FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1960
1960 - 2159.PDF
FLIGHT, 30 September I960 543 works out at 30° /sec. Because of the large dorsal fin anddifferential slotted ailerons there was much less adverse yaw when beginning the bank than with earlier Austers. Using full rudderas well, I banked 120° in 3.2sec, which means 37.5°/sec. Suspect- ing slow acceleration into the roll, I banked through 120° andtimed the last 60° in 1.8sec—but this is slightly less than 37.5 ° /sec and denied slow acceleration. When I yawed with rudder alone,the nose fell quite sharply. When I let go completely in a bank, the D.6 wound up in a gradually tightening spiral to 150 m.p.h.and then recovered on its own by winding die other way into level flight. It paused and then began another spiral the otherway, but I did not wait this one out. Closing the throttle, hands- off, resulted in a fairly rapid entry into a dive. Effect of change ofpower on longitudinal trim was fairly marked. The rudder was the heaviest of the controls, but the forces in general werepleasantly light. Trimmed at 70 m.p.h., lowering of flap caused a firm nose-downchange with the first setting and less with the landing setting. Changes were reversed with raising of flap and speed increasedvery rapidly. There was only slight sink. Application of full power in a full-flap trimmed glide raised the nose rapidly, but theD.6 could be trimmed out and climbed at 450ft/min indicated. With full flap and power off at 65 m.p.h. the rate of descent wasl,000ft/min, making a very useful gradient. Propeller fine-pitch with the throttle closed provided a good quota of drag for steepapproaches. With flaps down, stability and stick forces remained largely unaltered and I timed the rate of roll from a steady 45°left bank to passing 45 ° right bank at 2.2sec, using both aileron and rudder—41° /sec and perfectly adequate for landing. Trying the clean stall, I throttled back and held the v.s.i. atzero. Angle of attack and stick-back movement increased steadily down to 60 m.p.h. and much more rapidly thereafter. The D.6clawed at the air, juddered firmly for an instant at 40 m.p.h. and then broke cleanly into a dive and immediately returned to50 m.p.h. With the stick still held hard back, the aircraft then tried to stall again and went sedately downstairs. During severalstalls the right wing went down about 30°, quite innocuously; but aileron remained usable, because the speed returned so quicklyafter the nose dropped. In a power-off stall with flap, the process was simply emphasized; the break was sharper and we wentjerkily downstairs. Descent was l,000ft/min indicated and aileron control remained. There seemed to be insufficient elevator to stall easily out ofa 30° gliding turn. I flew with full control at 30 m.p.h. with a good deal of power and flap down and then cut power and glidedat 35 m.p.h. The change in stick-back position was marked in the transition between these two states, as it had been when passingbelow 60 m.p.h. while approaching the lg stall. I noticed this charac- teristic during several landings after power-on approaches. Eleva-tor trim ran out at 60 m.p.h. in a power-off glide with full flap. Having now lost some height, I timed the climb at full powerand 80 m.p.h. from 1,500ft to 2,500ft. It came out at 50sec, making l,200ft/min—exactly what the v.s.i. had told me. So I returnedto the circuit with a fair idea that the approach would be steep and could be made at about 65 m.p.h.; that stick movement duringthe round-out would be pretty rapid; but that there would be no particular problems except those associated with visibility in theturn. On the descent, the roof window gave very useful inward visibility in a turn, but in a climbing turn the airfield was lostfrom view. I flew downwind at 80 m.p.h., made the few necessary checks and left flap up until the base leg. Of three approaches, the first two were power-on, cutting duringthe round-out and having to snatch the stick back after slipstream effect left the elevator. The ensuing touchdown was a little gropingand once I bounced, partly because visibility sharply decreased as the nose came up. The tailwheel had a markedly good effectin damping the bouncing tendency and the tail stayed down nicely. The ground-run was short and simple and I could findenough brake to lift the tail (unintentionally) at the end of the landing run. The last landing, made carefully from a final glide,was simplest and cleanest of the three. I once tried to side-slip, but there was not enough rudder to develop any great slip,although the rate of descent increased perceptibly. A condensed opinion on the D.6 is difficult to formulate, butI could put it as follows. If someone gave me the D.6 to fly as a completely strange, nameless aircraft, I would not be greatlyimpressed by its handling qualities, which are safe but unexciting; but I would recommend it for its straightforward simplicity andfor its comfortable seating, good equipment and powerplant. Knowing something of its predecessors, I would warmly con-gratulate Auster on this really big step forward into the executive field. But the legacy of the dark days is still too evident infeatures like trim control, the shape and size of the door, and the bungee undercarriage. I would be quite happy with the tailwheelundercarriage if it did not carry quite such penalties in forward visibility. Several more inches' head-room beneath the wingand a correspondingly higher door and seating level would prob- ably do the trick. Everyone clamours for a nosewheel, but I thinkwhat they really want is visibility and steering. A slightly stronger spring connection between tailwheel and rudder would give quiteadequate directional control and a higher cabin would improve the view. But, whatever the criticisms, the D.6 is hard to beat invalue for money—a point one is apt to overlook in an air test. AUSTER D.4/180 One Lycoming O-360 giving 180 h.p. Dimensions: span, 36ft; length, 23ft 2in; empty weight, 1,4501b; gross weight, 2,5001b; disposable load, 1,0001b; payload, with fuel for about 1hr, 750lb; wing loading, 13.55lb/sq ft; power loading, 15.9lb/h.p. Performance (figures in brackets for typical lightly loaded weight of 1,7501b), take-off run, 690ft (390ft); take-off to 50ft, 1,680ft (960ft); initial rate of climb: 850ft/min (1,350ft/min): max speed at sea level, 138 m.p.h. (141 m.p.h.); max cruising speed at 5.000ft, 133 m.p.h. (137 m.p.h.); range at max cruise speed, 490 miles; stalling speed, flaps down, 35 m.p.h. (30 m.p.h.). A more standard paint scheme on a D.6/160 with the 160 h.p. Lycoming engine. Choice of colours is apple green, poppy red, French blue, light orange, smoke grey, dove grey, black or white. On this aircraft there are no cuffs on the root of the struts
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
