Grounded: BP halt Puma helicopter flights

The suspension of operations involving the new generation Super Puma EC2225 was ordered as a team of ten experts from the government's Air Accident Investigation Branch (AAIB) arrived in Aberdeen to begin the daunting task of establishing the precise cause of the incident.

The decision to ground the remaining EC225s in the Bond fleet has been taken as a precautionary measure. Bond insisted last night that the aircraft were certified fit to fly and the Civil Aviation Authority said there were no plans to suspend operations involving the advanced Super Puma elsewhere in Britain or Europe.

The AAIB investigators are likely to face a protracted investigation to determine whether pilot error, the dense fog in the area at the time of the accident, or a systems or mechanical failure was to blame.

The pilot has already been praised for the skill he displayed in what appears to have been a controlled ditching of the French-built aircraft in poor visibility , 500m metres short of BP's ETAP (Eastern Trough Area Project) platform, 125 miles east of Aberdeen.

One of the survivors told a colleague yesterday how he thought the incident was simply a "hard landing" until he saw water starting to flood in to the helicopter.

Remarkably the aircraft, with its tail boom sheared off, remained afloat throughout the night.

By yesterday the fuselage had turned turtle in the water and efforts to recover the aircraft will continue today.

The Scotsman can reveal that the missing tail boom contains the unit which contains both the flight data recorder and cockpit voice recorder – vital to the AAIB's investigation.

But sources at Bond insist the unit will be easily located and recovered from the sea.

Yesterday, as the majority of the survivors arrived in Aberdeen on board the standby vessel which helped rescue them, oil giant BP announced that a decision had been taken to ground the remaining two EC225 Super Pumas in the Bond offshore fleet.

Bernard Looney, BP's North Sea managing director, said: "We have jointly taken the decision with Bond to suspend operations of the aircraft model in question.

"What happened last night was a very serious incident and until we understand more it seemed prudent to Bond and ourselves that we should suspend the operation of that particular model.

"That in no way presupposes that there is something wrong with the aircraft."

Mr Looney stressed it would be unwise the speculate on the possible cause of the ditching. "We are anxious to know what and happened ," he said. "This is going to require some patience. We need to get to the facts and the facts are going to take some time.

"BP will provide whatever support we can to ensure that the aviation industry and indeed the whole of the oil and gas industry gets to the bottom of this.

"We will no doubt look to learn as we do from any incident. We can always improve."

A spokesman for Bond Helicopters said: "The situation is that Bond's two other EC225s have been inspected and are fully approved and certified to operate.

"Bond has every confidence in the aircraft – which are available to fly."

He added: "There is no issue over this. The customer always has choice as to whether they use a particular aircraft."

A spokesman for the CAA said that there was nothing to suggest a requirement for other EC225s to be grounded.

He said: "We would not do that unless there was evidence that it needed to happen."

The 15 men who arrived in Aberdeen shortly before 6am on board the supply vessel Caledonian Victory appeared in good spirits as they disembarked.

A few waved at the waiting media and one of the survivors gave a defiant thumbs up sign.

Later, as some of the survivors arrived at an oil service company's offices in Aberdeen one of the men said simply: "We had an accident" and another declared "Everybody did a good job."

FACT BOX

The EC225 is French aviation company Eurocopter's most advanced version of the Super Puma.

Weighing eleven tonnes, it has twin engines and a five- bladed rotor to provide optimum reliability and lift.

Capacity: Up to 24 passengers and two crew.

Maximum speed: 174 mph

Range: 519 miles

The central structure is reinforced with rigid frames able to resist crashloads.

Bond Helicopters bought three of the new generation helicopters last year.

The company has invested 40 million in the three EC 225s and in training engineers and pilots on the EC225.

Why did copter crash? Here are four theories

MECHANICAL FAULT

Was there a problem with a tail rotor or gear box, or some other mechanical failure which forced the pilot to ditch?

Whatever happened, the helicopter pilot only had a few seconds to react, but somehow managed to land the aircraft safely, saving all 18 people on board.

STRUCTURAL FAILURE

The tail boom of the Super Puma is missing. It is still not known whether it became detached before or after the accident.

Jim Ferguson, an aviation expert, says: "If the helicopter hit the water as the pilot ditched nose up, then that could explained why the tail boom has become detached.

"But if you lose your tail boom in flight, the chances are you will be dead. If it had fallen off I think we would be looking at fatal casualties or at least serious injuries.

"If you lose a tail boom the chances are the aircraft would start spinning around its main rotor, and that would not be terribly good news.

"I would have expected much greater destruction."

THE WEATHER

The dense fog in the area may have been a factor and could have hampered the pilot's visibility as he approached the platform.

At least one helicopter has been downed in the past as a result of a lightning strike, but there is no suggestion of lightning in the area at the time of the accident.

PILOT ERROR

The pilot could have misjudged his approach to the helideck, distracted in the pitch dark and thick fog.

"Whatever happened, the pilot at the controls did a remarkable job in the circumstances," says Mr Ferguson.

"There is nothing pointing anywhere as to the cause at the moment and until we know exactly what happened it would be unwise to speculate."