Airworthiness Directive · Amendment 39-14938 · Bombardier Model DHC-8-400 Series Airplanes
Bombardier Model DHC-8-400 Series Airplanes
This AD applies to Bombardier Model DHC-8-400 series airplanes, certificated in any category; as identified in Bombardier Service Bulletin 84-78-01, Revision ‘A,' dated September 15, 2005.
The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires inspecting to determine the manufacturer's date of certain V-band clamps on the engine exhaust shroud assembly, and doing related investigative/corrective actions if necessary. This AD results from a report of a discrepancy found during a maintenance inspection on a V- band clamp located on the engine exhaust duct shroud. The clamp ends were touching (although the correct fastener torque had been applied), resulting in reduced clamp force on the flanges. We are issuing this AD to prevent vibration in the duct shroud and fretting of the V-band clamp and flanges, which could result in cracking of the flanges and consequent release of hot exhaust gases from the engine tailpipe and damage to adjacent structure. This situation could trigger the fire warning system and result in an in-flight emergency, such as the flightcrew shutting down the engine and activating the fire suppression system.
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 5,000 flight hours after the effective date of this AD: Inspect to determine the part number (P/N) of the V-band clamps on the engine exhaust duct shroud in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-78-01, Revision ‘A,' dated September 15, 2005. For any V-band clamp having P/N VC1642A-2030-A or VC1642A-1875-A, before further flight, determine the manufacturer's date and do all applicable related investigative and corrective actions (including inspecting the flange of the shroud assemblies for discrepancies), by accomplishing all the actions specified in the Accomplishment Instructions of the service bulletin; except as provided by paragraph (g) of this AD. Do all applicable related investigative and corrective actions before further flight.
(g) If, during the accomplishment of the corrective actions required by paragraph (f) of this AD, the service bulletin specifies contacting the manufacturer for repair instructions, before further flight, repair in accordance with a method approved by either the Manager, New York Aircraft Certification Office (ACO), FAA; or Transport Canada Civil Aviation (TCCA) (or its delegated agent).
Actions accomplished before the effective date of this AD according to Bombardier Service Bulletin 84-78-01, dated March 22, 2005, are considered acceptable for compliance with the corresponding actions specified in paragraph (f) of this AD.
(i) As of the effective date of this AD, no person may install a V-band clamp, P/N VC1642A-2030-A or VC1642A-1875-A, with a manufacturer batch stamp dated before “08-02,” on any airplane.
