AD 2018-16-11 Airworthiness Directives; Various Model 234 and Model CH-47D Helicopters

This AD becomes effective September 17, 2018.

(1) For operators of helicopters with type certificates issued by the Denver Aircraft Certificate Office or ACO Branch, the manager of the Denver ACO Branch, FAA, may approve AMOCs for this AD. Send your proposal to: Greg Johnson, Senior Aerospace Engineer, Denver ACO Branch, Compliance and Airworthiness Division, FAA, 26805 East 68th Avenue, Denver, CO 80249; phone: 303-342-1083; fax: 303-342-1088; email: Gregory.Johnson@faa.gov. (2) All other AMOC requests should be sent to the Manager, Seattle ACO Branch, FAA. Send your proposal to: Chris Bonar, Aerospace Engineer, Airframe Section, Seattle ACO Branch, FAA, 2200 S 216th Street, Des Moines, WA 98198; telephone (206) 231-3521; email 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. (3) 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.

Special Airworthiness Information Bulletin SW-11-03, dated October 22, 2010 (SAIB); Columbia Helicopters, Inc., Alert Service Bulletin No. 234-62-A0012, Revision 2, dated March 1, 2016; and Columbia Helicopters, Inc., Alert Service Bulletin No. 47D-62-A0002, Revision 0, dated March 1, 2016, which are not incorporated by reference, contain additional information about the subject of this AD. You may view the SAIB on the internet at http://www.regulations.gov in the AD Docket. For Columbia service information identified in this final rule, contact Columbia Helicopters, Inc., 14452 Arndt Road NE, Aurora, OR 97002, telephone (503) 678-1222, fax (503) 678-5841, or at http://www.colheli.com. You may view a copy of the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.

(1) Before further flight, remove from service any pitch housing P/N 145R2075-11, 145R2075-12, 145R2075-13, 145R2075-14, 145R2075-15, 145R2075-16, 234R2075-1, and 234R2075-2 that has accumulated 8,200 hours total time-in-service (TIS). (2) Before the pitch housing accumulates 200 hours TIS after the effective date of this AD and thereafter at intervals not to exceed 200 hours TIS, ultrasonic inspect the pitch housing for a crack in accordance with Attachment 1, paragraphs F and H through K, of Boeing Service Bulletin 145R2075-62-0001, Revision 1, dated September 27, 2011. If there is a crack, replace the pitch housing before further flight. (3) Within 400 hours TIS after the effective date of this AD or before the pitch housing has accumulated 4,000 hours total TIS, whichever occurs later, and thereafter at intervals not to exceed 500 hours TIS, eddy current inspect the pitch housing for a crack. If there is a crack, replace the pitch housing before further flight. The eddy current inspection must be accomplished using a method approved by the Manager, Seattle ACO Branch, or by the Manager, Denver ACO Branch. For a repair method to be approved as required by this AD, the manager's approval letter must specifically refer to this AD.

This AD defines the unsafe condition as a crack in a pitch housing lug. This condition could result in loss of a rotor blade and consequent loss of helicopter control.