Background
He was born in Brighton and educated in Bournemouth.
He was born in Brighton and educated in Bournemouth.
He started work for Airco in 1915, aged 27, and worked as a draftsman on the DH4 in 1916. He transferred to the de Havilland Aircraft company (Stag Lane) when it was created in 1920. At de Havilland he invented the differential ailerons used on the Tiger Moth and other de Havilland aircraft eventually becoming chief designer.
In this role he was responsible for the designs of the DH88 Comet racer and of the Albatross and the Express airliners.
Hagg became interested in boat building and in early 1937 he resigned his position as director and chief designer at de Havilland to set up the Walton Yacht Works. In January 1943 he joined Airspeed Limited. as technical director and was responsible for the Airspeed Ambassador (Bureau of Economic Analysis Elizabethan).
He retired in 1947.