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Aviation History
1957
1957 - 0912.PDF
FLIGHT SKEETER IN THE AIR . . . range permitted is quite wide. For cruising they should not fallbelow 300 or rise above 335. Normal maximum is 340 r.p.m., maximum overspeed, 345. Maximum continuous power isobtained at an engine speed of 2,500 r.p.m. with full throttle and 320 rotor r.pjn. The collective pitch levers, with their fine-adjustment twist-grip throttles, have a sliding friction adjuster on the starboard side lever. The tall—overtall for me—cyclic pitch levers carrysmall electric trim switches which are pushed against light spring loading in the direction in which a trim change is desired. Theselevers also carry press-to-transmit buttons. The rudder pedals, which, according to circumstances, must beused very sensitively or to their full extent, are perhaps a little primitive in design. The rudder is the most tricky control for thenew pilot to master, and thus it should be as convenient in operation as possible. The use of the fine adjustment throttleis probably the next most difficult action, and this, too, should have just the right amount of smooth angular movement tocover the range of in-flight throttle changes with natural wrist flexion. On the Skeeter, the slightest twist produces a markedchange in engine power (and thus in torque—to be countered by rudder movement). Each time we prepared to take-off, the Gipsy Major fired firstcartridge, and it was, I thought, an improvement to be able to run the engine at any speed desired without bringing in the rotorclutch until it was wanted. When I first took over the Skeeter, not having handled ahelicopter for some months, I was tense and clumsy with the controls, but—and this was important to me—I felt safe and hadno fear that anything would get out of hand so long as the engine kept going. This was due, I believe, to the responsiveness of thecontrols, the good flying qualities of the Skeeter, and to the unusual stability of this little machine.All control movements are small and precise; it is difficult at first not to lag on rudder correction, for anticipation rather thanquick reaction is necessary. There is no shake or roughness about the cyclic stick, and the Skeeter answers to it naturally,more like a light fixed-wing type than any helicopter I have tried. With careful trimming and setting, the hands can be takenoff the controls and the Skeeter will hover into wind with rudder guidance alone. On this particular machine, on this hot day, and Above and left, Suggestive of the A.O.P. role but, in fact, low-level* Skeeter cruises comfortably at 80 m.p.h. John Jeffries holds a steady with full fuel load, 195 bJi.p. was only just enough and it wasbest to keep the rotor revs at the top of the green limit marking before moving off from the hovering position, or making power-using manoeuvres such as pirouetting against torque. Once trans- lational lift is helping, the Skeeter climbs away readily at itsrecommended speed of 45 kt. The various transitions from climb to level, level to descent orinto autorotation, are things that do not come smoothly and easily when a pilot is new to a helicopter. Even allowing for the factthat each additional flight brings an extra experience, I felt more capable and confident of flying and trying out the Skeeter, ratherman guiding it gingerly, than any machine I had previously flown. dearly a good deal of trouble has been taken to get the rightbalance of power and pitch alteration which together follow move- ment of the collective pitch lever. This means that rev watcherslike me do not worry and thus relax and fly better. Turns are made as with any other aircraft. Take your clubpilot and put him in the Skeeter at its easy cruising speed of 75 m.p.h. and he would fly it like a Tiger—though perhaps need-ing relatively more rudder when turning right against torque. John Jeffries, the Saunders-Roe test pilot who demonstratedthe Skeeter's performance to me, and is to be seen in some of the pictures, showed how confidently and smoothly the machinewill about turn, dive and climb at low level, much as it had done during several Farnborough Show demonstrations.One of the impressive points of handling is the controllability of the machine in full autorotation. Certainly you are comingdownhill rapidly at l,25Oft/min, but direction can be controlled and there is some freedom of choice in emergency to alter forwardspeed in relation to rate of descent. Minimum rate of descent is held at 25-30 kt forward speed, andthe horizontal distance of glide seems to be about 350 yd per 1,000ft of height. With a forward speed of 50 kt, mis distancecan be stretched to perhaps 600 yd. Rotor r.p.m. in autorotation reach a maximum of 345.Recovering from autorotation needs practice if it is to be smooth, and over-rewing of engine and rotor is to be avoided.It is again a case of anticipation and quick, concise use of rudder is called for as power comes in. In autorotation, there is
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