Airworthiness Directive · Amendment 39-13976 · Saab Model SAAB SF340A and SAAB 340B Series Airplanes
Saab Model SAAB SF340A and SAAB 340B Series Airplanes
This AD applies to all Model SAAB SF340A and SAAB 340B series airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Saab Model SAAB SF340A and SAAB 340B series airplanes. This AD requires a one-time inspection to determine the part and serial numbers of certain engine vibration isolators (mounts) and the cure dates of certain molded assemblies incorporated in those engine mounts; and related corrective actions if necessary. This AD is prompted by a report that disbonding of the elastomer from the inner metal core and shim of certain engine vibration mounts has occurred within a few hundred hours of operation, causing heavy chafing of the engine support system and chafing of the fire sensor loop. We are issuing this AD to prevent reduced integrity of the fire-shielding capacity of the nacelle structure and a possible fire detector fault.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 500 flight hours after the effective date of this AD, perform a one-time inspection to determine the part and serial numbers of certain engine vibration mounts, and the cure dates of certain molded assemblies incorporated in those engine mounts; and a general visual inspection for chafing of the nacelle structure and fire sensor loop; and related corrective actions, as applicable; in accordance with the Accomplishment Instructions of Saab Service Bulletin 340-71-059, dated May 16, 2003. Corrective actions must be accomplished prior to further flight.
Note 1: Saab Service Bulletin 340-71-059 refers to Barry Controls Service Letter 93948-71-05, dated April 30, 2003, as an additional source of service information.
Note 2: For the purposes of this AD, a general visual inspection is “a visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normal available lighting conditions such as daylight, hangar lighting, flashlight or droplight and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.”
As of the effective date of this AD, no person may install on any airplane an engine vibration mount unless the part and serial number of the engine vibration mount, and the cure date of the molded assembly incorporated in the engine mount, have been determined and any applicable corrective action accomplished before further flight, in accordance with the requirements of paragraph (f) of this AD.
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
