Airworthiness Directive · Amendment 39-13745 · Eurocopter France Model EC155B and B1 Helicopters
Eurocopter France Model EC155B and B1 Helicopters
Model EC155B and B1 helicopters with auxiliary system unit (ASU) board 10 Alpha 2, part number (P/N) SE07451, installed, certificated in any category.
This amendment adopts a new airworthiness directive (AD) for the specified Eurocopter France (ECF) model helicopters that requires cleaning the auxiliary system unit (ASU) board and modifying the wiring and wiring harness. If a temporary modification is done, the AD requires inserting a placard regarding on- ground operation of the emergency landing gear pump (pump). Also, this AD revises the Limitations section of the Rotorcraft Flight Manual (RFM) to limit the operation of the pump. Permanently modifying the wiring and wiring harness and removing the placard and limitations from the RFM is terminating action for the requirements of this AD. This amendment is prompted by the report of an emergency landing with the landing gear retracted. The landing gear failed to extend in normal and emergency extension modes following failure of the ASU board 10 Alpha 2. The actions specified by this AD are intended to prevent an electrical short circuit, failure of landing gear to extend, and a landing gear-up emergency landing.
To prevent an electrical short circuit, failure of landing gear to extend, and an emergency landing, accomplish the following:
(a) Within 15 hours time-in-service (TIS), clean the auxiliary system unit (ASU) board 10 Alpha 2. Clean the ASU board by following the Accomplishment Instructions, paragraphs 2.B.1, and 2.B.2.a., of Eurocopter EC155 Alert Service Bulletin (ASB) No. 31A005, dated August 20, 2003 (ASB No. 31A005).
(b) Within 30 days, modify the wiring and wiring harness permanently by complying with paragraph (c) of this AD or temporarily by following the Accomplishment Instructions, paragraphs 2.B.1. and 2.B.2.a. through 2.B.2.d. of ASB No. 31A005. If temporarily modified:
(1) Install a self-adhesive placard of the size and in the location depicted in Figure 4 of ASB No. 31A005 with the following text in white letters on a red background: “CAUTION: ON GROUND OPERATION OF EMERGENCY LANDING GEAR PUMP IS TIME LIMITED —SEE OPERATING LIMITATIONS” and
(2) Revise the Operating Limitations by inserting the following text into the Rotorcraft Flight Manual (RFM):
“(i) Limit the emergency landing gear pump (pump) to 10 minutes of continuous operation.
(ii) When the pump is continuously operated from 1 to 5 minutes, allow it to cool for 15 minutes before further use.
(iii) When the pump is continuously operated from 5 to 10 minutes, allow it to cool for 30 minutes before further use.”
Note 1: Modifying the electric wiring covered by Alert Telex No. 31A005R1, dated September 19, 2002, led to inhibiting the protective thermal switch of the electric pump. This resulted in the need for a limitation placard. The purpose of the limitation placard is to remind operators about the on-ground operating limitations that apply to the electric pump.
(c) Within 10 months, modify the wiring and wiring harness by following the Accomplishment Instructions, paragraphs 2.A. and 2.B., of Eurocopter EC155 ASB No. 31A008, dated August 20, 2003 (ASB No. 31A008). If you made the temporary modifications described in paragraph (b) of this AD, remove the placard from the helicopter and the limitations inserted in the RFM as a result of paragraphs (b)(1) and (b)(2) of this AD.
(d) Permanently modifying the wiring and wiring harness following ASB No. 31A008 is terminating action for the requirements of this AD.
(e) 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 Safety Management Group, Rotorcraft Directorate, FAA, for information about previously approved alternative methods of compliance.
