Gnat — Two Flying Incidents

By Air Mshl MSD Wollen (Retd)
First Incident

The Gnat Handling Flight (GHF) moved to Palam in the second week of Jan 1961. It had completed its last phase of air to ground, 30 mm cannon firing at Tilpat range and was due to move to Jamnagar to complete its final task viz.,prove the effectivness of engine fuel-dip system, during cannon firing at 45,000 ft over the Porbunder A/A range.

2. On 11 Mar 61, I took off in the early evening (my third sortie of the day) in Gnat IE1067, to carry out a post 100 hr flight-inspection. The aircraft was fitted with unfilled drop tanks.The Gnat aircraft fuel flow proportioner had in recent months been malfunctioning. During the climb out, the aircraft’s ‘c of g’ was thought to be moving aft, since fore-aft movement of the control column did not result in precise response (a typical sign of flow proportioner malfunction).

3. The emergency drill in such a case was to split the tail-plane, shut off hydraulic power, retain ailerons in power (ie not exhaust power by small aileron movement, thus bringing the ailerons to manual) and land. This drill was followed, since it is stated in the Company’s Pilots’ Notes. On the final approach to R/W 33 (Palam’s main R/W was under renovation), at about “flare” height (undercarriage down, ailerons drooped) the control column moved fully left ; it could however be moved forward/backward. The aircraft rolled to the left ; the airspeed was around 150 kts. I slammed the throttle open and gained whatever height was possible before the aircraft reached the 90 deg. banked position. The rate of roll could not be hastened or slowed. On my back, I gained more height. The aircraft entered a second roll ; I re-selected hydraulic power ‘on’. Movement of the control column was restored. I landed the aircraft with the tail plane split. No over-sensitveness in controlling pitch, during landing, with an aft ‘c of g’, occurred.

4. After switch ‘off ‘, F/O Kashnobish, the GHF engineer, was able to confirm by touch that the starboard aileron was in manual, whilst the port, remained in power. I exited the aircraft to find my socks/shoes soaked in persperation. It had been a frightening incident.

5. The reason for blockage of the filter of the starboard servodyne was debris from failing hydraulic seals. Eleven Gnat aircraft, from a small fleet, were found with blocked filters.Seals were changed, hydraulic systems flushed, Company Pilots’ Notes amended and a mod introduced, whereby a pilot could select ailerons to manual, instantly.

Second Incident

The main task of the Directorate of Air Staff Inspection, Air Headquarters was to inspect/report on the capability of Wings/Squadrons/G.W.Units to excute war-time tasks,as stated in the concerned Command Operational Instruction. Inspectors were from all branches (they wre often co-opted). It was mandatory for the Director, ASI to verbally debrief Staff at Command Headquarters, at the end of a visit.

2. A flying inspector normally carries out a familiarisation flight (aicraft, airfield, flying-areas etc) before flying on a ‘chase’ or an air engagement mission. On 13 July 1976, I got airborne in Gnat E 305 from Sirinagar. Landing was normal on R/W 36, but after touchdown, the aicraft pitched up rather voilently and veered to the left, off the runway. It traversed the shoulders and came to an abrupt halt, when it hit a storm drain.

3. The accident was reported by the Stn Cdr telephonically to the AOC-in- C, WAC, who spoke to the CAS. A Court of Inquiry was ordered. It was found, the same afternoon, that the undercarriage radius rod had failed, causing the accident. A few weeks earlier, a similar failure had occurred at Bakshi Ka Talab airfield. A young pilot had been killed.

4. HAL rapidily changed the material of radius rods.

4 thoughts on “Gnat — Two Flying Incidents”

  1. Air Marshal Wollen sir,
    The incident you describe at Palam is a legend in my house. Anytime a discussion of pilot skill came up, my father talked about seeing you roll on your back while landing and keeping your wits about you, slamming throttle and taking the Gnat into the sky. He was in a Dakota (with 10 Sqn) waiting to takeoff and saw the entire incident.
    Every time we go by the perimeter of the international airport, he also reminisces about a Gnat accident in 1960 with RK Mehta. He points out the approach end of the runway and says that the Officers Mess was close by. He was tying his turban when he heard the crash. Running to the crash he saw some villagers already there. One of them said,”Woh udhar padda hai”. Mehta was thrown out or ejected late and had passed away.

  2. Anandeep told me the bare detail incident many years ago. But reading the whole story from the man who experienced it himself is something else!

  3. Air Cmde Tiku Sen via a comment on the ‘Overview’ wanted more juicy details. In response, Air Mshl Wollen says that his demand is answered by what is said in the first Flying Incident. Perhaps no more needs to be written.

  4. My hats off to Pilots , and engineers of the GHF , but for their efforts the Gnat would not have become lot safer and sweetheart it had to become of the pilots in later years . They really deserve all the praise specially because I had heard rumours that in the late sixties there were pilots posted to gnat squadrons ,who “lagoesd patty” to get it cancelled .

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