Airworthiness Directive · Amendment 39-18160 · Main rotor head
The Enstrom Helicopter Corporation
Superseded. A later AD replaced this one: AD 2018-02-01. Comply with the one in force.
This AD applies to Enstrom Model F-28A, 280, F-28C, F-28C-2, F-28C-2R, 280C, F-28F, F-28F-R, 280F, and 280FX helicopters, all serial numbers; and Enstrom Model 480 helicopters, serial numbers 5001 through 5006; with a main rotor spindle (spindle), part number (P/N) 28-14282-11 or 28-14282-13, installed, certificated in any category. This AD applies to any helicopter that has a spindle with 1,500 or more hours time-in-service (TIS) or where the hours TIS of the spindle is not known.
We are publishing a new airworthiness directive (AD) for Enstrom Helicopter Corporation (Enstrom) Model F-28A, 280, F-28C, F- 28C-2, F-28C-2R, 280C, F-28F, F-28F-R, 280F, 280FX, and 480 helicopters. This AD was sent previously to all known U.S. owners and operators of these helicopters and supersedes Emergency AD (EAD) 2015- 04-51, dated February 12, 2015. This AD requires inspecting certain main rotor spindles (spindles) for cracks and reporting the inspection results to the FAA. This AD is prompted by a fatal accident and reports of spindles with cracks. The actions specified in this AD are intended to detect a crack in a spindle and prevent loss of a main rotor blade and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has been accomplished on or after February 11, 2015.
(1) Before further flight, conduct a magnetic particle inspection (MPI) of the spindle to determine if a crack exists, paying particular attention to the threaded portion of the spindle. The MPI of the spindle must be conducted by a Level II or Level III inspector qualified in the MPI in the Aeronautics Sector according to the EN4179 or NAS410 standard or equivalent. If there is a crack in the spindle, replace it with an airworthy spindle before further flight.
(2) Within 72 hours after accomplishing the MPI, report the information requested in Appendix 1 to this AD by mail to the Manager, Chicago Aircraft Certification Office, Federal Aviation Administration, ATTN: Gregory J. Michalik, 2300 East Devon Ave., Des Plaines, IL, 60018; by fax to (847) 294-7834; or email to gregory.michalik@faa.gov.
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.
