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Aviation History
1964
1964 - 1862.PDF
FLIGHT International, 18 June 1964 1033 flame-out. Automatic acceleration control allows the throttles to be slammed open, but some harmless "choo-choo" surging occurs on the centre engine during slam acceleration or decleration at high altitude, unless anti-icing air is being bled. Random reluctance of the middle engine was experienced during early flights, but Boeing say it is no longer a 727 problem any more than in the 707. Goodrich multi-disc wheel brakes with Mk 2 modulated anti- skid system are fitted to all three pairs of landing wheels (i.e., nose as well as mainwheels), and provide a degree of braking which can only be described as fantastic. After a maximum-braking stop they remain cool enough to be touched with the bare hands after a few minutes. Brakes, reverse thrust and spoilers give the 727 quite exceptional stopping capability, a great confidence factor for poor- weather operation or accelerate/stop action. Quick-stopping capability also pushes the Vj speed right up to the VR during most take-offs. VR for 152,0001b is only 128kt and V2 is 144kt. Gear retraction takes 8sec and, because the door opening causes a brief drag increase, retraction is left until a positive rate of climb has been established. Initial climb is at 160kt, and high-speed climb is 340kt up to Mach mainwheels through the grass. The brakes were, I thought, slightly insensitive, and extremely powerful, so that I tended to "rock the boat" slightly when slowing down. Our take-off weight was 118,0001b, giving a VR of a mere 109kt and a V2 of 130kt. I was told to rotate into a 15° nose-up attitude to unstick, and to climb in this attitude, taking my time about retracting gear. In the event, I had no trouble keeping straight as we accelerated very rapidly down the 10,000ft runway; but I had to give up the attempt to set 100 per cent power, rather than my in- stinctive full throttle. Tom Lane did it for me, and we very soon reached VR. With the gentlest rearward movement on the wheel, the 727 unstuck cleanly and launched into an exhilarating climb, with the speed increasing inexorably at the constant attitude. A babble of traffic control instructions left me fiddling with the director compass and trying to make an outbound VOR radial for the climb-out from the Seattle area, but soon we cleared the lower traffic and were left to ourselves. The 727 felt very pleasant, with light and positive controls giving excellent response without physical effort. Boeing have obviously made a good job of their power and feel combination, which seems mm' ' f Landing deceleration, for which high-lift devices, three reversers, full spoilers and almost savagely powerful brakes on all three pairs of wheels give amazing retardation 0.8. A more conventional climb speed is 27Okt, but there is little difference in time to height and the higher speed saves some block time. On short sectors the emphasis is always on high speed. When N9178 taxied in from its 25min initial check from Renton, I entered through the rear stairway, walked forward and was ushered straight into the left-hand seat. The nose tapers quite sharply around the flight deck so that while getting in one is inclined to touch head, knees and elbows on roof, console and back- rest. Once settled, the pilot finds adjustments for seat position, height and reclining angle, as well as for pedal reach. The side windows are very large, but only just give a glimpse of the near wing-tip at least 90ft aft of the nose. The two front screen panels form rather a pillar-box slot for visibility, but the geometry will be completely familiar to 707 pilots and conversion training is considerably simplified thereby. Idle power sufficed for taxying, though a burst was needed to get rolling. An excellent feature was that 6° of nosewheel steering was available through the rudder pedals, allowing instinctive control for normal taxying, take-off and landing. The pedal steering could be disabled by holding the steering tiller steady; or the tiller could be used to obtain the maximum turn and to swivel the nose leg even with the aircraft stationary. Because the mainwheels are no less than 62ft aft of the flight deck, steering gave some weird visual impressions and we were able to roll right up to an imaginary obstacle and then steer the nose sharply sideways away from it. I was told to take care not to cut corners too close and trail the quite natural despite distinct click-centering of the aileron wheel. I could see the rudder position indicators showing the corrective motions fed in by the dual yaw-dampers as I made fairly fast turns in both directions. Use of the stick-top tailplane trim switches sent the trim wheel whizzing jerkily round in traditional 707 fashion. The slow-speed trim switch on the console provided a pleasant means of fine trimming. Very soon I was told to increase climbing speed to 340kt and we were trading i.a.s. for Mach number at 300kt and Mach 0.78 as we passed 29,000ft at l,000ft/min rate of climb. We still had a full test schedule to complete, and settled for an initial series of checks at 31,000ft at Mach 0.82 and 300kt, using 80 per cent r.p.m. Maximum continuous power at this height was 92 per cent, with an e.p.r. (engine exhaust pressure ratio) of 2.1, and the speed then settled at Mach 0.895 and 335kt. The striped VNO and MNO needles were just ahead of the indicators at this point. Though I felt that we should really be close to compressibility effects by now—I think my mind went instinctively back to the complete mess in which a Meteor 8 would have been at this speed—I could sense only a very slight reduction in aileron effectiveness and a hard burble when pulling the nose up in a 30° banked turn. There was no noticeable loss of stability, nor any wing-dropping or other phenomena. Boeing would probably be cross with me for even expecting any. Height holding inevitably took some concentration here, but the instantaneous v.s.i. was a great help. The drum and pointer alti- meter was, I thought, too hard to decipher. The rudders were
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