AD 97-20-13 Airworthiness Directives; Eurocopter Deutschland Model EC135 P1 and T1 Helicopters

Models named: EC135 P1, T1. Read the applicability below — it usually turns on serial or part numbers too.

Model EC135 P1 and T1 helicopters, certificated in any category. Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (d) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Required as indicated, unless accomplished previously. To prevent failure of the tail rotor and subsequent loss of control of the helicopter, accomplish the following: (a) Before further flight, and thereafter before the first flight of each day, visually inspect all stator blades in the stator hub area for cracks (see Figure 1). Inspect the stator blades in the areas where they are riveted to [[Page 65200]] the stator hub. Pay particular attention to the radius areas where the stator blade base attaches to the stator hub. (1) If the inspection reveals a crack at the base of a stator blade, remove the paint from the area and perform a dye-penetrant inspection. (2) If the inspection reveals 3 or less cracked stator blades and a total crack length per stator blade of less than 15mm, stop- drill each crack with a 2mm diameter drill. BILLING CODE 4910-13-P [GRAPHIC] [TIFF OMITTED] TR11DE97.000 [[Page 65201]] (b) Within 400 hours time-in-service (TIS), and thereafter, at intervals not to exceed 400 hours TIS, remove the paint from all stator blades in the stator hub area and perform a dye-penetrant inspection for cracks. (c) If the inspections reveal cracks on any stator blade with a total crack length of 15mm or longer, or if more than 3 stator blades are cracked, remove the affected stator blades and replace them with airworthy stator blades before further flight. The inspections required by this AD must continue to be performed on all stator blades including replacement stator blades. Note 2: Eurocopter Deutschland Alert Service Bulletin No. EC 135-53A-001, Revision 01, dated August 8, 1997, pertains to this AD. (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Standards Staff, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Standards Staff. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff. (e) Special flight permits will not be issued. (f) This amendment becomes effective on December 29, 1997, to all persons except those persons to whom it was made immediately effective by Priority Letter AD 97-20-13, issued September 25, 1997, which contained the requirements of this amendment. Note 4: The subject of this AD is addressed in Luftfahrt- Bundesamt (Germany) AD 97-249, effective September 25, 1997. Issued in Fort Worth, Texas, on December 2, 1997. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 97-32255 Filed 12-10-97; 8:45 am] BILLING CODE 4910-13-P