How Gnat Rolls

By Air Commodore A.C.Goel AVSM (Retd.) I A F [TUBBY To IAF]

How Gnat Rolls

Having flown Toofanis, Sabres, T-33, and Mysteres and a total fighter experience of about 250 hours, I found myself posted to No- 9 SQN at Ambala in the end of year 1964. Flying officer Tubby Goel was in the exalted group of stalwarts like, R J M Upot [C O] and Johnny Greene, A J S Sandhu Black 1 as flt cdrs and Denzil, Chatto the Flt Lts to lead us. We had recently formed and No 23 Sqn was the oldest and well established along side under the command of test pilot Bhopinder Singh with Sikki as the leader of boys of both the units for good things of life.

A quick, two sortie check on Hunter with 2 notch of flaps at Halwara with Rustie Sinha and lo, behold, I was cleared to pilot the formidable gnat at Ambala and my conversion started immediately. The instances of Hobson unit not working properly and also the gnat rolling most unexpectedly were grilled into us very thoroughly and we were mentally and physically prepared to face the situation. After a few sorties, I was on an exercise that had a low level circuit at 500 feet and a landing thereafter. As I settled on the down wind leg and moved the U/C lever to the down position, the a/c went out of control. It started a vicious roll to the left, the rate of roll being so high, that all actions by me were of no use. I transmitted the sit to ATC for posterity and suddenly the a/c became wings level as if nothing had happened. Please believe me that this correction was as sudden as the start of roll and I had no part in recovery. After gaining my wits around, I made a landing and a/c was handed over to main staff to check.

As I reached the dining table in the mess for lunch, a few of my colleagues got up to congratulate me for having survived the ordeal. As the news spread at the table, S TO of 23 SQN, finished his lunch, came to me and took all details of the incident and said that all though he is not the EO of 9 Sqn, he is immediately going back to work and start investigations. [I forget his name and he rose to be AOC-in-C, maint command] It was only due to his efforts that the real reason could be established. He found that there was a rag stuck in the cable and pulleys, which lower the ailerons causing, undesired differential and unmanageable roll.

Analysis—The roll was due to carelessness on part of a worker and lack of supervision. Had I not lived through it, may be we would never have found out the real reason. Taking over of investigation, on his own, by STO of another sqn speaks volume of the goodwill that existed during those times.

Second Incident Of Roll
No 9 sqn at Halwara, sometimes in 1966, I was leading a two a/c formation for some exercise. We had lined up nice and good and brakes were released. As the speed gathered, the nose wheel was off the ground, a/c was picking up speed, the weight of the a/c was coming off the wheels as the lift component was increasing with speed, and I find that right wing is lifting, right wheel is off the ground, the left wheel is in contact with ground and the a/c wants to roll to the left, In another split second the right wing rose a little more in spite of moderate control connection. I felt prudent to abort take off rather to continue with a rolling machine.

Group Captain, Dilbagh Singh, Stn Cdr, Halwara reacted with W A C and Gp. Capt. Das, test pilot HAL arrived within two days to investigate. After detailed discussions with all concerned, he decided to remove the pylons, clean all external fittings and attempt a take off. We all watched as he took off. After the air test, he confirmed the tendency to roll to the left on takes off and attributed to faulty wing tips, which were changed subsequently.

Analysis—The gnat suffered not only from design features, which resulted in control problems but also a host of other issues which could go un noticed and result in difficult situations for the pilot.

How The Small Size Saved My Life

You have heard about Gnat being the Saber Slayer. I would tell you about Gnat as a lifesaver from the bullets fired from the guns at ground.

During the 1965 war, 9 sqn had been moved to Adampur. In addition to the air defense roll, we were also assigned to escort Mysteres on strike missions across the border.

In one such strike, Sqn. Ldr. Gill of 8 sqn was leading a four a/c strike with full external and internal load. We were escorting this formation with four gnats. The target was very heavily defended with air defense guns and sabers on call. It was also very necessary for us to destroy the target and soften the defences. We arrived over the target and hell broke loose. The Paks, fired in the air at us with every thing that they had. Gill was undeterred with the opposition and set up a pattern, wherein, the Mysteres repeatedly carried out steep glide bombing in turn with an umbrella of Gnats all around them. He was so cool and took his time picking up targets and doing precision attacks, like on a range. I can vividly recollect faces of Pak gunners firing at us in spite of a/c dive-bombing at them. We spent a fairly long time over the target. The shells were bursting all around us and one did not know if his name was written on one of them. As we were preparing to leave the target, I felt a burst next to the a/c and the Gnat went out of control, shaking, rolling, pitching and so on. I called up on R/T that I have been hit and would be ejecting. Since, we were on a course home I decided to delay it as much as possible. In a little while the a/c was flying normally. My joy knew no bounds as I discovered, RPM / JPT, within limits and the craft responding to controls.

On landing, we found that there were shrapnel/ bullet holes in seven out of eight a/c. The leader, Gill was given VIR CHAKRA while the rest of us were happy to have returned in one piece.

Analysis—The small size of gnat made the probability of receiving a hit that much less. This saved us from enemy gunfire. There is not a single case of losing a gnat in combat due to enemy gunfire when escorting strike missions.

4 thoughts on “How Gnat Rolls”

  1. Dear Air Cmde,

    When I joined Gnat fraternity in 74′,many of the control problems had been removed for good except trim runaway.By mid 76′,the Gnat was a docile aircraft and stastically perhaps, can prove that many accidents/incidents were not merely inherent design problems but,were perhaps,combination of piloting techniques and at times gross mishandling.Testimony to this is the fact that an average pilot like me flew the Glorious Gnat for four and a half years with just two emergencies,Invertor failure during a valley flying sortie and trim failure after take off.This transition from a tricky and possibly dangerous aircraft to an excellent AD training platform,would not have been possible but for the efforts of our pioneering pilots and engineers,technicians and the ubiquitous senior Flt Lts’who taught us more by words and deeds.I raise a toast to all my Gnat seniors where ever they may be.

    Arvind Kumar

  2. Hi Tubby,

    Nice write up that took me back to the days in early 1965 when Ambala skyline used to be littered with contrails of gnats doing 2V2 and 4V4s.

    I wanted to mention that the EO you mentioned could be none other than (the then Sqn Ldr) IG Krishna an ace engineer and a fantastic person at work or in the bar. Let me raise a toast to an unassuming guy who spoke the same language as us fighter jockeys.



    PS I am aware that this email would be repeated to the entire group as I would like it to.

  3. Hi Arvind Kumar “shorty”.
    Could not agree with you more . Flew the “Gnat Gaddi” from 1969 to 1983-84 . In the 80s only on and off. managed to log 750 plus hours WITH OUT any longitudinal or lateral control problems .Gnat is no more long live the Gnat !!!!

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