AAIB report 7 March 2007

Available from Government News Network.

Initial reports are being disseminated because of the importance of helicopter operations in support of the offshore oil and gas industry. I don't understand all the terminology used, but it seems the co-pilot was not happy with the approach. When the commander took over he could not get the helicopter to climb and it continued to fall a great rate. However, there is not explanation about why he had this problem.

Excerpts from the report are shown below.

It is estimated that more than 90% of the helicopter has been recovered including the tail rotor, the main rotor head, the main gearbox and both engines. There are no signs of a mechanical failure prior to the crash

Also, the combined data and voice recorder has been recovered and successfully replayed. From this the following has been determined. "During the later stages f the approach the helicopter slowly pitched nose down and commenced a slow roll to the right. At the same time the collective lever was raised, increasing power from the engines, and the indicated airspeed and altitude began to increase. The crew became unhappy with the approach and decided to abort the attempt to land.

A go around was commenced during which the helicopter continued to roll to the right and pitch nose down. The co-pilot asked for assistance and the commander took control. The data indicates that one second later the helicopter had attained a maximum nose down pitch attitude of 30o, coincident with a bank angle of 38o to the right. The indicated airspeed was increasing through 80 kt, and the radio altitude was reducing through 300 ft with a rate of descent of approximately 1,400 ft per minute. Over the next two and a half seconds, the helicopter rolled level and the pitch atitude reduced to 13o nose down. The radio altitude indicated 170 ft, with an indicated airspeed in excess of 100 kt and a rate of descent of about 1,400 ft per minute. During the next five and a half seconds, there was no significant change in the pitch atitude and the indicated airpseed continued to increase as the helicopter descended; over the same period, the helicopter commenced a slow roll to the right. The last recorded parameters indicate a radio altitude of 30 ft, a 12o nose down pitch atitude, an indicated airspeed of 126 kt, and an angle of bank of 20o to the right.

A review of the recorded data to date has not indicated any problems of a technical nature and no helicopter maneuvers have been identified which were not in response to flight controls."