hen Toyota first developed the Hilux utility, I don’t think they foresaw the appeal that this vehicle would create amongst tradesmen, leisure drivers and the man on the land. When Jeremy Clarkson tried to break one on Top Gear, it proved to be near unbreakable. In the world of aviation, the GippsAero GA8 Airvan is the aeronautical equivalent of the venerable Toyota ‘Ute’.
The Airvan is an Australian export success and the workhorse can be found all over the world hauling supplies into remote areas, performing humanitarian tasks, conducting scenic flights, parachuting and, in the future, multi-mission surveillance roles. This is a light aircraft that can fulfil a number of roles with its proven simplicity of design and ruggedness.
There are currently over 163 flying, of which 100 are overseas – primarily in North America, Europe and Africa. The Airvan will soon hold the record for the most number of certified civil aircraft built in Australia, as it is about to edge past the 172 GAF Nomads that were built.
Most orders today are for the Turbocharged version, but the Airvan used for this evaluation (VH-BYI) is powered by a 320hp Lycoming TIO-540-AH1A. The only external differences for the turbo-charged version are the inclusion of a large cowl flap and a slightly deeper nose cowl to accommodate the turbo-charger’s exhaust system.
One operator of the Airvan has been quoted as saying that it is the perfect aircraft to fit between the Cessna C205/206 and the larger turbine-powered, more expensive Caravan.
The Airvan has been certified to the latest standards, meaning it doesn’t rely on ‘grandfather’ rights. When I say ‘grandfather’ rights, I’m referring to the many aircraft that are certified on the basis of being a variant of an existing design that has already been certified before. But the certification standards may have changed since that time to include new safety requirements for crashworthiness, safety or features to combat human error.
The Airvan isn’t that new, having first flown in 1995 and entered the market in 2000, but GippsAero strive to keep up with the changing regulatory requirements around the world.
When I walked around the Airvan, I couldn’t help but notice the rugged design and the thought put into features making it easy to maintain in rugged conditions. From the rugged-looking pitot tube – great, big and protruding out of the forward leading edge of the left wing tip – to the slightly oversized main wheel tyres.
All flaps and ailerons use external low-slung hinges, making inspection and maintenance easy. The wing is mounted high enough that potential strikes from obstacles are reduced. The wing mounted landing lights are widely spaced with two lights just inboard of each wingtip and can be fitted with optional LED units for long life and durability.
The Airvan uses many components that are readily available around the world from far-reaching aviation suppliers, so there’s no need to wait for specialist spares to arrive from GippsAero themselves. Even the airframe is of simple, readily available all-metal construction. The wings, for example, only use two different rib components, one with the flanges one way for the left wing and the other way for the right wing, giving the wing a constant chord and rectangular plan form. This simplifies the construction process, and in the unlikely event of repairs in the field makes life easier for maintenance organisations.
The fuselage is also built with strong box-style floor sections with sidewalls and top sections that result in a spacious, uninterrupted cabin volume. The tail cone section, which accommodates a large moulded composite cargo bin capable of holding 22kgs, is a separate component that the empennage is then attached to. The overall fuselage shape was even designed to contribute to the overall lift of the aircraft with its unique shape approximately an aerofoil.
Other features include the use of a sprung nose wheel strut instead of the commonly used oleo strut of other designs, which avoids the potential of having an oleo go flat in the field and not being able to get it reinflated. The main landing gear uses a sturdy steel tube section covered with a streamlined fairing that also houses the hydraulic brake lines, which limits damage on rugged fields.
Other features that help in rough field operations include the high set horizontal tailplane, which minimises damage from debris such as prop-blown stones. The higher tailplane also makes it safer for parachutists on exiting. Equally, the ground clearance to the bottom of the fuselage is also quite high for rough unprepared fields.
The forward entry door opens fully forward, allowing easy access to the cockpit, and is held open by a simple latch against the side of the engine cowl. This is particularly handy if the Airvan is used for transporting large loads, as access in and out of the cockpit is still possible while the cabin is being loaded.
Looking inside the cabin, the Airvan that I tested was configured with six seats along with the two cockpit seats. These seats are easily removable using a supplied tool that is inserted into the floor locks to release them. The whole unit, including the three-point inertia reel seatbelt assembly, can then be removed as a single unit allowing cargo to be loaded or parachutists to sit on the floor. The seats are also constructed to the latest certification standards and are 18G impact rated.
If more space is required for baggage or bulky loads, a cargo pod can be attached to the lower side of the fuselage and loaded through side doors. GippsAero are also planning to use this pod in a development that will see the Airvan equipped with sensors and cameras and employed in surveillance roles. By fitting the pod when needed, the aircraft could be used for passenger transport, freight and then surveillance all in the space of a day or so, giving operators the capability to tender for a variety of tasks.
Access to the rear cabin is via a large sliding door on the left side and a simple fold down internally mounted step. This step can be removed when carrying cargo or parachutists to avoid obstruction of the opening; this door is certified to be opened inflight.
Modifications that have been incorporated into later Airvan models include the redesign of the fuselage frame just behind the front seats that supports the front spar, thereby allowing the front seats to slide further aft to accommodate longer legged pilots. There are eyeball style air outlets fitted in the ceiling above each seat position and run off an electrically powered fan mounted in the rear fuselage.
Climbing into the front seat, I found this Airvan was laid out in a conventional manner and used robust, workmanlike controls – large, purposeful and designed to last in a high utilisation and rugged environment. Like the cabin, the cockpit is spacious, boasting a width of 1270mm.
General visibility was good with a clear view ahead over the large engine cowl and through the many cabin windows. The tips of the horizontal tailplane were clearly in view, but this would obviously be obstructed depending on the load carried. There are even small eyebrow windows above the windscreen, allowing unobstructed views above the aircraft.
This particular Airvan was equipped with conventional round dial flight instruments; alternatively, the Airvan can be optioned with modern EFIS style displays. Surprisingly, the main attitude indicator was vacuum powered and the standby was electric. Having been flown around the world for the Millions Against Malaria fundraiser in 2010, VH-BYI was comprehensively equipped with twin Garmin GNS430 COMM/NAV units and GTX330 Transponder, along with a Garmin GMX 200 multi-function display installed on the right instrument panel.
The flight deck seats slide fore and aft to get a comfortable seating position. I found with my long legs I needed the seat just forward of fully aft. The control column is pivoted from the floor like a big jet. To keep things simple, the control grips are only equipped with a PTT switch and no electrical trim switches. In fact, the elevator trim is only manually selected and is operated via a large diameter trim wheel mounted on the left side of the centre quadrant stand. A small mechanically linked trim indicator is located alongside atop the quadrant. This was reminiscent of the pitch trim wheel in the old HS748, and like the ‘draggie’ it required large turns to adequately trim the aircraft out in flight.
To the far left of the panel were the two fuel gauges and just below the fuel shut-off red T-handle and priming press button. The conventional ignition switch was just below these controls. The lower upward angled sill panel accommodated the various engine management monitoring indicators that could be used to accurately monitor cylinder head temperatures, fuel flows, TIT and EGT along with electrical system power monitoring. Above the six-pack instrument layout were grouped a set of large amber warning lights for vacuum (VAC), oil pressure (OIL – red light), alternator (ALT), pitot heat (PITOT HEAT) and a blue fuel boost pump light (FUEL BOOST PUMP).
The Airvan’s instrument layout can be customised to the client’s needs and for their operation. Currently the Airvan has been certified with the Aspen EFIS 1000 system and the King KFC225 autopilot, but Garmin systems may also be available in the future.
The workmanlike centre console houses a good-sized throttle, pitch lever and mixture control. On the back of the quadrant stand was the alternate air source control and the large cowl-flap operating lever. The simple park brake knob stood vertically up from the top of the quadrant stand. To release the park brake, a push downwards was all that was required.
Like any big commercial aircraft, there was an overhead panel. In the case of the Airvan, it housed the electrical system circuit breakers and twin master switches. This was logically laid out in a schematic that showed which system was powered by BUS 1 and which by BUS 2. Also like any commercial aircraft, the Airvan’s Aircraft Flight Manual (AFM) also includes a list of what the industry would call the Minimum Equipment List (MEL), where there is a list of what is the minimum equipment required to operate the aircraft or what limitations exist if something
Flying the Airvan
It was now time to fly the Airvan. On this day I was flying with GippsAero Test Pilot Ross Bowden. The configuration for our test flight was just the two of us up front and a cabin of six empty seats and around half of the 320 litres of usable fuel loaded.
After getting comfortable in the left seat and making myself familiar with the various controls, we started the big Lycoming and warmed the engine up as it was a cool 15°C on the day.
To begin taxiing, the park brake is released by simply pushing the PARK BRAKE knob down. Steering is via direct linkage from the rudder pedals to the nose wheel. Although quite heavy to use at first, I found it no problem after a few metres along the taxiway. It has good feel and was easy to maintain direction. The rudder pedal angle has also been redesigned compared to earlier models.
After performing the customary engine run-up, ignition and prop checks, with flaps set to half we lined up on Latrobe Valley’s Runway 21. With only the two of us in the aircraft, the C of G was almost on the forward limit and so the pitch trim was selected almost full forward. With such a light load, advancing the throttle to 40” of boost produced instant acceleration. Taking up the backpressure at around 60KIAS, the nose wheel easily cleared the sealed runway. Lift-off occurred shortly afterwards at around 71KIAS; the AFM recommends a climb speed of 76KIAS to clear take-off obstacles.
When clear of obstructions and with a positive rate of climb, the flaps were retracted and power stabilised at 40” and 2500rpm. This produced an average climb rate in the slight turbulence of 900fpm.
I immediately became aware of the control forces. The elevator felt a little heavy as soon as you moved it away from the trimmed position, but trimming immediately alleviated this. This reminded me of an old instructor who used to say repeatedly, “trim or die”.
Like the ‘748 I had flown years ago, large amounts of trim movement on the large trim wheel were required to maintain the desired flight path. After a little while this became a natural thing – change the attitude, take a handful of trim and everything felt fine. This reluctance of the aircraft to vary from its trimmed control position meant that it was quite stable, but it also meant that if the pilot didn’t follow up with trim he could easily criticise the Airvan for being too heavy. Not for one moment do I suggest flying on trim, but good technique of selecting an attitude, holding it and trimming out the forces helps in either VFR or IFR flying.
Climbing out to the south of Latrobe Valley, visibility was on the whole good. With the long nose cowl and as a result of the light weight and associated climb angle, a few clearing turns were required, but this is common airmanship.
During the climb at such a low speed of 76-85KIAS, Ross pointed out that in the turbo model it was quite important to monitor the operation of the large cowl flap to help control the large amount of heat build-up under the cowls caused by the big Lycoming. This could be monitored with reference to the LED cylinder head temperature indicator at the bottom of the panel.
Slow speed handling
After climbing out to around 3500ft, we levelled off and prepared to explore the Airvan’s slow speed handling and general feel. At this level, the throttle was reduced to 25” and 2400rpm, which closely approximated 65 per cent power and produced a cruise speed of 120KIAS. Mixture was leaned using the Turbine Inlet Temperature (TIT) indicator.
This involves a practice of leaning the mixture until the TIT reaches a peak and then increasing it again until 25°-50°C off peak TIT for best economy, or 100°-125°C for best power. As speed was increased the cowl flap was partially closed, thereby reducing some of the drag from such a large opening.
Before looking at slow speed handling and to help clear the area, I performed some turn reversals from 45° bank to 45°. Average time equated to about the same as for most light aircraft these days with 3.5–4 seconds required. The Airvan has quite a powerful rudder and I found it easy to balance turns, although Ross indicated that he would like to see a little more effectiveness. This may be required when the extra horsepower of the turbine is added in the forthcoming GA10 variant; but the fuselage is longer and therefore offers a bigger moment arm.
Reducing the power to look at the clean stall, a significant amount of backpressure was required as a result of the stick forces previously described. An electronic stall warning sounded at around 65KIAS and full stall with just a light buffet occurred at 60KIAS. The stall-warning sensor is located on the right wing. The sensor is heated along with the pitot head.
Using full flap and with the reasonably forward C of G, we didn’t really achieve a clear buffeted stall. The stall warning sounded at 55KIAS, but with the stick on the rear stop, the aircraft just stabilised in a constant nose-high gradual descent. It was easy to keep the wings level with slight inputs of aileron, but no clear stall.
With just a little power applied you could hold the nose up with full back stick, and with the airspeed at approximately 53KIAS you could easily lower and pick up a wing using the rudder alone while holding the ailerons absolutely neutral. In all it was quite docile handling with no noticeable vices evident.
Later during our air-to-air photo shoot, I couldn’t help but notice that the elevator is predominantly deflected down in reference to the fixed part of the tailplane in level flight. This would represent positive lift from the tailplane, therefore also making the aircraft more stable and reducing any tendency to pitch uncontrollably nose up at the stall.
The other side effect is to reduce trim drag in the cruise. In a lot of aircraft, the elevator is used to develop a downward force to stop the natural tendency of the nose to pitch down. This downward lift subtracts from the overall lift required to maintain level flight, where in this case the tailplane contributes to the overall lift production. Remember back to basic aerodynamic principles where all the forces, and mainly lift versus weight, have to be equal?
Another design feature that helps to reduce overall trim drag is the Airvan’s use of an all trimming tailplane, meaning the elevator trim system adjusts the angle of the horizontal tailplane incidence, rather than using a tab to deflect the elevator.
Airvan in the circuit
Returning to the Latrobe Valley circuit, I set up to land on the gravel Runway 27. The wind had become a little variable in direction and now favoured landing more to the west.
After progressively lowering the flaps, initially to half on the later part of downwind and then to full on base, final approach was flown at 75KIAS, taking into account the slight gustiness of the wind. Normal VREF at 50 foot would have been 71KIAS.
I found I needed to use quite a bit of trim adjustment on approach, which was indicative of good feedback to the pilot that if the aircraft is trimmed for one speed, then any off speed excursion could be felt as an out of trim force. With ample horsepower available on such a cool day, and our lowish airfield elevation, any speed increase was easily attained from the Lycoming. With so much power available, care should be exercised with any power increase as the speed could very easily build uncontrollably and this could result in a long landing or excessive float.
With this in mind I was careful with speed control, especially when accelerating, and I didn’t find the approach that challenging. One last check on final approach to make sure the cowl flap was fully open and we were cleared to land.
A coordinated reduction in power and flaring brought the Airvan to a smooth touchdown. Visibility over the nose in the flare was good and directional control was again excellent in the conditions as we accelerated for a touch and go.
The second approach was made on Latrobe’s sealed runway, which afforded a short taxi back to GippsAero’s flight line. This second approach had a bit more crosswind, but with the powerful rudder it was easy to ‘kick’ the Airvan straight just prior to touchdown after a crabbed approach. This second landing reminded me of when the Airvan put on a sterling aerial display in a strong crosswind at the 2009 Avalon Airshow. This was a day when many larger, more capable aircraft avoided flying. The Airvan’s maximum demonstrated crosswind limit is 15 knots.
Smooth brake application brought the aircraft to a taxiing speed to exit from the runway. Only a slight tendency to lean away from the wind was noticed when taxiing back in the crosswind. Any tendency was easily countered with into wind aileron.
The final word…
In all, I was suitably impressed with the Airvan for handling and design ruggedness and flexibility of roles. It also proved to be an excellent platform when it came to shooting air-to-air photography – shooting out of the open rear cargo door is a photographer’s dream.
Compared to some of the overseas competition, with pricing starting from just over the $650,000 mark, the GA8 Airvan is good value for money.
The future at GippsAero is bright as they are currently working on developing a turbine-powered version of the GA8 Airvan, to be known as the GA10 Airvan. This version will also have 10 seats, rather than the eight of the GA8. For the GA10, the aircraft has been stretched by almost a metre for the extra capacity, and while GippsAero have chosen a Rolls-Royce turbine engine for the bigger model, a high number of airframe parts will in common with the GA8 Airvan.
My thanks to Mark MacNamara, John Willis and Ross Bowden of GippsAero for their help in preparing this flight review.
Flight Test: GippsAero GA8 Airvan
Cabin height 1.14m
Cabin width 1.27m
Typical empty IFR-equipped weight 1014kgs
Max take-off weight 1814kgs
Max landing weight 1814kgs
Max useful load 800kgs
Max airspeed VNE 185KIAS
Max manoeuvring speed VA 121KIAS
Max cruising speed VNO 143KIAS
Ground roll 800ft (244m)
Total distance over 50 ft Obstacle 1600ft (488m)
Ground roll 483ft (147m)
Total distance over 50 ft Obstacle 1621ft (494m)
Cruise @ 75% power, 10,000 ft 134 KTAS 79 litres/hr – 4.2 hrs (no reserves)
SL rate of climb 904ft/min
Certified operating ceiling 20,000ft