JUMPING AUTOGIRO

King Country Chronicle, Volume XXXIII, Issue 4806, 5 July 1939, Page 7

JUMPING AUTOGIRO

FOR NAVY AND ARMYt TESTS MADE IN BRITAIN. NEW TYPE OF MACHINE. The direct take-off autogiros ordered some time ago by the Air Ministry are now being delivered, says the aviation correspondent of The Times. Three are intended for the Fleet Air Arm, or.e will be used at the School of Army Co-operation at Old Sarum, an one will probably be allotted to experiments at Farnborough. A sixth aircraft of this type, known as the C. 40, remains in the hands of the Autogiro Company for the training of pupils and the carrying out of development work. The effect and sensation of the jump take-off were tested on April 27 at the Hanworth aerodrome.

The C. 40 autogiro is a two-seater fitted with a Salmson engine rated at 200 h.p. It is different from the original aircraft designed for the direct take-off in having less flexible and smaller rotor blades, but in principle it is the same. That is to say, that the rotor is turned at a high speed by the power of the engine while the aircraft stands with brakes on. During this process of storing energy in the rotor the blades are held in a position in which they develop no lift. When a rate of about 280 revolutions a minute is reached the blades are freed. They at once assume a lifting angle, and the aircraft leaps vertically into the air. A Lower Jump Made. In the earlier model the height of the jump .was about 20ft. In the present case, as a result of the change in the rotors and of increased weight, the jump is about 12ft. Sitting alongside Mr. R. A. Brie, chief pilot of the company, one found the sensation of this leap into the air to be wholly different from most other sensations in flying. The rate of acceleration is high, but not violent. The passenger had the sensation of being pushed into the air rather than of being hauled up as in a lift. There was no feeling of emptiness in the pit of the stomach; the movement was too sudden and too soon over for that, but there was the same sense of irresistible upward pressure that is gained when pulling out of a fast power dive.

The strangeness of the feeling arose particularly from the rapid change in trim of the aircraft. From the “tail down” attitude the autogiro assumed the “tail up” position as it rose vertically off the ground so that forward speed might be the more quickly obtained for the purpose of keeping the rotor turning at speed sufficient for climbing. Usefulness Tested. R.A.F. and Fleet Air Arm officers have already been trained in the flying of the new type. This summer the navy the question will probably position to judge its usefulness. In then avy the question will probably resolve itself into an examination of the possibility of flying the autogiro from cruisers. The value of a slowflying aeroplane for anti-submarine patrol and for certain types of reconnaissance is easily seen, but it is doubtful whether the best results would be obtained by putting this type of aircraft in the aircraftcarriers. For use from cruisers a special deck, like the one invented by Mr, Brie to swing outwards over the side of the ship, might be needed to permit the jump take-off and spot landing. . The most likely use of the type for the army is for communication behind the lines. Autogiros of the C3O type which need a run at the take-off, are already used to take officers from one headquarters to- another. The new type, needing no forward run, could take off if necessary from broken ground and land almost anywhere. The jumping start would not upset the gravest staff officer after his first experience of it; and until the helicopter, towards which this development tends, is produced the C4O appears to offer him the most vital of its characteristics.