Aircraft
by Nation
United States
Army/Air Force (1924 - 1962)
Bombardment: In 1924, the
U.S. Air Service used Light Bombardment (LB) and Heavy Bombardment (HB)
designations. By 1930, these two designations had been simplified to "B" for
bombardment.
The U.S. Air Force considered missiles to be pilotless
aircraft and, starting in 1951, designated ground-to-ground missiles as
bombers.