Category Archives: Narrow Escapes

Orpheus Mod 113 & Its Aftermath

Excitement after emergency was over!
By Gp Capt Kapil Bhargava (Retd)

During my deputation to HAL as a test pilot, I had several incidents which could have been a lot worse that they turned out to be. One of these was on Gnat IE 1073 on January 23, 1960. The incident itself was not much to write home about. But its consequences are well-worth recounting.

Let me first describe a bit about the background to this little tale. My first flight in a Gnat was on November 24, 1959 on the first HAL assembled Gnat. Prior to the rather exciting flight which is the main subject of this anecdote, I had a grand total of 8hrs 55mts of production test flying on several Gnat aircraft. I completed eight flights adding up to five hours on IE 1073 in clean configuration till the aircraft and all its system were working satisfactorily. I cleared it for installation of the drop tanks for its final flight to get it ready for delivery to IAF.

Meanwhile one of my initiatives was to record several parameters of each aircraft which were not part of the production test schedule. My idea was to collect all possible statistical data of the fleet to validate the performance figures of the Flight Manual. The record would have also generated other information which was not given in it. This would have helped identify any aircraft which did not perform to the same level as the rest of the fleet. A pertinent reason for the need of such data was that extra fuel tanks were about to be installed on the aircraft. But no flight tests were planned by HAL or advised by Folland for a revision of the Flight Manual.

My fateful flight on the IE 1973 with drop tanks went well in excellent weather. I got a few extra performance figures for my record. The final point was to note the maximum level speed at full throttle at 20.000 feet. As soon as the drop tanks were empty, I opened full throttle to accelerate to the maximum speed roughly over Kolar airfield. A few seconds after the speed stopped increasing, the engine wound down to idling with no warnings of any kind. My immediate reaction was to pull up and gain maximum possible height until the speed dropped to about 170 knots. I had already turned towards home and was sure I could land the aircraft back at the HAL airfield. My next action was to consider if there was anything else I could do to get the engine working again. It was still running at idling rpm but did not respond to throttle movements. An attempt to relight was no help. Of course, unlike the Vampire, there was no isolation switch in the aircraft. There was nothing I could do except plan my approach and landing. I kept the drop tanks on with the thought that I could jettison them if I needed a last minute stretch of the glide. By about 1700 feet amsl. I told myself that ejection was ruled out and that I was committed to the landing.

As it turned out, I landed exactly on the initial part of old 09 runway (now relegated to a taxi tack). With normal braking and the parachute, I stopped comfortably in about 800-900 yards and turned off to stop at the normal spot from where we used to operate the aircraft. I switched off the aircraft and got out. I had warned you at the beginning of my tale that the incident did not generate much excitement. But some fun was soon to begin.

As I got a few yards away from the aircraft, I saw that much fuel was draining out of the aircraft as the engine rpm was dying. A Bristol Siddeley engineer watching me come in, ambled over and said to me, “I see that you are a victim of Orpheus Mod 113.” In some surprise, I asked what this mysterious mod was. He still very casually told me that one of the fuel pipelines of the engine must have broken. I asked him how and why would such a thing happen. He said the the pipelines were all steel and they often cracked and broke due to fatigue. This was a shock and I explained that the aircraft had just done a few minutes over five hours and perhaps the engine would have run another couple of hours on the test bed during production. Did that mean that fatigue failure could occur in well under ten hours of operation? Still very casually, he said, “Oh, we have had failures on the test bed itself some times in less than two hours of operation. That’s why Orpheus Mod 113 replaces the steel pipelines with rubber ones. The engine on your aircraft has not been modified.” This was the big shock of the day and asked him rather rudely, “How the hell, have you cleared the engine for flight?” The calm Brit engineer just shrugged his shoulders.

I got back to my office, changed into my uniform and charged off to send an official telegram to Air Headquarters. It basically said that the Orpheus engines as installed on the aircraft were dangerous and the last few words said. “All Gnats are grounded till Orpheus Mod 113 is introduced.” I do not remember where Wg Cdr Roshan Suri the Chief Test Pilot was, away or what. But I did not wait for him since I perceived the risk to be too great and unnecessary. The engine failure could occur during take off, leading to a certain fatality. The reaction from Air Headquarters was almost instantaneous by a telegram addressed to Flt Lt Kapil Bhargava. It informed me that I had absolutely no authority to ground the fleet of Gnats. This privilege rested only with the Defence Minister and the Chief of Air Staff. I responded with an abject apology for my lack of knowledge of the protocol but added, “However, no Gnat should be flown till Orpheus Mod 113 is implemented. The risk of a major accident without it is excessive”. Authority or no authority, that did ground all Gnats.

Obviously Air Hq was in a hurry to get the fleet back in the air. I soon got a letter from a Wg Cdr Tech (Eng) advising me what I should do to restart flying the aircraft without waiting for the mod to be carried out. Basically the letter said that I should check the engine before every flight and if it was satisfactory, I could resume flying. I replied to the Wg Cdr that I was not an engineer and hence did not know how to check the engine. I also said that I was not clear what instructions to give to the technical staff on how to check it. I mentioned that the incident was caused by the servo pipeline cracking due to fatigue. This controlled the stroke of the fuel pump and its failure had led to the pump going to its idling stroke. Since there were many steel pipelines, I would be unable to identify which one would fail next. Besides my visual inspection would not indicate if a pipeline was about to fail due to fatigue. I asked if we should do dye-penetrant tests or x-ray for all the steel pipelines. I requested the Wg Cdr to come and show us the methods suggested by hin or Air Hq could please send another engineer on a short TD to HAL to show us how to do the visual and other checks to clear the engine for each flight. I never got a reply to this polite mail and at least in HAL all Gnats remained grounded till Orpheus Mod 113 was implemented on each aircraft.

The epilogue of this tale was not related to the Gnat. AVM AM (Aspy) Engineer (Later CAS) then Managing Director HAL phoned me on hearing about the successful retrieval of the Gnat. After congratulating me, he said, “Even though you do not want to be the number two on the HF-24 project, you are now detailed for it”. The order meant that I made three flights on the HF-24 Glider. Luckily, I was soon pulled out of HAL for the Avro project in the UK. My reluctance was due to the fact that I had been convinced that the HF-24 would fail to get airborne with Roshan Suri flying it on its maiden flight. I had offered bets on this of a bottle of scotch to many people in HAL but no one took me up on it. As it turned out, my fear was too prophetic, to everyone’s sorrow. But flying the Gnat in HAL and the errors on the HJF-24 project helped me a great deal to handle Messerschmitt’s HA-300 prototype in Egypt. It was mostly a case of avoiding the errors committed on these two projects, and forestall any new ones. But I did succeed in getting the control system of the HA-300 to feel almost completely like the Gnat, but without its pitfalls. The aircraft became quite a pleasure to fly with control movements and forces very similar to our Gnats.

A frightening dive

Air Marshal PK (Babi) Dey

During the Gnat development programme at Folland’s airfield at Chilbolton, we were having trouble with accurate measurements of free air temperature in flight. So one fine morning I found a small probe on top of the canopy when programmed to carry out high Mach dives.

As the speed built up in a steep 60° dive from 45,000ft, and approached 0.9M, the aircraft suddenly went into a violent lateral oscillation. I could do nothing to control it and expected the fin to break off any moment. Instinctively, I had ‘closed throttle and was trying to ease out of the dive. I took my feet off the rudder pedals which were also moving viciously. As suddenly as they had started, the oscillations stopped, and I gently returned to base, very shaken and relieved that the aircraft was still in one piece.

Investigations proved that the tiny probe on top of the canopy was the villain, creating shock waves that hit the fin and started the oscillations as the aircraft speed went past 0.94M. It was a lesson I never forgot, and always thereafter I treated any projections that the ‘boffins’ wanted to stick onto an airframe with the greatest suspicion.

A landing with tail split and stick fully forward!

By Augustine JohnSingh

After the exciting Indo-Pak War of 1971 in which 6 other course mates and I of 103 Pilots Course (7 Flying Officers with 2 years service – Ajit Agtey, RK Poonia, DR Patankar, SS Hothi, late AS Sidhu, RS Khangura, and myself AJ) in No. 2 Squadron under the Command of the legendary then Wing Commander Jonathan William Greene (God is Greene and Greene is God), flying the LITTLE FIGHTER in a mainly Air Defence Role took part from Rajasansi, Amritsar then No. 4 M.E.M.U. and kept the people of Amritsar safe from any damage whatsoever, the Winged Arrows were ready to relieve its sister squadron at Ambala, the Flying Bullets (No.18 Squadron) of its duties temporarily at Srinagar (Late Fg.Offr.Sekhon PVC’s Sqn) and make our presence felt in that area to prevent any misadventure by our neigbour.
Continue reading A landing with tail split and stick fully forward!

Another Narrow Escape

By Shyam Hattangdi

There was never a dull moment in Gnats that I had an opportunity to fly, off
and on, from 1965 to 1982 and I had my share of incidents in ample measure.
One particular incident is worth mentioning.

It was a routine air test on a bright clear day and as I was climbing
through about 22,000 feet, I felt a slight “click” on the control column and
the aircraft began to gently roll to one side. This was easily controllable
and there was no indication of any other problem and the hydraulic pressure
and cycling were within normal limits. However since the problem involved
flight controls I decided to discontinue the air test and return, informing
ATC accordingly. Passing about 20,000 feet I decided that it would be wise
to get the wheels down as soon as possible as it could be an impending
hydraulic failure and, informing ATC of my intentions, reduced speed and
selected the undercarriage down.
Continue reading Another Narrow Escape

A Tale that ended well!

Air Mshl Raghu Rajan (Retd)

We were flying Gnats operating from Ambala.That morning we got airborne for a 2vs1 sortie, with G’Man in the lead, self as No2 and DDS as the attacker. Those days we had the privilege of having two Gnat and two Mystere Squadrons op from Ambala.On completion of the sortie, we pealed off for the landing, and I and DDS were in the Queue . That day G’Man had one tyre burst followed by the other and hence blocked the R/W30 some 2/3 way up and slap bang on the center of the R/W. I went around and we both Gnats orbitted for endurance as directed by the ATC. We also had two Mysteres-Hemu Khatu and VPSingh also orbitting Ambala. As the fuel state dropped to a low figure, we elected to divert to Chandigarh-the hitch, we did not have Chg R/T freq on board. We tried our Emer R/T but no joy, so we followed Hemu and VP to Chandigarh .Since my fuel state was 100lbs lower ,DDS let me be in the lead, and between ourselves we cleared each other on D/W and on Finals.Hemu landed safely on the right lane but VP had a tyre burst on the left lane, and hence came to a stop about 2000ft to go!! I had meanwhile rounded off for the landing and my fuel state did not allow any leeway (it was reading 50lbs or thereabouts) I stuck like a leech to the right lane, warned DDS to do the same and we taxied to 47 Sqn dispersal and switched off. We were surrounded by a host of officers and airmen who were heard shouting”Oye, Yeh Gnat walon ki Gaddi Hawa se chalti hai!!”The lessons learnt are too many but I leave it to you all who may have faced a similar situation!!

How I survived a spin!

By Daboo Dewan

I want to recount one of my experiences during my flying days in the Gnat.My name is Daboo Dewan and I opted to leave service prematurely in 1981.I had the privelage of flying the Gnat from 1972 through 1977 at 21,9 and 15 squadrons.During my conversion at 21 squadron in Gorakhpur I was on a training sortie 1 vs 1 combat and my leader was then Flt Lt Gujral.Whilst we were carrying out manouevers at 30000 feet at slow speeds I mishandled the aircraft and entered into a spin.I relayed this on the RT and my leader immediately spotted me even though I was loosing height rapidly. He instructed me in great clarity all the measures we were taught to counter the spin ,however I was frozen on the controls and cannot recollect whether I carried out his instructions explicitly though I presume I must have as I wouldnt be alive today.He was in constant visual and RT contact with me and asked me to eject when I had descended to 10000 feet.It was precisely at that moment that the aircraft recovered from the spin and I finally leveled out at 3000 feet.

On landing and reaching the crew room I was scared out of my wits but needless to say the squadron made sure that I flew the very next day to ensure I did not suffer from lack of confidence.The recovery from the spin was totally attributable to the professional manner in which my leader handled the situation rather than any skill on my part.I have lost touch with Gujral sir however I would like to take this opportunity to thank him for saving my life and I would appreciate if anyone can give me his contact.I would also be keen to learn from anyone else their experience of spinning this aircraft .

Even though I have been on civvy street for over 25 years We have been rather fortunate to have been in touch with a number of people from the airforce days.The reunion at Bangalore on 21st November will be a once in a lifetime event and I regret that I will not be able to attend due to a prior commitment of visiting our son overseas .

On behalf of my wife Meera and me I want to convey our best wishes to the entire Gnat brotherhood

Cheers
Daboo

Gnat Handling Flight: An Accident, Lesson Therefrom.

By Air Mshl MSD Wollen (Retd)

The IAF celebrated its 38th Anniversary by conducting a Fire Power Demo, Hunter Formation Aerobatic Display and a Flypast over Marine Drive, Bombay on 03 Apr 60.It was a magnificent airshow ; never seen before ; and meant for Bombayites. Credit goes to the late Air Mshl MM Engineer, AOC-in-C, WAC and the team he selected, particularly S/L A Sudhakaran, who delivered a superlative commentary.

Three Gnats from the GHF had to operate from Santa Cruz airfield. Two Gnats were to formate, one on each wing-tip of a newly acquired Boing 737, which was in the Flypast.

The Gnats took off from Kanpur on 19 Mar 60. Westerly winds at the tropo-pause necessitated a landing at Nagpur enroute to Santa Cruz; a safety measure. The formation was led by S/L Wollen, no 2, S/L Raghavendran (OC 23 Squadron), no 3, F/L Jakatdar. Before descent, at about 175 nm from Nagpur, Wollen contacted ATC Nagpur on Channel ‘C’. What was not known to the formation was that all transmissions on this channel were recorded (most fortunate for Wollen).

The Gnat flown by R’vendran, experienced an engine flame-out. Relights, carried out below 28,000 ft, were unsuccessful. Wollen warned R’vendran they were approaching 10,000 ft AGL and to eject. Ejection was successful ; the pilot landed in an open field ; the aircraft crashed in open country. The site was approx 60 nm from the airfield. Wollen overflew “a standing-up” R’vendran and reported details to ATC Nagpur. He gave Jakatdar “pigeons” to the airfield and instructed him to land there. Wollen then flew to the airfield. A Tiger Moth trainer was available. Captain Baker, CFI, of the local Flying Club, flew Wollen to the crash site (no fees were charged). A Police party was at the site but the pilot was absent (we later learnt he had walkd to the nearby railway line and caught a goods train to Nagpur railway station). Wollen and Jakatdar completed their flights to Santa Cruz.
Continue reading Gnat Handling Flight: An Accident, Lesson Therefrom.

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.
Continue reading Gnat — Two Flying Incidents

A narrow escape from automatic ejection, or worse

By AVM RD (Limy) Limaye AVSM (Retd)

It happened with me way back in Mar 78 at Bagdogra. I was then posted to 22 Sqn AF (Gnats) based at Hasimara as one of the 4 Sqn Ldrs. I had taken the Sqn Det to Bagdogra for an AD Ex with the SUs in that sector. On 16 Mar 78 I was on an ORP Msn with Sqn Ldr KC Tremehere as my No-2. That afternoon at about 1400h we were scrambled from S/By 5 Min on a Tgt which was S-SW of Bagdogra near Purnea. Scramble TO was normal and we climbed on the initial vector upto 22000 ft and at KG turned westwards towards Purnea. While approaching Purnea (we were then about 90 nm away) the SU ordered us to go ‘Buster’, I ordered the Msn accordingly. The ac was accelerating and I had seen my ASI coming to 380 kts. Moments later there were severe vibrations followed by a Big Bang. I found myself facing tremendous airflow, minus the canopy. I was expecting to get ejected automatically (having remembered all other such earlier incidents in the past), however, I found myself still in the cockpit. While all this was happenings which was no more than a few seconds, I had acted extremely quickly and had throttled back to idling and flicked my Air-Brakes Out and had done a kind of Half-Roll to the left (my No2 was on my Right in a fighting posn). The aim was to turn back for base, drop my speed and descend to lower heights. I managed to put the ac on a reciprocal course heading eastward with wings level and descending, the speed too was dropping fast. While all this was happening, my Helmet was trying to get lifted up but held firm – thanks to my Flying Instructor at JTW late Gp Capt AK Choudhary, VM (Mountaineer) whose words flashed through my mind “Your Helmet must be Uncomfortably Tight” and he used to insist on it. I had tightened my chin straps which I had always done that saved me. Moreover, my Visor too was down. In spite of these, my eyes were watering profusely and I could just about see things. I could hear only Strength 0-1 (very feebly) because of the loud noise created by the strong oncoming airflow. All these must not have taken more than a minute or so. I was now comfortable in the cockpit. I heard somebody telling me to “Eject”. However, since everything else – I mean all other flying and engine parameters – were normal, I decided to fly back the ac and attempt a landing back at Bagdogra. I had dropped my speed to 160 kts where it was comfortable to fly, from the point of view of the oncoming airflow. Unlike the MiG-21 or Hunter the front windshield panel is rather small in size which does not protect the pilot to that extent. I had to sit in one position slightly crouched and the movements were restricted. I now looked for the Ejection Seat Handle and found that it wasn’t there. I tried to put the Ejection Seat to Safe (the Knob/Lever is situated right behind the Pilot’s Head). I could not do so as the oncoming airflow was so strong that it was pushing my elbow back with force. After several attempts I gave up. I had checked my Seat Harness Straps which were locked and tight. I was quite prepared to get ejected, if it happened that way. This was my first ever sortie from Bagdogra and I was not very familiar with the area of operation but I knew the Narrow Siliguri Corridor between B’Desh and Nepal and that River Mahananda flows southwards from Siliguri. A while later I could see a shining river which I presumed as Mahananda and slowly executed a left turn towards North to Bagdogra. I was finding it difficult to turn the ac as the airflow which by then had scared the hell out me was hitting me from inside of the turn till I had established/stabilized in the turn. Anyway I was now flying along the River. A little later I heard a very familiar voice – that of Sqn Ldr CR (Chandu) Dantale, our senior Flt Cdr who was airborne from Hasi.  When he learnt about this emergency he flew to Bagdogra and south of it to look for me for giving whatever assistance I might need. He was asking me my ground position. I tried to tell him south of Bagdogra approaching base. Within a few minutes he called up to say that he had me in visual contact. He said that I was on track to the base and asked “What is your Height?” I instantly looked inside and found that I was continuing to descend below 5000 ft (that’s about 4000 ft agl). I woke up and slowly opened power and gradually climbed to 6000 ft (about 5000 ft agl). A safe height to fly, minimum height for safe ejection in Gnat was 500 ft agl. While concentrating on all other aspects I had completely overlooked this very vital aspect. I had asked for landing on RW-36  though I had scrambled from RW-18. I did not think it right to attempt to land on RW-18; it would have meant me flying close to Siliguri Town and go towards the Darjeeling Hills to make an approach from the North. Anyway I was cleared for RW-36. A little later I spotted the RW and executed a perfectly smooth landing. On landing first thing, after switching off the engine that I did was to put the Ejection Seat to Safe. The ac came to a halt at the ORP Dispersal where all concerned were there to receive me. The first question asked was,” Did you inadvertently pull the Canopy Jettison Handle?” The answer was NO. The red tell-tale thread was still in its place. On coming out of the cockpit I realized that my French G Suit was shredded on the shoulders due to the airflow. I later saw that my eyes were bloodshot red and both my shoulders and parts of the upper arms were lacerated. The Ejection Seat Handle had been pulled out of its housing in spite of the ac being Post-Mod (a Steel Plate had been fixed above the Ejection handle to prevent it from getting pulled out by the airflow in the reverse direction – backwards). The Handle wire which has seven strands had only two left on it and was flapping on the fuselage immediately behind the cockpit. . The technical investigation concluded that the Canopy probably opened due to the disengagement of the geometric locks which are near the canopy hinges. Secondly, the ejection plunger had been pulled up to halfway and that even with the alternate handle the Ejection Seat would not have fired. Well I was fortunate. The ac I was flying that day belonged to 15 Sqn AF which was under conversion to MiG-21s and was in the process of getting all their ac ready to be flown out to other Gnat Sqns in that very month. This ac had been place on the ORP after 25 Hours routine inspection (which entails a normal sortie and not an Air Test), because they wanted that ac to fly a sortie that very day, as there was not much flying in that Sqn (as most of the pilots had been posted out).

It’s a rather a long story but I thought I would give a first hand account.