Brown demonstrates “hands-free” flying during his first helicopter test flight, in a Sikorsky Hoverfly Mark I (R-4) from Speke to Farnborough, England, in February 1946. (©Bonhams/BNPS)
Brown demonstrates “hands-free” flying during his first helicopter test flight, in a Sikorsky Hoverfly Mark I (R-4) from Speke to Farnborough, England, in February 1946. (©Bonhams/BNPS)