From a suggestion by Forrestal, Roosevelt assigned Johnson to a three-man survey team covering the Southwest Pacific.[47]
Johnson reported to General Douglas MacArthur in Australia. Johnson and two U.S. Army officers went to the 22nd Bomb Group base, which was assigned the high-risk mission of bombing the Japanese airbase at Lae in New Guinea. On June 9, 1942, Johnson volunteered as an observer for an airstrike on New Guinea by B-26 bombers. Reports vary on what happened to the aircraft carrying Johnson during that mission. Johnson's biographer Robert Caro accepts Johnson's account and supports it with testimony from the aircrew concerned: the aircraft was attacked, disabling one engine and it turned back before reaching its objective, though remaining under heavy fire. Others claim that it turned back because of generator trouble before reaching the objective and before encountering enemy aircraft and never came under fire; this is supported by official flight records.[48][49] Other airplanes that continued to the target came under fire near the target about the same time Johnson's plane was recorded as having landed back at the original airbase. 