AIRWORTHINESS DIRECTIVE

CAA-AD-T-032/1999R3

Nahrazuje CAA-AD-T-032/1999R2

Date of issue: March 01, 2002

HELICOPTER – TAIL ROTOR HUB PITCH-CHANGE PLATE BEARING (ATA 05, 65) – INSPECTION/REPLACEMENT

Applicability: AS 355 helicopters, versions E, F, F1, F2 and N, fitted with tail rotor hub pitch-change plate, P/Nos. 350A33-2004-00/-01/-02/-03/-05 and which do not incorporate MOD 076551 (new generation bearing P/No. 6010F234M16 (704A33.651.190) introduced by EUROCOPTER AS 355 Service Bulletin No. 65.00.15 R1).

Effective date: March 02, 2002

Compliance : Required as indicated in DGAC AD 1999-084-057(A)R3.

Remarks:. The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 33320922, fax: 420 2 20562270

Ing. Pavel MATOUŠEK
Director of Airworthiness Division
CAA CZ

DGAC ref: No. 1999-084-057(A)R3

EUROCOPTER

AS 355 Helicopters

Tail rotor hub pitch-change plate bearing (ATA 05, 65)

 

1. EFFECTIVITY:

AS 355 helicopters, versions E, F, F1, F2 and N, fitted with tail rotor hub pitch-change plate, P/Nos. 350A33-2004-00/-01/-02/-03/-05 and which do not incorporate MOD 076551 (new generation bearing P/No. 6010F234M16 (704A33.651.190) introduced by EUROCOPTER AS 355 Service Bulletin No. 65.00.15 R1).

 

2. REASONS:

This Airworthiness Directive (AD) is issued subsequent to some cases of deterioration of the tail rotor hub pitch-change plate bearing, which can lead to seizure of the bearing and loss of control of the aircraft.

 

Revisions 1 and 2 of this AD covered Revisions 1 and 2 of EUROCOPTER Service Bulletin No. 05.00.30.

 

Revision 3 of this AD covers the replacement of Service Bulletin No. 05.00.30 R2 with referenced Alert Service Bulletin (ASB) No. 05.00.30, with no change to the technical content.

 

3. MANDATORY ACTIONS AND COMPLIANCE TIME:

3.1. Within 10 flying hours following the effective date of Revision 1 of this Airworthiness Directive, check the rotation torque of the bearing, in accordance with the instructions described in paragraph 2.B 1) of the referenced ASB unless already carried out.

 

3.2. Check the bearing for axial play, friction points and brinelling in accordance with the instructions described in paragraph 2.B 2) of the referenced ASB.

 

3.2.1. within 10 flying hours (without exceeding 2 weeks).following the effective date of Revision 1 of this Airworthiness Directive, except for bearings which underwent this check less than 40 flying hours ago or less than 6 months ago.

 

3.2.2. every 50 flying hours (without exceeding 6 months between two checks).

 

3.3. Before installing a pitch-change plate assembly or a tail rotor gear box assembly, held as spare, on an aircraft, check the rotation torque and carry out the axial play, friction point and brinelling check in accordance with the instructions described in paragraphs 2.B 1) b) and 2.B 2) of the referenced ASB.

 

3.4. Interpretation of results:

 

3.4.1. If the measured rotational load is greater than 300 grams, remove the pitch-change plate assembly from the aircraft, or do not install the pitch-change plate assembly or tail rotor gear box assembly, held as spare, on the aircraft.

 

3.4.2. If the rotational load is less than 300 grams, and if the measured axial play is greater than or equal to 0.4 mm, and/or friction points or brinelling are detected :

- Check the condition of the parts (excluding the pitch-change plate bearing) and replace them according to the criteria defined in paragraph 2.B 3) b) of the referenced ASB.

- Replace the pitch-change plate bearing with a bearing in airworthy condition.

 

REF. : EUROCOPTER AS 355 Alert Service Bulletin No. 05.00.30.

 

This Revision 3 replaces AD 1999-084-057(A) R2 dated October 20,1999.

 

EFFECTIVES DATES :

Original AD : MARCH 06,1999

Revision 1 : On receipt of the Telegraphic AD issued on MAY 14,1999

Revision 2 : OCTOBER 30, 1999

Revision 3 : MARCH 02, 200