The P-38 saw service with both the 8th and 9th Air Forces, initially based in Britain. These were the airforces seen as allocated to the European Theatre of Operations (ETO). The P-38 was always the junior partner to the P-47 and P-51 in these air forces, but did perform some valuable service.
8th Air Force
The P-38 entered service with the 8th Air Force at a crucial moment in the daylight bombing campaign. 14 October 1943 was the date of the disastrous raid on the ball bearing factory at Schweinfurt, well beyond escort range for the P-47. For 370 miles the B-17s were unescorted. Sixty aircraft were lost, without making any significant dent on ball bearing production. For the rest of October the daylight bomber offensive was virtually suspended.
The next day the 55th Fighter Group flew its first P-38 mission from Britain, a fighter sweep over the Dutch coast. Equipped with 75 gallon drop tanks, the P-38 had an effective escort radius of 520 miles (compared to 375 miles for the P-47). In February 1944 the P-38 units received 108 gallon drop tanks, which increased their effective radius of operations to 585 miles, long enough to reach Berlin. Between October 1943 and March 1944, the P-38 was the longest range fighter available to the 8th Air Force (in March 1944 the P-51D finally received drop tanks that gave it an effective escort range of 650 miles).
These ranges are all significantly shorter than those given for the various types involved. Even taking into account the smaller drop tanks in use, one might expect the P-38 to have been able to reach 700 or more miles into Germany. So where have the missing miles gone? The answer is that the P-38 could indeed reach that far into Germany, as demonstrated by the PR models of the aircraft, but only if it was allowed to fly at its most efficient cruising speed and height for the entire journey, did not want to spend any time at its target, and could guarantee that it would not need to indulge in any aerial combat. In contrast the escort fighters had to either travel somewhat below their most fuel efficient speeds or to circle around the bombers they were guarding. They also needed to be able to spend as long over the target as the bomber formation they were escorting, and be able to fight for at least ten minutes.
One problem faced by the 8th Air Force was that many of its aircraft were shipped across the Atlantic only partly assembled. On their arrival in Britain they would be assembled at one base, and then shipped to a second base to be modified. In December 1943 this was partly resolved by the establishment of a production line at Burtonwood, where newly arrived P-38s could be assembled and modified in one place. In January 1944 the Burtonwood base assembled 389 aircraft.
The P-38 also suffered from unexpected engine unreliability problems when used from Britain. Sometimes attributed to the British climate, a more likely cause was the different type of aviation fuel used in Britain (the same engines performed well in the much more severe climate of the Aleutian Islands). This caused no problems in British engines (which used mechanical superchargers), or with the combination of radial engines and turbo-superchargers used in the B-17, but seems to have caused problems when the exhaust-driven turbo-superchargers were combined with Allison in-line engines.
The P-38 was never used in great numbers by the 8th Air Force. It was always outnumbered by the P-47, and was overtaken by the P-51 during the Spring of 1944. It was most important numerically in the summer of 1944, when the 8th Air Force mustered just over 200 P-38s, 300 P-47s and 300 P-51s. After that it (and the P-47) were rapidly phased out in favour of the P-51, which was undoubtedly a better escort fighter than the P-38, with longer range and better manoeuvrability. It was also always easier to maintain the single engined P-51 than the twin engined P-38, especially with the Lightnings well known reliability problems in Europe. By the end of 1944 no 8th Air Force Fighter Groups were still using the P-38. In all five 8th Air Force fighter groups used the P-38 (20th, 55th, 78th, 364th and 479th).
Despite its limited numbers, the P-38 playing an important part in the renewed bomber offensive. On 3 November the 55th Fighter Group flew its first escort mission, guarding a formation of heavy bombers attacking Wilhelmshaven. Unaware of the presence of the new long range fighters, the fighters of JG 1 prepared to attack the bombers. Instead, they were ambushed by the P-38s, and lost seven aircraft to the new American fighter.
The Germans soon recovered from their initial surprise, shooting down seventeen P-38s during November. They also developed a tactic that temporarily reduced the effectiveness of the Lighting – a small number of German fighters would pretend to attack the American formation as soon as possible, forcing the P-38 pilots to drop their fuel tanks to deal with the fighter threat. With the drop tanks gone, the fighters would no longer have the range to escort the bomber formation, which would have to push on unescorted. The eventual solution to this problem was to give most members of a P-38 formation orders to ignore these early attacks and fly on with the bombers, while a couple of P-38s would drop their tanks to chase away the German fighters.
The P-38 was given an important role on D-Day. As the most instantly recognisable Allied fighter it was given the role of proving fighter cover over the invasion fleets and the D-Day beaches. Naval anti-aircraft gunners were notoriously trigger happy, but the Germans had nothing that looked even slightly like the P-38, and it was hoped that it would not be the target of “friendly fire”. In the event the Luftwaffe did not make an attack on the invasion fleets, nor did it appear in strength over the beaches and so the P-38 units had a relatively uneventful day, although they did indeed come under some fire from the fleet.
9th Air Force
The P-38 equipped three groups of the tactical 9th Air Force. These groups went operational in the spring of 1944 (474th FG on 25 April 1944, 370th FG on 1 May and 367th FG on 9 May). At first these groups lent their aircraft to the 8th Air Force, acting as bomber escorts. They also took part in providing fighter cover on D-Day. All the units then moved onto the continent, providing tactical support for the allied armies as they advanced across France.
By October 1944 all three P-38 groups in the 9th Air Force had been equipped with the Droop Snoot equipment. This consisted of a specially modified version of the P-38 with a bombardier in a glass nose. This single aircraft dropped the bombs of an entire formation of P-38s.
The 474th FG was the only fighter group in the 8th and 9th Air Forces to keep the P-38 until VE day. The 370th FG converted to the P-51 in January 1945 and the 367th FG to the P-47 Thunderbolt in February.