Date:	Friday 30 September 1949
Time:	day
Type:	Sikorsky R-4 Hoverfly Mk I
Owner/operator:	TFU RAF
Registration:	KK988
MSN:
Fatalities:	Fatalities: 0 / Occupants: 2
Aircraft damage:	Destroyed
Location:	RAF Defford, Worcestershire, England -   United Kingdom
Phase:	Landing
Nature:	Military
Departure airport:	RAF Defford, Worcestershire
Destination airport:	RAF Defford, Worcestershire

Narrative:
Sikorsky R-4 Hoverfly I KK988, TFU (Telecommunications Flying Unit) RAF: Written off (damaged beyond repair) 30-9-1949 in a landing accident at RAF Defford, Worcestershire, England.

The helicopter rolled to starboard when only just clear of the ground (at an altitude of less than 10 feet). The rotor blades hit the ground and shattered. The stubs of the shattered rotor blades, still rotating, then acted as a "tractor", and pulled the airframe along the ground until the engine stopped. The crew of two were uninjured.

Being the first "practical" helicopter, the Sikorski R-4 Hoverfly has a reputation of being difficult to fly. The aircraft's blades were made of wood ribs around a steel spar and covered with doped fabric. The blades were difficult to keep rotating in the same plane and vibrated excessively. The cyclic made continuous small orbits, vibrating continuously. There was no governor to control rotor speed, and the pilot had to correlate the throttle continuously with collective pitch inputs.

1. Halley, James (1999). Broken Wings – Post-War Royal Air Force Accidents. Tunbridge Wells: Air-Britain (Historians) Ltd. ISBN 0-85130-290-4.
2. Final Landings: A Summary of RAF Aircraft and Combat Losses 1946 to 1949 by Colin Cummings p.550
3. https://en.wikipedia.org/wiki/Sikorsky_R-4
4. https://en.wikipedia.org/wiki/RAF_Defford#Postwar_use
5. https://en.wikipedia.org/wiki/Telecommunications_Research_Establishment#Malvern
6. https://air-britain.com/pdfs/military/Crashes_Wales_and_West_Midlands.pdf

No photo found of KK988: Above is very similar Sikorsky R-4 Hoverfly I KK990 (of the same production batch) at Fairey Aviation, Hayes, Middlesex in October 1945.

Date/time	Contributor	Updates
20-May-2023 21:13	Nepa	Updated