The US National Transportation Safety Board (NTSB) has called on the Federal Aviation Administration to issue an airworthiness directive mandating a two-year-old service bulletin issued for the Eurocopter BK 117.
The NTSB believes the service bulletin, issued in 1997 recommending the installation of a hook-type latch, would prevent access doors from opening in flight and hitting rotor blades.
On 28 August last year, a BK 117 twin operated by St Louis Helicopters touched down and rolled over during an emergency landing after the No 1 engine cowling and its access door separated during a landing approach. The rotorcraft suffered substantial damage. The engine cowling and its access door had separated and hit the main rotor blades and tail rotor blades, resulting in a tail rotor imbalance and subsequent loss of the tail rotor gear box.
Source: Flight International
