FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1962
1962 - 0666.PDF
664 FLIGHT International, 26 April 1962 ,, IN THE AIR A Brantly 8-2 over its native Oklahoma. About 200 have now been made and two are in Britain has been so arranged that throttle and lever remain co-ordinated over all but autorotative power ranges if correctly set before take off. Also, the linkage has made it impossible to overpitch the rotor —one of the main nasty corners when operating near load/tem perature limits. I found consistently that a full-power climb could be attained with steady application of full-up lever without any sign of loss of r.p.m. We were flying with two occupants, no baggage, half fuel and plenty of wind, so we could not get anywhere near overpitching during take-off. Top intake pressure of about 28.2in was used in the climb, but 100 m.p.h. was sustained with only 23in and the hover with about 24.5in in a wind of perhaps lOkt. Apart from this thoroughly docile rotor and airspeed performance, the Brantly is not particularly easier to fly than other helicopters, although it is commendable that the feel of a much larger machine should be reproduced in one so small and therefore potentially so skittery. Access through the upward-opening doors is quite easy. The seats are comfortable and ventilators provided. The instruments are very well displayed on the pylon, with mixture and carburettor hot-air levers on the floor. Carb air has to be watched, but not so much as in a Hiller. There is a bungee and electric motor cyclic fore-and-aft trim system, but the switch is rather too tucked away on the floor for use during hovering. Stick forces are normal by helicopter standards. The Lycoming VO-360-A1A engine—vertically mounted 180 h.p. —is started with the rotor brake on, and warmed-up at 1,700 r.p.m. When the brake is released, the rotor begins to speed up and the two r.p.m. needles come to overlap at 1,700 engine r.p.m. The magnetos and freewheel are checked at 2,100 r.p.m. and the system is then accelerated rapidly through a vibration range between 2,400 and 2,600 engine r.p.m. Normal operating range is between 2,700 and 2,900 r.p.m., equivalent to the unusually high rotor r.p.m. of 428 to 472. The ejector exhaust makes a good deal of noise and the rumble and whine of the transmission peaks at about 2,400 r.p.m., to settle later to a level at which conversation is just possible between the pilots. The engine is so close behind one's back, that very slight alteration of r.p.m. is distinctly felt by noise and vibration, greatly assisting r.p.m. control when the pilot is not watching the gauge. I first took control during the climb at 55 m.p.h. and l,000ft/min and found average stability (or lack of it). Visibility was very good, although at first glance the horizontal door hinge beside one's face and the bubble into which one's head protrudes looks awkward. At no time did I notice any interference from the structure and I feel that the hoop round the nose blister and the "face bar" completely remove that vertigo-inducing feeling of being strapped to a tilted bookshelf, which can be very off-putting to the inexperienced passenger. General handling in turns and during repeated climbs and descents was very pleasant, although I kept trying to move the twist-grip when there was no need to, upsetting the built-in co ordination. In any case, the gearing of the twist-grip was quite the best I have noticed and made r.p.m. adjustment very easy. We buzzed around the countryside for a while and I took some photographs while Ron Taylor, the BE AS Brantly manager, flew. After a while he located the attractive stone farmhouse of Mr Kerr Elliot, BEAS director, and dropped down onto the lawn, beside some power cables, for a very civilized sherry. This sort of thing might become known as "Brantlying." When we flew back to Kidlington, I had my first chance to hover. The Brantly was averagely easy to hover—a little untidy with my experience, but rock-steady when Ron Taylor flew it. After lunch I had a second trip with Spencer Kendal, BEAS Brantly instructor, and he put me through the full treatment of circuits and landings, and turning at the hover in various ways. I was told to hover with the skids two feet off the ground, which feels very low, in order to keep well within the ground cushion. As I turned on the spot, I had to take care to prevent the skids brushing the grass as I allowed for forward and then backward flight relative to the wind. Direc tional control was very sensitive after the first few degrees of rudder- pedal movement. It was helpful to apply some left rudder and lateral stick before lifting off, to avoid a sudden slew as the skids left the ground, but all this is normal and in no way a Brantly peculiarity. When we set down, the Brantly sank gratefully into its oleos with a pleasantly soft sensation. When making the forward transition from the hover, the Brantly accelerated very rapidly and required relatively little forward stick movement at the transition point. It went into its fast climb very quickly and each time I had settled at 55 m.p.h. I found that the lever was just nudging the top stop without any tendency to gain or lose r.p.m. The approach was made at 15in intake pressure and 55 m.p.h. for a very comfortable angle, rounding out late and straight into the ground cushion, decelerating to the hover with only a slight tail-down angle. Twice out of four times I found I dropped rather rapidly at the end and had to catch it with a surge of power: once I got the tail a little too far down in the transition. It takes a little time to get used to making the transition so close to the ground. I learned on Widgeons, which can be cocked up to a surprising angle 20ft off the ground and then rotated into the level hover quite comfortably. Both Hiller and Brantly are best flared much later. I had an unexpected trial when making the final approach to the petrol pumps, instead of to a piece of open airfield. We were descending close to the final approach for runway 31 and there were numbers of more or less experienced pupils Colting around the circuit. We hawked it like a watch, for which the Brantly windows are good, but were ultimately caught short by a dirty dart from a Chipmunk. The most difficult manoeuvre to learn to do instinctively is a change from descent to climb, or vice versa, when all the co-ordination has to be used quickly. When the Chip munk loomed in the window, I pulled up on the lever as gingerly fast as I dared and he passed below. After that Spencer took over and made his approach between some hangars. I enjoyed the Brantly: it has more to offer the two-seat operator than anything hitherto, and I hope it catches on. The potentiali ties for amusement are almost unlimited, without the usual penalties of expense and elaborate maintenance.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
