For a period of six months the
Twentieth Air Force operated two bomber commands, each with a different method of identifying its
B-29 Superfortress groups. From April 1945 forward all twenty groups, organized into five bomb wings, were assigned to XXI Bomber Command, which standardized its markings.
XX Bomber Command The 58th Bomb Wing had been the first to deploy, beginning combat in June 1944 with only a handful of B-29's painted in the standard olive drab camouflage. Each of its four groups employed a different method while based in the
China Burma India Theater as part of XX Bomber Command. The 40th BG painted four horizontal stripes across the upper tail fin with the letter identification of the airplane below it. The 444th BG numbered its aircraft and placed it within a large blue diamond outlined in yellow on the tail fin. The 462nd BG painted its
rudders but otherwise did not designate the group. The 468th painted two diagonal stripes on the rudders of its aircraft. When the wing and its groups transferred to Tinian in April 1945 the 58th Wing changed to a letter-symbol system.
XXI Bomber Command .) Note aircraft's call sign "X Triangle 9". The 73rd Bomb Wing began combat in October 1944 from Isley Field,
Saipan, and marked its aircraft similarly to that of the Fifteenth Air Force 55th CBW. A letter denoting the group was painted on the upper third of the tail fin, with a
square symbol in the center, and an aircraft identifier, known as the "victor number," in the lower third. Aircraft commonly used their tail identifiers as radio voice calls (
call signs), i.e.
Lucky Irish (serial 42-24622) of the 870th Bomb Squadron, 497th Bomb Group (lost November 24, 1944, over
Tokyo) had the voice call "A Square 26". The 313th Bomb Wing moved to
North Field (Tinian), in January 1945. Its aircraft used a system identical to that of the 73rd Wing, with its symbol a
triangle. The 314th Bomb Wing was based at North Field, Guam (now
Andersen Air Force Base) beginning in January 1945, with some of its groups beginning combat operations in February. In order to quickly mark its increasing numbers of aircraft, the 314th Wing painted 96-inch black boxes on the tail fins and stenciled the group identifier, either M, O, P or K in BMF 72-inch block letters. This was later infilled with a bright orange/yellow in mid summer 1945. The 58th Bomb Wing was relocated from
India to West Field, Tinian (now
Tinian International Airport), in April 1945 and the 315th Wing began arriving at Northwest Field, Guam, in May. The earlier system of marking aircraft was discarded in April by both the 73rd and 313th Wings. The 73rd Wing dropped all use of symbols and marked its aircraft with the group letter only, painted in black lettering. Except for the 314th Wing, which maintained its markings throughout the war, the remaining wings of the XXI Bomber Command used symbols in black to outline group letters. The symbol outline of the 313th Wing was a circle, that of the 58th Wing a triangle, and that of the 315th Wing a diamond.
20AF group letter identifiers: 58th Bomb Wing (triangle outline symbol): ::40th BG -
S, 444th BG -
N, 462nd BG -
U, 468th BG -
I 73rd Bomb Wing (square outline symbol, 10.5-foot letters): ::497th BG -
A, 498th BG -
T, 499th BG -
V, 500th BG -
Z 313th Bomb Wing (circle outline symbol): ::6th BG -
R,
9th BG -
X, 504th BG -
E, 505th BG (January to March) -
K, (April to September) -
W 314th Bomb Wing (solid black square):
315th Bomb Wing (diamond outline): ::16th BG -
B, 331st BG -
L, 501st BG -
Y, 502nd BG -
H 509th Composite Group The
509th Composite Group, sent to
Tinian to drop the
atomic bomb, was assigned to the 313th Bomb Wing. Consisting of a single squadron, its tail marking was a circle outline around an
arrowhead pointing forward, but while flying combat missions
its fifteen B-29s used the tail markings of other groups and wings as a security measure. Richard H. Campbell, in
The Silverplate Bombers, reports that XXI Bomber Command feared that Japanese survivors on Tinian were observing 509th operations, which had been quite extensive before August 1, and reporting them by clandestine radio to
Tokyo. The 509th repainted the tail identifier with those of four XXI Bomber Command groups already in combat, and altered victor numbers to avoid misidentification with actual aircraft already bearing the numbers. New victor numbers
82,
89,
90, and
91, carried the markings of the 6th Bomb Group (Circle R); victors
71,
72,
73, and
84 those of the 497th Bomb Group (large "A"); victors
77,
85,
86, and
88 those of the 444th Bomb Group (triangle N); and victors
83,
94, and
95 those of the 39th Bomb Group (square P). ==Other air forces in the Pacific==