Airworthiness Directive · Amendment 39-17559 · Tail rotor blades
Agusta S.p.A. (Type Certificate Currently Held by Agusta Westland S.p.A) (Agusta) Helicopters
This AD applies to Agusta Model 109E helicopters with tail rotor (T/R) hub and blade assembly, part number (P/N) 109-8131-02-151 and P/N 109-8131-02-157, certificated in any category.
We are superseding an airworthiness directive (AD) for Agusta Model A109E helicopters that required reducing the tail rotor (T/R) blade life limit, modifying a T/R hub and grip assembly, re-identifying two T/R assemblies, clarifying the never-exceed speed (Vne) limitation, and reducing the inspection interval. Since we issued that AD, the manufacturer has redesigned a T/R grip bushing (bushing) that reduces the loads, which caused the T/R cracking, on the T/R blades. This action requires installing the new bushing and re-identifying the T/R hub-and-grip and hub-and-blade assemblies and requires a recurring inspection of each bushing. These actions are intended to prevent fatigue failure of a T/R 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 already been accomplished prior to that time.
(1) Before each start of the helicopter engines, visually check both sides of each T/R blade for a crack in the inspection area depicted in Figure 1 to paragraph (f)(1) of this AD. This action may be performed by the owner/operator (pilot) holding at least a private pilot certificate, and must be entered into the aircraft 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.
(2) For helicopters with T/R hub and blade assembly, P/N 109-8131-02-151 (consisting of two T/R blades, P/N 109-8132-01-111, and one T/R hub and grip assembly, P/N 109-8131-02-127), before further flight, modify each T/R hub and blade assembly by installing a new bushing, P/N 109-8131-30-109, in each grip assembly and two zero-hour time-in-service (TIS) T/R blades, P/N 109-8132-01-111; re-identifying the hub and grip assembly as P/N 109-8131-02-159; and re-identifying the T/R hub and blade assembly as P/N 109-8131-02-157 in accordance with the Compliance Instructions, Part V, paragraphs 2. through 13., of Agusta Bollettino Tecnico No. 109EP-30, Revision C, dated September 29, 2006 (BT). A T/R blade, P/N 109-8132-01-111, which has been operated as part of T/R hub and blade assembly, P/N 109-8131-02-151, must be retired regardless of TIS and may not be used as part of the T/R hub and blade assembly, P/N 109-8131-02-157. Returning the removed T/R blades, grips, or bushings to Agusta is not required.
(3) For helicopters with T/R hub and blade assembly, P/N 109-8131-02-157 (consisting of two T/R blades, P/N 109-8132-01-111, and one T/R hub and grip assembly, P/N 109-8131-02-159), within 25 hours TIS, and thereafter at intervals not to exceed 25 hours TIS, and before further flight any time there is an increase in vibration levels, using a 5x or higher power magnifying glass, visually inspect each T/R blade for a crack in accordance with the Compliance Instructions, Part III, paragraphs 1. through 5. of the BT. Reporting to Agusta is not required.
(4) On or before accumulating 200 hours TIS on the T/R hub and grip assembly, P/N 109-8131-02-159, and thereafter at intervals not to exceed 200 hours TIS, inspect the linings and measure the internal diameter of the bushings, P/N 109-8131-30-109, by referring to Figure 2 of the BT. If the internal diameter of the bushing exceeds 41.35 millimeters, replace the bushing.
(5) If there is a crack in a T/R blade, before further flight, replace the cracked T/R blade.
(6) Revise the Airworthiness Limitations section of the maintenance manual to reflect that a T/R blade, P/N 109-8132-01-111, which has not been operated as part of T/R hub and blade assembly, P/N 109-8131-02-151, has retirement life of 1,000 hours TIS.
