|
|
Observation and Liaison aircraft alternated their designations. From 1924 until 1942 the O for Observation series was used. In 1942 this was changed to L for Liaison, with six old O aircraft getting early L numbers. The 1962 tri-service system reverted to O for Observation and Forward Air Control. Most surviving L class aircraft moved to the new U for Utility type, but some were given new O class numbers.
O - Observation (1924-42)
Curtiss O-1
Douglas O-2
Dayton-Wright O-3 Mohawk
Martin O-4
Douglas O-5
Thomas-Morse O-6
Douglas O-7
Douglas O-8
Douglas O-9
Loening XO-10
Curtiss O-11 Falcon
Curtiss XO-12 Falcon
Curtiss O-13 Falcon
Douglas O-14
Keystone O-15
Curtiss XO-16
Consolidated O-17
Curtiss XO-18
Thomas-Morse O-19
Thomas-Morse O-20
Thomas-Morse O-21
Douglas O-22
Thomas-Morse O-23
Curtiss O-24
Douglas O-25
Curtiss O-26
Fokker O-27
Vought O-28 Corsair
Douglas O-29
Curtiss O-30
Douglas O-31
Douglas O-32
Thomas-Morse O-33
Douglas O-34
Douglas O-35
Douglas XO-36
Keystone O-37
Douglas O-38
Curtiss O-39
Curtiss YO-40
Thomas-Morse O-41
Thomas-Morse O-42
Douglas O-43
Douglas O-44
Martin O-45
Douglas O-46
North American O-47
Douglas O-48
Stinson O-49 Vigilant (later L-1)
Bellanca O-50
Ryan O-51 Dragonfly
Curtiss O-52 Owl
Douglas O-53 Havoc
Stinson O-54
ERCO O-55
Lockheed O-56 Ventura
Taylorcraft O-57 Grasshopper (later L-2)
Aeronca O-58 Grasshopper (later L-3)
Piper O-59 Grasshopper (later L-4)
Kellett O-60
Pitcairn O-61
Stinson O-62 Sentiel (later L-5)
Interstate O-63 Grasshopper (later XL-6)
L - Liaison (1942-62)
Stinson L-1 Vigilant (previously O-49)
Taylorcraft L-2 Grasshopper (previously O-57)
Aeronca L-3 Grasshopper (previously O-58)
Piper L-4 Grasshopper (previously O-59)
Stinson L-5 Sentinel (previously O-61)
Interstate L-6 Grasshopper (previously O-63)
Universal L-7
Interstate L-8 Cadet
Stinson L-9
Ryan L-10
Bellanca L-11
Stinson L-12 Reliant
Stinson/ Convair L-13
Piper L-14 Cub
Boeing L-15 Scout
Aeronca L-16 Champion
North American L-17/ Ryan L-17 ( later U-18)
Piper L-18 Super Cub
Cessna L-19 Bird Dog (Later O-1)
de Havilland Canada L-20 Beaver (previously C-127, later U-6)
Piper L-21 Super Cub (later U-7)
Ryan L-22 Navion
Beechcraft L-23 Seminole (later U-8)
Helio L-24 Courier (later U-24)
McDonnell L-26 Aero Desgn (Later U-4 and U-9)
Aero L-26 (later U-4 and U-9)
Cessna L-27 Blue Canoe (becomes U-3)
Helio L-28 Super Courier (becomes U-10)
O - Observation/ Forward Air Control
Cessna O-1 Bird Dog (L-19)
Cessna O-2 Skymaster
Lockheed YO-3 (post 1962)
Wren O-4
de Havilland Canada O-5 ARL
OA - Observation, Amphibian
Loening OA-1
Loening OA-2
Douglas OA-3 Dolphin (C-21)
Douglas OA-4 Dolphin (C-26)
Douglas OA-5
Consolidated OA-6
Douglas OA-7
Sikorsky OA-8
Grumman OA-9 Goose
Consolidated OA-10 Catalina
Sikorsky OA-11
Grumman OA-12 Duck
Grumman OA-13 Goose
Grumman OA-14 Widgeon
Republic OA-15 Seabee
Grumman SA-16 (later HU-16)