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Aviation History
1950
1950 - 0885.PDF
FLIGHT, II May 1950 57c (indicator green lights confirm operation, as do tfie sound effects over the intercom), but the cross-feed cock remains off- Two buttons are pressed for a cold start, one for th,e starter proper and the other for the priming valve. The main services—wheels, flaps and brakes—are pneumatically operated. Each engine carries a compressor and an air cylinder, port and starboard cylinders being con- nected by a balance pipe. In addition, the port compressor serves a second port-side cylinder for emergency operation. This system is brought into use independently of the main controls by two valves on the port side of the main panel. Having discovered this much while the Leonides warmed up, we called for chocks away and taxi clearance from the tower. Control on the ground is adequate, though not the best of the Prince's features. A hand-brake lever is pro- vided on each of the "open w" control wheels, and the rudder (adjustable for reach by means of a star wheel) pro- vides differential action. The nosewheel is coaxed round as required with brakes and engine, and, when bowling along over the irregular grass surface at Luton, the Prince is found to be well sprung and to offer a quite remarkably good view forwards, sideways, above, and almost literally, below. To be fair, it must be added that the aircraft I flew —an early model and the one, in fact, which made the tour of Africa—is awaiting the removal of surplus friction washers in the nosewheel system. They became obsolete when possibilities of shimmying were removed by re-rigging the nosewheel in the near-vertical position. Steering on the ground is reported to be much simplified on production aircraft. The brief take-off check is concerned with trimmers (all neutral except for elevator, which is placed at \ deg for- ward into the black sector); pitch, full fine (3,000 r.p.m. at 43m Hg for take-off); flaps at take-off gate; oil cooler manual controls, full or part-open according to temperature. With the Prince properly lined up, the throttles may be opened quite quickly without any tendency to swing. As speed increases—as it does unusually quickly—the nose- wheel is pulled off the ground and then held. This occurs at about 60 m.p.h. Shortly afterwards, with pull load on the stick, to hold the nosewheel up, diminishing, the aircraft flies smoothly off at about 95 m.p.h. (100 m.p.h. at max. a.u.w.). She is ready to climb steeply almost immediately, and the wheels are fully retracted in about 20 seconds. Flaps follow wheels at 2oo-3ooft, and the angle of climb to maintain the best climbing speed of 120 m.p.h. is unusually steep. Continuous climbing is carried out at 2,900 r.p.m. and 36m boost, .and at between 8,000 and 9,000 lb a.u.w. this gives an indicated rate of over 1,200 ft/min. Pulling up wheels and flaps causes a small nose-up trim change, and in the latter case a very slight sink. I did not try any engine cuts on take-off, but measured tests indicate, for example, that with starboard engine feathered, flaps at take-off and u/c still down, the climb is just over IQO ft/min at no m.p.h. at maximum weight (10,650 lb). When the wheels are up the climb increases to 290 ft/min. With wheels and flaps both up, climbing power will provide a full-load climb of 200 ft / min. For a short period while climbing away from the field, with wheels and flaps both up, the port engine was feathered. With take-off power and slightly reduced weight, the climb was indicated as about 500 ft/min. Direction was easily held with rudder at 120 m.p.h.; a few degrees of rudder trim accounted entirely for the asymmetry and a hands-off climb was then possible. Normal level flying was much the same as with two engines running. All three controls are light and smooth in operation, and the ailerons are especially effective. Little use need be made of the rudder for ordinary flying, and thus it is no disadvantage to find it slightly heavier than the other two controls. The controls remain effective and positive down to the stall, and there is no appreciable tightening-up accompanying the nose-up trim change on the way up to 220 m.p.h. I.A.S., the highest speed at which I flew. A top-speed limit of 250 m.p.h. (217 kt) is quoted. Weak-mixture cruising conditions are 2,600 r.p.m. and 3oin boost as a maximum, and these—61 per cent of take- off power—give a speed of 190 m.p.h. At 2,200 r.p.m. and 28in, which 1 used for stooging, the indicated speed at 1,500ft was about 160 m.p.h. This setting represents just under 50 per cent power. Stalling is unlikely to cause any trouble, being entirely normal and straightforward, with plenty of warning I tried stalls, engines off, with everything up and everything down. In the former case the speed was near enough 90 m.p.h. I.A.S., and in the latter case, 75 m.p.h. The onset was marked with gentle buffeting, and when com- pletely stalled this felt more pronounced, particularly in the elevators. Recovery is rapid, and a little engine power seemed to smooth out the buffeting even before speed started to build up and full control return. Time was found to make a couple of take-offs and land- ings, and in both the experience of the first enabled me to improve the second. On the first take-off I continued for a little too long the hard early pull required to raise the nosewheel, and consequently leaped off the ground a little too steeply. The attitude on the ground seems slightly nose-down, and one feels particularly close to the grass. On The Prince has a single, large, flexibly-mounted panel carrying engine instruments on the star- board side; to port is the standard flying-instrument layout. On the pedestal, paired throttles (left) and airscrew levers (gated for feathering and later to include reverse-pitch braking) are flanked by undercarriage and flap levers. Also seen on the pedestal are the three trimmers with their in- dicators, operating in natural plane and sense. A starting panel is located centrally above the main instrument panel; the emer- gency panel, with oil-cooler-flap controls, is centrally in the roof; the pilot's switch panel is on the cockpit port side; and the fuel- control switch pane! (with the cabin-heat lever) is on the bulk- head above the cockpit door. The flying-control locking device is seen engaged, with its safety bar across the quadrants.
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