Airworthiness Directive · Amendment 39-19401 · Rotorcraft tail boom
Airbus Helicopters
Superseded. A later AD replaced this one: AD 2021-02-08. Comply with the one in force.
This AD applies to Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N1, and SA-366G1 helicopters, certificated in any category.
We are adopting a new airworthiness directive (AD) for Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N1, and SA-366G1 helicopters. This AD requires repetitive inspections of the aft fuselage outer skin. This AD was prompted by several reports of aft fuselage outer skin disbonding. The actions of this AD are intended to address an unsafe condition on these products.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) Within 110 hours time-in-service (TIS), tap inspect the aft fuselage outer skin for disbonding between frames X4630 and X6630 in the areas depicted in Figure 1 of Airbus Helicopters Alert Service Bulletin (ASB) No. AS365-05.00.77, ASB No. SA366-05.48, or ASB No. EC155-05A033, all Revision 0 and dated July 21, 2017 (ASB AS365-05.00.77, ASB SA366-05.48, or ASB EC155-05A033), as applicable for your model helicopter. Examples of acceptable and unacceptable disbonding areas are depicted in Figure 2 of ASB AS365-05.00.77, ASB SA366-05.48, and ASB EC155-05A033, as applicable for your model helicopter.
(i) If there is no disbonding, repeat the tap inspection at intervals not to exceed 660 hours TIS.
(ii) If there is disbonding within one square-shaped area measuring 3.94 in. x 3.94 in. (10 cm x 10 cm) that does not cross two skin panels, repeat the tap inspection at intervals not to exceed 110 hours TIS.
(iii) If there is disbonding that exceeds one square-shaped area measuring 3.94 in. x 3.94 in. (10 cm x 10 cm) or crosses two skin panels, before further flight, repair or replace the panel. Thereafter, tap inspect the panel at intervals not to exceed 660 hours TIS.
(2) Within 220 hours TIS, and thereafter at intervals not to exceed 110 hours TIS, clean the aft fuselage outer skin and using a light, visually inspect for distortion, wrinkling, and corrosion between frames X4630 and X6630 as depicted in Figure 1 of ASB AS365-05.00.77, ASB SA366-05.48, or ASB EC155-05A033, as applicable for your model helicopter. If there is any distortion, wrinkling, or corrosion, before further flight, tap inspect the area for disbonding by following the inspection instructions in paragraph (e)(1) of this AD.
