FAA Issues Emergency AD for Helicopter Air Conditioning

 - March 31, 2014, 12:50 PM

An emergency airworthiness directive, effective immediately–AD 2013-12-06–was issued March 24 covering Airbus Helicopters legacy models MBB BK117A-3, BK117A-4, BK117B-1 and BK117C-2 that use a Metro Aviation vapor-cycle air conditioning kit pulley. Affected aircraft use pulley number 30001 installed in accordance with supplemental type certificate SH3880SW, which now requires immediate inspection of the drive pulley for looseness and properly installed lock wires and reinstallation of the pulley.

The AD was prompted by two reports of the pulley detaching from the rotor-brake disk on the tail-rotor driveshaft, causing the pilot to lose control of the helicopter.