An alarming departure from Masirah but there was no stopping now - Tony Cunnane's Autobiography

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An alarming departure from Masirah but there was no stopping now



I took this pic from the 'top' of the only hill in the area of RAF Masirah. Some years after this visit a new long runway was constructed at roughly right angles to the existing runway which is just visible on this pic running left to right just below the skyline.

I noticed that there was quite a crowd of residents out on the airfield and at various high vantage points behind the Messes to watch. At two minutes to eight, the co-pilot and I having independently re-checked the take-off performance figures, I decided that it was safe to go. Any further delay would have meant that the outside temperature was rising faster than we could burn off fuel to compensate and in any case, any further fuel consumption would have reduced the safety margin required for Gan island holding.

I decided to let my co-pilot do the take-off so that I was able to concentrate my attention on the performance of all four engines - but especially the one in number 3 position. All the engine instruments indicated normal parameters at 100 per cent rpm as we accelerated along the runway. We passed our calculated Stop Speed (the maximum speed at which we could abort the take-off and stop in the remaining runway distance) with everything looking normal so, in accordance with SOP, I gave the order to the co-pilot "Continue". As soon as I said that, the 5,000ft marker board (that was 5,000 feet from the start of the runway) flashed past and I knew that there was no way we could stop in the remaining 2,500 feet. At that same instant I knew that there was not enough runway remainig to reach take-off speed either. We were experiencing the dreaded gap in performance where take-off speed exceeds stop speed. I pushed the four throttles forward a further inch against the stops to give us an extra smidgen of thrust. We were not permitted to use that setting of 101.5% except in an emergency because the extra pressures and temperatures generated within the engine dramatically reduced the engine's life. This was an emergency!

The white lines marking the end of the runway were rapidly approaching and beyond that was the desert. I also knew that just off the end of the runway at the desert's edge was an outcrop of rocks directly in line with our path. I hauled back on the control column when we were still 15 knots below unstick speed and hoped for the best.

"What are you doing?" cried Alan, the co-pilot, in alarm. He had been concentrating, quite properly, on operating the aircraft.

"I have control," I said abruptly. That was a recognised command and he immediately relinquished control of the aircraft to me.

XH667 left the ground just before the wheels crossed the white lines marking both the end of the concrete and the start of the desert. I was told afterwards that the Duty Air Traffic Control officer had already activated the crash alarm several seconds earlier thinking a disaster was imminent. An eye witness, who had been standing at that end of the runway waiting to cross on foot, told me later that our wheels missed the outcrop of rocks by inches and the efflux from our jet engines created an enormous cloud of sand which completely enveloped him.

"What was all that about?" asked one of the crew in the rear compartment. They faced rearwards of course and could not see out - fortunately.

"Nothing to worry about," I said, as calmly as I could. "Tell you about it later." Once we had reached normal climbing speed, I was able to reduce power back to 100% on all four engines - and start breathing again. (I have often wondered what my heart rate was.) There were no abnormal readings on any of the engine instruments.

What a relief when I saw that Gan was in the clear at the southern limit of the lagoon. I took this shot at about 2,000ft on short finals for a straight in approach and landing on Runway 09. Compare the sky in this image with the one below, taken half an hour after landing.

The entire flight to Gan was over water: the Arabian Sea. The planned time for the flight was 3 hours 40 minutes and, as near as makes no difference, the airfield was right on the Equator. If you want the exact Latitude & Longitude, the centre of Gan runway was 00°41' 29" South, 73° 09' 22" East and at its highest point the island is, or was in 1972 (before Global Warming started to affect things), just two metres above sea level.)  We landed at Gan just before an enormous thunderstorm broke over the island (image below). Only then did I tell my rear crew what had happened on take-off.



So, what had happened on take-off from Masirah? On the ground at Gan the co-pilot and I got the performance tables out once again and we independently worked out that the aircraft had performed as though the outside air temperature had been 35°C not the 28°C that the Met officer had confirmed was the actual temperature. I submitted another serious incident report by signal to our Headquarters but it was literally several months before we got the answer to that one - and a rather alarming answer it was.

Jet engines, when newly-installed into a Victor, were ground tested by engineers to ensure that they were producing the correct rated thrust. However, there was an acceptable 'small' tolerance for each engine of plus or minus 3 per cent. It had never been anticipated that all four engines in one aircraft could be at the lower limit of tolerance and yet, when all the calculations were made, we were told that would have accounted almost exactly for what happened when we took off from Masirah. That apparently satisfied the engineers but, after the report became public knowledge amongst Victor aircrew, I understand most captains operating in hot and marginal conditions, certainly including me, added an extra safety factor 'for the wife and kids' until the performance tables were amended months later.

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