The US Federal Aviation Administration has ordered operators to inspect their Boeing 767s for broken "shear rivets" in the elevator mechanism.
The rivets are designed to break in case of a jam in one part of the system, disconnecting the jammed part to free the system, allowing control of the aircraft. The airworthiness directive covers rivets on elevator bellcrank assemblies.
The bellcrank, attached to a hydraulic power control actuator, moves the elevators. Failed shear rivets on two or more bellcrank assemblies could produce abnormal elevator movements and possibly loss of aircraft control.
Operators of 322 US-registered 767s have 30 days to respond to the AD which followed the release of a Boeing service bulletin. Nearly 800 767s are in service worldwide. The US agency says the AD does not relate to the fatal crash of an EgyptAir 767 last October. EgyptAir believes that the crash may have been caused by an elevator control system malfunction.
Source: Flight International
