Me and some friends are thinking about purchasing a semi built kitplane, (not ultralight though), and I was wondering if the AH community does not have some gurus in that field.
We found one that looks quite interesting, - its a Spitfire replica, a nice fast all-metal plane for a very decent price.
What do you think:
TEST PILOTS REPORT:
General
Pilot weight 85 kg Military style hard helmet worn.
Weather was fine with a 7-knot headwind, 22degrees OAT, short dry grass, level surface. 2 sorties were flown solo and with a pax. AUW solo 545 kg. With pax 620 kg. Max fuel weight at start of 115 litres.
The aircraft was fitted with a composite four-blade fully variable pitch propeller without an automatic constant speed control. A manual pitch selection switch on a panel on the upper left front console gave an 8-second adjustment range between fully coarse and fully fine. The Mk 26 has also been flown with a two bladed wooden propeller as fitted to the RV6 aircraft.
Some pilot seating and rudder control adjustments must be made prior to strapping in.
The aircraft is fitted with differential toe brakes on the rudder pedals. They are adjustable for length via panels either side of front lower fuselage. The front seat has three fore aft positions selected by removing two bolts on the seat frame. The rear seat has no adjustments with no stick or rudder controls fitted.
Walkround and Prestart Checks
A positive check of the undercarriage locking levers, with their big black knobs fully forward on the front starboard cockpit wall is advised before clambering under the aircraft. Combine this with a check of the two tell tale locking pins protruding from the wings. More on the gear later. The aircraft has no fabric surfaces, and only a couple of fibreglass fairings on the base of the fin attached by self-tapping screws. The aircraft is otherwise riveted aluminium.
The low wing requires a fair degree of bending and crawling around to check control rod connections, access panels, undersurfaces and undercarriage. The main engine panels on this prototype required 20 minutes to remove and replace (production models have redesigned panels) if a visually check of the engine is desired. Otherwise it is a simple task of checking quick release fasteners and 4 intakes for carby and cooling air.
A look up, for oil leaks, in the lower engine sump area, can be achieved if the engine cooling cowl, which hinges down immediately in front of the firewall, is fully opened on the initial cockpit check. This push /pull control is handily placed at the lower front console.
Fuel and oil caps are on the upper surface of the top engine panel a couple of feet in front of the windscreen. A small step-up device is recommended, as standing on the leading edge will damage the surface of the wing.
The oil dipstick, under a quick release panel, is an awkward long reach, fine threaded, plastic affair. Heat soak makes this device difficult to remove and check quickly and accurately. Fuel drain is directly under the 115 litre tank on the under belly.
The end of the U/C down lock pins can be seen in the large holes at the top of each oleo leg and the tell tale pins mechanical linkage connection (vital) should be checked. Otherwise, all other connections and micro switches are internal to the wing root and cannot be checked. Each leg and its controls are a completely separate system. Only one half of the wheel is covered by the oleo mounted door on retraction. The tail wheel sits on a strong leaf spring and is linked to the rudder by a horizontal bar. Electric flaps are fully variable to 55 degrees and are very large extending to almost half the wing span. A large vertical blade radio antennae sits behind the canopy on the upper fuselage.
Cockpit General
Entry is over the port inboard trailing edge with flaps up. A small fold down door is easy to open after sliding the lockable bubble canopy fully rearwards. The removable seat cushion is canvas-covered foam. I added a small leather document case with a polystyrene filling to increase my height in the cockpit by approximately one inch (pilot 185cms) until my hard helmet was just clear of the canopy.
Entry is fighter style by standing on the seat and lowering oneself using the cockpit arch and surrounds. Care must be taken to prevent stressing or marking plastic transparencies is recommended. The spade shaped, Spitfire style, control column is comfortable and has trim and RT switches fitted.
A four point Sutton type harness system for both seats provides good restraint and is easy to adjust and lock safely. Instruments and switches were generally well sited and easily read and operated, the main fuel cock is low behind the stick but easily checked.
There was little forward vision available over the long nose and forward wing. This can be improved down the left side only if the side door is opened and one leans out of the cockpit.
A master switch centre console gives 12-volt power and is flanked by two mag switches. Start is by pressing both Boost and Start buttons simultaneously. Boost has no function other than decorative, why not! Having sat in the real thing, this cockpit certainly feels and looks remarkably like the real thing, it just smelt new.
Undercarriage locked or unlocked position lights were not fitted to this aircraft. All aircraft are fitted with 2-inch telltale pins mechanically linked to the leg oleo. These pins protrude through the top of each wing by the inboard leading edge to indicate gear position.
Only the colour BLACK showing on a shorter pin length indicates locked down. A longer pin showing RED and BLACK indicates unlocked. NB. These pins will only indicate locked (up or down) if both large undercarriage locking levers are fully forward also.
Difficulty was experienced siting these pins with the canopy fully closed and hard helmet fitted. My helmet touched the canopy despite the concave moulded into the canopy curve.
The undercarriage emergency lowering system: to be used if the gear motor fails in the up position, are two black handles 4 inches long situated either side on the floor behind the stick. The handles are easily reached and pulled separately. This direct cable link pulls a pin thereby disconnecting the control arm of the electric motor from the top of the leg. This enables the pilot to unlock the leg with the black knobbed locking lever starboard cockpit and use G forces to lower it before locking it again by pushing the lever forward. This simple system was seen to work on the ground during trials.
Engine Ground Runs
The sliding canopy can be opened under full power. No parking brake is fitted. The aircraft was tied to a small sapling via a rope attached to the tail-wheel spring with chocks in place.
Full choke was applied for start but cancelled immediately; idle was 800rpm at 5-7 L/hr. There was no tendency to over-temp during prolonged running. 3000rpm was obtained at full power and fully fine on prop setting. No significant mag drops noted. Pick up and throttle response was smooth and instant over the full rpm range. The engine emits a loud powerful bark and a noticeable torque roll left during slam accelerations to high power.
Taxi
The aircraft moved forward at 1000rpm there is no forward vision and a constant weave is required to clear ahead. Turning is easy, the tail-wheel is liked to the rudder and the progressive toe brakes enable tight areas to be negotiated. The aircraft is capable of turning through 180 degrees almost within its own length.
Take-off and Climb
No flap was used; zero trim was selected on the electric stick trimmer as indicated by the gauge. There are no aileron or rudder trimming controls.
The undercarriage electric motor switches (they are three position UP, OFF, DOWN) can be selected to the UP position pre take-off if desired. Only by selecting unlock (rearward) on the levers on the starboard cockpit wall does a lever attached to the locking pin move a micro switch allowing the motors to start. These switches were not selected on the ground on these first two sorties. However, subsequent flights proved the viability of this technique as it saves time and some actions after take-off during high cockpit workload situations.
Run-up produced an easily controlled port swing right rudder was immediately effective and no brakes were required to hold it straight. The tail lifted quickly and smoothly pitch control was good throughout the ground roll.
The aircraft flew itself off at 60 knots after approximately 100 metres. Gear retract takes 8-10 seconds and a change of hands on the throttle and stick is needed to bring the locking levers rearwards.
To be followed...
