Thanks to the skill of the pilot and moderate conditions at sea after days of severe gales the operation went so smoothly that the men did not even get their feet wet as they stepped from the helicopter to a liferaft. They were rescued 80 minutes later by an oil-platform standby ship.
Tony Jones, general manager of Bristow, the helicopter's operator, praised the pilot, Captain Cedric Roberts, 44. He said: "It takes some skill to land a helicopter in the sea in these conditions. What is clear is that the crew performed in a workmanlikemanner and did everything correctly."
Richard Crawley, a spokes-man for the Coastguard, described the rescue as a "textbook operation".
A combination of relatively calm seas and extensive flotation equipment on the helicopter prevented it turning turtle and sinking when the pilot ditched the aircraft.
Lightning strikes are not unusual on aircraft and several helicopters have been forced to carry out a "controlled ditch" in the North Sea without loss of life in recent years.
However, there have also been tragedies, including the deaths of 11 men when their Super Puma came down in the North Sea two years ago. The worst disaster was in 1986 when a Boeing Chinook crashed because of a mechanical failure, causing 44 deaths.
Yesterday's accident took place as the aircraft, flying from Aberdeen, was 22 miles from the Brae field, where the men were bound for one of Marathon Oil's three platforms.
The pilot sent out a Mayday call at 12.38pm saying that he was ditching after the tail-rotor, which gives the aircraft directional stability, had been struck by lightning, setting up some kind of vibration through the fuselage.
Coastguards at Aberdeen launched a rescue, with RAF Sea-King helicopters from Lossiemouth and Boulmer, Northumberland, and a coastguard helicopter from Sumburgh, Shetland, directed from above by an RAF Nimrod.
But the men were eventually picked up from the life rafts by the oil company standby vessel Grampian Freedom at about 2pm and given an initial medical on board before being transferred to the Brae Alpha platform for further checks.
Last night three of the men chose to return to Aberdeen by the ship, while the rest were due to go ashore by helicopter. The damaged helicopter sank after remaining upright and afloat for several hours and despite being tethered to a supply vessel, the Highland Pride.
Aviation experts were able to suggest two possible reasons that a helicopter of this type hit by lightning would have been disabled but still able to put down with some kind of control.
John Osmond, editor of Helicopter World magazine, said that the force of the strike may simply have damaged the tail rotors. Alternatively, a strike on the tail - the most likely place as lightning would be attracted to the pointed extremity of the aircraft - may have set up an electrical current in the gearbox, fusing the metal components.
Either way, Mr Osmond said that if the helicopter had sufficient forward speed the pilot would still be able to fly, the difficulty coming when he attempted to slow to descend.Reuse content