AD 2013-20-16 Airworthiness Directives; MD Helicopters, Inc. (MDHI) Helicopters

This AD becomes effective December 5, 2013.

(1) The Manager, Los Angeles Aircraft Certification Office, Airframe Branch (ANM-120L), FAA, may approve AMOCs for this AD. Send your request to Roger Durbin, Aerospace Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, ANM-120L, 3960 Paramount Blvd., Lakewood, CA 90712, telephone (562) 627-5233, fax (562) 627-5210, email roger.durbin@faa.gov. (2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

MDHI Alert Service Bulletin SB900-116R1, dated April 9, 2010, which supersedes MDHI Alert Service Bulletin SB SB900-116, dated February 24, 1010, neither of which is incorporated by reference, contains additional information about the subject of this AD. For service information identified in this AD, contact MDHI, Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734, telephone (800) 388-3378, fax (480) 346-6813, or at http://www.mdhelicopters.com. You may review copies of the service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

(1) Before the first flight of each day: (i) Visually check each bolt for failure. Failure of a bolt may be indicated by movement of the bolt out of the bolt hole or by inconsistent extension of the bolt above or below the other bolts being inspected (a failed bolt migrates out of the bolt hole). (ii) Visually check for a gap between the thrust washer and the retainer, P/N 900R2100009-101 or -103. The thrust washer is depicted as item 2 and the retainer is depicted as item 8 in Figure 1 to paragraph (e) of this AD. BILLING CODE 4910-13-P ER31OC13.000 BILLING CODE 4910-13-C (iii) The actions required by paragraphs (e)(1)(i) and (e)(1)(ii) may be performed by the owner/operator (pilot) holding at least a private pilot certificate and must be entered into the aircraft maintenance records showing compliance with this AD in accordance with 14 CFR 43.9(a)(1)-(4) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439. (iv) If there is any indication of bolt failure or if there is no gap between the thrust washer and retainer, before further flight, remove and inspect the bolt for a crack. Replace any cracked bolt with an airworthy bolt. (2) Within 300 hours time-in-service (TIS), and thereafter at intervals not to exceed 300 hours TIS, inspect each bolt for a gap between the thrust washer and the retainer. (i) Determine whether an O-ring is installed. Install any missing O-ring. (ii) If there is no gap between the thrust washer and retainer, before further flight, remove and inspect the bolt for a crack. Replace any cracked bolt with an airworthy bolt. (iii) If there is a gap between the thrust washer and retainer, measure the gap in two locations, 180 degrees apart, with a feeler gage. If the gap is more than 0.100 inch (2.54 mm) at either location, before further flight, remove and inspect the bolt for a crack. Replace any cracked bolt with an airworthy bolt.

This AD defines the unsafe condition as bolt failure. This condition could result in loss of main rotor blade structural integrity and subsequent loss of control of the helicopter.