Raoul Hafner achieved limited success with R.I. and R.II helicopters, built Vienna with Scottish finance. Moved to Heston, England, 1932 and designed A.R.III autogyro, built by A.R.III Construction Co. in Martin-Baker factory at Denham, 1936, complete success. Chief designer at AFEE (Airborne Forces Experimental Establishment) Beaulieu, 1942-5, developed Rotachute and Rotaplane (Spec. 11/42) for precision delivery of payloads and troops using air tow and free-spinning rotor. Extended idea to deliver Valentine tank, and as intermediate step built and flew Rotabuggy based on standard army Jeep, tested using Whitley tug. After war formed and headed Bristol helicopter department.