Project Pika

The first of two Pikas, numbered C-1, (A92-1) was piloted on its first flight by GAF Chief Test Pilot Mr John Miles. He was later joined by RAAF test pilot Flt Lt Fred Knudson. On April 5, 1951, a Pika C-1 flown by Knudson experienced a compressor stall, and Knudson executed a dead engine crash landing on a nearby salt pan. Flt Lt Knudson was badly injured in the crash. By this time the second Pika, A93-2, was nearing completion, and Flt Lt (now Air Vice Marshall) Fred Barnes recommenced test flying for the RAAF.

The test flying program was divided into four stages. Firstly aerodynamic design testing where the basic Pika/ Jindivik design was flight proven. Secondly, the telemetry equipment was tested. This involved proving equipment that transmitted in-flight data such as heading and altitude to the external control station. Thirdly, the auto pilot system was thoroughly tested. Finally the radio control linkage was proven. The Pika also allowed the ground flying team to be trained, and provided opportunities for the taking of radar echoing measurements and checking air-to-air visibility. Flt Lt Barnes was joined by Squadron Leader Robertson and Flight Lieutenant Inger for test flying.

In addition to the normal flight controls in the Pika, a switch unit was provided in the cockpit to enable the pilot to switch on any one or all of the three auto-pilot servo motors controlling the aileron, rudder, and elevator. This unit was fitted with warning lights to ensure that the servo motors were lined up according to the trim of the aircraft before they were switched in. In an emergency, all three servo motors could be disconnected by a cut-off button situated on top of the control column. The servo motors could be operated from an external source via radio control or, with the aid of a control supervisory unit that disengaged the radio control link, the servos could be directed from the cockpit by a series of push buttons. For circuits peculiar lo the pilotless version (skid down, fuel cut, etc), and auxiliary systems such as throttle and flap operation, an indicator unit and signal box advised the pilot whether those functions were operating correctly.

As an aircraft, the Pika was found enjoyable to fly, but was not renowned for its gliding ability. The wings, which were quickly detachable, spanned 19 feet. The Pika was just over 23 feet in length and had a loaded weight of just 2900Ib. It had a short endurance, and its fuel was stored in two semi-circular metal tanks, each of 22 gallons capacity, mounted behind the pilot’s seat.

The Pika differed externally from the Jindivik Mk 1 in intakes, cockpit, and undercarriage. Pika intakes were situated on the fuselage sides beneath the cockpit, while early Jindiviks had a submerged dorsal intake. The Pika had a free-blown perspex canopy which was hinged at the rear to the fuselage and locked in position by a bayonet filling at the front. The cockpit itself was equipped completely with all necessary flying and engine instruments, warning lights and oxygen and heating systems for the pilot. The Pika was fitted with a retractable “tail dragger” undercarriage, and are perhaps the world’s smallest retractable undercarriage. The main legs were equipped with standard oleo-pneumatic struts and high-pressure tyres of less than 13-inch diameter.

The legs were retracted inwards into the wing-fuselage junctions by a pneumatic retracting system. The system allowed four complete cycles on one charge and was a high-pressure fixed-capacity supply. (2000psi. ) An unconventional tail skid, which was non-retractable, was fitted with a small oleo strut.

The Jindivik, however, has an unusual undercarriage system where the aircraft sits on a gyro-stabilised trolley for takeoff, from which it lifts off at take-off speed (about 120kts). At this time, speed activated brakes bring the trolley to a standstill 3000 feet from the starting point. The Jindivik lands on a retractable skid.

The overall weights of the Pika and Jindivik were not greatly different, as the Pika offset the weight of the pilot with a reduced fuel capacity, and by not carrying some equipment pertinent to the pilotless version only. Jindivik versions other than the Mark 1 were powered by the Armstrong-Siddeley (later BristolSiddeley) Viper expendable jet, which was also specially developed for the Jindivik project, and gave a thrust of about 1 ½ times that of the Adder.

The two Pikas were originally given RAAF cyphers A93-1 and -2, but A93-1 operated with the Department of Supply C-1 number and a prototype yellow circled “P”. A93-2 differed from C-1 in having an elongated streamlined nose cone. Both Pikas appeared in all silver colouring with a matt black anti-glare strip forward of the cockpit.

On June 25, 1954, A93-2 took off on its last flight, the 214th such flight by a Pika, and completed it successfully. Aerodynamic data from Pika flight trials showed that some modifications were necessary to improve the aircraft. Very early in the Pika program, it was found that a longer jet pipe was needed to eliminate the problem caused by the exhaust gases interfering with the elevators. The second Pika was modified accordingly. It was also found that turns could be effected to specified ratings without the use of the rudder, and as a result, the Jundivik Mk 1 had the rudder locked in position, which enabled the radio control unit to be simplified. The first Jindivik flew on August 28, 1952.

The success of the Pika project can perhaps be measured by the success of the Jindivik, about 500 of which have been sold to the RAAF, RAN, Royal Air Force, United States Navy, and the Swedish Government. Today A93-2 is on display at the RAAF Museum, Point Cook, and remains Australia’s only locally designed and built manned pure jet.