Flight tests continued during 1961 and 1962 with test pilot Flight Lieutenant Jock Thomson. Longitudinal stability tests were conducted to determine the dynamic stability characteristics at low speed. The decay of an oscillation generated by a single rapid fore and aft stick movement was recorded. The need for great precision in measuring the overall drag of the Avro 707 lead to the development of a most successful thrust-calibration technique. A static testing rig was devised to measure the thrust. The aircraft was suspended from a crane by a three point suspension system. and a space frame from the aircraft was used to transmit the thrust from the aircraft to the ground. The aircraft was restrained by attaching the frame to the attachment for the anti-spin parachute. The engine thrust produced was transmitted on to a single load measuring cell of a standard aircraft weighing kit. This enabled the relationship between the installed thrust and the jet pipe temperature to be established. These measurements were intended as a baseline for comparison after the aircraft was modified. Re-allocation of staff from the Avro project to the more pressing Project 108 hastened the termination of Phase II of the test programme.

At the University of Melbourne, wind tunnel tests on the 1/4 scale half wing were in progress using suction through discrete perforations in the wing as a means of boundary layer control. The possibility of using a Kruger leading edge flap was also considered. These experiments revealed a significant improvement in the boundary layer with suction. Separation was delayed to 14 degrees, corresponding to an incidence change of 6 degrees on the full scale aircraft. These promising findings were insufficient justification to continue with the Avro project. Whilst the wind tunnel results certainly suggested that the landing characteristics of the aircraft could be greatly improved, the cost of modifying the wings of the aircraft was considered to outweigh the value of knowledge that might be gained. On a more practical level it was becoming increasingly difficult to obtain spares and there were some signs of fatigue damage to the aircraft. The decision by the AARC to abandon the Avro project was based upon the high cost of modifications and consideration that results derived from the thick 707A wing would not be applicable to the supersonic Mirage.

The last flight was in 1963. During its seven years of research flying for the ARL, Avro 707A, WD280 flew 203 hours 30 minutes with flights mostly of 20-30 minutes duration. It was ironic that an aircraft designed for high speed flight research should spend so much of its operational life involved in low speed research. Whilst virtually all the flying involved aerodynamic research, some demonstration flights were conducted. The aircraft participated in the flying displays that were held at Laverton for the Air Force Week celebrations in September 1958 and again in 1962. In May 1964, an Open Day was held at Avalon. Whilst the Avro was on static display, there was a new delta wing aircraft to steal the show. Avalon, the Department of Supply's airfield, was the location of the workshops responsible for the final assembly and flight testing of the Mirage IIIO, the RAAF's new jet fighter. The Open Day had been arranged to give the employees and their families the opportunity to inspect the new aircraft. A flying display by Mirage A3-1 was the highlight of the day and would herald a new era of delta aircraft in Australian skies.

By 1964 the Aeronautical Research Laboratories were looking for a new research aircraft. Serious consideration was given to the Shorts S.B.5. An important consideration was the simplicity of maintenance -

"It should be easy to maintain in Australia (easier than the Avro 707A for example which had retracting U/C, powered flying controls, artificial feel, hydraulics and pressurisation) and could be flown from Avalon safely."

Her flying duties complete, Avro 707A, with 486 hours 40 minutes "on the clock", was to remain in storage at Avalon until 1967.

The final chapter of the WD280 story was written when, in 1967, the aircraft was sold at auction by the Department of Supply on behalf of the British Air Ministry to Mr. Geoffrey Mallett for $1000. Arrangements were made to transport the Avro from Avalon to Mr. Mallett's home in Williamtown in early June 1967. The aircraft was loaded on to a semi-trailer on Friday, 12 June 1967 in preparation for the journey to Williamtown. To take advantage of a quieter period on the roads the move, with police escort, took place on the Sunday in perfect weather conditions. Delivery was accomplished with only a minor skirmish with a light pole. The port wing tip scraped against the pole when negotiating a median strip at north Williamtown. Excitement was running high amongst the neighbourhood children when a 70 foot crane arrived to unload the aircraft. The electricity authority had removed power lines to enable the crane to lift the 42 foot 9 inch Avro into the 44 foot long garden. Residing a few hundred yards from a beach on the shores of Port Phillip Bay has necessitated the utmost attention to the airframe to prevent corrosion. Mr. Mallett, a maintenance engineer, artist and musician has spent many thousands of hours painstakingly maintaining the Avro. It has been repainted several times. Recently, the fear of corrosion in an inaccessible part of the airframe required the removal of the auto-observer panel, however the concern proved unfounded.

So what was the contribution of the Avro to aeronautical research in Australia. Was it simply an extension of the flight testing of the aircraft? There is little doubt that as a pure research aircraft, the Avro 707A presented the scientists at ARL a valuable tool to extend aeronautical knowledge. "The hot topic at the time was the so-called, validation of wind tunnel data, trying to establish confidence that the wind tunnel data could be translated into full scale flight." As a result of the Avro project, the staff at ARL were recognised as having an expertise and capability in low speed aerodynamics. With their work on boundary layer control with turbulators, the Australians were very much in the vanguard of such research. Another, not insignificant, benefit of the Avro 707A work was the development of skills in planning, conducting and evaluating flight experiments. Research techniques, recording methods and computational analysis were developed and refined. The RAAF also welcomed the opportunity to be involved in the research project. The 'research' unit at Laverton, ARDU, was more involved with 'problem solving' as well as establishing operational limits and performance data, so the chance to expose their staff and pilots to pure aeronautical research was opportune. And what of the aircraft? WD280 remains in suburban Melbourne in outstanding condition a long way from its northern origins.

©Denis W.O'Brien