Boeing's design of different engine mountings for the 767-400ER, compared to other members of the 767 family, has been vindicated by a US Federal Aviation Administration proposal to accept the new design under the special conditions clause of its regulations.
On 767-200 and -300 models, damage to the aircraft structure from the high torque forces induced by a catastrophic engine seizure is limited by "fuse pins" in the engine mount, which allow the engine to separate from the wing.
The manufacturer has anticipated the rule change for the 767-400 and the design incorporates the required strengthening. The FAA guidance indicates that the torque would be absorbed by "some deformation in the engine supporting structure". Boeing has already met the new requirement in its 777, 737NG and 757-300.
• All Boeing 727 fuel tanks are to be checked urgently for damage by electrical arcing to wiring conduits which pass through the tanks, says an FAA airworthiness directive. Two 727s had been found to have holes burned in the conduits by arcing from chafed wiring.
Source: Flight International
