Henry Alan Marsh, A.F.C., A.F.R.Ae.S., manager and chief test pilot of the Cierva Autogiro Co., Ltd., was recognized as the most experienced rotary-wing pilot in the world. Born in 1901, he served in the Royal Air Force from 1918 to 1930 and then became assistant instructor to the Hampshire Aero Glub, where he met Juan de la Cierva, and became interested in Autogiros. In 1932 he joined the staff of the Cierva Company, and became chief flying instructor at the Cierva Autogiro Flying School at Hanworth.
From 1933 onwards, Alan Marsh assisted Cierva with experimental flying, and also carried out the same duty for G. and J. Weir, until 1939, when he was recalled to the R.A.F. and was assigned to the experimental flying staff of the R.A.E. at Farnborough. In 1941 he took over No. 529 Squadron from W/C. Brie, the Squadron being equipped with Autogiros, and its duties being concerned chiefly with radar calibration. He left the Service in 1946 with the rank of squadron leader, and rejoined the Cierva Company,his post-war duties having been chiefly concerned with the experimental flying of the W.9, W.u and W.14 Cierva helicopters. He was killed on the 13th June 1950 along with Mr. F.J. Cable and Mr. J. Unsworth. All three were involved in an accident,which occurred near Eastleigh, to the Cierva Air Horse when the rotor blade broke away.
A member of the instructors' panel of examiners for the G.A.P.A.N., and
chairman of the Helicopter Association of Great Britain from 1946 to 1949.