AN2531, AIR FORCE-NAVY AERONAUTICAL STANDARD: INDICATOR ASSEMBLY AND WIND CONE (UNLIGHTED AND EXTERNALLY LIGHTED) (12 AUG 1944)
AN2531, AIR FORCE-NAVY AERONAUTICAL STANDARD: INDICATOR ASSEMBLY AND WIND CONE (UNLIGHTED AND EXTERNALLY LIGHTED) (12 AUG 1944).