older Hamilton Standard Hydromatic hollow steel propellers were replaced by new Curtiss Electric duraluminum propellers. The definitive (and now famous) armament configuration was settled upon, featuring four .50 in (12.7 mm) machine guns with 500 rpg, and a 20 mm (.79 in) Hispano autocannon with 150 rounds.

While the machine guns had been arranged symmetrically in the nose on the P-38D, they were "staggered" in the P-38E and later versions, with the muzzles protruding from 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 led to jamming.

The first P-38E rolled out of the factory in October 1941 as the Battle of Moscow filled the news wires of the world. Because of the versatility, redundant engines, and especially high-speed and high-altitude characteristics of the aircraft, as with later variants, over 100 P-38Es were completed in the factory or converted in the field to a photoreconnaissance 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 be used in action in April 1942.

P-38Fs and P-38Gs

After 210 P-38Es were built, they were followed, starting in February 1942, by the P‑38F, which incorporated racks inboard of the engines for fuel tanks or a total of 2,000 lb (910 kg) of bombs. Early variants did not have a high reputation for maneuverability, though they could be agile at low altitudes if flown by a capable pilot, using the P-38's forgiving stall characteristics to their best advantage. From the P‑38F-15 model onwards, a "combat maneuver" setting was added to the P-38's Fowler flaps. When deployed at the 8° maneuver setting, the flaps allowed the P-38 to out-turn many contemporary single-engined fighters at the cost of some added drag. However, early variants were hampered by high aileron control forces and a low initial rate of roll, and all such features required a pilot to gain experience with the aircraft, which in part was an additional reason Lockheed sent its representative to England, and later to the Pacific theater.

The aircraft was still experiencing extensive teething troubles, as well as being victimized by "urban legends", mostly involving inapplicable twin-engined factors which had been designed out of the aircraft by Lockheed. In addition to these, the early versions had a reputation as a "widow maker", as they could enter an unrecoverable dive due to a sonic surface effect at high subsonic speeds. The 527 P-38Fs were heavier, with more powerful engines that used more fuel, and were unpopular in the air war in Northern Europe. Since the heavier engines were having reliability problems and with them, without external fuel tanks, the range of the P-38F was reduced, and since drop tanks themselves were in short supply as the fortunes in the Battle of the Atlantic had not yet swung the Allies' way, the aircraft became relatively unpopular in minds of the bomber command planning staffs despite being the longest-ranged fighter first available to the 8th Air Force in sufficient numbers for long-range escort duties. Nonetheless, General Spaatz, then commander of the 8th Air Force in the UK, said of the P-38F: "I'd rather have an airplane that goes like hell and has a few things wrong with it, than one that won't go like hell and has a few things wrong with it."

The P-38F was followed in June 1942 by the P-38G, using more powerful Allisons of 1,400 hp (1,000 kW) each and equipped with a better radio. A dozen of the planned P-38G production were set aside to serve as prototypes for what became the P-38J with further uprated Allison V-1710F-17 engines (1,425 hp (1,063 kW) each) in redesigned booms, which featured chin-mounted intercoolers in place of the original system in the leading edge of the wings and more efficient radiators. Lockheed subcontractors, however, were initially unable to supply both of Burbank's twin production lines with a sufficient quantity of new core intercoolers and radiators. War Production Board planners were unwilling to sacrifice production, and one of the two remaining prototypes received the new engines, but retained the old leading-edge intercoolers and radiators.

P-38J, P-38L

The P-38J was introduced in August 1943. The turbosupercharger intercooler system on previous variants had been housed in the leading edges of the wings and had proven vulnerable to combat damage and could burst if the wrong series of controls was mistakenly activated. In the P-38J series, the streamlined engine nacelles of previous Lightnings were changed to fit the intercooler radiator between the oil coolers, forming a "chin" that visually distinguished the J model from its predecessors. While the P-38J used the same V-1710-89/91 engines as the H model, the new core-type intercooler more efficiently lowered intake manifold temperatures and permitted a substantial increase in rated power. The leading edge of the outer wing was fitted with 55 US gal (210 L) fuel tanks, filling the space formerly occupied by intercooler tunnels, but these were omitted on early P-38J blocks due to limited availability.

The final 210 J models, designated P-38J-25-LO, alleviated the compressibility problem through the addition of a set of electrically actuated dive recovery 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 600 mph (970 km/h), although the indicated air speed was later corrected for compressibility error, and the actual dive speed was lower. Lockheed manufactured over 200 retrofit modification kits to be installed on P-38J-10-LO and J-20-LO already in Europe, but the USAAF C-54 carrying them was shot down by an RAF pilot who mistook the Douglas transport for a German Focke-Wulf Condor. Unfortunately, the loss of the kits came during Lockheed test pilot Tony LeVier's four-month morale-boosting tour of P-38 bases. Flying a new Lightning named Snafuperman, modified to full P-38J-25-LO specifications at Lockheed's modification center near Belfast, LeVier captured the pilots' full attention by routinely performing maneuvers during March 1944 that common 8th Air Force wisdom held to be suicidal. It proved too little, too late, because the decision had already been made to re-equip with Mustangs.

The P-38J-25-LO production block also introduced hydraulically boosted ailerons, one of the first times such a system was fitted to a fighter. This significantly improved the Lightning's rate of roll and reduced control forces for the pilot. This production block and the following P-38L model are considered the definitive Lightnings, and Lockheed ramped up production, working with subcontractors across the country to produce hundreds of Lightnings each month.

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 1944, in time to support the Allied invasion of France on D-Day. Lockheed production of the Lightning 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."

P-38K

Two P-38Ks were developed from 1942 to 1943, one official and one an internal Lockheed experiment. The first was actually a battered RP-38E "piggyback" test mule previously used by Lockheed to test the P-38J chin intercooler installation, now fitted with paddle-bladed "high-activity" Hamilton Standard Hydromatic propellers similar to those used on the P-47. The new propellers required spinners of greater diameter, and the mule's crude, hand-formed sheet steel cowlings were further stretched to blend the spinners into the nacelles. It retained its "piggyback" configuration that allowed an observer to ride behind the pilot. With Lockheed's AAF representative as a passenger and the maneuvering flap deployed to offset Army Hot Day conditions, the old "K-Mule" still climbed to 45,000 feet (14,000 m). With a fresh coat of paint covering the reshaped cowlings, this RP-38E acts as stand-in for the "P-38K-1-LO" in the model's only picture.

The 12th G model originally set aside as a P-38J prototype was redesignated P-38K-1-LO and fitted with the aforementioned paddle-blade propellers and new Allison V-1710-75/77 (F15R/L) powerplants rated at 1,875 bhp (1,398 kW) at War Emergency Power. These engines were geared 2.36 to 1, unlike the standard P-38 ratio of 2 to 1. The AAF took delivery in September 1943, at Eglin Field. In tests, the P-38K-1 achieved 432 mph (695 km/h) at military power and was predicted to exceed 450 mph (720 km/h) at War Emergency Power with a similar increase in load and range. The initial climb rate was 4,800 ft (1,500 m)/min and the ceiling was 46,000 ft (14,000 m). It reached 20,000 ft (6,100 m) in five minutes flat; this with a coat of camouflage paint, which added weight and drag. Although it was judged superior in climb and speed to the latest and best fighters from all AAF manufacturers, the War Production Board refused to authorize P-38K production due to the two- to three-week interruption in production necessary to implement cowling modifications for the revised spinners and higher thrust line. Some had also doubted Allison's ability to deliver the F15 engine in quantity. As promising as it had looked, the P-38K project came to a halt.

Pathfinders, night-fighter, and other variants

The Lightning was modified for other roles. In addition to the F‑4 and F‑5 reconnaissance variants, several P-38Js and P‑38Ls were field modified as formation bombing "pathfinders" or "droopsnoots", fitted with a Norden bombsight or an H2X radar system. Such pathfinders would lead a formation of other P‑38s, each loaded with two 2,000 lb (907 kg) bombs; the entire formation releasing their ordnance when the pathfinder did.

A number of Lightnings were modified as night fighters. Several field or experimental modifications with different equipment fits finally led to the "formal" P-38M night fighter, or Night Lightning. In total, 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 rear cockpit was limited, requiring radar operators who were preferably short in stature.

One of the initial-production P-38s had its turbosuperchargers removed, with a secondary cockpit placed in one of the booms to examine how flight crews 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. Concerns arose that saltwater spray would corrode the tailplane, so in March 1942, P-38E 41-1986 was modified with a tailplane raised some 16–18 in (41–46 cm), booms lengthened by 2 ft, and a rearward-facing second seat added for an observer to monitor the effectiveness of the new arrangement. A second version was crafted on the same airframe with the twin booms given greater sideplane area to augment the vertical rudders. This arrangement was removed and a final third version was fabricated that had the booms returned to normal length, but the tail raised 33 in (84 cm). All three tail modifications were designed by George H. "Bert" Estabrook. The final version was used for a quick series of dive tests on 7 December 1942 in which Milo Burcham performed the test maneuvers and Kelly Johnson observed from the rear seat. Johnson concluded that the raised floatplane tail gave no advantage in solving the problem of compressibility. At no time was this P-38E testbed airframe actually fitted with floats, and the idea was quickly abandoned, as the U.S. Navy proved to have enough sealift capacity to keep up with P-38 deliveries to the South Pacific.

Variants

XP-38: United States Army Air Force designation for one prototype Lockheed Model 22 first flown in 1939

YP-38: Redesigned preproduction batch with armament, 13 built

P-38: First production variant with 0.5 in guns and a 37 mm cannon, 30 built

XP-38A: Thirtieth P-38 modified with a pressurized cockpit

Lightning I: Former Armée de l'air order for 667 aircraft (being reduced to 143 Lighting Is), it was taken by the Royal Air Force, three delivered to RAF, and the remainder of the order was delivered to USAAF. It used C-series V-1710-33 engines without turbochargers, and right-hand propeller rotation (not counter).

Lightning II: The Royal Air Force designation for a cancelled order of 524 aircraft using F-series V-1710 engines, the only one built was retained by the USAAF for testing. The rest of the order was completed as P-38F-13-LO, P-38F-15-LO, P-38G-13-LO, and P-38G-15-LO aircraft.

P-322-I: 22 Lightning Is of the 143 built were retained by the USAAF for training and testing. Most were unarmed, although some retained the Lighting I armament of two .50 cal and two .30 cal guns.

P-322-II: 121 Lightning Is were re-engined with the V-1710-27/-29 and used for training. Most were unarmed.

P-38B: Proposed variant of the P-38A, not built

P-38C: Proposed variant of the P-38A, not built

P-38D: Production variant with modified tailplane incidence, self-sealing fuel tanks, 36 built

P-38E: Production variant with revised hydraulic system, 20 mm cannon rather than the 37 mm of earlier variants, 210 built

Operators

Military

Civil

Colombia

Noted P-38s

Yippee

The 5,000th Lightning built, a P-38J-20-LO, 44-23296, was painted bright vermilion red, and had the name YIPPEE painted on the underside of the wings in large white letters, as well as the signatures of hundreds of factory workers. This and other aircraft were used by a handful of Lockheed test pilots including Milo Burcham, Jimmie Mattern, and Tony LeVier in remarkable flight demonstrations, performing such stunts as slow rolls at treetop level with one prop feathered to dispel the myth that the P-38 was unmanageable.

Surviving aircraft

Of the ten thousand aircraft built, there are 26 survivors of which ten are airworthy.

Noted P-38 pilots

Richard Bong and Thomas McGuire

The American ace of aces and his closest competitor both flew Lightnings and tallied 40 and 38 victories, respectively. Majors Richard I. "Dick" Bong and Thomas B. "Tommy" McGuire of the USAAF competed for the top position. Both men were awarded the Medal of Honor.

McGuire was killed in air combat in January 1945 over the Philippines, after accumulating 38 confirmed kills, making him the second-ranking American ace. Bong was rotated back to the United States as America's ace of aces, after making 40 kills, becoming a test pilot. He was killed on 6 August 1945, the day the atomic bomb was dropped on Japan, when his Lockheed P-80 Shooting Star jet fighter flamed out on take-off.

Charles Lindbergh

Charles Lindbergh became famous for his transatlantic solo flight before the war. By WWII he was a civilian working for Vought in the South Pacific area. He received preferential treatment as if a visiting colonel.

In Hollandia, Lindbergh attached himself to the 475th Fighter Group which was flying P-38s. Although new to the aircraft, Lindbergh was instrumental in extending the range of the P-38 through improved throttle settings, or engine-leaning techniques, notably by reducing engine speed to 1,600 rpm, setting the carburetors for auto-lean and flying at 185 mph (298 km/h) indicated airspeed, which reduced fuel consumption to 70 gal/h, about 2.6 mpg. This combination of settings had been considered dangerous as it was believed this would upset the fuel mixture, causing an explosion.

While with the 475th, he took part in a number of combat missions. On 28 July 1944, Lindbergh shot down a Mitsubishi Ki-51 "Sonia" flown by the veteran commander of the 73rd Independent Flying Chutai of the Imperial Japanese Army Captain Saburo Shimada. In an extended, twisting dogfight in which many of the participants ran out of ammunition, Shimada turned his aircraft directly toward Lindbergh, who was just approaching the combat area. Lindbergh fired in a defensive reaction brought on by Shimada's apparent head-on ramming attack. Hit by cannon and machine-gun fire, the "Sonia's" propeller visibly slowed, but Shimada held his course. Lindbergh pulled up at the last moment to avoid collision as the damaged "Sonia" went into a steep dive, hit the ocean, and sank. The unofficial kill was not entered in the 475th's war record. On 12 August 1944, Lindbergh left Hollandia to return to the United States.

Charles MacDonald

The third-ranking American ace of the Pacific theater, Charles H. MacDonald, flew a Lightning against the Japanese and scored 27 kills in his aircraft, the Putt Putt Maru.

Martin James Monti

Martin James Monti was an American pilot who defected to the Axis powers in a stolen F‑5E Lightning, which was handed over to the Luftwaffe Zirkus Rosarius for testing afterward.

Robin Olds

Robin Olds was the last P‑38 ace in the 8th Air Force and the last in the ETO. Flying a P‑38J, he downed five German fighters on two separate missions over France and Germany. He subsequently transitioned to P‑51s and scored seven more kills. After World War II, he flew F‑4 Phantom IIs in Vietnam, ending his career as brigadier general with 16 kills.

John H. Ross

Ross is a decorated World War II pilot who flew 96 missions for the U.S. Army Air Forces under the U.S. 8th Air Force's 7th Reconnaissance Group in the 22nd Reconnaissance Squadron. Ross flew the Lockheed P-38 Lightning as a photo-reconnaissance pilot out of RAF Mount Farm in England during the war. He received 11 medals and was awarded the Distinguished Flying Cross twice for missions that were integral to Allied victory at the Battle of the Bulge.

Antoine de Saint-Exupéry

At midday on 31 July 1944, noted aviation pioneer and writer Antoine de Saint-Exupéry (Night Flight, Wind, Sand and Stars and The Little Prince) vanished in his P-38 of the French Armée de l'Air's Groupe de Chasse II/33, after departing Borgo-Porreta, Corsica. His health, both physically and mentally, had been deteriorating. Saint-Exupéry was said to be intermittently subject to depression and talk had arisen of taking him off flying status. He was on a flight over the Mediterranean, from Corsica to mainland France, in an unarmed F‑5B photo-reconnaissance variant of the P-38J, described as being a "war-weary, nonairworthy craft".

In 2000, a French scuba diver found the partial remnants of a Lightning spread over several thousand square meters of the Mediterranean seabed off the coast of Marseille. In April 2004, the recovered component serial numbers were confirmed as being from Saint-Exupéry's F‑5B Lightning. Only a small amount of the aircraft's wreckage was recovered. In June 2004, the recovered parts and fragments were given to the Air and Space Museum of France in Le Bourget, Paris, where Saint-Exupéry's life is commemorated in a special exhibit.

In 1981 and also in 2008, two Luftwaffe fighter pilots, respectively Robert Heichele and Horst Rippert, separately claimed to have shot down Saint-Exupéry's P-38. Both claims were unverifiable and possibly self-promotional, as neither of their units' combat records of action from that period made any note of such a shoot-down.

Specifications (P-38L)

Data from Lockheed P-38H/J/L Pilot's Flight Operating Instructions, P-38H/J/L Pilot's Flight Operating InstructionsGeneral characteristics

Crew: 1

Length: 37 ft 10 in (11.53 m)

Wingspan: 52 ft 0 in (15.85 m)

Height: 12 ft 10 in (3.91 m)

Wing area: 327.5 sq ft (30.43 m2)

Aspect ratio: 8.26

Airfoil: root: NACA 23016; tip: NACA 4412

Empty weight: 12,800 lb (5,806 kg)

Gross weight: 17,500 lb (7,938 kg)

Max takeoff weight: 21,600 lb (9,798 kg)

Powerplant: 2 × Allison V-1710 (-111 left hand rotation and -113 right hand rotation) V-12 liquid-cooled turbo-supercharged piston engine, 1,600 hp (1,200 kW) each WEP at 60 inHg (2.032 bar) and 3,000 rpm

Propellers: 3-bladed Curtiss electric constant-speed propellers (LH and RH rotation)

Performance

Maximum speed: 414 mph (666 km/h, 360 kn) on Military Power: 1,425 hp (1,063 kW) at 54 inHg (1.829 bar), 3,000 rpm and 25,000 ft (7,620 m)

Cruise speed: 275 mph (443 km/h, 239 kn)

Stall speed: 105 mph (169 km/h, 91 kn)

Combat range: 1,300 mi (2,100 km, 1,100 nmi)

Popular culture

Harley Earl arranged for several of his designers to view a YP-38 prototype shortly before World War II, and its design directly inspired the tail fins of the 1948–1949 Cadillac.

The P-38 was also the inspiration for Raymond Loewy and his design team at Studebaker for the 1950 and 1951 model-year Studebakers.

The whine of the speeder bike engines in Return of the Jedi was partly achieved by recording the engine noise of a P-38, combined with that of a North American P-51 Mustang.

The popular eight-bit video game 1942 puts the player in command of a P-38 flying over the Pacific, fighting against Japanese Zeros and the Nakajima G10N bomber. The game was made by Japanese company Capcom, intended for Western markets, and finishes with the player raiding Tokyo.