AIRWORTHINESS DIRECTIVE

CAA-AD-074/2001

Date of issue: August 13, 2001

AIRCRAFT - NAVIGATION - INERTIAL REFERENCE UNITS (ATA 34) - REPLACEMENT

Applicability: AIRBUS INDUSTRIE A310 and A300-600 aircraft, all certified models and all serial numbers, fitted with HONEYWELL 10 MCU inertial reference units, part number (P/N) HG1050BD02 or HG1050BD05.

Aircraft on which AIRBUS INDUSTRIE modification No.12304 has been embodied in production (or AIRBUS INDUSTRIE Service Bulletin (SB) A310-34-2158 or A300-34-6135 in service) are not concerned by the requirements of this Airworthiness Directive (AD).

Effective date: October 04, 2001

Compliance: Required as indicated in DGAC AD 2001-303(B).

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 AD No.: 2001-303(B)

AIRBUS INDUSTRIE

A310 and A300-600 aircraft

Navigation - Inertial Reference Units (ATA 34)

APPLICABILITY:

AIRBUS INDUSTRIE A310 and A300-600 aircraft, all certified models and all serial numbers, fitted with HONEYWELL 10 MCU inertial reference units, part number (P/N) HG1050BD02 or HG1050BD05.

Aircraft on which AIRBUS INDUSTRIE modification No.12304 has been embodied in production (or AIRBUS INDUSTRIE Service Bulletin (SB) A310-34-2158 or A300-34-6135 in service) are not concerned by the requirements of this Airworthiness Directive (AD).

REASONS:

Due to the aircraft motion when the inertial reference unit alignment procedures were not finished, an operator noticed the loss of aircraft positioning data and erroneous pitch/roll data, a short while after take-off.

Such a situation might have hazardous consequences on the aircraft airworthiness if the aircraft is flown without any visual cue.

Analyses of this incident in service led to the development of new standards of HONEYWELL inertial reference units.

The replacement of the three aircraft inertial reference units by these new standards is rendered mandatory.

In addition, magnetic variations tables are updated in the new standards.

ACTIONS:

Before June 30, 2004, unless already accomplished, remove HONEYWELL inertial reference units P/N HG1050BD02 or HG1050BD05 and replace them by HONEYWELL units P/N HG1050BD06 or HG1050BD07, in accordance with the instructions of SB A310-34-2158 or A300-34-6135.

REF.: AIRBUS INDUSTRIE Service Bulletins:

A310-34-2158

A300-34-6135

Any later approved revision of these SBs is acceptable.

EFFECTIVE DATE: AUGUST 04, 2001