AIRWORTHINESS DIRECTIVE
CAA-AD-4-093/98
Date of issue: December 07, 1998
AIRCRAFT - POWER PLANT - MOUNTS - INSPECTION/REPLACEMENT
Applicability: SAAB SF 340A -004 through -159 and SAAB 340B -160 through -459.
Effective date: December 31, 1998
Compliance: Required as indicated in SAD AD No. 1-135.
Remarks: Where applicable, the requirements of this AD must be integrated into the Aircraft's Logbook(s). Address inquiries con
cerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyně Airport, 160 08 Prague 6, Czech Republic, tel.: 420 2 324086, fax: 420 2 364112.Ing. Pavel MATOUŠEK
Director of Airworthiness Division, CAA CZ
LUFTFARTSVERKET Aviation Safety Department SWEDISH AIRWORTHINESS DIRECTIVES (SAD)
SAD No 1-135
Section 1. Swedish Manufactured Aeronautical Products
AIRWORTHINESS DIRECTIVE NO: 1-135
AIRCRAFT TYPE: SAAB SF 340A and SAAB 340B
SERIAL No’s AFFECTED: SAAB SF 340A -004 through -159 and SAAB 340B -160 through -459
SUBJECT: Power Plant - Mounts - Inspection of the engine mounts and replacement if necessary
BACKGROUND: It has been found that the elastomeric material in certain bottom forward engine mounts after a short time in service have degraded. This degrading will reduce the redundancy and change the stiffness and damping characteristics of the engine support system, causing heavy chafing on the nacelle structure and chafe on the fire sensor loop. Heavy chafing of the structure may reduce its integrity and fire shielding capability and chafing of the fire sensor loop may ultimately cause a nuisance fire warning leading to a precautionary engine shut down.
This SAD calls out an inspection to locate degraded engine mounts and replacement if necessary.
REFERENCE DOCUMENTS: Saab Aircraft AB Mandatory Service Bulletin SAAB 340-71-057 dated 20 November,1998.
ACTIONS: Perform actions described in Saab Aircraft AB Mandatory Service Bulletin SAAB 340-71-057 dated 20 November, 1998, or later revision
COMPLIANCE TIME: To be performed within 400 flight hours.
Repeated inspection after 250 flight hours, if applicable (Ref. para.2.B.(3)) in Saab Aircraft AB Mandatory Service Bulletin SAAB 340-71-057 dated 20 November, 1998, or later revision.
EFFECTIVE DATE: 27 November,1998