Airtest – Britten Norman BN2 Islander

My first thought, when seeing where the pilot, Richard Maclean, had parked the aircraft, was that the aircraft had reverse pitch propellers. Despite a wingspan of about 53 feet, Richard had placed the Islander in a spot where a Cessna 150 would have had difficulty entering. The mystery was soon solved -he had not pushed the aircraft back, but used an effective nosewheel steering system where the rudder bars provide 35 degrees of nosewheel steering, then the wheel becomes free casting, allowing very tight turns. A touch of power, a touch of brake, a careful peer past the engines at the difficult to see wingtips, and there you are – shoehorned into a tight parking spot.

There were six of us to be transported to Sydney. With 10 seats in the aircraft, this was an easy fit. With a bit of luggage shuffling we were soon aboard. The aircraft had about 80 gallons of fuel remaining from the full load of 117 gallons, so the total load would provide a good measure of the aircraft’s performance on normal operations. I asked to sit in the right hand seat and spent a couple of minutes finding the relevant knobs and dials. The warm Lycomings easily started and after the usual ATC formalities, we were taxying for a departure from runway 12. On the taxi out, I asked about the takeoff technique. At the time I thought he was being a bit casual, but I later came to realise that the Islander is sufficiently flexible not to require very precise flying techniques. He said, “Well, you can rotate and lift off at 40 knots if you like, or you can let it fly off at 80 knots, or something in between – it’s really up to you. ” I thought a full STOL takeoff might be a bit much for the passengers. I noticed that the ASI had a blue line at 65 knots which must have been there for a reason, so I mentally opted for that speed.

During the taxi, I found the rudder and nosewheel very solid, needing a good push to get a reaction. A bit of power assist from the appropriate throttle speeded things up. We obtained our airways and takeoff clearances and lined up. A blip on the flap button runs the electrically driven flap to the takeoff position where it stops. The wind was 170 degrees at 12 knots, gusting to 20 knots, so with a long tail and lots of fin and rudder side area, I added a strong swing on takeoff to my list of things to do in those few seconds between opening the throttles and rotation.

With 300 horsepower per side, the throttles produced a solid roar and the acceleration, despite a biggish passenger and fuel load, was impressive. Despite my mental briefing; there was a slight swing to the right, but a push on the left rudder and a tap on the left brake and the aircraft was soon straight and showed no further tendency to swing. After 20 to 25 seconds, the ASI showed 65 knots, so I gave a solid pull back on the elevator control and the Islander lifted cleanly away from the ground. Passing 1,000 feet AGL I reduced the power to 25 inches of pressure and 2,500rpm. The rate of climb dropped from about 1,500 feet per minute to a steady 800 feet per minute. After a couple of heading changes from Canberra Departures, we intercepted the 062 radial en route to Shellys NOB. At 9,000 feet, we again reduced power to full throttle of about 22 inches pressure and 2,300rpm. There are no sophisticated systems on the Islander. For example, the tachometers are simple electronic gauges that make accurate RPM setting difficult. The airspeed settled to 130 knots, giving a true airspeed of about 145 knots.

A bit of fiddling produced a good audio synchronisation of the engines and some more fiddling produced a trimmed rudder such that the aircraft would stay on heading. I found that the rudder trim set in the roof between the pilots was easy to use, but set up in the wrong sense. All aircraft seem to be full of these little foibles, but after making a mental note of the direction of the control it provided no further problems, being very positive in application.

I also looked for the autopilot to get a height lock but found there was none. Some fine trimming had to suffice but, with a positive trim system that allows an attitude to be precisely set, the lack of automatic attitude and height hold only required a touch of pitch trim every few minutes.

With the hard work done, we had a few minutes to chat about the aircraft. Early versions had, he said, a reputation for being noisy. On this version, two bladed propellers were used which had a couple of extra inches clearance from the fuselage. These changes have had the effect of reducing noise and making the residual sound more acceptable. With a propeller spinning just a few centimetres from my right ear, I tested this theory by removing my earphones. The noise was quite low pitched and less than in most light aircraft and would be acceptable to passengers on the short trips for which the aircraft is designed. Some operators have added headphones and sound systems for longer legs.

At about 35 miles from Bankstown, I lowered the nose and we made a cruise descent at about 500 feet per minute and 145 knots. I expected the Islander to have a lot of drag and therefore be easy to slow down, but I was wrong. I had been warned that a common error is to be too fast, late in the approach, then be unable to slow the aircraft by short finals. We tracked via the 2FC radio station and Warwick Farm racecourse, then lined up for a straight in approach.

Regardless of what aircraft I fly, be it an ultralight or a jet fighter, I use the same approach technique. I position myself on an imaginary line projected from the flare point, ideally about 3 degrees. The aircraft is flown so that the flight vector is running down this approach path towards the flare point. Cross reference to the ASI shows whether the approach has too little or two much energy.

In this case, I was much too high with about a 5 degree glide slope. The airspeed was consequently too high so I first lowered the takeoff flap. The airspeed stayed too high. Another blip on the flap button produced full flap. The airspeed stabilised but was still a bit too high, so power was reduced to 12 inches or so. Now the airspeed was under control and dropped below 100 knots. Richard suggested that 65 knots over the threshold would be a good target speed.

Landing on runway 11 at Bankstown also produced a right crosswind of about 10-15 knots, so I mentally prepared for the combination of a flare in two directions before landing. I asked about the preferred landing technique and was again advised that either of the two standard techniques, or a combination, would be adequate.

On short finals, the speed was 75 knots, so I reduced the power to idle for a moment, then as the speed reduced below 70 knots, introduced a trickle of power. The landing became a nonevent. A positive pull on the elevator to initiate the flare, plus a touch of rudder to line up the aircraft with the runway was rewarded with a double squeal as the tyres touched and ran up to speed. The aircraft did not bounce, so I released some backpressure, lowered the nosewheel, applied some gentle braking and turned off at the centre taxiway about 1,800 feet from the threshold.

At the Monarch Aviation hangar, I took a closer look at the aircraft. I like the way the doors are arranged. To save space, there is no aisle, so passenger access is through doors on left and right. The doors are caught by clips on the port undercarriage leg and the starboard engine cowl. This provides a good safety feature as it directs passengers away from propellers should they be hopping in or out of the aircraft while engines are turning.

The high wing is placed over the fuselage to prevent the ‘hump in the middle’ effect found inside some aircraft. Looking along the inside of the fuselage, you see a long, straight, box-like structure with clean insides for freight or passengers. This aircraft was fitted with 8 passenger seats and two seats up front, it could comfortably carry 1 O people.

Access to the engines was good, as turning a few Dzus fasteners is all that is required to remove the bottom cowl. The fixed undercarriage requires little attention. For an aircraft with such a good low speed performance, I had a good look at the wing and flap combination, but found them unremarkable. Running the electric flap down to full shows a slotted arrangement with about a 70 degree angle between flap and wing, but no other special high lift devices. Nonetheless, the arrangement seems to be very effective aerodynamically.

The long tail provides plenty of space for baggage, albeit with some weight and balance limitations. Depending on other loads, up to 181 kilograms may be carried in the baggage hold. There is no baggage space at the front of the aircraft, as the space in the nose is filled with avionics. This arrangement makes them easily accessible.

The wingtip treatment is interesting. I am fascinated by current wingtip design such as winglets and curved tips. The Islander with tip tanks has a bird wing spread at the tips which looks aerodynamically efficient, but which does give taxying clearance problems as the tips cannot be seen from the cockpit past the engine nacelles.

We then returned to the air for some more airtest work. This time I sat in the left seat and asked for a demonstration of the short field performance on the first circuit so that I could try it on the second circuit.

I must say with no passengers and only 50 gallons of fuel, the Islander readily leapt into the air. To make the rotation easier we rolled in some rear elevator trim at an indication of plus 2. ‘For STOL takeoffs, the flap is kept at the ‘takeoff’ position as full flap is not required. After about 20 seconds and a ground roll of about 600 feet, we reached 40 knots and the nose was pulled up at 20 degrees. A short blip on the stall warning horn, a very slight nose lowering, and we were climbing away. After a full stop it was my turn.

A repeat performance gave an exhilarating STOL exhibition. I plucked the aircraft off at 40 knots and being a bit more circumspect with the nose attitude, we climbed cleanly away at 45 knots. I let the speed come up to 65 knots and set a 15 degree climb angle. When past 100 feet, I lowered the nose and at 75 knots raised the flap.

We cruised out to the Bankstown training area to try some more exotic handling. This area is notorious for high traffic densities, so we both kept our eyes peeled. The Islander is no F-18 when it comes to cockpit visibility. The view is quite adequate for normal operating conditions, but when you are trying to clear an area in a steep turn, you have to literally lift your arm and turn your head upside down to peer out of the side window. Every cloud has its silver lining though and I can see that in the hotter parts of the country, the smaller glass area and the overhung top of the fuselage would keep cockpit temperatures down, especially in comparison with some of the US aircraft which are mobile glasshouses. I found the stalling characteristics very interesting. My approach to a stall is that you either hit the back elevator stops and the nose lowers safely and automatically with a reduction in speed (the phoney stall). Alternatively, the nose cannot be held up with elevator as the centre of pressure races backward (the real stall). The Islander confounds both these approaches to stall testing.

Our first stall was with flaps up and no power. At about 45 knots the stall warning light and horn came on, but with no airframe buffeting or tendency of the nose to drop. I had plenty of back elevator left, so held height by continuing to haul back on the control column. Eventually, the right wing dropped and a hefty boot full of left rudder was applied to bring things back to an even keel. An anticlockwise rotation developed which could not be slowed by reversing the rudder, so I lowered the nose, whereupon full control was immediately restored. Height loss was only 100 feet or so.

Full flap stalls were approached more circumspectly in what I would call ‘short approach’ configuration, that is with full flap and about 15 inches of power. The 40 knot red line was easily exceeded without loss of control. In fact, I saw 33 knots! This time, I lowered the nose as one wing started to drop and with an application of power, the aircraft flew smoothly away, again with loss of about 100 feet. Even at this low speed, there was no buffeting or tendency for the nose to drop. The effect of pushing deep into the stall would be either to generate a high sink rate or to suffer a rapid wing drop. Neither situation would be healthy at low altitude.

This excellent low speed handling is a testament to the design of the aircraft. Despite its size, the Islander’s handling is very docile. I suspect the 40 knot ‘red line’ and stall warning devices are designed to keep the inattentive pilot well away from the true stall when things could quickly become irrecoverable close to the ground.

We tried some steep turns. The aircraft is easy to keep at a given height in a turn which can be made very tight if required. Changing turn direction shows that the Islander is fairly slow to react to aileron inputs. Even with nearly full aileron and with enough rudder to push the skid ball well to the outside of the turn, the roll rate is very slow. However, for the passenger carrying role, it is quite adequate.

Our last test was single engine performance. Setting zero thrust on one engine (I try to avoid shutting serviceable engines down in flight) and full power on the other produced a climb rate of about 400 feet per minute. We were quite light, so it was not a fair test. I would like to see what the rate would be in some of our hotter and higher places. Nonetheless, the aircraft was easily controllable and the positive rudder trim allowed the asymmetric thrust to be quickly and completely trimmed out.

After these tests, we returned to the circuit at Bankstown where I achieved a better approach but a worse landing. The Islander has a fairly high compression rate and if you don’t touch down very lightly, you know about it. I over rotated slightly after touchdown and the result was a balloon of a couple of feet. I managed to achieve quite a smooth second landing!

I am always interested in the economics of operating aircraft. Charles Cruickshank provided me with some of their estimates of operating costs, emphasising that these should be used for indicative planning only. The aircraft being demonstrated has a sales price of $A880,000.

Monarch Aviation have gone to some trouble to ensure a good spares supply. Mike Lewis has spent some time talking to Islander operators in the area to determine just what first line spares are needed. He compared this information with the factory suggestions and now finds that they can meet a high percentage of customer needs from in house stocks. The factory at Bembridge supplies ‘Aircraft Operationally Grounded’ spares in less than a week.

Overall, I found the Islander a delightful aircraft to fly. The original design purpose is for a short haul aircraft capable of operating into very short airstrips. After testing the low speed handling characteristics and the STOL performance of this aircraft, I concur that the performance envelope is such that it can easily operate into places that are normally the province of the general aviation light aircraft. The ability to achieve this performance with up to nine passengers and luggage must create commercially viable areas of operation where the Islander is the only aircraft that will fill the niche. Islander aircraft also traditionally retain their value on the secondhand market where examples do not take long to find new owners.

As far as flying the aircraft goes, it is virtually viceless, with good sound handling characteristics that make it both safe and pleasant to fly. In fact, I rate it easier to fly than the run of the mill general aviation aircraft, despite the complication of twin engines. The ultimate test is, of course, the market place. With over 1,100 Islanders sold throughout the world, and no signs of production slackening, there seems to be plenty of support for this solid, reliable and easy to operate aircraft.