In 1922 the USN received eighteen UF-1 two-place scout-observation aircraft, A6482-6499, all re-designated to UO-1. One hundred and forty Vought UO-1 Aztec two seat biplane, were built from 1922, powered by 200hp Lawrance J-1 engines, as landplanes and seaplanes: A6482-6499 (converted from UF-1), A6546-6551, A6603-6615, A6706-6729, A6858-6877, A6984-7023, A7031-7050, of which one was converted by NAF to racer UO-2, and 13 to UO-5.
The UO-1 model was used in trials as hook-on scout/fighters with airships.
The two 1928 UO-1C (A7007 and one other) were a wheeled trainer version for USN Reserve. Possibly other conversions as the designation was also used for planes modified for catapult launching, regardless of floats or wheels.
In 1922 NAF modified, wheeled UO-1 A6546 for 1922 Curtiss Marine Trophy competition. It was damaged in ground handling and did not race.
The UO-3 was re-designated as FU-1.
Two UO-4 were built in 1935 for the USCG with a single float; 404=V104, 405=V105.
The UO-5 were modification of UO-1 with 220hp Wright R-790 engines. Thirteen were built; A6729, A6860, A6866, A6988, A6997, A6999, A7005, A7010-7012, A7016, A7035, and A7038.
UF-1
Engine: 220hp Lawrance J-1
Wingspan: 26’0″
Length: 20’1″
Speed: 132 mph
Ceiling: 21,700′
Seats: 2
UO-1
Engine: 200hp Lawrance J-1
Wingspan: 34’1″ length: (landplane) 22’1″ (seaplane) 28’6″
Speed: 122 mph
Ceiling: (landplane) 18,200′ (seaplane) 16,550′
UO-5
Engine: 220hp Wright R-790.
All Aero 