アメリカ陸軍航空隊の重戦闘機。
特徴的な双発双胴の機体で、最高速度と火力に秀で、ヨーロッパでは「双胴の悪魔」と呼ばれ、主に地上攻撃で活躍し猛威を振るいました。
しかし過給機を装備し高空での速度を追及した本機は低高度での性能が悪く、また旋回性能も非常に悪かった為、格闘戦で勝敗の決していた太平洋戦線では日本の零戦相手に次々と敗北、P-38をもじった「ペロハチ」という愛称を付けられカモにされていました。
しかしそれでもスピードと火力という長所を活かした作戦に於いてはその性能を遺憾なく発揮し、ブーゲンビル島上空にて山本五十六長官の搭乗する一式陸攻を追撃、これを撃墜し日本海軍の最高司令官を葬る事に成功します。
その後米軍でも格闘戦を避け一撃離脱戦に持ち込むやり方が確立されると、P-38は従来通りの力を発揮し、日本軍の脅威となりました。

"Lockheed P-38 Lightning":http://en.wikipedia.org/wiki/Lockheed_P-38_Lightning was a heavy fighter aircraft of the United States Army Air Corps.
It was known in Europe as "fork-tailed devil" because of its distinctive "twin booms":http://en.wikipedia.org/wiki/Twin_boom and superior speed and firepower. It played an active role mainly in ground strafing, where it was a powerful menace.
However, it was equipped with superchargers, and while it could reach high speeds at high altitudes, it performed poorly at low altitudes, and its maneuverability was also extremely poor. Thus it was repeatedly defeated by the Japanese Zero fighters in the dogfights of the Asia-Pacific War. The P-38 was an easy target for the Japanese, and was nicknamed "Pero-Hachi," a parody on the Japanese pronunciation of its name, "Pii Sanjuu-Hachi." (In Japanese, "perori" is an onomatopoeic word meaning "gobble up.")
However, when used in tactics making the best of its virtues of high speed and firepower, it showed its full ability. And in the skies over Bougainville Island, the Lightnings pursued and shot down two "Mitsubishi G4M":/wiki_pages/show_or_new?title=mitsubishi_g4m bombers with "Admiral Yamamoto Isoroku,":http://en.wikipedia.org/wiki/Isoroku_Yamamoto thus wiping out the Commander of the Imperial Japanese Navy.
After this in the US Army, once it established its role of avoiding hand-to-hand fighting and bringing in "hit and away" tactics, the P-38 was able to demonstrate its existing strengths and become a serious threat to the Japanese troops.