Answer: sprucegoose

AnswerCrossword Clue
SPRUCEGOOSE

Aircraft that flew only once, in California

SPRUCEGOOSE

Flying boat built by Hughes Aircraft

SPRUCEGOOSE

Hughes Aircraft prototype

SPRUCEGOOSE
Unexpected nickname of a Hughes Aircraft plane built mostly of birch
SPRUCEGOOSE
Famed wooden flyer
SPRUCEGOOSEHughes aircraft
SPRUCEGOOSEMemorable Hughes plane
SPRUCEGOOSEHughes' wooden plane
SPRUCEGOOSEHuge Hughes airplane
SPRUCEGOOSEHoward Hughes's seaplane
SPRUCEGOOSEAttraction at the Evergreen Aviation Museum
SPRUCEGOOSEPlane that flew only once