Guy Leitch with Murray Kester
Due to the huge value and the irreplaceable nature of a real Spitfire, very few select pilots will ever get the opportunity to pilot the real thing.
For lesser mortals there is the option to build and fly your own replica. This is what Australian enthusiast Mike O’Sullivan did after completing a couple of homebuilt projects.
O’Sullivan built his first Spitfire replica in the early 1990s as a 75%-scale version of the original, which he called the Mk.25. Inspired by legendary Spitfire test pilot Alex Henshaw, O’Sullivan completed his own Spitfire and liked it so much he decided to sell kits to like-minded enthusiasts worldwide.
Several Mk.25s were built before he came out with a slightly larger model that had bigger engine options and added a second seat behind the pilot. This was naturally designated the Mk.26. However the second seat was cramped and so he expanded the fuselage yet again to become a 90% version, which he called the Mk 26B.
Whether in Mk26 or Mk.26B forms, the aircraft is an all-metal, monocoque design with a fiberglass cowl.
An important goal for Mike O’Sullivan was for his Mk.26 to look like an original. This ruled out any Rotax engine options. Fortunately Australia is also a great source of aero engines – in particular, the widely used Jabiru air cooled direct drive engines. There are hundreds of Jabirus flying in South Africa and so there is a vast repository of skills and experience for the operation and maintenance of these simple yet proven engines.
Top of the range is the 8-cylinder Jabiru 5100 which is good for 180 hp. Despite this being far less than the original Merlin’s 1,600 hp, this still gives much the same power to weight ratio yet with a proven engine that is far simpler and cheaper to maintain than a supercharged Rolls Royce Merlin that needs to be overhauled around every 250 hours.
Murray Kester’s Mk.26
Watching the development of this home-grown Aussie product with great excitement was Murray Kester from Western Australia.
Murray acquired Mk.26 kit #47 and after around 1,665 hours of passionate work, finished his beautiful aircraft in 2016. Perhaps surprising, given the more traditional Battle of Britain camouflaged paint schemes that are most often used, Murray elected to paint it in the bright red livery of the Royal Canadian Air Force.
Murray says, “I bought the kit in 2005 and work on it progressed slowly as I was still employed up until 2014. I’m originally Canadian so I thought the maple leaf roundels looked good and I didn’t want yet another war bird. When I gave Mike O’Sullivan the cheque I told him it was not going to be a war bird and would likely be red and white. He thought that would be great.”
On the ground
On the apron at Serpentine Airfield south of Perth, Murray’s Spitfire Mk.26 is a thing of beauty and a great crowd pleaser at the airshows he has graced with its presence across Westen Australia. The fit and finish are exemplary, tempting you to run your hand across the smooth flush-riveted skins.
With its nose high stance, it looks ready to leap into the air. The only slightly discordant note is the narrow 2-bladed prop which is a fixed pitch two-blade black painted wooden Hercules prop. Jabiru insists that only a two bladed wooden prop with a maximum diameter of 72” be fitted to this engine. The prop was specially designed by Hercules in the UK for this engine and airframe and has a 61” pitch. The spinner is a four hole from a King Air, installed in anticipation of fitting a 4-bladed prop to a Toyota V12 engine.
The front cockpit of the Mk.26 is on a par with most tandem 2-place aircraft such as the RV-8, although the rear seat is more cramped and reminiscent of a weight shift trike with the seat squab up against the back of the front seat. The rear seat may be tight but thanks to the large bulged canopy, is not claustrophobic. There is no heater, but there are two large eyeball fresh air ducts.
The pilot’s seat is ground adjustable to optimise the pilot’s position relative to the rudder pedals and cushions can be used to vary height and comfort. While there are two seats in the Mk.26, the rear seat does not have rudder pedals or a stick and is only suitable for a person under 70 kilos.
Entry into the cockpit is via an authentic bottom hinged door, a feature found on the original Spitfire and carried through for both nostalgia and practicality.
Murray’s choice of instrument panel for VH-BPD features low maintenance modern glass avionics. The panel is dominated by a large Dynon Skyview touch screen Primary Flight Display with comm and transponder controls on either side. The comm radio has a feature (that hasn’t been used in this plane) that can detect a tower frequency when within reach and switch to it.
Below the Dynon is a row of rocker switches for the engine and systems. Notable is the rocker switch bottom left for the flaps and two rocker switches bottom right to operate the undercarriage. Once the switches on the panel are ‘on’ two levers on the right sidewall operate the ‘chassis’ or undercarriage – or if you speak American, the landing gear.
To raise the undercarriage the pilot places both left and right selector switches in the retract position before takeoff. Once a positive climb rate has been achieved, the pilot reaches over to the right sidewall (switching hands on the stick), and pulls back on both undercarriage levers, which unlocks the pins and causes the electric motor to run in the direction selected by the switch. After 5 to 10 seconds the wheels should be in the wells and the Up-indicator light comes on. The pilot then pushes the levers forward to lock the undercarriage in the Up position.
Lowering the undercarriage is the same procedure, with the switch in the opposite position. This all takes getting used to for new pilots, and operations need to be deliberate. Emergency extension is achieved by pulling release cables and letting them free-fall.
Like an RV, the flaps are selected down for the pre-flight to discourage the pilot from stepping on them to enter the cockpit. The flaps operate similar to car windows. A switch is held down to deploy the flaps – which stop as soon as the switch is released. Pushing the switch upwards stows the flaps with a nonstop movement. As there is no cockpit indicator, the flaps have to be eyeballed to judge the position. Murray says, “I put a mark on the port flap which indicates mid-flap position. Maximum flap angle is 50 degrees, but I wouldn’t advise going that far. The pilots who have flown her are quite happy to look out the window and set the flap by feel.”
An novel feature is the screen below the instrument panel which is connected to two on-board cameras. One on the left wing lets the pilot see what’s coming while taxying. The other is on the belly and clearly shows the undercarriage. It gives a bit more confidence that the gear is either up, down or in transit. A toggle switch on the screen selects which camera is displayed.
The throttle is a single lever on the left sidewall, sharing its quadrant mount with the pitch trim lever in the place of the mixture control. The mixture control is now a simple push-pull knob on the instrument panel in front of the throttle. Below the throttle quadrant is a large push-pull knob that operates the cowl flap.
The wing inspection covers the usual points: aileron and flap hinges, brake fluid leaks, tyre condition and any sign of undue rubbing which might suggest poor undercarriage rigging. Three hatches take care of the engine inspection. A second set of hands is needed to lift the tail so that the oil level can be checked.
A single fuel drain at the front of and below the left wing is all that’s needed to check for water. The inspection procedure is repeated for the right wing.
There’s little about the tail section which needs any special attention.
Flying the Mk.26
Entry to the cockpit requires a big step up onto the training edge of the left wing (all proper fighters are entered from the left). Thanks to the side door, you don’t need to stand on the seat to slide your legs down through an oval bulkhead aperture.
The cockpit is spacious for an average-size pilot, and despite the classically high cockpit sills, the visibility to the sides is good. Because it uses a flat-8 engine, the top of the long cowl does not need to be as wide as that over the V-12 of a Merlin and so visibility forward is slightly better than the full scale Spit. But it is still a classic taildragger and so S-turns while taxying are essential.
Once settled into the cockpit, the Mk.26’s four-point harness is an improvement on the original’s pin-secured belts and the buckle is easy to secure and release.
At first glance the spade grip control stick replicates the famous hinged loop Spitfire wheel, but it is fixed to the stick and thus articulates only at the base.
For the before-start checklist, you start inside the cockpit to make sure the undercarriage and flaps are selected down. The fuel level is checked via the tube which runs from the top of the tank in front of the instrument panel to a point close to the bottom. Shaped like a T, the fuel tank is located on the centre of gravity behind the firewall and between the pilot’s legs.
With its SDS electronic fuel injection, the big flat-8 Jabiru engine fires up as smoothly as a car and has a beautiful deep throated rumble through stub exhausts on either side of the long cowl. Like any air cooled aero engine, it must to be warmed up, but this is an improvement over the original Spitfire which needs to get airborne quickly after start otherwise the coolant overheats.
Like any prudent tail dragger pilot make sure it’s lined up straight for takeoff. Open the throttle and the whole airframe comes alive – just as though there were 1,600 horses raring to go.
The steerable tailwheel gives good control on the ground, whether on pavement or the Spitfire’s natural element: grass runways. Just like the original, rudder authority is limited, and so pushing the stick forward to raise the tail early in the takeoff roll runs the risk “of running off the left hand side of the runway under engine torque,” Murray says.
After a brief takeoff roll, the Mk.26 is ready to fly but it’s not a good idea to try get airborne too early. At 70-75 mph it will fly itself off and have plenty of rudder authority to manage any threatened swing. Climb out at 2400 rpm with one up and full fuel is a healthy 1,100 fpm at 90 mph IAS.
The fuel tank holds 110 litres and with the engine burning around 35 litres an hour, a two and a half hour endurance is not unreasonable, with the Mk.26’s cruise speed of up to 160 mph (140 knots) at 2600 rpm and economical cruising at 120 knots at 2400 rpm, burning 30 litres/hr.
The airframe is stressed for plus 6 G and minus 3 G and is capable of most aerobatic manoeuvres, but no flick rolls. Loop entry speed is 180 mph, and rolls are started at 140 mph. “It’s a lovely plane to fly basic aerobatics”, says Murray.
Back in the circuit, the undercarriage can be lowered at a usefully high 130 mph, with the limit being 140. 110 mph is the target speed for base leg, and with full flap, final approach speed is between 75-95 mph, depending on weight and wind.
The aircraft can be 3-pointed, but is best wheeled on, purely because of the rapidly diminishing view over the nose at anything near a three-point touch-down.
Murray says “There’s little to see of the ground, and the only points of reference are each side, and in front of the wing. I bring the flaps up as soon as the tail is down to place more weight on the wheels as early as possible.
“The Mk.26 can be landed and stopped in 400 metres, but if you get it wrong, the results can be humbling. Also, I far prefer landing on tarmac because the wheels are quite small – even a small tuft of uneven grass can start a swing on the ground,” says Murray.
Whilst the Mk.26 does not present too much of a skills jump for a pilot with 50-100 hours on a taildragger, those used to a benign taildragger like a Piper Cub might find it a challenge.
Conclusion
Seeing the Mk.26 in the air is a reminder that any Spitfire is very special indeed. The iconic shape is defined by its slim fuselage, relatively wide chord wings and the beautiful elliptical planform of the wings.
It is a shape which arouses very strong emotions in any pilot with a high aesthetic sensibility. Even those with no connections to the Battle of Britain will struggle to remain unmoved by a Spitfire’s iconic airframe flying overhead, or better still, doing a low pass ‘runway inspection’.
Now it’s possible to approximate the real thing in the Mk.26, which is an affordable yet rewarding modern day replica.
Box
Mk 26 vs The Original
As the designer of the Mk.26, Mike O Sullivan has done a brilliant job making his scale replica as close as possible to the real thing – and in some cases it is even better.
Neil Thomas has flown both the real Spitfire and the Mk 26. He says, “The scaled replica is very similar to a real Spitfire to fly. The Mk.26 has the same beautifully light and harmonised controls throughout the speed range. The stall is benign with a gentle roll-off in any configuration: 52-mph clean and 44-mph with the gear and flaps out.”
Neil’s descriptive words are exactly what designer Mike O’Sullivan aimed to achieve, as he feels strongly that the flying experience needs to be just as authentic as flying the original aircraft.
In a number of key areas, the Mk.26 is better than the original. As mentioned, in the original, you need to start the takeoff run within four minutes of starting a Merlin. The coolant temperature rises by 10°C every minute at idle and the two big and important gauges were the temperature and boost. Too much boost from the supercharger and the engine would flood. The fuel/air ratio is important to the Merlin’s ability to run smoothly – it’s a lot more temperamental than the Jabiru 5100.
“Another Spitfire foible is its horrible brake system, which requires squeezing a handlebar-type lever on the circular control grip. Applying the brakes relies on pushing the rudder pedal on the side you want the brake to work. Before applying the opposite brake, the pressure has to be released by letting go of the handle first. It takes a good 12 hours to get used to it and I suspect it was a major cause of ground loops in a Spit during and after World War II. I still don’t know why the Brits didn’t simply adopt the system found on US trainers and eventually the Mustang. But imagine the British admitting to copying the Americans!”
“In the air the Mk.26 is uncannily like the real thing to fly. Although the cockpit is much smaller, the same harmonious handling and light controls are almost identical. The Mk.26 and the real thing are stunning to fly and it’s easy to be lured into the spirit of a real Spitfire whilst flying the Australian copy. However, the Merlin is far more temperamental, and the Rolls Royce engines barely made 300 hours before overhaul – and only then if they were lucky.
The real Spitfire really talks to you, including the engine, but it is very temperature sensitive, requiring care throughout a sortie. In a real Spit the Merlin easily overheats due to the undercarriage legs disrupting the airflow into the radiators beneath the wings. It also fouls up the plugs when pilots come back on the power in the cruise – it is an aeroplane that requires flying at high power settings – just like a Formula One car or thoroughbred horse, That is where it is designed to perform as the air force wanted. The Mk.26 has no such demands.
“Landing a real Spitfire, I watch for the tarmac either side to grow as that is the only indication there is any drift. On a narrow runway it needs to be confronted immediately as the view all but disappears when the tail goes down.”
Overall the Mk.26 is the nearest thing to a Spitfire the right side of two million dollars “
_____________________________
Box 2
Own this Spitfire!
Murray Kestrel has retired from flying and wants to find a good home for his beautiful and proven Mk.26.
Supermarine Spitfire Mk26 Serial #47 is painted a vibrant red with white trim and underside. It has custom made engine cowls that give it that unique Spitfire appearance.
The Jabiru 5100 5-litre 180 hp 8-cylinder engine has a total time of 31.4 hrs. The TBO is 2000 hrs, The engine has SDS electronic fuel injection and is CASA compliant. It has 8 new pistons and the cylinders are honed. The engine is running beautifully and sounds fantastic.
This aircraft features:
- Dynon Skyview Avionics
- Upgraded undercarriage
- Matco brake conversion
- +6 / -3 aerobatic limits
- 30 litres/hr fuel consumption; 115 litres fuel capacity
- Hercules 72 inch diameter, wooden propeller.
- Backup 12 volt electrics to run the fuel injectors and EMS
Included in the package is a completely refurbished Toyota 1GZ-FE 300 hp V12 engine with an aviation logbook.
Murray Kestrel says, “This makes this whole package an ideal project for someone who wants a superb Spitfire with a V12 engine. It adds at least $10,000 to the value to the plane. Had I found that engine earlier, it would now be in the plane. At 300 hp, it will liven the plane up quite a lot. The engine has been stripped down by an AME who said it was in pristine condition. I took the opportunity to change all bearings and chains. It owes me $13,000. I have an aviation log book for the engine. Should the plane be bought locally, I would be keen to assist in the engine conversion.”
Price is negotiable around AU$130,000 and all genuine offers will be considered.