U.S. aviation safety agency calls for replacement of helicopter part involved in N.W.T. crash

The Federal Aviation Administration (FAA) has directed American helicopter operators to remove and replace a tension torsion strap for several Bell aircraft.

The FAA regulates aircraft maintenance in the U.S.

In its directive, the FAA said it was prompted after a Bell 212 helicopter "experienced a separation of a main rotor blade from the main rotor head and subsequent impact into terrain shortly after takeoff."

The description of the incident is reminiscent of the crash that happened in Fort Good Hope, N.W.T.,earlier this year, in which pilot Tom Frith died. However, the FAA wouldn't confirm whether the directive was referring to that crash specifically.

The directive calls for operators to replace four types of tension torsion straps manufactured by Airwolf Aerospace, affecting about 120 helicopters on the American registry.

"Failure of an affected (tension torsion) strap could occur at any time without any previous indications and result in a sudden and catastrophic condition," reads the directive.

The directive comes into effect on Oct. 11.

Preliminary results from an investigation by the Transportation Safety Board showed a broken tension torsion strap, manufactured by Airwolf, was the cause of the crash in Fort Good Hope.

On July 18, Transport Canada issued a safety alert calling on Canadian operators with Bell 204, 205, 206, 210 and 212 model helicopters to inspect their Airwolf straps. That alert references the Fort Good Hope crash.

Transport Canada has confirmed that the U.S. ban extends to Canadian operators as well.