Supersonic Over Central Paris

...even pulling the control column fully backwards would not get the Victor out of the dive and the aircraft would continue to accelerate up to and past Mach 1.0

This incident took place in 1971 on a flight from RAF Luqa (Malta) to Marham. We were flying in the international airway at 41,000 feet escorting four F3 Lightnings from Malta back to their home base at Wattisham in Suffolk and refuelling them several times en route. I was a new Captain serving on 214 Squadron at the time although the tanker I was flying, XH648, and some of my crew members belonged to 55 Squadron. We frequently flew non-constituted crews. XH648 was a rare Victor B1A K2P; there was just one on each of the three operational squadrons (55 had XH648, 57 had XH647 and 214 had XH667). This very aircraft was later transferred to 57 Squadron and ended its days at the Imperial War Museum Duxford where I put it on 1 June1976. The Victor B1A K2Ps were, as the first part of the name implies, a variant of the Mk 1A bombers from the 1960s. The K2P suffix denoted that they were 2-point tankers. When it had been decided in 1966 that some of the Victor Mk 1 bombers should be hastily re-configured as tankers to replace the suddenly grounded Valiants, six aircraft were given an interim fit as 2-point tankers. The 3-point tankers, known simply as Victor K1, with the large Hose Drum Unit (HDU) on the centreline in addition to the two under-wing refuelling points, came later because extensive modifications to the bombers’ existing airframe and fuel systems were required and all that took time.

In the 1970s, the K2Ps were rarely used on international flights for a variety of reasons. Tanker to tanker refuelling, essential for long flights, was obviously not possible without a centreline hose and refuelling fighters through the under-wing hoses was a much slower process than through the HDU, although that was not too much of a drawback with Lightnings. The K2P’s main problem was the configuration of the Victor’s internal fuel system. Because the aircraft had not been designed as a tanker and because a rapid retrofit had been needed, only a minimum number of changes were made to the fuel system and this meant that great care had to be taken when carrying out AAR. It was, for example, most undesirable to feed the refuelling hoses from the same fuel pumps as those supplying the Victor’s engines because of the danger of starving the engines with the resultant inevitable engine flame out. Towards the end of a long sortie, you were likely to end up with the remaining fuel scattered amongst the many internal tanks. To make most effective use of that fuel, a scavenge drill was employed whereby all the remaining fuel was gathered into the two bomb bay tanks. This was done only after the final external transfer of fuel had been completed. The scavenge drill had to be done very carefully to make sure that a supply to the engines was not interrupted. It was essential that the pilot carrying out the drill was not interrupted until he had completed the scavenge.

It was very easy to lose familiarity with the quirks of the K2Ps even though all crews had to fly them periodically in the simulator to retain currency. Standard Operating Procedures (SOP) required the 2-point scavenge drill to be carried out with the aid of the check list. Because the scavenge could take quite a long time, as much as 10 to 15 minutes depending on how much fuel was remaining in the various tanks, the usual practice was for the non-flying pilot to carry out the drill unaided and uninterrupted, with the check list on his knees, rather than have the checks read out to him by another crew member. I knew that experienced pilots could, and probably did, carry out the drill quite safely without the need for referring to the check list even though that was contrary to the SOPs. On this particular flight in 1971, as the relatively new Captain in the left hand seat, I handed control of the aircraft to my experienced co-pilot (he was not my normal co-pilot and I will withhold his name to save his embarrassment) shortly after the final transfer of fuel to the Lightnings. It was the first time I had flown a 2-point tanker on such a sortie. I wanted to get experience of carrying out the scavenge drill for myself and I had briefed the crew accordingly before take-off. We had known, even before we took off from Luqa, that we would be very short of fuel when we arrived at the top of descent for Marham but that was nothing unusual. More often than not, tankers were short of fuel when they landed at the end of a busy refuelling sortie.

I started the scavenge drill, reading each item on the check list carefully and then fingering the appropriate fuel pump and transfer cock switches at least twice before actually moving them. After some time, while consulting the check list and waiting for a couple of wing tanks to empty completely, I saw from the corner of my eye the co-pilot reaching over to the central fuel panel and making a couple of selections without my permission. I told him curtly to keep his hands off and concentrate on what he was supposed to be doing – monitoring the auto-pilot. Thinking about it afterwards, I assumed he, impetuous youth and out to impress the new captain, was getting frustrated with my slow, methodical progress through the check list, but there was no need for any rush.

Almost immediately, my eyes were attracted to the RCDI (the Rate of Climb and Descent Indicator – some pilots call it the VSI, the Vertical Speed Indicator) in the bottom left hand corner of the 1st pilot’s instrument panel. I was astonished to see that it was indicating full-scale deflection down – representing something in excess of 4,000 feet per minute rate of descent. Right next to that instrument was the Mach meter and I was horrified to see the needle creeping inexorably towards Mach 1.0.

I need to make two short digressions here. The Victor Mark 1/1A was a very slippery aircraft, aerodynamically very clean. The tanker versions could cruise quite happily, safely and relatively economically, at Mach 0.93. There were many stories of bomber pilots, allegedly, having exceeded Mach 1.0 in a slight dive just for the hell of it and because the aircraft would do it. There was just one major problem. Above Mach 0.96 the aircraft ran out of pitch control because the large supersonic shock wave forming over the wings completely blanked the elevators making them ineffective. This meant that even pulling the control column fully backwards would not get the aircraft out of the ever-steepening dive and the aircraft would continue to accelerate up to and past Mach 1.0. For this reason, speeds above Mach 0.96 were forbidden. The only way of recovering from that situation was to slow down by closing the throttles and extending the air brakes. As the speed reduced through Mach 0.96 elevator control was regained.

The second digression concerns the Victor’s auto-pilot. It is always important to keep any aircraft in trim when flying with the auto-pilot engaged but it was especially important with the Victors. The auto-pilot height lock, which was supposed to keep the aircraft flying at a constant height, was less than totally reliable and would frequently trip out for no obvious reason. If the aircraft had a nose up or nose down trim when the height lock tripped, the aircraft would naturally go into a climb or a dive. Height lock trips were insidious; they sometimes occurred when the aircraft was only very slightly out of trim and then the event could easily pass unnoticed if the pilot was not completely attending to his duties.

That is what must have happened on this occasion. Moving the fuel around during the scavenge drill had changed the aircraft C of G. The co-pilot instead of doing his proper job of monitoring the auto pilot and maintaining a good external lookout, started fiddling with the fuel cocks against my instructions and had failed to notice two things: that the aircraft had gone slightly out of trim and the height lock had disengaged itself. The aircraft had entered a descent, gentle and barely perceptible at first, which caused the speed to increase rapidly which in turn caused the nose to drop further. Calling out on the intercom, “I have control”, I grabbed hold of the control column, thereby operating the auto pilot instinctive cut out switch under my left thumb, closed the four throttles and extended the airbrakes. I saw the speed hovering on Mach 1.0 and found out for myself that hauling the control column all the way back into my chest had no effect. It was, I can tell you, a completely weird sensation, pulling the control column back as far as it would go without it having any effect on the aircraft's attitude. As the engines wound down to flight idle and the powerful air brakes took effect, we started rapidly decelerating. The deceleration caused the nose to start pitching up and I quickly had to retract the air brakes, open the throttles and push the control column forward again. Having bottomed out at about 37,000 feet, I regained straight and level flight at 41,000 feet again, give or take a few hundred feet. Worried about the four Lightnings that had been flying in close formation with me, I called on the formation radio frequency, “Sorry about that!”. “Sorry about what?” came the nonchalant reply from the lead Lightning pilot. I looked out of my cockpit side window and saw two of the Lightnings close by in immaculate echelon formation. We were directly over the centre of Paris; the Champs Elysées and the Arc de Triomphe were clearly visible. What I said to my co-pilot is best left unreported but he was very apologetic and told me that he accepted full responsibility for what had happened. That, of course, was irrelevant: as Captain of the aircraft I was solely responsible.

After landing I reported the incident to my Flight Commander but, to my surprise and relief, I heard nothing more about it. The French authorities apparently never made any complaint about supersonic booms over their capital, nor did the airways controller report that five aircraft had made an unauthorised deviation of several thousand feet from their assigned flight level. Fortunately, in 1971 radar height finders were not very accurate and the airways were far less crowded than they are these days.

Some months later, that experienced co-pilot, who had certainly impressed me but not in the way he had intended, left the RAF and started a new career, flying as a second officer for a well-known British independent airline.

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