By Gp Capt PM Velankar VM (Retd)
After doing production testing of overhauled Gnat aircraft for two years and logging almost 150 plus hours of flight test time at 5 BRD Sulur I was posted to ASTE to under go No 5 PTP course !
Dear reader , remember I was a student officer , so I became privy to what is written in the next para only after the event as they say .
ASTE was allotted a Gnat aircraft for some development trials . To this day I do not know what those trials were . The aircraft was instrumented for the trial purposes and to the extent required for the trials . All this work took time and may be the trial work was getting delayed too much . Unfortunately the aircraft was taxied out a few times but never got airborne and returned to tarmac .
Then one day I was called by Wg Cdr “Tommy ” Thomas , a TP with transport back ground I think . Being staff TP with ASTE he was fully aware of my flying background . We talked of Gnat flying for a little while . Then he told me that I was required to do an air test on the Gnat .He told me just to get airborne and see if there was nothing drastically wrong with it .
I went to the aircraft did externals found some attachments and gadgets which were not on other Gnats I had flown . I was informed that they were for telemetering and part of the trial instrumentation . So far so good . Jumped in strapped up and found the cockpit lay out was also altered . The gun sight was missing .There were some extra instruments , some regular instruments were missing , lots and lots of extra of wiring in cockpit. The answer to the query was ditto .
Started up and taxied out . Even before I had got out of the tarmac I realised that the aircraft WAS unserviceable . It was “pulling too much to the left ” . A fairly common snag which almost every gnat pilot knows and has encountered some time or the other . Any way I thought to myself to carry on and see what happens at higher speeds . Lined up for take off . I was cleared for take off and given winds as 10 to 15 Kts from the left . I commenced T/O run and found that the aircraft had a hell of a lot of bent thrust , by 100 Kts or so , things had become very lively indeed !!! Taking off was just out of question !!! As all Gnat pilots know too much of bent thrust needs little careful handling on takeoff . If , to add to the problems , there is strong cross wind from the left , things get compounded and “right rudder Left aileron ” , a very unnatural control application and combination , can be quite disconcerting and needs skill acquired through experience for safe take off . In the squadron aircraft with excessive bent thrust were always taken by experienced pilots !! I abandoned the T/O which I had no intention to carry out in any case . Now I knew why the aircraft had not taken off on earlier occasions. As during those days there were fairly strong cross winds from the left for runway in use . I returned to tarmac & switched off . Entered the snag as ” air craft pulling too much to the left ” and went to report to Wg Cdr Thomas .
When I told him that the aircraft was U/S and what the snag was . He said that he had also felt that the aircraft was pulling to the left but thought that it was due to the “bent thrust ” all gnats are supposed to have . So I told him that bent thrust came in to the picture only during take off run & at full throttle .If aircraft pulled during taxi it was unserviciability . He said no wonder they had problems taking off and had to abandon every time .
After the snag was rectified I did do an air test / general handling on that aircraft . First and the only time I had ever flown in an instrumented Gnat ! Wg Cdr Thomas also flew after that and I presume completed the trials .
That incident did increase my respect for the staff TPs by a notch . The TPs are exceptional to above the average pilots , possessing very high degree of flying skill , As Philip Rajkumar used to say ” TPs need to be good pole man ” and they were all really really good “pole man ” all of them . Still , they had no hesitation to accept some thing which they did not understand and ask any one they thought could answer , even if it was a student officer !
It is truly said ” there is no substitute to experience “.