An investigation was under way yesterday into how the Bond-operated S-92 aircraft ended up making an unscheduled landing on a drilling rig.
The aircraft had set out from Aberdeen headed for the Buzzard platform around 60 miles north.
But instead, it landed unannounced on the Ensco 120 “jack-up” rig – nine nautical miles from the Buzzard installation.
Aircraft operator Bond yesterday confirmed two pilots had been taken off the flight roster while an investigation took place.
Regional organiser for the RMT union, Jake Molloy, said he could not understand how the pilots made the mistake.
He said: “I find this astonishing. We’ve come across wrong deck landings before but they tend to be in clusters.
“It’s relatively easy to land on the wrong deck but nine miles beggars belief.
“There could be any number of reasons why this has happened and there are clearly lessons to be learned to make sure it doesn’t happen again.”
He added: “There are obvious risks associated with landing on the wrong deck. It’s the operations on board the platform that could cause the grief – crane operations, any problems or productions issues etc.”
It is understood the Ensco drilling rig was fully operational at the time and the crew was unprepared for a helicopter landing.
The Buzzard installation consists of a series of four large connected platforms which contain wellhead and production facilities, as well as living quarters.
One concerned oil worker claimed the jack-up rig’s crew were shocked by the sudden and unexpected arrival of a helicopter on deck.
He said: “When this chopper landed on the rig, the radio operator called the helicopter and said, ‘Can we help you?’
“They replied, ‘We appear to have landed on the wrong rig’.
“Most helicopter accidents occur on approach or departure – you must have a crew on the rig ready to receive the helicopter and a standby boat there to offer help if needed. When a chopper is approaching a rig, you are not allowed to move the cranes – the rig was fully operational with cranes working.
“Most of the time, the crane operator is the helicopter landing officer so that takes care of the problem.”
A spokesman for Bond confirmed yesterday the Sikorsky S-92 ended up diverting from its original flight plan, having left Aberdeen at 5:30pm on Friday.
The spokesman said: “We can confirm that an S-92 helicopter landed briefly on the deck of the Ensco 120, a platform that was not on its original flight plan. An investigation is under way.”
North-east MSP Lewis Macdonald described the incident as “concerning”.
He said: “Clearly, everybody who uses helicopters – and their families – needs to have confidence in the systems and procedures used by companies like Bond and anything that undermines that confidence must be investigated urgently.
“An incident such as this is bound to throw up questions and concerns.”