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Aviation History
1983
1983 - 1987.PDF
lock would more likely be used at high level, especially in wind or temperature shear. Operation of the director synchro button on the control wheel is compatible with autopilot engagement, and I found it the easiest way to re-datum the speed or rate of climb modes. Disconnect is annuciated by a red panel among the group top right of the PFD, but I was disappointed to find no aural warn ing. The yaw damper always drops out at the same time as autopilot disconnect. This is a guard against leaving it in for landing, from low automatic approach limits—since the parallel damper is not compatible for take-off or landing. I had to develop the habit of re-engagement, although I found the absence of yaw damper to be quite unnoticeable in anything but the most vigorous manoeuvre. The auto capture and level-off at FL370 was very gradual from the remaining l,500ft/min climb, and the two-digit Mach number window quickly wound up to 0 • 75. (The second digit clicks from one number to another in a way that rather obscures speed trend.) The climb from 2,000ft had taken 14min—the book time at 20,9001b start climb weight. Still only 1,1001b of fuel had been used, in spite of the protracted low-level hold, against 6501b expected for the climb alone. Acceleration finally stopped at Mach 0 • 78, 453kt TAS, with the total fuel flow at l,7501b/hr with ISA+1°C. This was "spot on" the thrust limit cut-off of the high speed curve for 20,0001b, with 0-262 air miles per lb. (The Mach 0-7, 402kt long-range figure would be 0-324 and the Mach 0-62 peak at 0-34 n.m./lb.) Pitch was at the aft trim end of the scale with stick well forward, and was 2° nose-up at most. Turns and stick pull-back felt quite tolerable to buffet. Looking around for traffic in the turns showed the good free dom from screen distortion, apart from very light ripples at the joins of the gold film heating. Beyond an 8ft galley/luggage area and a club-style smoked glass door I entered the 13ft-plus passenger cabin, outfitted in sober but elegant dark brown wood and brass for the. coming NBAA show. The airflow hiss gave credit to the drag improvements—all the more so as only one seat was then installed to contribute to the sound absorption. The sound level reflects well on the new trim, profiled back into the frame structure. The standard executive layout incor porates a three-place settee on the port side with five "universal" pivotable passenger seats. There is a slight variation in space optimisation from the -700, putting the wardrobe to starboard rear of the cabin instead of in the front luggage area. I was told that the Garretts have yet to be finally "tuned" but, at the back of the cabin, through into the fair-sized and newly shaped toilet, opposite the rear baggage compartment, there seemed to be no irritating beat at all. When seated, the feeling of space about the head and shoulders from the sculptured-back passenger service modules is very apparent. Re-positioned air supply ducts have added slightly to foot space. What is also striking is the way that the extra lin of headroom, up now to 5ft 9in, enabled me merely to duck— compared with stooping slightly in the -700. I returned through the front galley area, identical in size to the -700, but with the food modules and coat storage rationalised. The flight continued off the Norfolk coast, climbing to the FL430 certification ceiling at full throttle and leaving the computer to sort out the ITT. This settled at about 880°C. Just below 20,0001b now, the speed topped at Mach 0 • 74 and 417kt TAS; the OAT had now dropped to ISA-7°C and the fuel flow settled at l,1501b/hr. The ISA datum flow would be just over l,2001b/hr—0-342 n.m./lb. An engine throttled back was slow to induce roll and had absolutely no effect in any cabin rate of climb, even with the air valve finally shut. We were cleared to descend again to FL370, and the speed could be built toward the new MMo of Mach 0 • 80. This was more out of interest, as the trim was not representative and the elevator scoops (first fitted to the lengthened -600) may be modified in respect of suspected flow effects at the normal envelope extremes. Distinct "burbling" started around Mach 0 • 79, and could be felt and seen on the control column. The airbrakes retain the 125 disposi tion, with panels above and below the wing. Complete absence of pitch disturbance on extension is retained, as is the absence of any real buffet. The feeling is more of an unseen hand and of a light aerodynamic growl rather than of vibration. I dare say that these are the most passenger-acceptable airbrakes that I have experienced. Cleared for a rapid descent, I eased back the throttles. It felt odd that nothing much happened until the datum fell below the automatically controlled setting. Even keeping to 280kt IAS below FL350, the idling descent rate was more than 7000ft/min, adding to the appreciation of the airbrakes' effectiveness. A level-off added to the feeling of very good aerodynamic qualities in this config uration. Airbrake with any flap is not permitted, though, and I cleaned up for 15" flap extension at the 220kt IAS limit at FL200. Hands-off, the pitch-up was very mild and slow, if anything decreasing at the final stage. Retraction at lOkt above the clean stall was no more disturbed, and pitch change with power alteration insig nificant. Mike Goodfellow ran through a series of classic stalls to the g-break in the various configurations. I watched the IAS count down on the digits alongside the speed datum marker at the left of the PFD display, and the accuracy of the predicted shaker and breakaway was uncanny. The 125 configuration does not require a stick- pusher or nudger—generally attitudes reached 13°-16° maximum—and all recoveries were the merest pitch forward with power application. Only the 45° flap gear-down stall, at 88kt for 19,5001b, produced a slight drop of the right wing. I found lateral control near the stall to be good throughout my own handling. In a well-tried aircraft I only had to make two touch-and-goes and an asym metric full-stop landing to be able to say that the new wing and ailerons give very good circuit handling and that the wind screen angles of view are up to the best standards. The wind was now across the runway at a little more than lOkt, but 20kt until late on the approach, with a sneaky little updraft in the approach area. I had to build up the descent at a late stage to get back into the slot of the PAPI on runway 24, and the speed drifted up rather, but the -800 felt very amenable as I got the ap proach back together over the threshold. No reversers are fitted, but stopping from the VAT+15kt limit over the thres hold felt relaxed. With the flaps at 45° the airbrake can be extended to the lift-dump position, which also moves the flaps to a 75° angle. Weight was now only 19,0001b, with a VAT of llOkt and a landing distance of 4,100ft from screen height—well inside the 6,000ft Hatfield runway length. Taxiing speed kept up well with one engine shut down on return, and the aircraft could be smoothly tucked into the corner of the apron. The -800 shows what can be done with an established aircraft by radical refine ment in well-chosen areas. S3 "Weight was now 19,000lb, with a llOkt Vat and landing distance ^i^Pii*:*MJTWHpv^^K^^ of 4, WOft..." it-Mif - —--' mi - FLIGHT International, 29 October 1983 1159
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