Show the full text (5,410 characters)
98-24-21 EUROCOPTER FRANCE: Amendment 39-10906. Docket No. 98-SW-19-AD.
Applicability: Model AS 332C, AS 332L, AS 332L1, and AS 332L2 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 (e) 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 does the presence of anymodification, alteration, or repair remove any helicopter from the applicability of this AD.
Compliance: Required as indicated, unless accomplished previously.
To prevent failure of the rotor drive engine-to-main gearbox (MGB) coupling, which, if undetected, could result in an engine overspeed leading to an uncontained engine turbine wheel burst and subsequent loss of control of the helicopter, accomplish the following:
(a) For Model AS 332C, AS 332L, AS 332L1, and AS 332L2 helicopters, before further flight, insert the following statement into the Emergency Procedures section, Chapter 3, of the Rotorcraft Flight Manual:
"If at any time during flight, either the "OVSP 1" or "OVSP 2" amber warning light illuminates, even intermittently, reduce the affected engine to ground idle as soon as possible, then shut it down once all of the parameters on the remaining engine have been checked and found to be satisfactory."
(b) For Model AS 332C, AS 332L, and AS 332L1 helicopters, within 8 hours time-in-service (TIS) and at intervals not to exceed 25 hours TIS thereafter, measure the vibration level of the left and right 23,000 RPM input shaft (engine-to-MGB shaft). Record the mean value of the measured vibration level in the helicopter maintenance records.
(1) If the vibration level exceeds 0.65 inches per second (IPS), perform the inspections described in paragraph (c) and (d) of this AD before further flight.
(2) If the vibration level is less than or equal to 0.65 IPS, perform the inspections described in paragraph (c) and (d) of this AD within the next 25 hours TIS.
(c) For Model AS 332C, AS 332L, and AS 332L1 helicopters, measure and record the tightening torque on the three engine-to-MGB coupling bolts for the left and right 23,000 RPM input shafts. Accomplish this measurement every 50 hours TIS after the initial inspection if Eurocopter France MODs 0752316 and 0752317 have not been accomplished.
(1) If Eurocopter France MOD 0752316 (tie bolt replacement) has not been accomplished, the tightening torque should be 1.5 to 1.9 m.daN (133 to 168 in.-lbs.) (lubricated with NATO 0.156 oil or equivalent).
(2) If Eurocopter France MOD 0752316 (tie bolt replacement) has been accomplished, the tightening torque should be 1.2 to 1.4 m.daN (106 to 124 in.-lbs.) (lubricated with NATO 0.156 oil or equivalent).
(d) Perform the engine-to-MGB coupling 23,000 RPM input check in accordance with the applicable maintenance manual.
NOTE 2: Section 63.10.00.602 of the applicable maintenance manual contains procedures for accomplishing the engine-to-MGB coupling 23,000 RPM input check. Paragraph 5 or the Work Card date code 97-04 is not applicable to the subject of this AD.
(1) While inspecting the splined flanges, inspect the splines for wear. Also inspect the MGB end of the splined flange for impact marks on the end of the splines. If wear exceeds the allowable limits, or if impact marks are found on the end of the splines, replace the splined flange with an airworthy splined flange.
(2) Inspect for the presence of the O-ring on the splined flange.
(3) After accomplishing the engine-to-MGB coupling 23,000 RPM input check and reassembly, measure the vibration level and record the results. If the vibration level remains above 0.65 IPS, conduct the vibration level correction procedure.
NOTE 3: Maintenance Manual (MET) Work Card 63.20.00.501 provides correction procedures if the vibration level exceeds 0.65 IPS.
(e) 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 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff.
(f) Special flight permits will not be issued.
NOTE 5: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 97-288-065(AB), AD 97-303-066(AB), AD 97-289-008(AB), all dated October 22, 1997, and AD 86-012-023(A) R4, dated July 29, 1998.
(g) This amendment becomes effective on December 9, 1998.
