As the link has changed and the article is now in 'The Couriers' archives somewhere, I hope you don't mind me posting the news article here, for the benefit of those who have not yet had the chance to read it.
Fatal crash copter crew may have faced major fault
By Stefan Morkis
A ROYAL Navy inquiry into the cause of a helicopter crash that claimed the lives of two Dundee airmen has been unable to determine the reason for the accident.
However, their report suggests that the crew experienced a major malfunction and were forced to cut power to the helicopter’s rotor as they attempted to correct the fault.
The inquiry also found that it would be virtually impossible to recover from such a situation while flying at low level over the sea at night.
Pilot Lieutenant Robert Dunn (26), from Broughty Ferry, and naval aviator Lieutenant Jamie Mitchell (29), from Dundee, and two other crew members died when their Lynx helicopter came down off the coast of Cornwall last December.
They were carrying out a search and rescue mission around 17 nautical miles off Lizard Point when the helicopter crashed into the sea.
Despite interviewing 27 witnesses and examining radar data tapes and the technical accident investigation findings, the inquiry was unable to pinpoint the exact cause of the crash.
Its efforts have been hampered by the lack of any type of an accident data recorder, cockpit voice recorder—both of which were destroyed—or emergency radio report from the crew prior to the crash.
The inquiry has managed to determine the sequence of events that led up to accident.
The helicopter had been launched from HMS Portland at 6.20 pm on December 8 to assist in a search and rescue mission after HMS Montrose had reported a man overboard.
At 7.03 pm the helicopter descended to 100 feet above sea level as the crew searched and radioed in their position. After completing two orbits of a search pattern and about two minutes after reporting their position, the helicopter crashed.
Surveys of the wreckage of the helicopter on the seabed showed that although it was upright on the sea floor, it had suffered extensive damage.
Data from the aircraft’s radar tapes showed that when it hit the sea it had an extremely low forward speed but an extremely high rate of descent.
The initial investigation by the Royal Navy Flight Safety and Accident Investigation Centre indicated that neither of the helicopter’s engines was providing significant power to the rotor system at the time of the impact and that both appeared to have been shut down manually before the accident.
This action is known as a crash check and is extremely dangerous when flying at a low level over sea at night.
Therefore, the board of inquiry believes that the crew would only have taken this action if they had been firmly convinced they were dealing with a major emergency.
Simulations carried out after the accident also suggest that crew believed they had no other option but to cut power to the rotor because of a perceived major incident rather than inadvertently descending into the sea.
The inquiry was also unable to determine whether Lt Dunn was wearing his contact lenses when the helicopter crashed and so was unable to say whether this had been a contributory cause or not—thereby not completely ruling out the possibility of pilot error.
However, the inquiry did say that it was unlikely that a combination of disorientation and a minor malfunction had caused the crew to erroneously believe they had suffered a major malfunction.
The board of inquiry has made several recommendations in the wake of the crash, including that the RNFSAIC continues the investigation into the crash.
Wilma Donnelly, mother of Jamie Mitchell, said last night, “Whatever the inquiry finds will not bring my son back. The main concern of all the families was that there was no blame attached to anyone.”
Can we speculate now, as ;
The initial investigation by the Royal Navy Flight Safety and Accident Investigation Centre indicated that neither of the helicopter’s engines was providing significant power to the rotor system at the time of the impact and that both appeared to have been shut down manually before the accident.
Both engines manually shut down would certainly, as crab and wg13 mention, bring a tail rotor drive failure to the top of the suspects list.
edited because I've previously answered that question from wg13, dummy