Airworthiness Directive · Amendment 39-14747 · Agusta S.p.A. Model AB139 Helicopters
Agusta S.p.A. Model AB139 Helicopters
Superseded. A later AD replaced this one: AD 2007-25-14. Comply with the one in force.
Model AB139 helicopters, with tailpipe assembly left hand, part number (P/N) 3G7800L00131 and right hand, P/N 3G7800L00231, installed, certificated in any category.
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2006-17-51, sent previously to all known U.S. owners and operators of Agusta S.p.A. (Agusta) Model AB139 helicopters by individual letters. This AD requires, before further flight and at specified intervals, certain visual inspections of each tailpipe assembly for a crack and for overheating. If you find areas of overheating, this AD also requires, before further flight, certain inspections for damage to the surrounding structure, outside of the cowling, and inside of each tailpipe assembly in certain areas. This AD also requires, before further flight, if you find a crack, replacing the tailpipe assembly with an airworthy tailpipe assembly. This AD is prompted by several reports of tailpipe assembly cracks. The actions specified by this AD are intended to prevent a fire due to the structure in the cowling area overheating, separation of a part of a tailpipe assembly, and subsequent loss of control of the helicopter.
To prevent a fire due to the structure in the cowling area overheating, separation of part of each tailpipe assembly, and subsequent loss of control of the helicopter, do the following:
(a) Before further flight, and thereafter at intervals not to exceed 25 hours time-in-service, access the rear areas of each tailpipe assembly by removing the rear cowlings.
(1) Visually inspect each tailpipe assembly inside the cowling for a crack.
Note 1: Bollettino Tecnico No. 139-069, dated August 11, 2006 (BT), pertains to the subject of this AD.
Note 2: Aircraft Maintenance Publication (AMP) AB139 pertains to the subject of this AD.
(2) Inspect the structure surrounding each tailpipe assembly for overheating. If you find areas of overheating, inspect for heat damage to the surrounding structure. Inspect for overheating in the area of each tailpipe assembly outside the cowling. Inspect the internal part of each tailpipe assembly in the areas depicted in Areas A, Figure 1, of this AD.
(i) Clean the end of each tailpipe assembly with a cloth. While applying slight pressure on it, inspect for a crack using a flashlight.
(ii) Inspect each tailpipe assembly toward the centerline of the helicopter for a crack using a flashlight.
(iii) Inspect each tailpipe assembly toward the outboard side of the helicopter for a crack using a mirror and a flashlight.
(3) If you find a crack, before further flight, replace the tailpipe assembly with an airworthy tailpipe assembly.
(b) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Manager, Safety Management Group, FAA, ATTN: Ed Cuevas, Aviation Safety Engineer, Fort Worth, Texas 76193-0111, telephone (817) 222-5355, fax (817) 222-5961, for information about previously approved alternative methods of compliance.
Note 3: The subject of this AD is addressed in the European Aviation Safety Agency (EASA) AD 2006-0242-E, dated August 11, 2006.
Note 4: This AD differs from the BT and the EASA AD in that the BT and EASA AD allow repairs of certain cracks in each tailpipe assembly.
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
