Cierva C.40
For a description of the format and data included in Production Tables, see here.
Contents
Type Description
- C.40
- Side-by-side two seat autogyro featuring a jump-takeoff mechanism, to Air Ministry Specifications 2/36 for Army Cooperation and 43/36 for autogyros for Fleet Air Arm use (eg for shadowing and spotting). The jump-takeoff mechanism was part of what was termed “Autodynamic rotor” by Cierva, the system providing various functionalities by means of torque, inertial, and aerodynamic forces acting on tailored rotor blades rotating about inclined flap, drag, and feather hinges. For jump-takeoff, the rotor was accelerated in fine pitch until the rotor speed required for flight was achieved and was then declutched. The loss of torque caused the blades to swing forward on angled drag hinges with a resultant increase in collective pitch, causing the aircraft to leap into the air in a spectacular fashion. With all the engine power now applied to the forward thrusting propeller, it was then possible to continue in forward flight with the rotor in autorotation.
The C.40 was an all new design, with a nine-sided wooden monocoque fuselage rather than the circular section of the C.30. The horizontal unbraced tailplane was without elevators, the left side of the tailplane having an inverted aerofoil section to counter roll-axis torque produced by the propeller. Dorsal and ventral fins were fitted and, unlike the C.30, there was a substantial rudder which incorporated a fairing which extended the fuselage section to a point at its trailing edge. One 203 h.p. Salmson 9Ng powerplant.
| C.40 Specification | |||||||||
| Rotor Dia | Length | Disc Area | Empty Wt | Max AUW | Minimum Speed | Maximum Speed | Range | Service Ceiling | |
| 40 ft 1 in | 20 ft 8 in | 1350 lb | 1950 lb | 120 mph/ 104 kn | 200 mi | ||||
| 12.22 m | 6.3 m | 612 kg | 885 kg | 193 kph | 322 km | ||||
Production Details
C.40 Prototypes
| C/n | Initial Registration |
Notes |
| 1 aircraft built by the British Aircraft Co. First flew February 1938. | ||
| 1001 | G-AFDP | To the Cierva Autogiro Co Ltd, London Air Park. To RAF as T1419 against Contract 968954/38 in October 1939. |
| 1 aircraft initially constructed by the British Aircraft Manufacturing Co, but completed by Oddie, Bradbury and Cull of Southampton. | ||
| 1002 | G-AFDR | To the Cierva Autogiro Co Ltd, London Air Park, but delivered directly to the RAF as P9636 against Contract 968954/38 in December 1939. |
| Total Production 2 | ||
C.40 Production
| Serial Range | C/n | Batch Qty |
Conv. | Canc'd | Notes |
| 5 aircraft ordered from Oddie, Bradbury and Cull of Southampton, to Contract 649841/37. Delivered between. | |||||
| L7589 - L7591 | 1003-1005 | 3 | See note 1. | ||
| L7594 - L7595 | 1006-1007 | 2 | See note 1. | ||
| 2 aircraft ordered from Oddie, Bradbury and Cull of Southampton, to Contract 968954/38. | |||||
| P9635 - P9636 | 1008, 1002 | (1) | 1 | P9635 cancelled and replaced by purchase of G-AFDP as T1419; P9636 ex G-AFDR, delivered in December 1939. | |
| Total Production | 5 | (1) | 1 | ||
Production Summary
All Aircraft By Type
| Type | Built New | Conv | Canc'd | Total |
| C.40 | 5 | 1 | 6 | |
| 5 | (0) | 1 |
Notes
- Five aircraft ordered, intended as 3 for Fleet Air Arm, one for Army, and one for the RAE. Per [4], the eventual allocation (highly summarised) was:
L7589 to RAE.
L7590 to Comms Sqn RAF Andover.
L7591, L7594, L7595 to HQ Coastal Command for service trials.
Production References
- Cierva Autogiros - The Development of Rotary-Wing Flight, Peter W. Brooks (Airlife, 1988)
- https://www.ab-ix.co.uk/pdfs/BK_BAMco.pdf
- RAF Air Historical Branch: RAF Aircraft Movement Card (A.M. Form 78) (Dept of Archive and Aviation Records, RAF Museum, Hendon, Records MFC-77-15-17)
- BARG Roundel Oct 1996