Airtest – Brooklands/ASTA Scoutmaster

Flying the Scoutmaster

The Scoutmaster is basically a conventional aircraft shrouded in new ideas. The wings and control surfaces are normal. The twin-boom and high tail are conventional. The pusher engine, noted for its efficiency in many designs, is conventional. (For the purists, the propeller is in fact a rear mounted tractor propeller but I think we’ll leave that discussion for another time). The shrouded fan is slightly novel but in effect it is a multi-bladed propeller housed within a duct-again a known, efficient arrangement.

Certainly, there are innovative features in the arrangement of cockpit, fan and duct but aerodynamically, it is a normal aircraft and not surprisingly, it flies like a normal aircraft-normal in every respect but better than normal in many respects. The field of view is outstanding. The quietness and smooth ride are exceptional. The handling characteristics for an aircraft which will spend most of its life manoeuvring near the ground at low speed, are the safest I have tested.

But let’s take a closer look. . .

General Discussion

The Scoutmaster is the production version of the Edgley Optica and has been developed jointly by Brooklands Aviation and our own ASTA. It is an all metal aircraft powered by a 260hp. fuel injected Lycoming engine. It ordinarily features a cockpit designed for three abreast seating but this aircraft was fitted with a Forward Looking Infra-Red (FLIR) system and was designed for a pilot and observer. Thus there is plenty of elbow room in the cockpit. The flight controls are cable operated and fully conventional. Flaps are electrically operated. Fuel is carried in two wing tanks which gravity feed. The propeller or fan is interesting. It is a specially made five bladed, fixed pitch fan made of wood, laminated with epoxy.

There is an enormous door on each side of the cabin and entry and exit are easy. Each seat has a single point, four strap inertia reel harness. The harness is easy to fit and adjust, comfortable and offers full restraint. The aircraft is normally flown from the left seat with the stick being operated by the left hand but more about this later. View from the cabin is outstanding. Apparently it has been measured as 270° in the vertical plane and 340° in the

horizontal. The seat was comfortable but not adjustable. The rud- der bar being adjustable by a removable central pin.

The instruments are mounted in a centre pedestal similar to a helicopter and there is a console between the left and central seats for throttle and flap controls. There were dual controls fitted to the left and central seat positions. Starter and magneto switches and a standby altimeter were mounted in an overhead panel (which is far enough away for my aging pilot’s vision to accommodate without difficulty).

Also on this panel is an interesting caution display that evolved out of the aircraft’s unique configuration. Because the engine and fuel are mounted on the CG and the crew pod is well forward, the CG is significantly affected by the number of crew carried. The Scoutmaster has a clever, simple and effective solution-removable ballast blocks.

These ballast weights are mounted within the fin if there are two or three crew – and carried in a nose compartment if there is only the pilot on board. The weights are securely held and easy to relocate. In each compartment there is a spring loaded floor panel which operates a light on the overhead console. Thus the pilot has a cockpit display to confirm that the ballast weights are correctly located. With the FLIR it is possible that the weights will be fixed but in any event, they do provide a simple, safe and effective control of CG position.

The engine is started normally – and like all fuel injected engines, it can be cantankerous when it’s hot. This difficult starting condition highlighted one deficiency – the braking system. The brakes are operated by a hand brake lever on the centre console. When starting a hot engine with the throttle open, mixture closed and both hands fully occupied, it is embarrassing to find the aircraft slipping forwards. The rapid flurry of hands to close the throttle, open the mixture, release the starter and grab the brake simultaneously, is something to behold! I am told that the slipping brake was a fault on this particular aircraft and a fix is on the way.

The first surprise about the Scoutmaster is the incredible lack of noise and lack of vibration. I was wearing a normal headset and the noise was considerably less than a Cessna 150 or Warrior – just a faint hum in the background.

Taxying was easy and the view outstanding but the need to use the same hand to adjust the power and to apply the brake was annoying. Full power was similarly quiet and smooth, Acceleration was not startling but once the aircraft reached a walking pace, the acceleration improved to a normal rate.

The recommended nosewheel lift-off speed was 50 knots but I couldn’t lift it off until 60 knots due to the unexpectedly high stick force required. After the nosewheel lifted, the aircraft rose like a lift. The nose attitude was not high but the aircraft gave the impression of a steep climb angle. In the climb the aircraft settled to a trimmed speed of 70 knots at full power. It was easy to maintain an accurate speed although I felt that the aircraft preferred to fly at 65 knots. The aircraft was stable and any oscillations were quickly damped. The view was incredible but surprisingly, it was not as alarming as I had expected. The spectacular view is offset by the feeling of security that the aircraft gives you. It is quiet, solid and stable. It was 37° on a hot Adelaide afternoon and we flew along the beachfront. There was slight turbulence and the little aircraft behaved beautifully.

But nothing is perfect and two major shortcomings showed up.

The stall warning horn operated close to 65 knots – the very speed that felt most comfortable. So for most of the subsequent flight, the thing howled continuously.

Also the aileron control circuit was overly stiff – due to circuit friction and a powerful centring spring. This aspect combined with a not spectacular rate of roll and pronounced adverse aileron yaw, really detracted from the pleasure and operational effectiveness of the aircraft. The centring spring caused a further nuisance as fuel was used from one side and an imbalance occurred. The slight out of trim condition required an unreasonable counterforce by the pilot and this could become tiring on long surveillance flights.

The elevator circuit was· nicely light and responsive and the rudder was adequately powerful. The feel and response were quite reminiscent of a Tiger Moth albeit with heavier ailerons. Change of trim with flap extension was light at first but during the latter stages of full deflection, the nose down change of trim was marked and the required stick force was unusually high. However, the trim was powerful enough to counter the force. I didn’t like the operation of the flap switch which for extension had to be held against a spring until the flaps reached the desired position. I prefer the ‘select and forget’ system as was provided for up selection.

Low speed handling was pleasant once one became used to the ailerons and the aircraft was easy to manoeuvre at low speed. Again I felt that the aircraft preferred to loiter at 65 knots.

There are adequate cues to the approaching stall – if one could call it a stall. It was such a gentle little nodding motion that it was hardly discernable as a stall. There were warning sigris through the controls and some buffet through the airframe. The cues were sufficiently clear to provide adequate warning even over the blaring horn. Recovery was immediate on relaxation of back pressure. Ailerons remained effective at the stall and there was no tendency to drop a wing. Stall with flaps extended was similarly docile and the aircraft gave the impression of being safe and predictable at low speed. I would not be at all concerned about being caught out by a stall at low altitude while manoeuvring. The aircraft didn’t ‘bite’ at all. A practice forced landing was straightforward with the aircraft gliding through the standard pattern with less height loss than a Cessna 150. Sideslipping was effective and the lack of attitude reference proved not to be a problem.

Circuits were easy and the view was dramatic. I preferred an approach speed of 65 knots rather than the recommended 70, as the aircraft seemed to fit into this ‘groove’. Flare was easy to judge with a slight tendency to round out a little high. With the throttle closed and the airspeed reducing, there was a sudden and pronounced change of trim and to prevent a firm landing and subsequent firm touchdown of the nosewheel, a large movement of the stick was required and this required a high stick force. This was perhaps affected by the unfamiliar left handed operation of the stick. A flapless approach at 70 knots was simple and having no nose, there was no restriction to the forward view. Similarly, landing in a ten knot crosswind was easy and the rudders were sufficiently powerful to straighten the aircraft with plenty to spare. The aircraft has a demonstrated crosswind limit of 25 knots.

There was no tendency to skip once the nosewheel was down – although it was difficult to let it down gently.

The major shortcomings in regard to the stall warning and the aileron controls are already being addressed. The centring spring is to be modified and an aileron/rudder interconnect is being incorporated, to correct the adverse aileron yaw.

I was frankly impressed with the overall behaviour and capability of the aircraft and in its role, it’s really fun to fly. I believe that it will go beyond its published surveillance roles and become a sought after tourist aircraft. I have often dreamt of seeing Australia by light aircraft – especially places like Ayers Rock, Katherine Gorge, Wilpena Pound, the north west coast and the Glasshouse Mountains. Now my dream is to see these places from the Scoutmaster. If offers safety, view and economy and is of particular interest to the National Parks people, it is quiet and won’t spoil the appeal of these outback sites. The lack of vibration also makes it a great platform for aerial photography and yes, it has been tested for flight with the doors removed.

I also asked ASTA about possible problems with FOO. The thought of that huge vacuum cleaner sucking up stones and gravel was of some concern. These aspects have been carefully considered. Rain ingestion has not proven to be a problem. They have occasionally experienced minor stone damage to the fan. A fan guard has consequently been developed and tested in Egypt and for frequent operations from unprepared surfaces, the guard offers good protection for negligible loss of performance.

The nosewheel also is fitted with a close fitting guard to minimise stone pickup. Minor damage to the fan is easily repaired and during the tests in Egypt, a minor repair was made using Araldite. Similarly, birdstrikes haven’t proven to be a problem. The double curvature plexiglass windscreen is quite tough and at the Scoutmaster’s normal operating speeds, the birds are easily avoided – or the birds avoid the aircraft!

So that’s the Scoutmaster. A pleasantly docile, safe and enjoyable aircraft. It is exceptionally capable for the role it was designed to fulfil.

I hope it’s a successful business venture. It’s certainly a potentially successful aircraft. As they say in the ads, ‘Like it? – I loved it’.