Atlas XH-1 Alpha
Videos
The Atlas XH-1 Alpha is a prototype attack helicopter built by Atlas Aviation of South Africa, which used it as a concept demonstrator for the then-planned Rooivalk project.
Alpha XH-1
Bell 207 Sioux Scout
Videos
The Bell 207 Sioux Scout is a modified Bell 47 helicopter, developed by Bell Helicopter under contract from the United States Army, as a proof-of-concept demonstrator for the Bell D-255 helicopter gun
Bell 207 prototype during flight testing
The 207 prototype (N73927) in flight
Bell 207 Sioux Scout in the United States Army Aviation Museum