|World War II aircraft|
|Country of origin||USA|
|Dimensions||Wing span 52'|
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General master page for all P-38 Lightnings
The Lockheed P-38 Lightning was a World War II American fighter aircraft. Developed to a United States Army Air Corps requirement, the P-38 had distinctive twin booms and a single, central nacelle containing the cockpit and armament. The aircraft was used in a number of different roles, including dive bombing, level bombing, ground strafing, photo reconnaissance missions and extensively as a long-range escort fighter when equipped with droppable fuel tanks under its wings. The P-38 was used most extensively and successfully in the Pacific Theater of Operations and the China-Burma-India Theater of Operations, where it was flown by the American pilots with the highest number of aerial victories to this date. America's top ace Richard Bong earned 40 victories (in a Lightning he called Marge), and Thomas McGuire (in Pudgy) scored 38. In the South West Pacific theater, it was a primary fighter of United States Army Air Forces until the appearance of large numbers of P-51D Mustangs toward the end of the war.
The P-38 was the only American fighter aircraft in active production throughout the duration of American involvement in the war, from Pearl Harbor to VJ Day
Design and Development
Lockheed designed the P-38 in response to the 1937 United States Army Air Corps Circular Proposal X-608 request for a high-altitude interceptor aircraft having "the tactical mission of interception and attack of hostile aircraft at high altitude". Specifications called for a maximum airspeed of at least 360 miles per hour (580 km/h) at altitude, and a climb to 20,000 feet (6100m) within 6 minutes; the toughest set of specifications USAAC had presented to that date. The Bell P-39 Airacobra and the Curtiss P-40 Warhawk were designed to the same requirement, as was the unbuilt Vultee XP1015.
The Lockheed design team, under the direction of Hall Hibbard and “Kelly” Johnson, considered a range of configurations. All options considered by Lockheed were twin-engined, as it was judged that no single available engine was powerful enough to be able to meet the USAAC's requirements. (Engine development during World War II subsequently saw an approximate doubling of fighter engine horsepower, allowing many later single engine designs to achieve 400+ mph.)
The eventual design was somewhat unique in comparison to existing fighter aircraft. The Lockheed team chose twin booms to accommodate the tail assembly, engines and turbo superchargers, with a central nacelle for the pilot and armament. The nose was designed to carry two Browning .50" (12.7 mm) machine guns with 200 rounds per gun, two .30" (7.62 mm) Brownings with 500 rounds per gun, and an Oldsmobile 37 mm cannon with 15 rounds. Clustering all the armament in the nose was unlike most other U.S. aircraft, which used wing-mounted guns where the trajectories were set up to crisscross at one or more points in a "convergence zone". 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 up to 1,000 yards (910 m), whereas other fighters had to pick a single convergence range between 100 and 250 yards (230 m). The clustered weapons had a "buzz saw" effect on the receiving end, making the aircraft effective for strafing as well.
The Lockheed design incorporated tricycle undercarriage and a bubble canopy, and featured two 1000 hp (746 kW) turbo-supercharged 12-cylinder Allison V-1710 engines fitted with counter-rotating propellers to eliminate the effect of engine torque, with the superchargers positioned behind the engines in the booms. It was the first American fighter to make extensive use of stainless steel and smooth, flush-riveted butt-jointed aluminum skin panels. It was the first fighter faster than 400 mph (640 km/h).
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 US$761,000. Construction began in July 1938 and the XP-38 first flew on 27 January 1939 The 11 February 1939 flight to relocate the aircraft for testing at Wright Field was extended by General Henry "Hap" Arnold, commander of the USAAC, to demonstrate the performance of the aircraft. It set a cross-continent speed record by flying from California to New York in seven hours and two minutes, but landed short of the Mitchel Field runway in Hempstead, New York, and was wrecked. However, on the basis of the record flight, the Air Corps ordered 13 YP-38s on 27 April 1939 for US$134,284 apiece. (The initial "Y" in "YP" was the USAAC's designation for a "prototype" while the "X" in "XP" was for "experimental".)
Manufacture of the YP-38s fell behind schedule, at least partly due to the need for mass-production suitability making them substantially different in construction than the prototype. Another factor was the sudden required facility expansion of Lockheed in Burbank, taking it from a specialized civilian firm dealing with small orders to becoming a large government defense contractor making Venturas, Harpoons, Lodestars, Hudsons, and designing the Constellation airliner 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 Air Corps 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, included changes in engine fit, and the propeller rotation was reversed, with the blades rotating outwards (away) from the cockpit at the top of their arc rather than inwards as before. This improved the aircraft's stability as a gunnery platform.
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, 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 at this limitation, but first they had to concentrate on filling the current order of aircraft. Sixty-five Lightnings were finished by September 1941, with more on the way.
By November 1941, many of the initial assembly line challenges had been met and there was some breathing room 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; tabs that were designed to aid the pilot when control yoke forces rose over 30 pounds, 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. The expert test pilot, 43-year-old 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 prototype 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 3,000 ft (910 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 Army Air Corps was sure it was flutter, ordering Lockheed to look more closely at the tail.
Although the P-38's empennage was completely skinned in aluminum (not fabric) and was quite rigid, in 1941, flutter was a familiar engineering problem related to a too-flexible tail. 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—the increase in rigidity made no difference in vibration. Army Lt. Colonel Kenneth B. Wolfe (head of Army Production Engineering) asked Lockheed to try external mass balances above and below the elevator, though 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 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.
After months of pushing NACA to provide Mach 0.75 wind tunnel speeds (and finally succeeding), the compressibility problem was revealed to be the center of lift moving back toward the tail when in high-speed airflow. The compressibility problem was solved by changing the geometry of the wing's underside when diving so as to keep lift within bounds of the top of the wing. In February 1943, quick-acting dive flaps were tried and proven by Lockheed test pilots. The dive flaps were installed outboard of the engine nacelles and in action they extended downward 35° in 1½ seconds. The flaps did not act as a speed brake, they affected the center of pressure distribution so that the wing would not lose its lift. Late in 1943, a few hundred dive flap field modification kits were assembled to give North African, European and Pacific P-38s a chance to withstand compressibility and expand their combat tactics. Unfortunately, these crucial flaps did not always reach their destination. In March 1944, 200 dive flap kits intended for ETO P-38Js were destroyed in a mistaken identification incident in which an RAF fighter shot down the Douglas C-54 Skymaster bringing the shipment to England. Back in Burbank, P-38Js coming off the assembly line in spring 1944 were towed out to the tarmac and modified in the open air. The flaps were finally incorporated into the production line in June 1944 on the last 210 P-38Js. The delay in bringing the dive flap and its freedom of tactical maneuver to the fighting pilot was far too lengthy. Of all Lightnings built, only the final 50% would have the dive flaps installed as an assembly line sequence.
Buffeting was another early aerodynamic problem, difficult to sort out from compressibility as both were reported by test pilots as "tail shake". Buffeting came about from airflow disturbances ahead of the tail; the airplane would shake at high speed. Leading edge wing slots were tried as were combinations of filleting between the wing, cockpit and engine nacelles. Air tunnel test number 15 solved the buffeting completely and its fillet solution was fitted to every subsequent P-38 airframe. Fillet kits were sent out to every squadron flying Lightnings. The problem was traced to a 40% increase in air speed at the wing-fuselage junction where the chord/thickness ratio was highest. An airspeed of 500 mph (800 km/h) at 25,000 ft (7,600 m) could push airflow at the wing-fuselage junction close to the speed of sound. Filleting forever solved the buffeting problem for the P-38E and later models.
Another issue with the P-38 arose from its unique design feature of outwardly rotating counter-rotating propellers. Losing one of two engines in any twin engine non-centerline thrust aircraft on takeoff creates sudden drag, yawing the nose toward the dead engine and rolling the wingtip down on the side of the dead engine. Normal training in flying twin-engine aircraft when losing an engine on takeoff would be to push the remaining engine to full throttle; if a pilot did that in the P-38, regardless of which engine had failed, the resulting engine torque and p-factor force produced a sudden uncontrollable yawing roll and the aircraft would flip over and slam into the ground. Eventually, procedures were taught 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. Single-engine takeoffs were possible, though not with a maximum combat load.
The engine sounds were a unique, rather quiet "whuffle", because the exhausts were muffled by the General Electric turbosuperchargers on the twin Allison V12s. There were early problems with cockpit temperature regulation; pilots were often too hot in the tropic sun as the canopy could not be opened without severe buffeting, and were often too cold in northern Europe and at high altitude, as the distance of the engines from the cockpit prevented easy heat transfer. Later variants received modifications to solve these problems.
On 20 September 1939, before the YP-38s had been built and flight tested, the USAAF ordered 66 initial production P-38 Lightnings, 30 of which were delivered to the USAAF in mid-1941, but not all these aircraft were armed. The unarmed aircraft were subsequently fitted with four .50s (instead of the two .50 and two .30 of their predecessors) and a 37 mm cannon. 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. Due to reports the USAAF was receiving from Europe, the remaining 36 in the batch were upgraded with small improvements such as self-sealing fuel tanks and enhanced armor protection to make them combat-capable. 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. The P-38D's main role was to work out bugs and give the USAAF experience with handling the type.
In March 1940, the French and the British ordered a total of 667 P-38s, designated Model 322F for the French and Model 322B for the British. The aircraft would be a variant of the P-38E, without turbo-supercharging (due to a U.S. government export prohibition), and twin right-handed engines instead of counter-rotating, for commonality with the large numbers of Curtiss P-40 Tomahawks both nations had on order. After the fall of France in June 1940, the British took over the entire order and re-christened the plane Lightning I. Three were delivered in March 1942 and, after discovering, without superchargers, at low altitude and when using lower-octane British aircraft fuel, they had a maximum speed of 300 miles per hour (480 km/h) and poor handling characteristics, the entire order was canceled. The remaining 140 Lightning I's were completed for the USAAF with counter-rotating engines but still minus turbo-superchargers. Most 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. A few Model 322 aircraft were later used as test modification platforms such as for smoke-laying canisters and dual air-dropped torpedoes. The RP-322 was a fairly fast aircraft (some of the fastest post-war racing P-38s were virtually identical in layout to the P-322-II)at low altitude and well suited as a trainer. The other positive result of the failed British/French order was to give the aircraft its name. Lockheed had originally dubbed the aircraft Atalanta in the company tradition of naming planes after mythological and celestial figures, but the RAF name won out.
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 out of 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 (2,000 km)–long island chain, and it would be flown there for the rest of the war. The Aleutians were one 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, and there were cases 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, Eleventh 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.
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, a P-38F and a P-40 operating out of Iceland shot down a Focke-Wulf Fw 200 Condor over the Atlantic. This was the first Luftwaffe aircraft destroyed by the USAAF.
P-38 Lightnings had a number of lucky escapes, exemplified by the arrival of the 71st fighter squadron at Goxhill (Lincolnshire, England) in July 1942. The official handover ceremony was scheduled for mid-August, but on the day before the ceremony, Goxhill experienced its only air raid of the war. A single German bomber flew overhead and dropped a very well aimed bomb right on the intersection between the two newly concreted runways, but it didn’t explode and the aircraft were able to continue their mission. (As it turned out, the bomb could not be removed and, for the duration of the war, aircraft had to pass over it every time they took off.)
After 347 sorties with no enemy contact, the 1st, 14th and 82nd Fighter Groups were transferred to the 12th Air Force in North Africa as part of the force being built up for Operation Torch. On 19 November 1942, Lightnings escorted B-17s on a raid over Tunis. On 5 April 1943, 26 P-38Fs of the 82nd destroyed 31 enemy aircraft, helping to establish air superiority in the area, and earning it the German nickname "der Gabelschwanzteufel" – the Fork-Tailed Devil. The P-38 remained active in the Mediterranean for the rest of the war. It was in this theatre that the P-38 suffered its heaviest losses in the air. On 25 August 1943, 13 P-38s were shot down in a single sortie by Jagdgeschwader 53 Bf 109s without achieving a single kill. On 2 September ten P-38s were shot down, in return for a single kill, the 67-victory ace Franz Schiess (who was also the leading "Lightning" killer in the Luftwaffe with 17 destroyed).
Experiences over Germany had shown a need for long-range escort fighters to protect the Eighth Air Force's heavy bomber operations. The P-38Hs of the 55th Fighter Group were transferred to the Eighth in England in September 1943, and were joined by the 20th, 364th and 479th Fighter Groups soon after.
In the Mediterranean Theater, Italian pilots started to face P-38s from late 1942 and considered the type a formidable foe even compared to other lethal fighters including the Supermarine Spitfire. A small number of P-38s fell into the hands of German and Italian units and were subsequently tested and used in combat. Col. Tondi used a P-38, possibly an "E" variant, that landed in Sardinia due to a navigational error. Tondi claimed at least one B-24, downed on 11 August 1943. The P-38 eventually was acquired by Italy for postwar service.
The P-38 performed well in the ETO, but suffered frequent engine failures, due to the inadequate cooling system. Many of the aircraft's problems were addressed by the P-38J, but by September 1944, all but one of the Lightning groups in the Eighth Air Force had converted to the P-51. The Eighth did continue to operate the F-5 reconnaissance version with more success.
The P-38 was used most extensively and successfully in the Pacific theater, where it proved ideally suited, combining excellent performance with very long range. The P-38 was used in a variety of roles, especially escorting bombers at altitudes between 18-25,000ft. The P-38 was credited with destroying more Japanese aircraft than any other USAAF fighter. Freezing cockpits were not a problem at low altitude in the 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; pilots taking low altitude assignments would often fly stripped down to shorts, tennis shoes, and parachute. While the P-38 could not out-maneuver the Mitsubishi Zero and most other Japanese fighters, its speed and rate of 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'. The concentrated, parallel stream of bullets allowed aerial victory at much longer distances than fighters carrying wing guns. It is therefore ironic that Dick Bong, the United States' highest scoring World War II air ace (40 victories solely in P-38s), would fly directly at his targets to make sure he hit them (as he himself acknowledged his poor shooting ability), 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.
On 2-4 March 1943, P-38s flew top cover for Fifth Air Force and Australian bombers and attack-planes during the Battle of the Bismarck Sea, a crushing defeat for the Japanese. 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).
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. Lightning pilots began to compete in racking up scores against Japanese aircraft.
The Lightning figured in one of the most significant operations in the Pacific theater, the interception, on 18 April 1943, of Admiral Isoroku Yamamoto, 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 P-38G Lightnings were sent on a long-range fighter-intercept mission, flying 435 mi (700 km) from Guadalcanal at heights from 10-50 ft (3-15 m) above the ocean to avoid detection. The Lightnings met Yamamoto's two Mitsubishi G4M "Betty" fast bomber transports and six escorting Zeros just as they arrived. The first Betty crashed in the jungle and the second ditched near the coast. Two Zeros were also claimed by the American fighters with the loss of one P-38. Japanese searchers found Yamamoto's body at the jungle crash site the next day.
The P-38's service record shows mixed results, but usually because of misinformation. P-38s have been described as being harder to fly than single-engined planes, but this was because of inadequate training in the first few months of the war. 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. Up 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 made it safely back to base after having an engine fail en route or in combat. On March 3, 1944, the first Allied fighters reached Berlin on a frustrated escort mission. Lt. Col. Jack Jenkins of 55FG 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 in to Berlin, Jenkins reported one rough-running engine and one good one, causing him to wonder if he'd 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 Theatre of Operations (ETO), P-38s made 130,000 sorties with a loss of 1.3% overall, comparing favorably with ETO P-51s which posted a 1.1% loss, considering that the P-38s were vastly outnumbered and suffered from poorly thought-out tactics. The majority of the P-38 sorties were made in the period prior to Allied air superiority in Europe when pilots fought against a very determined and skilled enemy. Lt. Colonel Mark Hubbard, a vocal critic of the aircraft, rated it third best Allied fighter in Europe. The Lightning's greatest virtues were long range, heavy payload, high speed, fast climb, and concentrated firepower. The P-38 was a formidable interceptor and attack aircraft and, in the hands of any pilot, dangerous in air-to-air combat.
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. 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 miles (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.
The end of the war left the USAAF with thousands of P-38s rendered obsolete by the jet age. 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 AMI by 1952. The Lightnings served in 4 Stormo and other units including 3 Stormo, flying reconnaissance over the Balkans, ground attack, naval cooperation and air superiority missions. Due to unfamiliarity in operating heavy fighters, old engines, and pilot errors, a large number 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 at takeoff. The Italian P-38s were phased out in 1956; none survived the inevitable scrapyard.
Surplus P-38s were also used by other foreign air forces with a dozen sold to Honduras and fifteen retained by China. Six F-5s and two unarmed black two-seater P-38s were operated by PRD forces based in Cuba in 1947. The majority of 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.
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. 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.
F-5s were bought by aerial survey companies and employed for mapping. From the 1950s on, the use of the Lightning steadily declined, and only a little more than two dozen still exist, with few still flying. One 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. Two other examples are F-5Gs which were owned and operated by Kargl Aerial Surveys in 1946, and are now located in Chino, California at Yanks Air Museum, and in McMinnville, Oregon at Evergreen Aviation Museum.