Plans to develop guided weapons for the United Kingdom armed services were initiated within the Admiralty in the autumn of 1943. By March, 1944, the Third Sea Lord had formed a Guided Anti-Aircraft Projectile Committee. In October 1945, with a view to establishing a test range in Australia, the United Kingdom approached the Chifley Labor Government and it was decided that a United Kingdom Mission headed by Lieutenant-General J.F.Evetts should visit. After extensive investigations, Evetts major recommendation was that a Range Head be established at Mt.Eba (subsequently changed to Woomera, 70 miles South-East of Mt.Eba ). On November 19, 1946, subject to a suitable agreement between the two Governments, Cabinet approved the establishment of a Guided Weapons Testing Facility.
As part of the Long Range Weapons Project, it was considered necessary to develop a pilotless target aircraft. On May 24, 1947, Prime Minister Chifley received a cablegram from the British Prime Minister, Clement Attlee, part of which read, ".... our experts would like to discuss with yours as soon as possible an accelerated programme for the development of guided and air-launched weapons. We should also like you to consider the design of a small unmanned experimental aircraft capable of sub-sonic speeds and eventually supersonic speeds". This formal request was followed by negotiations between the two Governments and on September 6, 1947 a cablegram accepting the proposal was sent by the Chifley Government .
A meeting was held at Thames House, London, between representatives of the Ministry of Supply and representatives of the Australian Defence and Munitions Departments on November 24, 1947, and was chaired by Mr. H.M. Garner PDSR(A)1 . It was agreed that specifications for a small target aircraft be prepared by the Ministry of Supply in collaboration with the Australian Department of Munitions. It was envisaged that Australia would be responsible for the design and construction of the aircraft and the development of the radio equipment and the United Kingdom would provide the engines and auto-controls.
Following on from this meeting it was arranged that Mr. I. B. Fleming and Mr.R.H.B. Cannon would visit the United Kingdom to be involved in the drafting of the specifications for the pilotless target aircraft. Mr. Ian Bowman Fleming was appointed to head the design and development of the aircraft. With degrees in Civil Engineering from the University of Sydney and a Master of Science from Cambridge University, Fleming had worked at Avro's and then at Fairey's before returning to Australia to commence work at the Commonwealth Aircraft Corporation (CAC) in 1939. Mr. R.H.B.Cannon was Chief Stress Engineer at the Government Aircraft Factory (GAF) and held Bachelor of Science and Bachelor of Engineering (Aeronautical) degrees from Sydney University. He had been employed by GAF since 1942 having previously had service with Qantas Empire Airways and in the Engine Assembling and Testing Section of CAC.
Fleming and Cannon arrived at London Heathrow on January 19, 1948, reporting their arrival to Mr. Hanford Stevens at Australia House. In the following two months a series of meetings were held at Thames House and visits were made to RAE Farnborough, to discuss aerodynamics and automatic control, and to Armstrong Siddeley at Coventry to obtain details of the engine. Much of the initial discussion tended to concentrate on the proposed power plant, and the question of a piloted prototype. Early on, Fleming canvassed the idea of utilising the "Nene" as this engine was to be produced in Australia. It was, however, not considered economically feasible to utilise such a sophisticated engine in an expendable aircraft. The proposed power plant was a yet to be developed turbojet adaptation of the Armstrong Siddeley Mamba turboprop engine. The original concept had called for an expendable engine. Initially, this engine was designated "Mooroobi", the aboriginal name for the Death Adder, one of Australia's most deadly snakes. The early estimates were for a life of 10 hours!
The major policy issue that was exhaustively debated related to the provision of piloted versions in addition to some 6 to 12 pilotless aircraft. Fleming argued strongly against a piloted version, fearing the airframe modifications necessary to accommodate a pilot would compromise the design of the pilotless aircraft. It was, however, generally agreed that a piloted aircraft would expedite the testing, not only of the aerodynamic design, but also of the auto-pilot and telemetry equipment. By March 3, 1948, Fleming was in a position to table several variations on the design of both a piloted and a pilotless aircraft. Various arrangements, including a bifurcated jet pipe, had been considered. Among the proposed designs was one for a prone pilot cockpit. As well as extensive assessments relating to aerodynamics and engine performance, details of proposed auto-pilot, telemetry equipment, and launch and landing gear were discussed. It was planned that the pilotless version would have a tricycle take-off trolley and utilise a skid for landing. The question of a landing skid had been carefully evaluated and the results of landing tests on the Messerschmitt Me163 reviewed. Preliminary design features aside, the major achievement had been the drafting of the specifications detailing the operational requirements for the proposed target aircraft.
Fleming returned to Australia on March 23, 1948, armed with Specification No. E7/48. Cannon remained in the United Kingdom as a Technical Liaison Officer. E7/48 called for "a pilotless target aircraft for the use with guided missiles." It was required to have a maximum speed of 435 knots (500 m.p.h.) at a height of 40,000 feet and to have a capability of at least 2g turns at this speed and height. Endurance requirements called for sufficient fuel to permit the following operating sequence:- 1 minute at full power plus 5 minutes idling for ground running, take-off and climb to 40,000 feet, 15 minutes at maximum r.p.m. at 40,000 feet, 1 hour economic cruise at 40, 000 feet and finally, fuel to return to base and land.
The United Kingdom Government was advised by Prime Minister to Prime Minister cable on June 1, of Australia's agreement to the development of an unmanned target aircraft. On June 4 the Department of Defence advised that the Minister had approved the design and production of two manned prototypes and six unmanned versions. Funds totaling £450,000 were allocated to the project and the design work began. The piloted and pilotless aircraft projects were officially known as Project "C" and Project "B", however, to the staff of GAF, they were known, more informally, as "Cat" and "Bat". By March 7,1949, Projects B & C were more or less finalised with the publication of Design Survey No.3. The B & C designs, soon to become known by their aboriginal names, Jindivik ( meaning 'The Hunted One' ) and Pika ( meaning 'Flier'). In what proved to be a brilliant design, the piloted aircraft achieved a high degree of structural similarity to the pilotless aircraft. The major airframe components were largely identical, with only the air intakes and canopy distinguishing these two versions of E7/48.
In September 1949, there was an indication that the British Services could also be interested in the pilotless aircraft when a letter was sent to the Australian agency requesting technical details, costings, delivery dates, etc. However, by November 1949, the Ministry of Supply (MoS) had issued Specification No. U22/49. The operational requirements called for by this specification were somewhat more challenging than those of E7/48. It was considered that the Australian aircraft could be modified to satisfy all the potential users. Although not meeting all the requirements, the ability to to commence quantity production with a minimum delay was considered an advantage. Fleming again visited the United Kingdom in early March, 1950. A meeting was held on March 10, 1950, to discuss the E7/48 target aircraft and the two other target aircraft specifications that had been prepared by the MoS, U22/49 and U25/49. This visit was successful in that it was decided that all work in the United Kingdom on target aircraft should cease pending receipt of evidence on the suitability of E7/48 for the British Staffs requirements. It was regarded that the current design of E7/48 was acceptable with certain equipment changes and that quantity production would be required if flight trials proved satisfactory.
The first prototype, Pika C-1, was assembled at GAF, Fisherman's Bend, and completed mid-October, 1950. Wing, tail unit and fuselage stiffness tests were completed and the engine was ground run to check the power plant installation. On October 21, the wing was removed and together with the fuselage it was loaded onto a Bristol freighter for transportation to the Long Range Weapons Establishment at Woomera. The test flying was the responsibility of GAF test pilot, John Miles. Miles had been a member of the fifth Empire Test Pilot's Course at Cranfield. The Pika was ready for taxying trials late in the afternoon of October 29, 1950. The strip from which all the tests were made runs almost due N-S and was sealed for a length of 7300 feet and a width of 150 feet. The sealed portion was loosely covered with 1/8" water washed pebbles. The tail skid produced a shower of sparks as it glided over the bitumen-sealed quartz gravel taxyway. Arthur Cooper, the Armstrong Siddeley engine representative, to his later embarrassment, ran alongside the Pika screaming at John Miles to stop as the Adder engine had blown up.
The first flight, a brief lift off, with an immediate return to the strip was planned for the October 31, 1950. Three attempts to get airborne failed! The aircraft tail could not even be coaxed to leave the ground to assume a take-off attitude. Ian Fleming commenced some hurried calculations on the back of an envelope. These calculations," led me to conclude with outward confidence and inward hope that we could get airborne by using 20 degrees of flap." The ensuing take-off run saw the tail lift off after 1000' at 75 knots and after a further 1000' the aircraft lifted off at 100kts. It remained airborne for 3500' and landed, stopping within 1800' of the touch down point. Following a discussion between Ian Fleming and John Miles, it was decided to perform a circuit to assess the control response and landing behaviour.
Following an uneventful second flight, the third flight on November 15, 1950 was marred by a wheels-up landing. Prior to this flight of C-1, the undercarriage had been modified after which ten complete retraction test cycles were performed. Take off was made at 1820 hours and after being airborne for approximately 5 minutes the pilot raised the undercarriage. Retraction occurred normally and the warning lights functioned in a normal manner. When the pilot selected DOWN the warning lights remained red indicating an unsafe condition. Several attempts to re-cycle the undercarriage were unsuccessful. The pilot flew low over the field and observations from the ground confirmed the unsafe condition. Preparations were then made for a belly landing. The pilot started his approach at 150 knots with 25 degrees of flap, reducing to 130 kts over the end of the strip with 60 degrees flap. At 1850 hours he made a perfect belly landing with practically zero rate of descent, touching down at 92 kts. The aircraft skidded for 1010 feet before coming to rest. Investigation revealed that the cause of the incident was due to the failure of a microswitch. Fortunately the damage was rather light. The only major items requiring replacement were the landing flaps, wheels and brakes, starboard up lock assembly and the bearing drain fairing. While the airframe was repaired, modifications were also carried out to the fin. The leading edge was sweptback and the area increased. Repairs and modifications completed, the aircraft was airborne again in two weeks.
The next few flights were without incident. On December 5, 1950, the application of dive brakes at a speed of 240 knots whilst at 15,000 feet produced severe buffeting, the control column snatching full left and producing two fast rolls. Inspection of the aircraft following the flaps up landing revealed that both dive brakes were twisted as a result of their hinges giving way. The port aileron having been forced down by the twisted dive brake explained the roll. In order to conduct a demonstration the following day for visiting V.I.P.s, temporary repairs were effected on the ailerons and flaps, and the dive brakes were riveted into a closed position. During these early flights none of the auto-pilot or telemetry equipment was installed, the flight test programme called for evaluation of these systems in the second Pika. The final phase involved remote flight control from the ground controllers and from a Gloster Meteor Mk.7 aircraft. The handling characteristics were quickly established. Forward visibility was poor and acceleration slow until the tail lifted off at 75 knots. At 85 knots there was a pronounced nose pitch down with the stick neutral. Lift off occurred smoothly at 102-105 knots. In flight the ailerons and elevators were light although effective. A result of this 'lightness' was a tendency to over-control. The tendency of yaw, at low speed, to induce a "Dutch roll" was corrected by the modifications to the fin.
Between October 31,1950 and March 31,1951, John Miles carried out 34 flights in C-1, covering some 14 hours. After the 31st flight the engine was changed. The elevator gearing was also changed to reduce the sensitivity of this control and the jet pipe and extractor fairing was extended by 9" to reduce the jet effect on downwash at tailplane. Ground testing of the new engine revealed a problem with the jet pipe temperature indication. This was corrected and apart from the pilot being able to obtain only the maximum rpm of 15000 on static ground running, no other major problems were encountered. At the end of March, 1951, an RAAF Test Pilot, Flight Lieutenant F.O. Knudsen was introduced into the test programme. Knudsen made flights No.36 to the ill fated 44th.
On the April 5,1951, whilst on a demonstration flight Pika C-1 crashed at 0802 hours. At a pre-flight briefing it was decided that the programme would include a slow fly past to complete the first circuit, at a speed not less than 130 knots, with landing & drag flaps extended. This was to be followed by a fast fly-past, then two or three steep turns at a safe height, and finally an approach and landing. Take-off was at 0757 hours and the accident occurred at 0802, just after completing the first circuit. After passing the party at the end of the runway, the pilot opened the throttle and noticed a rise in the jet pipe temperature to about 800°C. This was checked by throttling back. It was certainly pointed out in the pilot's notes that the throttle should be opened up slowly from an engine speed below 11000 rpm. As the aircraft was put in a climbing attitude and after a transitory gain in height, it immediately started to sink impacting with the ground some 150' to the western side of the airstrip . The pilot was seriously injured. After preliminary treatment at Woomera hospital he was evacuated by air to Adelaide. Extensive examination of the wreckage failed to reveal any evidence of failure of the structure, flying controls and surfaces or engine controls. The investigating committee found that the prime cause of the accident was a lack of engine thrust at a time when the pilot required additional thrust to maintain horizontal flight. The committee considered that the failure of the engine to respond was due to a compressor stall which could have resulted from too rapid an opening of the throttle by the pilot, a defect in the engine fuel system or fouling of the compressor blades from an oil leak. After recovering from this accident Knudson was later to go on to fly the second Pika, C-2, and the Gloster Meteor 'Shepherd' aircraft in the trials of the Jindivik.
Following the loss of C-1, construction of the second Pika was expedited. After ground tests at GAF were completed the aircraft was air freighted to Woomera on April, 26th 1951. Pika, C-1 had confirmed the suitability of the design to meet the requirements of a target aircraft; now it was necessary to establish the remote control systems. John Miles established that it was possible to fly both Pika aircraft without the use of the rudder. Indeed, several flights were carried out with the rudder locked in the central position. This greatly simplified the design as it enabled the rudder control system to be omitted. After initial test flights that revealed a 30 knot increase in level speed performance over its predecessor, C-2 was quickly introduced into the test programme with auto pilot trials commenced early in June. These continued without incident, until on Flight No.10 on August 1,1951, the engine cut out at 10,000 feet. The pilot, John Miles was able, with great skill, to complete a successful dead stick landing. All planned flight trials were cancelled.
The aircraft remained grounded until late October, 1951. However during the last week of that month, the aircraft was used on the ground to conduct initial tests on the take-off trolley for the Project "B" aircraft. C-2 was mounted on the trolley, a tricycle type, and several take-off runs were simulated. The results were encouraging. It was unlikely that rudder control would be effective under 50 Kts. These early trials on the trolley demonstrated that a steering mechanism would be required to maintain directional control during the take-off run. A system was devised which, ironically, employed a directional gyro taken from a German V-2 rocket that fed a K-12 servomotor. Test flying resumed on October 31, 1951 with Flight Lieutenant Fred Barnes conducting virtually all of the subsequent flights. On November 11, during manipulation of the auto-pilot controls, a marked skid occurred that resulted in a 'flame out' when the aircraft was at 12,000 feet. A re-light was successfully effected and the aircraft brought in for a normal landing.
A problem that continued to plague the tests was a difficulty in locking-up the undercarriage. To aid retraction of the undercarriage the aircraft was 'bunted'. Whilst the resulting negative 'G' was often successful in achieving an up and locked undercarriage, the manoeuvrer often caused partial engine cuts. This problem of engine cuts was thoroughly investigated by the RAAF's Aircraft Research and Development Unit (ARDU). The flying programme continued whilst flight tests on the fuel system were conducted by ARDU, and GAF conducted bench tests on a rig of the fuel system. Initial tests were directed at determining whether the problem was one of fuel or of air starvation. In spite of the cramped conditions in the cockpit, it was possible to mount a movie camera over the pilot's left shoulder to record changes in the Jet Pipe Temperature (JPT), engine r.p.m., slip needle and the two Bourdon pressure gauges that had been fitted into the fuel system. Inflight and bench tests demonstrated that the engine cuts resulted from air, released from solution as the fuel passed through the low pressure filter becoming trapped in the the top of the flow control unit chamber. Severe 'bunting' or skidding manoeuvrers caused the air to be displaced into the fuel pump. The problem was corrected by fitting a booster pump at the outlet of the fuel tanks.
Pika trials ceased in June 1954 with the last flight on June 25, 1954. Together the two Pikas made some 214 flights [C-1,44 & C-2, 170] for a total flight time of a little less than 100 hours. C-2 is preserved at the RAAF Museum Point Cook. It is perhaps salutatory that the derivative of the Pika, the Jindivik, continue to fly today at Llanbedr, Wales and at Nowra in New South Wales. Another accomplishment of the "small target aircraft" project was the successful marriage of the Viper jet engine, a development that, no doubt, contributed significantly to the subsequent success of this powerplant.
SPECIFICATIONS
Dimensions Span 19'
Length 24'7"
Tailplane Span 6'6"
Areas Wing 76 sq.ft.
Tailplane 13 sq.ft.
Fin & Rudder (prior to mod.) 8.96 sq.ft.
Rudder 2 sq.ft.
Weights All-up 2900 lbs
Empty 2300 lbs
Aerofoil Section NACA 64A-010
Mean Chord 4'
Aspect ratio 4.75
Taper ratio 1.00
Dihedral 2.50°
© Denis W.O’Brien