Jan Zurakowski:
Test Flying the Arrow. pg2

continued from page 1,

     Nearly twenty years ago, on the 25th of March 1958, the first Canadian supersonic fighter aircraft, the Avro Arrow, became airborne. The development and proving flights were progressing well, aircraft performance was up to specification, the initial five Mk. I aircraft were flight tested and the production line was set up.

     In less than one year, on 20th February 1959, by a decision of the Canadian government, all work on the aircraft was stopped suddenly and nearly everything related to this project was destroyed. This was a very sad end to what were probably the most exciting times of the Canadian aircraft industry: 1949 to 1959.

    I would like to present to you my impressions as a test pilot during those times and to add a few remarks about the situation today.

    Let me begin a few years before that period.

    Close to the end of the war, when victory was only a question of time and my superiors were trying to push me from operational flying into a staff job in London, I discovered that there was a place for one Polish pilot in the Empire Test Pilots' School. I put in my application, was accepted, and started to learn to be a test pilot

    After a year's course I was posted to the Aircraft and Armament Experimental Establishment at Boscombe Down, where I had the opportunity to test most of the Royal Air Force fighters, Fleet Air Arm aircraft and American Navy fighters.

    Two years later I left the Royal Air Force and accepted the position of experimental test pilot with Gloster Aircraft Company in England, dealing mainly with the development of the Meteor, a twin-jet interceptor aircraft, which was first flown in 1943.

    Five years of experimental testing taught me not to accept much at face value, to doubt nearly everything until proven, and to respect evidence and the importance of collecting flight test information by special instrumentation.

    Up to the end of 1955, about 3 500 Meteor aircraft were produced in more than ten variants and about 600 aircraft were exported to seven countries.

     In the meantime design of a new interceptor was progressing, and in November 1951 a prototype of the Javelin made its first flight. This aircraft was of 'modern' design, having a delta wing, but a conventional tail.

     On the evidence of wind tunnel tests it became obvious to me, more than two years before the first flight, that longitudinal instability was present in the Javelin at lower speeds. I was faced with a difficult problem. Urgent modifications were required, but control of the flight test programme was in the hands of the design office which did not want to face the facts. The stability flight test programme therefore called for stability measurement only within the stable range of speeds.

     During one of the flights I decided to check the low speed range. It did not look safe, so I climbed to 30,000 feet and slowly started reducing speed. I reached a condition when, with the tailplane setting fully up and elevator fully down (both controls in diving position), the aircraft was still climbing, and finally stalled and went into a spin. Spin recovery was satisfactory.

    Of course, after this experience I made it clear to the design office that stability of the aircraft was unsatisfactory as proven by the flight recorder.

     Unfortunately, the design office had the authority to issue the final flight report. Not all the evidence from the recorder was included and the only comments were, if I remember correctly, "Pilot investigated the stalling characteristics of the aircraft and height lost in recovery was recorded." There was no mention of extreme instability or spin.

    This report convinced me that I was wasting my time at Gloster, and the conclusion accelerated my move to Canada.

    Why Canada? Canada was a young country with high development potential. A. V. Roe Company had the Jetliner, the first jet transport on the American continent, and the CF-100, the first Canadian twin-jet interceptor. I had good flight testing and development experience on fighters, so I could be useful; besides, I hoped for a good future for my two sons.

On 21 April 1952 I landed in Canada, and the next day I started work as experimental pilot for A. V. Roe at Malton.

     The Toronto Telegram reported: "The 37-year-old Zurakowski is small and balding, and looks like anything but a test pilot."

     I started work on the CF-100. This was the first interceptor aircraft designed and built in Canada to the requirements of the Royal Canadian Air Force for the defence of Canada. These requirements were: two engines for safety of flying in the far north, crew of two, heavy armament, high speed and high ceiling, and ability to intercept at night and under all weather conditions. I think the CF-100 was the best design compromise at the time.

     The Flight Test Section was under Mario Pesando, a very experienced engineer, with a clear, practical approach to any problem, and believe me, we had enough problems. This small group of flight test observers and test project engineers was most enthusiastic, and it was a pleasure to work with them.

     Peter Cope, the experimental test pilot who arrived from England some time before me, was an excellent and reliable pilot, and helped me a lot by introducing me into the new organization. In the experimental hangar, undergoing all sorts of trials, were the prototype CF-100 Mk. I with Rolls-Royce Avon engines, first flown on 17 January 1950. and a few CF-100 Mk. II and III. A Mk. IV prototype was expected to be ready for first flight in a few months.

     Meanwhile the Jetliner prototype, with chief test pilot Don Rogers, was somewhere in California with Howard Hughes, powerful personality in Trans World Airlines, who was gaining experience on jet aircraft and investigating the introduction of jet passenger transport. Flight development work was very similar to that which I carried out at Gloster on the Meteors and Javelin.

     Let me give you three examples of the problems experienced in our flight test programme.

     First example: Diving speed. The CF-100 had a maximum design speed of Mach 0.85 (85% of speed of sound), but its level flight speed at high altitude was slightly faster. I asked the experts what would happen if a pilot accidentally exceeded this speed. The answer was that wind tunnel tests indicated the aircraft could become uncontrollable, and that besides, Pilot's Notes clearly showed Mach 0.85 to be the limiting speed.

     For me, this answer was not satisfactory. The CF-100 was an all-weather and night interceptor, and if the pilot was not careful he could exceed aircraft limitations in no time. I considered it my duty to investigate behaviour of the aircraft at higher speeds and, if dangers were discovered, to recommend some action. With an instrumented aircraft I ran a series of dives at high altitude, checking recorded results between flights. Finally I reached Mach 1.08 indicated in a dive at full power. A sonic boom on the ground confirmed passing the speed of sound. Behaviour of the aircraft was satisfactory.

     The flight test department, company management and the Air Force were delighted, but to the design office, I discovered, I was enemy number one.

     Previously, without the knowledge of either the flight test section or the pilots, the design office had prepared a proposal for the RCAF, recommending extensive redesign of the CF-100 by decreasing the wing thickness, sweeping it slightly back, and increasing the area - all this mainly to obtain a maximum diving speed of Mach 0.95.

     The RCAF investigated the proposal, but when the Mk. IV reached the speed of sound and expensive improvements were expected to show lower performance, the proposal was rejected with some sharp remarks.