Crossing the equator at last! - Tony Cunnane's Life and Times

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I decided to let the co-pilot do the take-off so that I was able to concentrate my attention on the performance of the engines - and especially the performance of the new engine fitted in number 3 position.

We roared off along the runway. All the engine instruments indicated normal conditions at 100 per cent rpm. However, when we arrived at Decision Point, that split second in time when aircraft captains have to decide whether to continue with the take-off or abort, it was obvious to me that something was seriously wrong. As we passed the 5,000 feet marker board (that's 5,000ft from the start!) we had not reached decision speed but there was no way we could have stopped in the remaining 2,500 feet. On the other hand it was obvious to me there was not enough runway left to reach take-off speed either. We were experiencing the dreaded gap in performance where take-off speed exceeds stop speed.

After making my split-second decision, 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 this 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 a real emergency!

The white lines marking the end of the runway were rapidly approaching and beyond that was the desert. I 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 safe unstick speed and hoped for the best.

"What are you doing," cried Al, the co-pilot, in alarm. He had been concentrating, quite properly, on operating the aircraft and so he’d not noticed that we’d used up far more runway than we should have done.

"I have control," I said abruptly. That was the recognised command. 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 Air Traffic Control officer had 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 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.

I’ve often wondered what my heart rate reached in those critical seconds.

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

"Nothing to worry about," I said, as calmly as I could. "Tell you about it later."

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 worked out that the aircraft had performed as though the outside air temperature had been 35 degrees not the 29 degrees that the Met officer had confirmed was the actual temperature. I submitted yet another serious incident report to our Headquarters but it was literally several months before we got the answer - 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 giving the correct rated thrust. However, apparently there was a 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 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 K1 aircrew I understand most captains, including me, operating in hot and marginal conditions added an extra safety factor "for the wife and kids" until the performance tables were amended - many months later!

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