AIRCRAFT UNDERWATER

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© Vice Admiral Vinod Pasricha, AVSM, VSM, NM (Retd.)

Images © Vice Admiral Vinod Pasricha (Retd.) via NHQ, New Delhi


"Brakes, Brakes, Brakes," ordered an urgent voice over the aircraft radio. Unfortunately, Commander Peter Debrass was to recollect this only as, "Some crackling sound which I could not distinguish," and wondered who was conveying a message and to whom. This crackle at noon on 04 March 1976, began the opening chapter of two fateful minutes in the life of this experienced naval aviator. Peter completed his basic flying training at the IAF stations at Jodhpur and Secundrabad. He then came back to the Navy for his operational flying training on the Vampires, soon converting onto the Sea Hawks, the carrier based fighters. An absolute delight to fly, the Sea Hawks formed the main strike force of the carrier. As one of Indian Navy's ace pilots, Peter continued to fly with dexterity and smoothness and was soon an obvious selection for the flying instructors course, where like everywhere else, he topped the honours list. On 04 March 1976, Peter was embarked on INS Vikrant as the Commanding Officer of Indian Naval Air Squadron 300. Identified as 'The White Tigers', because their crest displays this magnificent beast leaping into the air, the Squadron had embarked on board only the previous day.

Peter was the leader of four Sea Hawks and since the Squadron was operating from INS Vikrant after a break of six weeks, he spent quite some time highlighting aircraft drills and possible emergencies whilst briefing his formation on the sortie profile. "Remember that you are being launched (naval terminology for a catapulted take off) from the carrier after a break. Approach the catapult chocks gently, stop the aircraft in time and signal to the Flight Deck Officer that you are ready." For a launch from the carrier, the aircraft is required to fulfil two conflicting conditions. The first requires the aircraft engines to be revved up to full power as soon as it is loaded on the catapult. At the same time, the aircraft must remain at rest with its brakes off. What seems an impossibility is made easy by the introduction of a hold-back unit. One end of this unit is secured to the aircraft and other to the deck keeping the aircraft stationary. The aircraft end of the hold-back has four claws held together by a steel ring. With the jerk of the catapult firing this ring breaks, the claws open and the aircraft is free to move.

Unlike expectations, the catapult has no elastic rubber components with an aircraft stretched in the centre. It basically comprises two steel cylinders connected to a launch hook (shuttle) which moves along a tracked rail on the catapult. High pressure steam is trapped in the cylinders. When this steam is released, the shuttle travels forward at high speed. By connecting a wire ring (bridle) between the shuttle and the aircraft, this movement of the shuttle is transferred to the aircraft pulling it ahead. At this moment, the hold-back ring parts and the aircraft is shot into the sky. As precision and timing are of great significance, the entire operation is controlled by the Flight Deck Officer (FDO), who communicates with the pilot through a code of hand signals and flags and with the flying control position (flyco) on intercom. The FDO drops a green flag to launch an aircraft and in an emergency raises a red flag which is used to freeze the launch procedure. No matter how often one witnesses a catapulting off the deck, the fascination never wears off. One moment you see an aircraft at rest on the flight deck and by the time you blink your eyes, it is airborne ahead of the carrier having achieved its flying speed of over 200 km/h in a takeoff run of less than 30 metres. As the first aircraft gets into the air, one hears the familiar call "Leader Airborne." Over the years, a desire for brevity has changed this call to "Leader Borne."

"Go over the emergence drills on the catapult," Peter queried his wingman, David McKenzie, during the sortie briefing. David had revived these often enough and immediately rattled them off, "A 'Premature Breakout' will occur on the launch if, for some reason, the bridle disengages before the shuttle is fired. This may cause the aircraft to surge forward. In a 'Cold Shot', the power generated by the steam may not be enough for the aircraft to attain flying speed after the launch. In both cases look at the FDO, but keep the power on. If he crosses his red and green flags, chop the throttle and sit on the brakes. If he doesn't, just brace yourself for the impact with the water, hoping that the aircraft can be nursed into level flight."

The Sea Hawk takes a dive, nose-down, right after clearing the ship - while the men aboard stare in horror.

"Right. Let's man aircraft," said Peter and with that the four pilots went off to the flight deck to strap up into their Sea Hawks. As the carrier turned into the wind, Lieutenant Commander (Flying), affectionately called Little (F), blared over the flight deck broadcast, "Stand clear of jet pipes and intakes. Standby to start up the Hawks. Five, four, three, two, one, start up." All four starter cartridges fired simultaneously and a moment later, the engines started revving up. Pre-flight checks were completed and the R/T checked out. The search and rescue helicopter was ordered to get airborne and with all ready for the launch, Little (F) switched on the amber light, thereby permitted aircraft movement on the flight deck. Being the leader, Peter's aircraft moved straight onto the catapult. Little (F) flicked the control light to green and Peter started his launch procedure. All systems go, he gave the hand signal to the FDO who, after a last minute check, dropped his green flag and waited for the micro-second before the catapult would fire. As all eyes watched from flyco, Little (F) saw that something was amiss. The sequence had somehow gone awry as the hold-back parted and the bridle dropped down. The Sea Hawk was moving even before the catapult had fired. A second later, the shuttle shot forward but of what use? The aircraft and bridle had already disengaged. "Brakes, Brakes, Brakes," came the reflex R/T call from Little (F). David McKenzie and his colleagues heard this urgent message but on Peter's headset it came only as a crackle.

"Something seems wrong," thought Peter, "but since there is no signal from the FDO all must be well." Years of training to not throttle back on launch unless specifically signalled had its effect. The FDO noticed the bridle falling but could not figure out why? In that split second before he put his hands up to cross his flags, the Sea Hawk had overtaken him. He ran behind the aircraft, but was no longer in Peter's field of vision and so the Sea Hawk majestically plunged into the sea. Captain (later Admiral) Ram Tahiliani, in command of INS Vikrant was sitting on the Captain's chair on the bridge. Having himself commanded No.300 Squadron and been Little (F), his reactions were copy book and instantaneous. "Starboard 30. Stop both engines," followed immediately by "Full astern both engines." Both these orders are given only in a serious emergency. But the momentum of the carrier with its 20,000 tons displacement took time for the speed to reduce and the aircraft was already under INS Vikrant. The Martin Baker ejection seat of the Sea Hawk sends the pilot into the air along with the seat and his chute. For the parachute to deploy, the aircraft must have a forward speed of at least 175 km/h. As Peter fell off the deck, he realized that the aircraft did not have the necessary speed to eject and there was little that he could do to prevent his going into the sea.

"Should I eject underwater?" came the next thought. Theoretically it was possible but Peter also knew that in practice no one had ever tried it. For an underwater ejection to be successful, the aircraft would have to first sink for seven seconds to at least thirty feet so that when separation between the parachute and the pilot occurs, both are still below the surface of the water. "Thousand one, thousand two…….thousand six, thousand seven," as he counted it occurred to him that the propeller noise had died down, so the carrier must have crossed over." With that he pulled the blind. Bang! The ejection seat fired. What Peter didn't appreciate was that the carrier was still very much on top of him. It was only that the propellers had been stopped and thus there was no noise. The rescue helicopter, call sign 'Jumbo' was at its station, flying just clear of the carrier abreast the catapult. Strapped in this helicopter was the air crew man diver, ready to jump into the water to reach the ditched pilot and hoist him up by a winch into the Jumbo.

Lt. Timky Randhawa, the pilot of this Alouette was to later recall, "I saw the Sea Hawk plunge into the water at an altitude of 45º just twenty yards ahead of the ship. Immediately after hitting the water it started sinking very fast. It was almost fully underwater when the ship hit the starboard wing of the aircraft. Immediately after that I observed glass pieces flying out of the water on the port of the ship. At this stage I dropped a marine marker to mark the position and asked the air crew man diver to standby to jump. But thereafter, there were just no signs of the pilot or the aircraft." Action alarms sounded on board the ship and it was ready to deal with this emergency. The doctor, medical and rescue teams, and look-outs were all alerted with every one on the flight deck searching the water but Peter was nowhere in sight. Suddenly Jumbo called out "Flyco, I see a Mae West on the starboard side a little away from the ship. Am proceeding to investigate." This inflatable life jacket, aptly named after Ms Mae West, is bright orange in colour and is invariably the first object to be sighted during a search. Timky had done well, soon as his elated call came over the R/T, "It's Peter all right and he has given me a thumbs up signal." Relief all over and in less than a minute Jumbo had landed back on deck with Peter safe and sound. The entire chain of events had taken less than a hundred seconds. All was well and he was back with the Squadron.

"After I pulled the blind, the next thing that I became aware of was that I was scraping against the ship's side. I tried to push with my hands and kick with my feet to clear the ship. However, I felt I could not get away as there was a lot of turbulence in the water. I released my parachute which was dragging me down and inflated by Mae West whilst still underwater. Suddenly I found I was thrown away from the ship's side. When I surfaced I was well clear of the ship and was immediately picked up by Jumbo and brought back on board." Today, Admiral R.H. Tahiliani is at the helm of the Indian Navy as the Chief of Naval Staff, whilst INS Vikrant which has just completed 25 years of glorious service is commanded by Captain Peter Debrass. Their reactions when asked about the accident that occurred exactly ten years ago is, "We were lucky." Luck, perhaps yes, but it was years of experience, correct training and good drills which ensured reflexive and immediate actions. Peter's decision to wait before the ejection and Admiral Tahiliani's order to go 'Full Astern' causing the backwash to push him away from and not into the propellers, are together responsible for his second life. If Peter had time to make his R/T call on that fateful day, he would definitely have said, "Leader Reborn."

Captain Vinod Pasricha - Little (F) on that fateful day
June 1986


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