THE DIVERS on the wreckage of the Super Puma helicopter that crashed off Shetland nine days ago had to work at the edge of their safety zone with the sea crashing against the rocks around them to find the aircraft’s black box.
The Air Accident Investigation Branch were desperate to find the flight data recorder to find out exactly why the chopper carrying 18 people suddenly fell into the sea shortly before reaching Sumburgh Airport, with the loss of four lives.
By Wednesday morning, five days after the fatal accident, the AAIB team knew the black box lay within a large area at the point of Garths Ness, by Quendale Bay, because it was still sending out a radio signal.
However with the signal ricocheting off the rocks they could not pinpoint its location, and the heavy swell meant they could not take the large dive boat Bibby Polaris close enough in for divers to investigate properly.
On Wednesday morning the AAIB requested the help of local firm Ocean Kinetics, who assembled a team of four divers and a boatman and took a 20 foot aluminium boat with a hydraulic winch within five metres of the rocky shoreline.
Working under supervisor Roger Goudie they dived the steep shoreline, which dropped rapidly to 15 metres, with rocky shelves which were covered with debris from the helicopter.
“The AAIB provided assistance using a homing device that could pinpoint the location of the transponder on the black box, but they could not point out exactly where because the signal was bouncing off the rocks in an area roughly half the size of a football pitch.
“The only way to find it was by physically going there and looking, but we couldn’t get in close enough because of the weather conditions.
“The wind wasn’t very strong but there was a heavy swell, which was breaking in the area where we needed to search.
“We went in as close as was safe, but the conditions were not good enough to search the area we thought the tail section was located.”
At tea time on Wednesday the team aborted their dive and took their boat 300 metres north along the Quendale Bay side of Garths Ness, the opposite side from where the wreck of the Braer oil tanker lies after grounding 20 years ago.
“We realised we couldn’t get to where the black box was, so we used the remaining time to search this area,” Henderson said.
“We knew there had been debris spotted on the surface north of there and I soon found the gearbox with the rotor attached.
“We also found two engines and part of the cockpit and some personal items, some of the kitbags the guys had taken offshore.”
Using air bags and the hydraulic winch, the team lifted the gearbox and the rotor blades, key elements in the investigation into the cause of the accident, and took it to the Bibby Polaris, which immediately transported the machinery to Lerwick for onward shipment.
The team returned the following day by which time the conditions had improved slightly.
They contacted local creel fisherman Edwin Leslie, who gave them vital information on the tides and local knowledge of the conditions, having worked the area for more than 40 years.
With the AAIB investigators standing by on board the Lerwick-based tour boat Ruby May, Henderson and his crew went back in and around 1pm they tracked down the helicopter’s tail section with the brick-sized black box – which is actually coloured orange – bolted inside.
“We lifted the tail section on board the work boat Koada and as soon as the AAIB guys unbolted the black box and flew away, they were delighted.
“We then went back and lifted the two engines and most of the cockpit on the Koada, went back and that was the job done.”
Henderson said the weather conditions made it “a very difficult operation”, which involved them working at the “extreme end of the safety zone”.
He added that the mood was sombre throughout, with the thought of the four people who had lost their lives in the accident.
“We were also very conscious we had to get this black box to find out why the helicopter had crashed to save lives in the future, and you were conscious of the people sitting offshore and the people that will have to use them in the future.”