Helicopter crash: how training and equipment might be the difference between life and death

Wednesday, 24 April 2019

Two Otago Rescue helicopters arrived at Southland Hospital on Tuesday to transport three men who has survived a helicopter crash near the Auckland Islands.

The survival of three men who's helicopter crashed into the Southern Ocean was 'incredible', but their emergency training likely played a huge roll.

Pilot Andrew Hefford and winchman Lester Stevens were travelling with medic Lester Stevens to retrieve a sick seaman from a fishing trawler near the remote Auckland Islands when their helicopter crashed just off the coast of Enderby Island.

The survival of all three men was called 'absolutely incredible', by Southern Lakes Helicopters boss Sir Richard Hayes.

The chances of the men surviving was 'zero probably, nearly', he told The AM Show on Wednesday.

**READ MORE:

Otago Rescue helicopters arrived at Southland Hospital on Tuesday.

* Two survivors discharged from hospital

* Helicopter crash survivors a credit to Southland

* Survivors swam to shore in darkness after Southern Ocean crash

* Survival chance of crashed helicopter crew 'zero probably, nearly' says pilot Sir Richard Hayes**

Hayes said there had been lesser accidents with worse results over the years, 'but this one was right up there'. It was 'incredible, just absolutely incredible' that they survived, he said.

Stevens' father, John Stevens, said the group's survival skills saved their lives - and according to experts, he's likely right.

The intensive training and procedures that search and rescue helicopter crew undergo may have been the difference between life and death, according to experts Stuff spoke to.

It's not yet clear what caused the crash, and an investigation is under way.

However we asked some experts about over-water emergency situations involving helicopters, and about how important the training and equipment is for pilots and crew members.

WHAT COULD HAPPEN

Aviation NZ executive officer Bill MacGregor said if a mechanical problem had caused a complete engine failure or other serious fault, the pilot would put the aircraft into autorotation, which he said was 'effectively the equivalent of going into a glide for helicopters, but at a much steeper angle'.

The crew would jettison (throw off) the doors on the way down if possible, and try to land on the ocean surface. It's crucial to kill the rotors before landing, MacGregor said.

Helicopters are top-heavy, with each rotor potentially weighing hundreds of kilograms.

'Once you're in the water, if the rotors turn it can start to roll, and then when they hit the water it can flick you over with a lot of sideways force - it's kind of like being in a car crash and spinning out,' MacGregor said.

Unless the helicopter has float devices attached to the legs, the aircraft will inevitably start to sink.

ESCAPE TRAINING

Helicopter under water emergency training (HUET) is common practise for pilots and crew - especially for those who fly rescue helicopters in New Zealand.

The training involves crew knowing and practising a simulated emergency first-hand, by escaping an upside-down 'helicopter' submerged in water.

Simon Duncan is a training instructor at Garden City Helicopters. He trains pilots in how to escape from downed helicopters in the open ocean.

According to Duncan, the helicopter is likely to turn upside down due to the weight of the rotor, as it sinks underwater.

'The crew would then have to get out despite an upside down point of view, and they needed to escape out of there into an environment that is not ideal for survival - an extremely cold ocean,' Duncan said.

Crew are taught to unplug their helmets from the intercom system, and open the doors to clear a pathway before they remove their seatbelts.

Full immersion suits are an important piece of survival equipment carried on board many helicopters and also fixed-wing aircraft.

These are a type of waterproof drysuit which protect the wearer from freezing water temperatures. The crew were also wearing life vests.

Maritime New Zealand confirmed the crew who crashed in the Southern Ocean were wearing cold water immersion suits.

OTHER LIFESAVING EQUIPMENT

Many helicopters also have an inflatable raft on board. Duncan said crew are also trained to access the raft, which inflates rapidly using a ripcord.

The dinghys would also likely have a survival kit based on what the conditions might be like in the region.

It is possible to paddle the dinghys, 'but they're round and not designed to move in a hurry,' MacGregor said.

If they are unable to access the raft, and they're in open-water, they crew trained to stay together holding on to each other, to create a larger, more visible object.

It's understood once the three men escaped the submerged helicopter and swam to shore, they flashed lights at a boat, tying to flag it down.

MacGregor said these guys were pros. 'They push into rugged and remote areas, and they plan everything. Hence why they're still alive.'

John Stevens said that 'helicopters crash from time to time, and it's quite often that people don't survive them, so you can imagine that I was very concerned,' he said.

'They were well equipped to withstand any emergency. [Lester] is resourceful, if anyone was going to survive, he would survive.'