Friday, 6th October 2017 was another black day for people like me who fly helicopters. An Indian Air Force Mi-17 V5 helicopter crashed in Arunachal Pradesh while on a ‘routine’ air maintenance sortie, killing all seven crew members onboard. Many IAF helicopters have been lost to the deadly cocktail of capricious weather and mountains. But this crash was captured on camera. Weather was fine and the evidence simply cannot be dismissed as ‘occupational hazard’.
The helicopter was air-dropping kerosene jerry cans and essential supplies to a remote, high altitude drop zone (DZ) using a procedure that is as old as IAF’s tryst with mountains. Loads are secured onto flat boards called ‘skids’ placed on rollers. These skids are released through the Mi-17’s rear clam-shell doors using parachutes operated by static lines with the helicopter flying level or in a gentle climb at around 100-110 kmph indicated airspeed. In this case, a parachute or its appendage appears to have ‘candled’ into the helicopter’s tail rotor (TR), shearing off the TR assembly. In less than 10 seconds, it was all over. The crew apparently didn’t stand a chance.
For helicopters, losing the TR or its drive is a very dire emergency even under benign conditions. Tail rotor shearing off due ‘foreign object damage’ while flying at 100-110 kmph, reportedly at an altitude of 17000 feet, put that crew in definite harm’s way (read unsurvivable) for more than one reason. For one, parachutes respond to airspeed, not ground speed. When you are flying at that altitude, maintaining a flight path to ensure neat, static line-enabled para drops can push helicopters into a ‘coffin corner’ of the rotor’s envelope. But while airspeed deploys the parachute, ground speed determines whether the load lands on the mountainous DZ, or is lost forever. It is such a delicate balance, nobody but an IAF helicopter pilot (or nosy test pilots like me) can begin to understand the mechanics of what all can potentially go wrong. And then we call it ‘routine’.
Investigations will reveal the exact cause. It is not my intention to speculate. But with experience of having partaken in many such accident investigations, I can say with conviction that the Court of Inquiry will reach the most obvious findings and predictable recommendations. We will again miss the wood for the trees.
What killed the crew was not so much the accidental loss of tail rotor but an abject lack of training to handle such critical emergencies. For an Air Force without flight simulators, crews cannot be realistically prepared to handle emergencies of this nature. Not that the Indian Navy or Indian Army fare any better. Critical emergencies, to this day, are still rehearsed through briefing room drubbings and the occasional single engine landing practice. The doyens of training never saw any merit in investing in a device called Full Flight Simulator (FFS); always looking askance at this ‘unnecessary’ or ‘frivolous’ expenditure. After all, the quintessential QFI with his divine ‘patter’ is the fountain of all wisdom, isn’t it?
Like hell, it isn’t. Let us get serious.
Having flown a bit in civil aviation, I cannot help but ponder on the irony of what goes on in the name of flying training in our armed forces. Learning how to handle critical emergencies like losing tail drive through rote or briefing room charades is just as successful as trying to learn swimming by reading books. You are setting up crews for failure. And death, like in this case, inevitably follows.
Simulators, especially those with Level ‘D’ certification, don’t come cheap. But multiple cockpit modules can be sequentially hosted on a single motion platform, thereby enhancing cost and training value for a number of aircraft types. Cost should not be a significant consideration for armed forces that anyway drain millions of dollars through infructuous and unrealistic training exercises involving actual aircraft, ships and helicopters. It is not a problem of cost but mindset that needs to change.
Then again, one needs to ask deeper questions why Russian literature, Flight Manuals and their certification processes are quiet about certain emergencies. Kamov pilots like me have always been brought up to believe (and rightly so) that tail rotors are nothing but an essential drain on the propulsion system. We are ‘contras’ in a divided world.
Other helicopter manufacturers either give you adequate directional control by a low power-demand tail rotor with long moment-arm like the Russian Mi-series, or brute tail rotor power with added end-plates like the Dhruv ALH. Both have their genesis in staff requirements that were written for design and/or procurement of the helicopter. Did the IAF Mi-17 V5 Air Staff Requirements (ASRs) ask for adequate tail rotor authority to undertake missions at 6 kms? Or did it ask for capability to remain ‘flyable’ with loss of directional control while cruising at 6 kms? The difference, if it exists, is ominous. Staff requirements should never be taken lightly.
Designers of Russian helicopters like the Kamov dispensed with the tail rotor by adopting two contra-rotating main rotors. But even for naval ‘Eagles’ and ‘Falcons’ that operate these helicopters, the last part of recovery from autorotation in the event of a ‘double-engine failure’ exigency was shrouded in mist because you could neither train for it nor did we ever have access to any ‘simulator’ greater than the squadron QFI. Maybe that’s the reason why Kamov pilots are grounded and earthy. They know there are some things they know nothing about. No use pontificating. Accept what you cannot change.
Whatever be the case, make sure your helicopter manufacturer has covered critical emergencies in adequate detail. Also ensure you are trained through recurrent simulator training to handle such emergencies and there is a healthy match between what RFMs preach and what you practice. If not, don’t cheat yourself by flaunting ‘any mission, any weather, any time’ badges. You have a critical vulnerability. Prepare to kiss your ass goodbye when shit hits that small fan.
Even in this dark scenario there is hope. When I earned my ‘Dynamic Interface Testing’ badge as a young naval test pilot in 2006, I had a brief exposure to the USN’s multi-helicopter flight simulator complex at NAVAIR, Patuxent River, MD. Three years later when framing the case for Naval Utility Helicopters (NUH) and Naval Multirole Helicopters (NMRH) at Naval Headquarters we included, with some trepidation, simulators (flight & maintenance) in the basic case for ‘Acceptance of Necessity’. It has survived thus far and I was excited to see it part of the recent Naval ‘Request for Information’ for NUH and NMRH. Three years after hanging the uniform and several ‘Critical Emergency’ sessions on the Bell 412 and AW 139 FFS later, I feel we have done something right.
Whether you want better helicopters or better flight simulators, or both – the choice rests with the new generation. I will be very glad if someone from the Indian Armed Forces tells me ‘don’t preach to the already converted. We are arranging a simulator for each of the aircraft we fly’.
But remember, it came too late for seven crew who died on 06 Oct 2017.
So don’t be smug. Please hurry. And write those specifications well.
© KP Sanjeev Kumar, 2017. All rights reserved. Cover photo from indianairforce.nic.in
Views expressed are personal and written with a view to contribute to aviation safety. Feel free to debate and contribute to the discourse. I can be reached at firstname.lastname@example.org.