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Aviation History
1962
1962 - 0212.PDF
Catching the light on the right in this Belvedere cockpit view are the a.s.i. and two j.p.t. dials. Above them are the rotor r.p.m. and two-needle torque gauges. At top left is the yaw meter. The centre console carries engine instruments, hand throttles, trim wheel and control-position indicators. Collective lever and hydraulic hand-pump are immediately beyond. Other controls are in the roof panel. Heating filament bus-bars, windcsreen wiper blade and a rotor blade can be seen in the rain-clouded windscreen panel at top right WESTLAND BELVEDERE in the air . . . course, very brief and little extra power had to be applied to attain a stationary hover. There was a distinct change from slight right to left rudder to counteract the change in residual torque with loss of speed and increase in power. Despite my lack of practice, the hover seemed quite easy to hold. A slight reduction in lever position started us down for the landing and I found the Belvedere just about the same to set down as a Widgeon—except that I landed the back end, and then landed the front. I could hardly feel the rear wheels touch the grass, and tended to go on flying the machine for too long before I let the front end down and bottomed the collective pitch. The Belvedere normally lands happily "on all fours." As collective pitch was applied for take-off, throttle had to be considerably reduced to prevent the r.r.p.m. increasing, but other wise things felt very comfortable. A rapid lift-away from a bad landing was also easy. In the strong wind we could do no turns on the spot, but Fit Lt Salt made me speed-up to 60kt and cut one engine just as I began to climb away at about 30ft. The engine noise halved and the torque needles "split," but I had absolutely no sensation of loss of power. We simply continued through a normal circuit and came back to a hover over the grass. This concluded my first session and I translated gingerly past the control tower, hovered over the apron and let the machine down onto the con crete. Incidentally, if the engines are running at less than 16,300 c.r.p.m. the good engine will still automatically take up the load of a failed engine, but would need up to seven seconds to do so. During my second flight, some days later, I watched a Belvedere lifting a Land-Rover. The load itself, I was told, was hardly notice able to the pilot; but the drill was interesting. Because the pilot cannot really see the load when he hovers over it, the crewman lies on the cabin floor, looking out over the door sill, and talks the pilot across and down to the point where the lifting strop can be attached. Flying speeds are laid down for varying external loads, e.g., 70 to 80kt for an Army bridge unit, 50 to 60kt for the aerodynamically awkward Land-Rover with trailer attached. Obviously, the phenomenon to avoid is oscillation of the suspended load, which could become dangerous if allowed to build up. The cure is to accelerate or climb firmly to give an extra stabilizing tug on the strop. We flew across the airfield and hovered over the main runway where the Land-Rover was waiting. Unloaded, the vehicle weighed about 3,6001b, and was fitted with 214 FLIGHT International, 8 February 1962 a four-point harness and spreader bars. An 8ft nylon strop was fastened to the fuselage hook of another Belvedere. Under direc tions from his crewman, the pilot inched his way over the load and came slightly down, until the handlers attached the strop and jumped clear. He climbed very slowly until the crewman called that the harness was taking the strain, and then rose normally to the hover and transition. Several buttons and switches allow the load to be released or jettisoned, or the hook can be set to open as soon as the lifting strain is relieved when the load touches the ground. I was hardly sorry not to be doing the lifting myself, because I realized that the procedure requires precision hovering of a kind it would take me some hours to achieve. Perfect team-work between crewman and pilot, and cool, steady flying are needed. After watching the lifting operation, we made a quick circuit and jettisoned some fuel. This is a standard facility, originating from a search-and-rescue requirement. A Belvedere might go out with full tanks, prepared for a four-hour search operation and find several people to rescue after only 30min or so. If gross weight limitations were threatened, fuel could be jettisoned and delay in rescuing avoided. Dumped fuel vents in a fine plume from pipes near the rear landing wheels, and can be easily watched through the rear-view mirror beside the pilot. I was next given some more dual instruction, this time by Fg Off Nast. It was an instructive trip, because the weather was now silky smooth, with perfect visibility and virtually no wind. Much more power was required to come to the hover, and more airspeed had to be lost during the transition. For a few minutes I flew around and then brought the Belvedere to the hover over the end of the main runway. I worked around for some time, turning on the spot, flying squares on a constant heading and flying the nose round a square, pointing the fuselage always to wards the centre. The required control movements appeared entirely normal and I was quite happy manoeuvring about a runway light, watching it through the "chin" window. In these circumstances, with very little wind, the r.r.p.m. did not wander much. Turbines run far more steadily than does a piston engine under the same conditions. Normally, the Belvedere will turn on the spot about its e.g. (slightly forward of the fuselage mid-point), but it can be made to pivot about its nose or tail and, in practice, one can bring the tail or nose round almost instinctively. The only cyclic stick-force comes from the feel bellows; and the neutral, or zero-force, position depends upon the feel datum set at any given moment. As the stick position changes when speeding- up or slowing down, the residual force can be immediately cancelled by pressing the feel button on the stick, which works well and is very quick and comfortable to use. One must take care to press the button at a typical stick position and not during some corrective action, although out-of-trim forces are never in the least difficult. Finally, I began a circuit which was to teach me a firm lesson about inertia and ground cushion. I made a perfectly normal and unhurried approach to the grass beside the runway. Everything went according to plan until I was well into the transition and trying to level off and stop at about 30ft. I pulled progressively back on the stick to kill the last few knots and increased power to try to maintain height, but the Belvedere went resolutely on downhill at a fair clip. I pulled more and more power, but still we sank for wards, close past a little brick hut. Fg Off Nast took control in a hurry as the torque needles went into the red together. He pushed the stick forward to level the fuselage and we fairly bounded into the air again. As far as I can see, what happened was that, with the nose well up, the more power I applied, the more the increasing rotor down- wash clashed with the relative upward flow through the rotor discs and drove the ground cushion out from underneath us. Inertia, coupled with something approaching a vortex ring and lack of ground cushion, left me sinking fast in a way I had never seen a Widgeon do, even at much more pronounced nose-up angles. With a small helicopter, you can come to a virtual standstill over the ground, at about 20° nose-up attitude and almost in auto- rotation, before applying a surge of power and levelling off into the hover. A big machine like the Belvedere will not take anything like that treatment, and must be brought in a great deal more steadily. The cure for that sinking feeling is not to apply more power but to level the fuselage and gather the ground cushion in underneath. One or two more transitions from and to the hover served to drive the lesson home before we retired to the hangar. A brief pause while we waited for the groundcrew to signal that the droop-stops had gone home and we switched off.
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