Airworthiness Directive · Amendment 39-13764 · MD Helicopters Inc. Model MD900 Helicopters
MD Helicopters Inc. Model MD900 Helicopters
Model MD900 helicopters, with Fan Input Force Limiting Control Rod Assembly (control rod assembly), part number (P/N) 900C6010239-105 or 900C2010239-107, installed, certificated in any category.
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. Model MD900 helicopters. This action requires installing a fan input force limiting control rod assembly fail-safe device (fail-safe device). This AD also requires, after installing a fail-safe device, before the first flight of each day, checking the fail-safe device for bent clips, taut lanyards, and piston rod movement. If any of these conditions are found, this AD requires replacing the control rod assembly with an airworthy control rod assembly before further flight. This amendment is prompted by an accident report of fatigue failure of the piston rod in the spring capsule on a control rod assembly. The actions specified in this AD are intended to provide a temporary backup support system in the event of a piston rod failure and to prevent subsequent loss of control of the helicopter.
To provide a temporary back-up support system in the event of piston rod failure and to prevent subsequent loss of control of the helicopter, accomplish the following:
(a) Unless accomplished previously, install a control rod assembly fail-safe device (fail-safe device) by following the Accomplishment Instructions, paragraph A., of MD Helicopters, Inc. Service Bulletin SB900-094, dated March 17, 2004 (SB). Install the fail-safe device on or before September 17, 2004, or as indicated in the following table based on the hours time-in-service (TIS) of the control rod assembly, whichever occurs first.
| Install a fail-safe device | If the control rod assembly has |
|---|---|
| (1) Before reaching 200 hours TIS | Less than 200 hours TIS. |
| (2) Within 10 hours TIS | 200 or more but less than 790 hours TIS. |
| (3) Before further flight | 790 or more hours TIS. |
(b) Before the first flight of each day after installing a fail-safe device required by paragraph (a) of this AD, check the control rod assembly as follows:
(1) Unzip the ceiling panel of the baggage compartment;
(2) Examine the outer bell-crank assembly for any bent clip and any lanyard connected to a clip that is taut; and
(3) Check the piston rod for any movement.
(4) An owner/operator, holding at least a private pilot certificate, may perform these visual checks and must enter compliance into the helicopter maintenance records in accordance with 14 CFR sections 43.11 and 91.417(a)(2)(v)).
(c) Before further flight, replace the control rod assembly with an airworthy control rod assembly if a bent clip, a taut lanyard, or any movement of the piston rod is found.
(d) 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 Los Angeles Aircraft Certification Office (LAACO), FAA, for information about previously approved alternative methods of compliance.
(e) Install the fail-safe device following MD Helicopter, Inc. Service Bulletin SB900-094, dated March 17, 2004. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615-GO48, Mesa, Arizona 85215-9734, telephone 1-800-388-3378, fax 480-891-6782, or on the web at www.mdhelicopters.com. 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.
