P.1 Supersonic Testing at Warton
By Roland 'Bee' Beamont (Chief Test Pilot, Lightning Development Programme)
The following article is the second of two by Wing Commander Roland 'Bee' Beamont, the first President of the Lightning Association and Chief Test Pilot of the Lightning Development Programme, 1954-68 (the first appeared as the February SOTM). They formed part of his last book 'Test To The Limit', and we were proud to have been given permission to let them see the first light of day in the Lightning Review. It goes without saying that Bee's book is required reading for all serious Lightning enthusiasts. The Story of the Month for February is ‘P.1 Supersonic Testing at Warton.’
The P.1 prototype WG760 was well into its intensive experimental programme at Warton in March 1955 following its exceptionally successful initial Company trials at Boscombe Down from August to October 1954, during which handling and performance out to Mach 1.2 had been explored for the first time in a British aircraft in level flight.
Back at Warton the programme had settled into the routine of system proving, flight envelope expansion following flutter clearance, landing and take-off performance measurements and the vital SFC/cruise ampg/drag measurements; and after over 100 flights, most of them supersonic, this very advanced aeroplane was becoming acceptably routine in operation and a very pleasant experience.
The test pilot is not, of course, keyed up in anticipation of drama in every moment of every flight as is customarily implied by much of the media, but he must remain aware at all times of the need to watch for inconsistencies in systems performance or any sudden changes in flight conditions; that is, the normal professional approach essential in all flying operations, with perhaps slightly more emphasis due to the untried and unproven nature of the aeroplane on test.
So, it was with no more than the usual enthusiastic anticipation that I climbed into WG760 one morning in early March 1955. Flutter clearance to 650 KIAS was scheduled with excitation by wing-tip mounted explosive exciters which, known as 'Bonking', was a very different activity to the modern usage of the word and a lot less fun! The weather was clear over the Irish Sea supersonic run, and another of our most enjoyable P.1 flights was on its way.
The test point was achieved without problems and Vibrograph recorded, and then with its customary low fuel state remaining the P.1 was headed back towards Blackpool and thence into the Warton circuit. All systems serviceable and there was the chance of another sortie, possibly two more, before the end of the day. With a prevailing anticyclone to the North there was a light Easterly wind at Warton where Runway 08 was in use. A leisurely 451 climbing roll over the airfield into the downwind leg and then I selected u/c down on the base leg of a tight left-hand curved circuit to join Finals over the Ribble estuary at about 2000 yds from the 08 threshold, then - Stbd Green and Port Red lights!
This was our first P.1 u/c asymmetry and, with no more than two circuits fuel left, this changed the priorities into 'Precautionary', but not for long! Overshooting low past the Tower I called for their assessment which was 'Port leg half down'. Assuming air in the hydraulic system it was possible that reduced air loads or yawing air loads might help the hydraulics to complete the cycle, so I slowed to 190 KIAS - no change; then yawed sharply to Port with a boot full of right rudder, as much as could be contained with aileron to hold the resultant rolling moment due to yaw - no change!
An Up cycle was then successful, but the following Down cycle produced Port Red, Stbd Green as before. With fuel now down to 400 lbs per side, sufficient for only one more tight circuit and approach, here was the moment of decision - use the fuel to climb for ejection over the Ribble estuary or try a landing?
It had always been ruled at Warton that, with its 601 sweep shoulder wing, a landing with asymmetric u/c could prove fatal in the likely event of the aircraft turning over, and in any case the digging in port wing would cause a violent swing to the left, in this case landing on 08 straight towards the cluttered tarmac and buildings.
This prototype was being so successful and was so vital to Warton's programme and to the RAF that I did not give it a second thought but declared an emergency landing and lined up again on 08 with the last of the fuel, the port u/c still Red and the other Green. At short finals ATC called 'Port u/c still hung up'. I doubt if I acknowledged this, but at about 200 ft with 800 yds to go and at about 168 KIAS I gave it as much Port yaw (right rudder) as I could hold laterally with aileron - there was a clunk, the Port Green came ON, I throttled back, flared and landed.
Afterwards and ever since I have never been able to understand why I dismissed the 'safe' option of ejection and just went ahead to try the landing - but it turned out to be a fortunate though not necessarily 'the right' decision!