The Kensinger KF was a single seat, all metal Formula One racing aircraft designed and built by Ned Kensinger at Fort Worth in 1959 as N23S.
Only one was built which was later exported to the UK. In the UK, it was registered as G-ASSV c/n.2, fitted with a Continental C85-12F, later changed to a C90 engine.
This flight test was conducted in June 1965 by test pilot J.W.C. Judge and was to test the handling of G-ASSV for the issue of the Permit to Fly. The test flight took place at Halfpenny Green Aerodrome near to the town of Wolverhampton, England and lasted for 25 minutes.
The Kensinger KF (derivative of the Midget Mustang) is a small, all metal, single seat monoplane. The aircraft is powered by a Continental C.85 engine driving a two-bladed MacCauley fixed pitch propeller. The ground clearance of the propeller is satisfactory.
The fuel system comprise of an 11.5 U.S. Gallon gravity fed main tank situated forward of the cockpit and two 4 U.S. Gallon tanks situated in each wing root. The fuel selector cock was mounted on the cockpit floor below the pilot’s right thigh and was easily reached in flight when the pilot was strapped in. The main tank was fitted with an uncalibrated float-type guage on top of the scuttle but the wing root tanks were not guaged.
The cockpit was fitted with a good quality one piece blown perspex canopy that was hinged to fold to starboard for access. A simple and effective canopy locking lever was fitted to the port cockpit wall. A Z-type harness was fitted.
The forward view on the ground was poor but an adequate view could be obtained if the nose was swung from side to side while taxying in the Spitfire manner. The steerable tailwheel (mounted in the base of the rudder) was very effective and although sensitive, one soon got the hang of it. The hydraulically operated toe brakes were effective without being fierce and ther was no tendency for the tail to lift. The toe brakes were so arranged as to require a distinct movement to operate them, making inadvertant operation unlikely. The ground ride was good on tarmac surfaces. The main undercarriage legs were of the spring steel type, the spats were not fitted for this flight.
Max. power static gave 2280 R.P.M. An effective carburettor hot air control was fitted.
On take-off flaps up, there was no undue tendency to swing, the tail rose quite readily and the aircraft was lifted off at 85 mph The flight was made from a smooth tarmac runway in light and variable wind conditions, in fact there was a slight tail wind component.
A comfortable climbing speed was 120 mph, which gave 2550 R.P.M. at full throttle. Engine cooling appeared to be most satisfactory.
The aircraft was dived to 230 mph satisfactorily although the R.P.M. tended to get rather high (in excess of 3200 R.P.M., even when well throttled back). No information on VNE or other limitations was available, although there was a red mark at 250 mph on the A.S.I. There was no evidence of control over balance or flutter.
In cruising flight the aircraft flew with a nose-down attitude and the forward view was good.
Max. level speed at 750 feet (1013 mbs.) gave 185 mph at full throttle/3100 R.P.M.
At high speeds the aircraft was slightly tail heavy, requiring a light push force and making it difficult to assess stability and stick force/g. Stick forces were however light. It is understood that it is intended to fit a Tiger Moth type elevator trimmer eventually, in the meantime it might be worth while to fit a small fixed elevator tab.
On lowering the flaps there was a slight nose down trim change. The flaps were lowered fully at up to 110 mph (again no limitations were available). The flaps, operated by a lever on the port side of the cockpit, had four positions in addition to up. It was easy to lower them to the 3rd position but there was an increased force to reach the 4th position. There was little or no difference in stalling speed or handling between 3rd and 4th positions. The following stalling speeds were achieved, power off:-
Flaps Up – Min. I.A.S. 65 mph – No buffet warning, starboard wing drop at min
Flaps 3rd or 4th position – Min. I.A.S. 63 mph – No buffet warning, starboard wing drop at min.
Lateral stability was satisfactory power on and power off. The ailerons were effective but not as crisp as on the Cosmic Wind. The rudder forces were light but satisfactory.
In the event of an engine failure I recommend that the flaps be left up and 120 mph be maintained while manoeuvring. this gives a good view and a reasonably flat glide angle. The flaps may be lowered in the final stages of the approach but care should be taken not to let the speed fall off too much power off with full flap as it would then be easy to develop a high rate of sink. The 4 divisions of flap allow them to be lowered in stages as required.
The normal powered approach was made at 100 mph with full flap, the view was good and there was ample control, speed was allowed to fall off to 85 mph at the runway threshold and the recommended wheel landing was made (with the sensitive tailwheel steering it could be easy to introduce a swerve if a three point landing was made with the rudder slightly off centre). Speed fell off rapidly after the tail was lowered (even with a slight downwind component) and little braking was necessary.
Summary
This little racing aircraft is pleasant and reasonably easy to fly. Control forces are light but appropriate to an aircraft in the ultra light category. The flaps are effective and make the aircraft much easier to land than the unflapped Cosmic Wind.
It is recommended that the aircraft will be improved by the addition of an elevator trim control as it is at present slightly tail heavy at high speeds, requiring a light push force. There is also a slight nose down trim change when the flaps are lowered.
J.W.C. Judge – 10th June 1965
It was written off on 2 July 1969.
Span: 18.06 ft
Length: 16.05 ft
