Airworthiness Directives; British Aerospace Model BAC 1-11 200 and 400 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAC 1-11 200 and 400 series airplanes, that requires repetitive ultrasonic inspections to detect cracking of the lugs of the engine mounting beams, and replacement of the beam with a serviceable part, if necessary. This amendment is prompted by reports of fatigue cracking of the lugs of the engine mounting beams. The actions specified by this AD are intended to detect and correct such cracking of the engine mounting lugs, which could result in reduced structural capability of the engine mount.