Airworthiness Directive · Amendment 39-16819 · Agusta S.p.A. (Agusta) Model AB139 and AW139 Helicopters
Agusta S.p.A. (Agusta) Model AB139 and AW139 Helicopters
Models AB139 and AW139 helicopters, serial number (S/N) 31005 through S/N 31157 (except S/Ns 31007, 31094 and 31149) and S/N 41001 through S/N 41023, certificated in any category.
This amendment adopts a new airworthiness directive (AD) for the specified Agusta model helicopters. This action requires inspecting certain modules and related connectors for corrosion. If there is corrosion on the connectors, this AD requires cleaning the connectors before further flight. If there is corrosion on a module, before further flight, this AD requires replacing the module with an airworthy module. This AD also requires modifying the Number 2 Modular Avionic Unit (MAU) ventilation duct. This amendment is prompted by some in- flight emergencies due to internal corrosion of the MAU circuit card assemblies. The actions specified in this AD are intended to detect corrosion of certain modules to prevent the display of misleading data to the flight crew, disengagement of the flight director modes of the autopilot or other alert system, increased workload of the flight crew, and subsequent loss of control of the helicopter.
To detect corrosion of certain modules, to prevent the display of misleading data to the flight crew, disengagement of the flight director modes of the autopilot or other alert system, increased workload of the flight crew, and subsequent loss of control of the helicopter, do the following:
(a)(1) Remove the following items related to the Numbers 1 and 2 Modular Avionics Unit (MAU):
(i) Power supply (PS) module, part number (P/N) 7024440-1901;
(ii) Custom Input/Output (CSIO) module, P/N 7025410-1901;
(iii) Control Input/Output (CIO) module, P/N 7026534-1902;
(iv) MAU cabinet; and
(2) Inspect the PS, CSIO, CIO, and MAU cabinet and all related connectors for corrosion.
(i) If there is corrosion on a connector, before further flight, clean the connector.
(ii) If there is corrosion on a module, before further flight, replace the module with an airworthy module.
(b) Modify the Number 2 MAU ventilation duct by following the Compliance Instructions, paragraphs 6 through 11, of Agusta Bollettino Tecnico No. 139-166, dated April 6, 2009 (BT).
(c) Install and operationally test the Number 1 and Number 2 MAUs and the related PS module, CSIO module, CIO module, MAU cabinet, and all related connectors.
(d) Reinstall the AFT right float assembly or the lower panel, P/N 3P5340A01631, whichever was removed during the modification process required by paragraph (b) 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 Manager, Safety Management Group, ATTN: George Schwab, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5114, fax (817) 222-5961.
(f) The Joint Aircraft System/Component (JASC) Code is 3425: Navigation, Integrated Flight Director System.
(g) Modifying the ventilation duct shall be done by following specified portions of Agusta Bollettino Tecnico No. 139-166, dated April 6, 2009. The Director of the Federal Register approved this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Agusta, Via Giovanni Agusta, 520 21017 Cascina Costa di Samarate (VA), Italy, telephone 39 0331-229111, fax 39 0331-229605/222595, or at http://customersupport.agusta.com/technical_advice.php. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
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
