PB4Y-1 LiberatorPB4Y Liberator airplane model. The PB4Y 1 was a navalized version of the USAAF B 24. It had its origin in a deal cut in mid 1942 between the Navy and the USAAF. The Navy was anxious to acquire a long range, land based heavy maritime reconnaissance and patrol aircraft capable of carrying a substantial bombload, but the USAAF had always resisted what it perceived as an encroachment into its jealously guarded land based bomber program. However, the USAAF