Airworthiness Directive · Amendment 39-9572 · Saab AB, Saab Aerosystems Airplanes
Saab AB, Saab Aerosystems Airplanes
This AD applies to Saab AB, Saab Aerosystems SAAB 340B, 340A (SAAB SF340A).
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB SF340A and SAAB 340B series airplanes, that requires visual and dye penetrant inspection(s) to detect cracks of the nose rib of the rudder, and stop drilling and blending of minor cracks. This amendment also requires replacement of the nose rib with a new nose rib and reinforcement of the nose rib, if extensive cracking is detected or if an operator elects to terminate the repetitive inspections. This amendment is prompted by the result of an inspection that revealed a cracked nose rib on the front spar of the rudder due to vibration-related stress. The actions specified by this AD are intended to prevent such stress and cracking, which could result in the deformation of the nose rib; this condition may lead to friction and jamming between the fin and the rudder and subsequent reduced controllability of the airplane.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
