Two mailplane derivatives from the O series (types JYM and JWM) were single seaters with a 14″ stretch in the fuselage.
The JWM was a straightwing derivative of which two were built, including NX8550.
The JYM (ATC 2-361) was a taperwing derivative of which four were built, NR42M, NR631N, NC731K, NC991, for Northwest Airways in 1929.
JYM
Engine: 1 x Wright R975 / J-6-9, 330 hp (224 kW)
Seats: 1
JWM
Engine: 330 hp (246 kW) Wright R-975
All Aero 