The Bell 427 is the subject of a new FAA airworthiness directive requiring replacement of certain tailboom attachment hardware and at certain intervals determining the torque of the attachment hardware. It was prompted by a review of the tailboom attachment installation that revealed the torque value of the bolts specified in the maintenance manual, and applied during manufacturing, was incorrect and exceeded the recommended torque range.
Bell 206L-1 LongRanger, Heber Springs, Ark., Aug. 11, 2008–The NTSB determined the probable cause of the forced landing by the Hillsboro Aviation LongRanger following loss of power was improper installation of the PC line on the Rolls-Royce 250-C30P engine, which resulted in a partial loss of power.
Hawker Beechcraft King Air C90, Baton Rouge, La., April 25, 2008–Structural failure of the right main landing gear torque knee caused the King Air’s gear to collapse on landing at Baton Rouge Metropolitan Airport, the NTSB determined. Failure to inspect the torque knee at the designated 1,000-hour interval, as required by AD 2002-01-10, was a contributing factor.
Hawker Beechcraft King Air B300, Englewood, Colo., Jan. 8, 2007–The NTSB found that the King Air drifted left on landing and hit a snowbank because the main landing gear upper torque knee failed due to overstress. Investigators also attributed the incident to the pilot’s inability to maintain aircraft control. There were no injuries.
A special airworthiness information bulletin recommends that operators of Mitsubishi MU-2Bs comply with recently issued service bulletins (SBs) for a one-time inspection to check for corrosion and the proper torque of wing attach barrel nuts and bolts. The SBs were based on the discovery of a fractured barrel nut during a routine inspection.
Sikorsky has introduced a software fix for its S-92 that it says will address a 4R vibration some pilots have experienced at high cruise speeds. The company has already retrofitted new active vibration control software to some of the fleet.
The NTSB has asked the FAA to require MD Helicopters to conduct tests to “enable the full analysis” of all critical loads for tension-torsion (T-T) straps installed in the Notar anti-torque fan of MD 500Ns, 600Ns and 900s. The recommendations stem from the Safety Board’s ongoing investigations into two nonfatal accidents involving MD 900s in 2004.