FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1956
1956 - 1490.PDF
646 FLIGHT, 19 October 1956 HANDLING THE AGRICOLA Austers' New Agricultural Aircraft By C. M. LAMBERT WHEN I came to fly the Auster Agricola at Rearsby lastweek, I spent most of the flight in close formation with theAuster Aiglet Trainer demonstrator while air-to-air photographs were being taken. This experience of formationflying after only a few minutes in the air alone really impressed me. The aircraft was stable but responsive, easy to handle andpractically free from trim changes. I dropped five hundredweight of pelle'ed fertilizer across the airfield in a matter of seconds at70 m.p.h. and could trace no trim or control changes during that time. After one and a half hours in the air I was completelyconfident of the machine and not at all fatigued. The Agricola is an agricultural aircraft in the best sense of theterm. Great care has been taken to make it simple to fly and to operate, with particular emphasis on accessibility for maintenanceand resistance to corrosive chemicals used in spraying or dusting. The "un-Austerly" appearance of the machine is ample testimonyto the company's entirely new approach to the design, and special attention to operational requirements is evident in every com-ponent. The individual features can be gleaned from Flight's detailed description which appeared on January 13 last. The AirRegistration Board has thoroughly evaluated the Agricola and the accompanying performance figures are those checked by its pilots.The first prototype, ZK-BMI, which I flew, has now completed some 130 hours' flying with the minimum of maintenance and isstill in excellent shape. Corrosive fertilizer dust has been allowed to get into it and has not been cleaned out. The special protectivepaint finish inside and out has shown no signs of deterioration. A considerable quantity of fertilizer has been loaded and droppedor jettisoned and everything works smoothly and effortlessly. Advantages of the Agricola include good spray distribution inthe wing wake, easy access to spray tanks (total capacity 144 Imp. gal) in the wings, easy refuelling, wide track undercarriage (14.33ft)and easy access to the hopper filling-neck. During hopper loading, with the engine running, the pilot is protected by the closed andsealed canopy. Toughened glass windscreen panels are not scratched or clouded by dust, and flat plastic side panels are alleasy to replace or repair. The hopper load is located below and behind the pilot; and freight, or two rearward-facing passengers, "Flight" photograph can be carried in a cabin behind it. A strong cockpit structureprotects the pilot in case of accident and the seat is mounted directly on the wing centre-section. There is a strong four-pointadjustable seat harness. From the pilot's seat visibility in all directions except directlyrearwards is excellent. The engine cowling is flat and slopes sharply downwards. There is plenty of room and seat andposture are comfortable. All controls except windscreen wiper and rudder pedal adjustment are close to the left hand, and welldesigned. The hopper aperture can be precisely controlled with- out effort and jettisoning is rapid and simple. The flaps have twopositions. When fully down, hinged trailing edges deflect from the main flap to give high drag. A mechanical follow-up linkage givesa precise position indication. Hopper and flap controls are hydraulic, relieving the pilot of any heavy hand loads which mightbe irksome or tricky close to the ground. Both can be operated by sense of touch alone. There are no electrics and no battery, forsafety reasons, and engine starting is by standard external power source. A motor lorry battery at half charge is quite sufficient. Engine starting is simple. Fuel pressure is raised by a well-located and efficient hand-pump; the engine is primed by Ki-Gass pump, and both magneto switches are turned on. FollowingContinental tradition, the mixture lever is placed in the idle cut-off position for starting and, as soon as the engine catches after thestarter button has been pressed, full rich mixture is selected. Taxying is most satisfying. Visibility is superb, and the tail-wheel is precisely steered from the rudder pedals. Steering can be overridden when required for really sharp turns. The hydraulicbrakes, operated individually by tilting the rudder pedals, are not very strong or sensitive, but perfectly adequate in view of theexcellent tailwheel control. They will hold full engine power. For take-off the standard R.A.F. vital actions for piston-enginedaircraft once again proved entirely adequate: elevator trim was set at neutral. Having run through the mnemonic, I opened thethrottle smoothly to full power. Noise level in fine pitch was fairly high, but vibration was very low. Acceleration was excellent, thetail came up easily and the Agricola flew off cleanly after only about 50 yd run. Speed built up very rapidly from about 40 m.p.h.at unsticking and the climb was very steep. This speaks well for agricultural performance. Good control was immediately appa-rent, the machine being steady, but very responsive. Particularly remarkable was the high rate of roll attainable with the exception-ally long, slotted ailerons. The rudder was quite sufficiently effective for all normal purposes, though no great degree of sideslipcould be obtained at low speeds, with power off and take-off flap down. The feel of the rudder was, however, excellent and thedirectional effects of throttle variation or full power on take-off were negligible. The Continental 240 h.p. engine is inclined side-ways and downwards by a few degrees with this end in view. Lateral stability was effectively neutral, and displacement in thelongitudinal axis from the trimmed, clean, cruising flight condition resulted in one fairly pronounced oscillation with a positive andquick return to the trimmed attitude. The elevator trim was high-geared and very positive in its effect. In no condition didI run out of trim and at no time did I have to turn the trim wheel more than a third of a turn from the neutral position. Atabout 50 m.p.h. I trimmed for hands-off flight with the nose well up in the air. Application of right rudder caused the nose to riseand left rudder made it yaw to the left and fall away fairly sharply. At 80 m.p.h., extension of one-third flap gave a nose-up trim changewhich was cancelled out when full flap was selected. This latter setting gave a pronounced increase in drag which should be veryuseful for short-field operation. Cutting the engine during the final approach produced neither trim change nor noticeable sink.For the round-out there was plenty of elevator control and the aircraft could be stalled on or landed tailwheel first withoutdifficulty. A smooth three-pointer was very easy to achieve and the big low-pressure tyres, wide undercarriage track and goodshock absorbers made touchdown smooth and free from any tendency to bounce. The ride when taxying was smooth and very steady for thesame reasons. The rudder pedals have been made specially large to accommodate any footgear up to and even greater than Welling-ton boot size. The heels are firmly supported, foot straps prevent the feet slipping or lifting off, and the axis of tilting is so placedthat there is no tendency to slide off the pedal when braking hard. The Agricola in rural setting, left, and, on the next page, above the seasonal mist. The braking surfaces on the flap trailing edges and hopper doors are clearly visible in the view from the ground.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
