Ground Crew Servicing Hall X-1 Prototype on Remote Airfield (1928)

Ground crew mechanics in white overalls servicing the engine and undercarriage of the Hall X-1 elevated on a wooden maintenance horse. — Ground Crew Servicing Hall X-1 Prototype on Remote Airfield (1928) · Donald A. Hall Estate Collection

During field evaluations on a remote California airfield, Donald A. Hall Sr. documented his ground crew performing maintenance on the experimental Hall X-1 (X7621). The tail of the aircraft rests elevated on a sturdy wooden sawhorse to level the fuselage, allowing one mechanic in white overalls to inspect the underside control linkages while another services the radial engine and propeller hub. The image illustrates the thorough flight-line maintenance protocol required for advanced prototype flight testing.