Norwegian Authorities Have Listed The MR Gearbox As Possible Cause For April 29 Accident

Airbus Helicopters is defending the Main Rotor Gearbox on its Super Puma helicopters after Norwegian accident investigators declined to rule it out as a potential cause an accident April 29 that fatally injured 13 people.

The aircraft went down after the main rotor separated from the aircraft in flight. The AIBN, Norway's aviation accident investigation agency, listed the gearbox as one of three potential causes for the separation. Super Pumas have had problems with the gearbox in the past, and Norway and Britain have grounded commercial Super Puma flights until the investigation is completed.

Reuters reports that Airbus Helicopters said in a statement that the AIBN should focus on "suspension bars", struts that attach the rotor head to the helicopter. It also said maintenance of the aircraft should be investigated.

Analysis conducted by Airbus Helicopters produced seven potential scenarios that could have led to the accident, the company said in the statement. "Out of these seven scenarios, only one – the failure of the attachment of a suspension bar – can be assessed as probable by Airbus Helicopters, based on the information available to date," the statement said.

"Analysis of the helicopter’s maintenance history has just started and should provide a better understanding of the most likely causes," it added.

CHC, the operator of the helicopter, said the AIBN should continue looking at all three potential causes, adding that it is important to avoid speculation and focus on "factual details as they emerge."

(Image from file. Not accident aircraft)

FMI: www.airbushelicopters.com, www.aibn.no