By Gp Capt Kapil Bhargava (Retd)
At the outset I need to make it clear that I was never involved in any development testing of the Gnat. What follows is mostly hearsay as remembered by me over the years. This has been slightly refined with help from Air Marshals CS Naik and MSD Wollen. AVM PDA Albuquerque has also helped in some of its aspects. I, therefore, request that anyone who has authentic knowledge of the work done on the Gnat in UK, may please correct the events as I describe them in following paragraphs and add whatever I have missed. Corrections and additions should be distributed either as comments or in a new post.
Folland Aircraft Ltd. Henry P. Folland , formerly Chief designer for Gloster Aircraft Company, bought the one year old British Marine Aircraft and renamed it Folland Aircraft Limited on December 24, 1937. Folland began aircraft assembly at Hamble making parts for Bristol Blenheim and Beaufort bombers. Folland later took on sub-contract work making parts for de Havilland Mosquitos and Vickers Wellingtons. Meanwhile, WEW (Teddy) Petter having designed the Canberra and P-1 (later developed as the Lightning) at English Electric wanted to explore making smaller, lighter and hence cheaper fighter aircraft. His innovative idea for such a project was not accepted by English Electric. By then Henry Folland had passed away and Teddy Petter joined Folland as its Managing Director in 1951.The Midge, Gnat MkI Fighter and Gnat Trainer followed soon enough.
Longitudinal Control of early Gnat. When the Gnat prototype made its maiden flight on 18 July 1955, almost certainly its longitudinal control, similar to the Midge, was a variable incidence tail plane with a separate elevator. After one year of development testing almost to the day, the Chief Test Pilot EA (Ted) Tennant had to eject at 600 feet from the prototype. Flying at a low altitude, when he wanted to pull the nose up, he discovered that he had no control over the elevator. Apparently it had fluttered and flown off. Thereafter, the control was converted to a slab tail with one pin on each side locking the elevator to the tail plane. This was fine for high altitude operations but tended to be over-sensitive at low altitude at high speed.
Indian participation in development at Chilbolton. As is very well known, Sqn Ldr Suranjan Das was deputed to Folland quite soon after the contract for the aircraft was signed. He demonstrated the Gnat at the 1957 Farnborough Air Show, thus becoming the first Indian pilot to take part in it. His demonstration was simply labelled as awe-inspiring, especially the eight point roll. Flt Lt A Sudhakaran joined him in January 1957 after completing his test pilots course at Farnborough. Three Cranfield graduates, Squadron Leaders CS Naik, PDA Albuquerque and Flt Lt SB (?) Puranik strengthened the Indian team in August 1957. In March 1958, after Sudhakaran had already returned to India to be posted to A&ATU, Flying Officer PK (Babi) Dey joined in as the second Indian test pilot. The three engineers took part in instrumenting aircraft and extraction of test results. However, since the tropical trials of the aircraft were to be done in India, this team of three engineers concentrated on acquiring the necessary knowledge and expertise in planning, instrumenting, conduct, recording and extracting results.
The over-sensitive longitudinal control.
After completing some initial tests at A&ATU, Sqn Ldr Bhupinder Singh and Flt Lt Sudhakaran decided to do a two aircraft formation sortie. To his horror, Sudha soon found that he just could not hold a steady position in formation. After struggling with this for a while, they gave up and complained to Folland that the aircraft couldn’t be flown in formation – it was just impossible. The story I heard was that when A&ATU complained about this to Folland, the first reaction was, “Oh, those Indians don’t know how to fly”. But due to insistence by IAF, a two aircraft formation sortie was planned off Boscombe Down. Its leader was RM (Mike) Oliver with PK (Babi) Dey in formation with him from the take-off itself. As the speed picked up, Babi,whom the Brits used to call Bobby, began to bob up and down. Mike asked him, “Bobby, settle down”. Babi was smart, he promptly said, “I have the lead. You settle down on me”. That was when the Brits discovered that they also did not know how to fly! I have always wondered if this story is true or simply grew with each telling by the time it reached me. Either out of politeness or modesty, Babi has never confirmed or denied this tale.
Folland agreed that the elevator control was over-sensitive. Various cams were tried. The ratio of stick deflection to the slab tail movement was altered. Eventually, from 4° stick deflection for each degree of tailplane movement, the stick deflection was increased to 10° for 1° of slab tail deflection. Despite this, formation in the Gnat at low altitude and high speed was never easy. Some one recently said, “There I was steady as a rock. The whole formation was bobbing up and down”. As experienced Gnat pilots surely know, formation in the aircraft at high speed was never easy. And at times, it was impossible. A few months ago, Air Mshl Mally Wollen mentioned to me that flying the Gnats in formation for the Republic Day flypast always led to most pilots bobbing up and down (when I suppose as the leader, he was rock steady).
The Nasty 1957 Defence White Paper. The 1957 British White Paper on Defence set forth the future of the British military. It had profound effects on all aspects of the defence industry but probably the most affected was the British aircraft industry. Lord Duncan Sandys (Pronounced Sands), the recently appointed Minister of Defence produced the notorious paper.
Earlier, combat in the air would have been between aircraft; high flying bombers, especially the Tu-2, carrying nuclear weapons and fast interceptor fighter aircraft trying to stop them. But the White Paper stipulated that the guided missile, particularly the surface-to-air missile, threatened all aircraft and could easily intercept the threatening bombers even before they crossed the English Channel. According to Sandys, the emergent space age also showed that missiles could easily deliver nuclear weapons anywhere in the world. As such, fighter aircraft had no place in British defence planning. Several aircraft projects were abandoned. The English Electric P.1 (which would become the Lightning) was spared only because it was too far advanced to bother cancelling. The most famous aircraft to lose out was the TSR-2.
The paper laid down that the aircraft industry had to re-organise. Several smaller companies were to become a few larger ones. It was made clear that new contracts would only be given to such merged firms. Under official pressure, in 1960, English Electric, Bristol Aeroplane Company and Vickers-Armstrong merged to form the British Aircraft Corporation, or BAC. Hunting Percival Aircraft soon joined the BAC group. In the same year, de Havilland, Blackburn Aircraft and Folland merged into Hawker Siddeley, which had already consisted of Armstrong Whitworth, Avro, Gloster and Hawker since 1935. Westland Aircraft took over all the helicopter manufacturers, including Saunders-Roe, Fairey Aviation and Bristol’s helicopter work. Saunders-Roe’s hovercraft work was spun off and merged with Vickers Supermarine as the British Hovercraft Corporation.
The Gnat also became a victim of this short-sighted cost cutting.
Engine companies were also “encouraged” to merge. In 1959 Armstrong Siddeley and Bristol’s engine division merged to become Bristol Siddeley, but shortly afterwards in 1966 were purchased by Rolls-Royce, leaving RR as the only major British aircraft engine manufacturer.
Continued Trouble with Longitudinal Control. The British Government, especially Duncan Sandys, permitted very little support for Folland to develop the Gnat. A figure of funding for 1,000 hours of flight tasting has often been quoted. Today we would think this to be quite adequate to complete almost all development testing. But we must remember that more than half a century ago, data collection methods did not yield adequate quantity of high quality useful results. Moreover, I had heard that at Chilbolton the trace recorders’ squiggles were read and data in figures was produced. Then all data sheets were sent to Hamble to do the analysis, undertake modifications, etc. and plan further flight. According to Air Marshal CS Naik, Digby Brade in Hamble insisted that no analysis could be done or reported without his concurrence. He also controlled plans for further test flights. This was not the optimum method of developing an aircraft.
Babi Dey’s hard landing.
Flying Officer Dey was once again the central character involved. He took up a Gnat for a high altitude flight test. Unknown to him, the generator and its warning light had failed. The aircraft battery drained out and the first indication to him was that the tail trim stopped working. The R/T soon followed, cutting him off from any possible advice from the ground. He landed really hard at Chilbolton due to inadequate tail plane deflection available to him. The hard landing resulted in a spinal injury and he was hospitalised for several weeks.
It was after this accident that Folland concluded that if he had split the tail he would have had adequate elevator power of the follow-up tail since the hydraulics were just fine. One wonders why this failure was not anticipated and a procedure laid down. It is an essential requirement to test the aircraft trimming and handling in the landing configuration down to just 10% above the stalling speed. This must include the possibility of failures such as that of the tail trimming system. Almost certainly, Duncan Sandys through his White Paper was to blame for clipping Folland’s wings.
Engine Flame-out on Approach. Gnat pilots and engineers are very familiar with engine flame-out, usually due to Pressure Ratio Limiter (PRL) settings. During development in UK, this was so common that later while in HAL, Groupie Das used to say that he had more gliding hours on the Gnat than with the engine running, He was very comfortable flying the Gnat with the engine wind-milling. One day Dasu was flying a high altitude test and lost track of the time. At the last minute he noticed that he did not have enough fuel even to let the engine idle during descent. He cut the HP Cock and came down in a really fast descent. He relit the engine on downwind and landed without any trouble. But in the bargain, due to the excessive rate of descent, he had punctured both his eardrums. Fortunately, he recovered fast enough.
The trouble with the engine occurred with Wing Commander EJ Dhatigara, who had been posted in the Indian High Commission in London to monitor and help induction of Hunter, Canberra and Gnat aircraft. On 18 March 1958 at Chilbolton, Winco Dhatigara flew the earliest numbered Indian Gnat aircraft IE1059. Coming in to land his engine failed. This was attributed to lack or malfunctioning of the Air Fuel Ratio Control Unit (AFRCU). Since he was undershooting, Winco Dhatigara belly landed the aircraft on grass, resulting in minimum damage to it. For some reason this aircraft was not sent to India as IAF’s first Gnat.
The First Gnats for India. The Gnat earmarked as IAF’s first aircraft suffered damage just before it was due to leave for India. Folland’s test pilot, Mike Oliver remembers the event well, for a very good reason: He says, “The Gnat which was flown to India in a Fairchild Packet in a great rush to take part in the 26th January fly past, definitely departed from Chilbolton in January 1958. An earlier production aircraft IE1060 was scheduled to go, but on the 31st December 1957 Ted Tennant made a heavy landing in it as it was getting dark, and wrote off the nose wheel. I saw it happen because I was just about to leave for London to take my girl friend (later my wife, Barbara) out to a New Year’s Eve dinner. Because of the accident I didn’t get away until much later. By the end of 1958, I was married and living near Winchester. By a super human effort they managed to get another aircraft finished in time to get it to India in time for the 26th”.
In fact, the first aircraft IE1061 arrived in India in the Fairchild Packet IK451 piloted by Flt Lt John Philipose in January 1958. He had been instructed to minimise en route halts and get the Gnat to Kanpur as fast as possible. The aircraft was reassembled at A&ATU by IAF and a few Folland personnel in a great hurry. It was flown by Sudhakaran in the Republic Day Flypast of 1958. Both Teddy Petter and Ted Tennant watched the parade and the flypast by the lone Gnat. Another two Gnat Fighter aircraft, perhaps IE 1062 and certainly 1063 arrived in time to undergo tropical trials at Kanpur and Madras. In November 1958 Sqn Ldr Das took over as Commanding Officer of A&ATU. By then the three engineers had already returned from Chilbolton to conduct tropical trials in our hot summer conditions. The trial were flown mainly by OC A&ATU, Sqn Ldr Bhupinder Singh and Flt Lt Sudhakaran
Meanwhile, aircraft IE1060 had to undergo repairs. A site on the Internet says that IAF refused to have the aircraft repaired and delivered. But an aircraft eventually went to Boscombe Down for trials. This could have been either IE1059 or IE1060. Reports after these trials at A&AEE were not given to IAF. But GC (Geoff) Cairns, my ETPS course mates, had flown this aircraft. Later he asked me why IAF accepted the aircraft when it was not fully developed and was dangerous in many respects. Geoff eventually became an AVM and headed Boscombe Down as his last RAF job. In answer to his question, all one can assume is that we were very keen and in a hurry to get Gnats into the country.
The Gnat Handling Flight in A&ATU had to do much development work on the aircraft. The tasks have already been listed in a post by Air Mshl Wollen. Perhaps some details of the work of the Gnat Handling Flight also deserve a separate post. This should soon follow. But there is no escaping the fact that our much loved Gnats were not adequately developed and were too often dangerous to the welfare of the pilot. I understand that the Ajeet fared a lot better in service, albeit in a different role.