January 9: First flight of the Lockheed Constellation prototype NX67900.
January 21: Pan Am flight 1104, a Martin M-130 Flying Boat ("Philippine Clipper", reg. NC-14715), crashes in Ukiah, California, killing all 19 on-board. The aircraft, flying in very poor weather, descended for improved visibility, causing it to crash into a mountain after drifting off-course. The 10 passengers on the aircraft were all naval officers enroute to San Francisco.
January 27: The USAAF makes its first daylight raid on Germany.
January 30: The Royal Air Force de Havilland Mosquito made its first flight.
February 13: The Vought F4U Corsair naval fighter makes its operational debut in Solomon Island, escorting PB4Y-1 Liberators (the US Navy’s version of the B-24) raiding Bougainville.
March 5: First flight of the Gloster Meteor prototype
April 18: Admiral Isoroku Yamamoto is killed when T1-323, his Mitsubishi G4M, is ambushed by USAAF P-38 Lightnings over Bougainville.
June 15: The first operational jet-bomber, the German-built Arado Ar-234 Blitz, makes its first flight.
July 13: First flight of the Curtiss-Wright XP-55 Ascender.
July 18: US Navy airship K-74 is shot down by a German submarine, the only airship lost to enemy fire during World War II.
July 24: The Royal Air Force (RAF) use “Window,” metal foil dropped to confuse enemy radar, for the first time.
November 29: The Essex-class aircraft carrier USS Hornet is commissioned. Today she is a floating museum docked in San Francisco Bay at the former NAS Alameda.
December 2: First flight of the Grumman XF7F Tigercat.