AD/TBM 700/50 Amdt 1 Alternator and Vapour Cycle Cooling System Pulley Drive Assembly (Cth)
AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/TBM 700/50 and issues the following AD under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Aerospatiale (Socata) TBM 700 Series Aeroplanes
| AD/TBM 700/50 Amdt 1 | Alternator and Vapour Cycle Cooling System Pulley Drive Assembly | 2/2009 |
Applicability: | TBM 700 N aircraft from serial number (S/N) 434 and up. Note 1: TBM 850 is the commercial designation of the TBM700N. |
Requirement: | 1. For aircraft s/n 434 to 459 inclusive: (a) Remove the pulley drive assembly, the torque limiter, the compressor drive belt and the alternator/compressor support, in accordance with paragraph (§) C of the accomplishment instructions of EADS SOCATA SERVICE BULLETIN (SB) 70-161-21 amendment 2; and (b) Inspect for cracks, the pulley drive surfaces and the alternator/compressor support welds, in accordance with § D.1 of the accomplishment instructions of SB 70-161-21 amendment 2. (i) If any crack is detected, before further flight, replace or conditionally repair the cracked unit as instructed in § D.2 of the accomplishment instructions of SB 70-161-21 amendment 2. (c) Replace any pulley drive shear shaft that has never been replaced before the effective date of this AD, or that has, on the effective date of this AD, accumulated 30 Hours Time in Service (TIS) or more, with a serviceable shaft, in accordance with § E of the accomplishment instructions of SB In the event an operator is unable to establish the accumulated hours TIS on a given shaft installed on an airplane, the total hours accumulated on the airplane must be used in the determination of the replacement time for the shaft. (d) (i) Re-install the pulley drive assembly and the alternator/compressor support, without re-installing compressor drive belt or the torque limiter, as instructed in § F of the accomplishment instructions of SB 70-161-21 amendment 2; and (ii) Install on the instrument panel and in the Pilot’s primary field of vision, the following placard: |
| “AIR COND” INOPERATIVE RECOMMENDED “AIR COND” SWITCH POSITION: “MANUAL“ (iii) Insert SB n° 70-161-21 amendment 2 in the Pilot’s Operating Handbook. Permission to ferry an aeroplane to a maintenance location to accomplish actions required by Requirement 1 of this AD is granted provided that the air conditioning is switched off during flight. 2. Inspect for cracks, the pulley drive surfaces and the alternator/compressor support welds, in accordance with § C, D, F and G.1) to G.3) of the accomplishment instructions of SB 70-161-21 amendment 2. Note 2: For accomplishment of the repetitive inspections required by Requirement 2 of this AD, paragraph C.2) of the accomplishment instructions of SB 70-161-21 amendment 2 does not apply since the torque limiter has already been removed. Alternative means of compliance. Compliance with the requirements detailed below restores the capability to make use of the air conditioning system. As an alternate to Requirements 1 and 2 of this AD, do the following actions at the operator’s discretion and/or when motivated by spare parts availability: (a) Install a zero-timed pulley drive assembly P/N T700G215510000000 as instructed in § D.1, I and J of the accomplishment instructions of SB 70-161-21 amendment 3; and (b) Thereafter, at intervals not to exceed 100 FH, inspect for cracks in the alternator/compressor support welds, in accordance with the accomplishment instructions of § B,G, H, I and J of SB 70-161-21 amendment 3; and (c) Upon accumulation of 400 hours TIS, replace each pulley drive assembly The use of later approved revisions of this document is acceptable for compliance with the requirements of this AD. Note 3: EASA AD 2008-0129R1-E dated 31 July 2008 refers. | |
Compliance: | For Requirement 1 - Within 30 days after the effective date of this AD. For Requirement 1(b)(i) - Before further flight. |
| For Requirement 1(c) - Before accomplishment of Requirement 1(d) of this AD. For Requirement 1(d) - Within 30 days after the effective date of this AD and until further notice. For Requirement 2 - At the next scheduled maintenance inspection or within 100 Flight Hours (FH) after the effective date of this AD, whichever occurs first, and thereafter at intervals not to exceed 100 FH. | |
| This Amendment becomes effective on 12 February 2009. | |
Background: | A rupture of the alternator and vapour cycle cooling system pulley drive assembly has been reported. Such a failure could lead to the loss of the alternator and vapour cycle cooling systems and could also cause mechanical damage inside the powerplant compartment. This AD required a check for leakage from the pulley drive assembly and, as an interim action, and required the removal of the compressor drive belt from the assembly, and adopting a new operational procedure to deactivate the air-conditioning system. More recent cases have involved the rupture of the alternator and vapour cooling system compressor drive shaft and cracks have developed on the standby alternator and compressor support. This amendment revises the replacement of certain parts and introduces an alternative means of compliance to allow the restoration of the air conditioning system. A definitive solution to the problem is still under consideration. The original issue of this AD became effective on 3 July 2008. |
James Coyne
Delegate of the Civil Aviation Safety Authority
22 December 2008
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