Sqn Ldr Pete Boothroyd

Lightning marks flown: F1a, F2a, F3, F3a,F6, T4, T5

Lightning flying hours: 2,393 hours

Personal Lightning Story:

"The original operational requirement for the Lightning, OR268 issued in 1947, was purely for a point defence interceptor for the UK Bomber bases in Britain. The concept was for a supersonic interceptor with a rapid response time to scramble and intercept incoming bombers (from Russia) as far away as possible over the North Sea, destroy as many as possible (with missiles and guns) and then rapidly recover back to base for a quick operational turnround and then repeat this until:

a) There were no bombers left

b) There were no fighters left

c) There was no Britain left.

The assumption that the bombers would be at high altitudes to avoid any anti-aircraft fire, up at 36,000 to 45,000ft. The Lightning was thus designed to operate at these altitudes and was deliberately designed with limited fuel to facilitate acceleration and a fast recovery.

Most of the operational flight testing was therefore done at these heights.

One of the areas of flight testing was spinning the aircraft. Trials at altitude showed that the spin characteristics of the aircraft were reasonably predictable and that the aircraft would recover if the correct spin recovery action was carried out. However, it would take about 10 seconds for the recovery action to take effect and then after the spin stopped the aircraft would be in a very low nose down attitude and the speed would be very low. Therefore it took a lot of height to recover from the dive.

If you reluctantly find yourself in a spin in a Lightning at these high altitudes, you realize that you are in a spin, and you take the correct recovery action, then 10 seconds is a very very long time. What would happen is that pilots would wait an eternity, but which was usually only two or three seconds, believe that the aircraft was not recovering and then try something else. A number of aircraft were lost in these circumstances although no pilot died.

Intentional spinning was thus banned and this was reflected in the pilots operating manuals.

In the late 1960s and early 1970s it was realized that surface to air missiles would take out high level bombers and therefore the Lightning had to intercept and fight at all levels including low level. Further, after the 1956 Defence White Paper which cancelled numerous fighter projects (and nearly the Lightning) the original point defence intercept fighter had now become an all round fighter, and actually it was very good at it. But further trials of spinning at lower altitudes were not, to my knowledge, carried out.

My first introduction to losing control and departing at the start of an incipient spin occurred when I was on my third Lightning tour, serving with 11 Squadron at RAF Binbrook in the period 73 to 75.

I was on a general handling sortie (we had to do a couple a month). I was around 8000ft or maybe lower and I decided to practice a Lightning rotation. You will have seen Lightnings rotating just after take-off, in full reheat, pitching up in a rotation to about 80 degrees. And climbing away. Impressive stuff.

I reduced speed to about 180 kts then applied full reheat and at about 210kts pulled hard back.

To my horror the aircraft sliced sideways. I immediately threw the stick fully forward into the instrument panel it seemed.....and the yaw stopped, the aircraft flew out of the situation and I lost just a few hundred feet. I flew back to Binbrook somewhat chastened and didn't tell anyone about my incident. I realized I had probably rotated at too low a speed and at too high an altitude.

I started to think about seriously about why the aircraft had responded as it did.

My conclusion, after much deliberation, was this: At the top of the canopy there was a sharks fin shaped IFF aerial. I realised that at high angles of attack this would cause a large vortex probably amplified by the canopy which, at a certain angle of attack, would envelope the fin striking it on the side and causing the massive yaw. By applying full nose down control, the aircraft’s tailplane, which was still in free air, pitched the nose down and therefore the vortex would be pushed back down the fin allowing much of it to become effective again in free air. Thus the yaw would stop.

If the action was not implemented rapidly, the yaw would stall the wing on the side it was going and increase the lift on the other wing causing a rapid roll and into an incipient spin.

I learnt to rotate successfully but never forgot the lesson and the theory behind it.

Then, just before I was posted from 11 Squadron to 92 Sqn at RAF Gutersloh there was a tragic accident. The Cyprus war of 1974 had ended. No 56 Squadron, based at RAF Akrotiri in Cyprus was always going to be disbanded early in 1975. 11 Squadron had been tasked with sending a detachment to Cyprus to replace 56 Sqn and cover the Vulcan Bomber squadron based there until it too disbanded in June 1975. The detachment duly flew to Cyprus. As I was due to be posted in April 75 to RAF Gutersloh in Germany I wasn’t included in the detachment.

Early on in the Cyprus detachment a pair of 11 Sqn Lightings departed from RAF Akrotiri for a 1v1 combat training sortie in Limassol bay. During the combat one of the pair lost control in a spin at 10000 ft. Although the pilot regained control there was not enough height to recover and he hit the sea and was killed.

I was sent out to replace him as an authorizing officer and my Germany posting delayed for a few months.

This accident enhanced my interest in the Lightning spinning characteristics.

Some 5 years later I was a Flying Instructor on the Lightning Training Flight at RAF Binbrook. This was after a QFI course and a tour at RAF Cranwell. On the LTF I became the CFS (Central Flying School) agent responsible for the pure flying standards on the wing as an examiner of squadron pilots. I would fly (along with another LTF QFI).with all the squadron pilots to assess their flying standard. I was also responsible for the pure flying syllabus on the Lightning Training Flight and indeed taught new pilots to the aircraft when they arrived on the LTF.

I was still very interested in the spin characteristics of the Lightning and conducted many experiments. All these experiments were conducted solo.

Flying the aircraft at 20000 ft straight and level, I would reduce power and slowly decelerate maintaining altitude so the angle of attack (AoA) would increase. I discovered that along with normal low speed buffet (buffet at most speeds was a characteristic of the Lightning) a lower, deeper frequency buffet could be discerned and this preceded the rather violent yaw. If the stick was pushed forward of the neutral position when the buffet occurred, the aircraft would recover nose down with little height loss. This low frequency buffet was the first cue to an impending spin.

If the deep buffet was ignored the aircraft would slice rapidly sideways, usually to the left (the direction of the vortex rotation?) as the speed reduced. As previously described an immediate action of slamming the control column fully forward would recover the aircraft. This worked 9 times out of ten but in the 1 out of 10 instances the aircraft would roll and enter an incipient spin in the direction of the yaw. Standard stall recovery would safely recover the aircraft after one turn: full opposite rudder (to the yaw direction) stick fully forward (it already was) ailerons neutral and full power. The aircraft would quickly recover in the thicker air at 20000 ft (as opposed to the trials at 40000ft). The nose would be low and the speed slow but recovery would only take 5 or 6000ft.

I discovered during my check sorties with squadron pilots, that some 85% of pilots had experienced some sort of departure associated with spinning. I decided to write a teaching sequence which I would incorporate in the slow speed handling sortie taught on the Lightning Training Flight, and also incorporate this sequence when I was flying check flights and LTF training sorties. It was very illegal but I knew perfectly safe and may save lives.

I would take the aircraft to the point at which the low frequency deep buffet became noticeable an apply power to hold it there. I let the other pilot experience this buffet and we discussed it. I would return to a reasonable speed and let the other pilot fly to the same point, hold it there and then return to the higher speed.

I would then take control and repeat the exercise asking the other guy to point out the low frequency buffet. I would continue reducing speed until the aircraft sliced, and then show the instant recovery by slamming the stick forward. I would be pattering this through the demonstration. I then let him practice that. Finally I would let the aircraft enter that first turn and the recovery. I would let him do that as well.

My examinee, or student pilot (I did this with some LTF students as well) would now have a far better understanding of the spin characteristics and would know what to watch out for and how to prevent a fully developed spin.

I reached the stage where I was about to write a paper on my experiments and conclusions. and forward it to RAF Boscombe Down who did in service testing of aircraft. My idea was to see if I could have this all introduced formally. I was confident that this may well save lives, or at least aircraft.

And then another tragedy. One day in March 1986 a young pilot flying a 1 v 1 combat sortie found himself in a spin and he could not recover.

It so happened that I had not flown a check sortie with this young man and therefore he had not experienced my spinning sequence.

The young pilot ejected from the aircraft but the Lightning was in a flat spin and the air above the aircraft was stagnant. This prevented his parachute from opening and very sadly he was killed.

If that young man had flown that sortie with me he would have recovered that aircraft safely.

At the subsequent board of Inquiry I was called as a specialist matter expert (as the CFS agent). The President was an old friend of mine and by now a group captain. I told him, off the record, about my incipient spin trials and my sequence. I also told him that I had ascertained that some 85% of squadron pilots, according to my research, had departed from flight in some sort of a spin. I told him that if I had flown my sequence with the young victim he would have recovered.

The president took my statement off record but we both decided that it was not the right time to publicly broadcast my trial nor send a paper to Boscombe Down. In any event I was due to be posted in the next few months, and the Lighting was going to be retired in the next couple of years. But my sequence never progressed.

But it has always deeply saddened me immensely that I never flew my sequence with that poor young pilot. He would not have died."