The U.S. aircraft register, updated daily
FAA orders · airworthiness directive · current

2013-20-16: Main rotor blade retention bolts

FAA order 2013-20-16 is an airworthiness directive in force since December 5, 2013. The FAA's subject line: Main rotor blade retention bolts. It names Md Helicopters Inc MD 900: about 11 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: rotorcraft systems.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
MD Helicopters, Inc.
Models
MD900
On this site
Md Helicopters Inc MD 900 11 registered

Dates and paperwork

In force since
December 5, 2013
Published
October 31, 2013 (signed September 27, 2013)
Docket
FAA-2013-0486
Status
Current
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

We are adopting a new airworthiness directive (AD) for MDHI Model MD900 helicopters with certain main rotor blade (MRB) retention bolts (bolts) installed. This AD requires a daily check of the position of each bolt, a daily check and a repetitive inspection for a gap in each bolt, and, if necessary, removing and inspecting the bolt for a crack and replacing any cracked bolt with an airworthy bolt. This AD was prompted by multiple reports of in-service bolt failures. The actions are intended to prevent failure of a bolt, which could lead to loss of MRB structural integrity and subsequent loss of control of the helicopter.

The order itself the regulatory text, as published

Show the full text (4,824 characters)
Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: PART 39--AIRWORTHINESS DIRECTIVES 0 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Sec. 39.13 [Amended] 0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): 2013-20-16 MD Helicopters, Inc. (MDHI): Amendment 39-17622; Docket No. FAA-2013-0486; Directorate Identifier 2010-SW-031-AD. (a) Applicability This AD applies to Model MD 900 helicopters with a main rotor blade retention bolt (bolt), part number (P/N) 900R3100001-103 or 900R3100001-105, installed; certificated in any category. (b) Unsafe Condition 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.(c) Effective Date This AD becomes effective December 5, 2013. (d) Compliance You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time. (e) Required Actions (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 [[Page 65197]] [GRAPHIC] [TIFF OMITTED] TR31OC13.000 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. (f) Alternative Methods of Compliance (AMOCs) (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. [[Page 65198]] (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 standardsdistrict office or certificate holding district office before operating any aircraft complying with this AD through an AMOC. (g) Additional Information 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. (h) Subject Joint Aircraft System Component: 6210: Main rotor blade retention bolts.

Related safety bulletins advice on the same designs, not orders

2007-11-14SW-08-05 · MD900 Main Rotor Blade Retention Bolt Check

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 5, 2026. Connections as data: /graph/directive/2013-20-16.json · aircraft systems.