# AD 67-30-01: Auxiliary Hydraulic Power System

- Type: Airworthiness directive
- Status: Current
- Products: Airbus BAC 1-11 200 Series
- Effective: December 4, 1967
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-506
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/27C95525BD91354D8625699F006B9515.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/67-30-01

## The airworthiness directive

67-30-01 BRITISH AIRCRAFT: Amdt. 39-506, Part 39, Federal Register November 4, 1967. Applies to Model BAC 1-11 200 Series Airplanes.

Compliance required as indicated, unless already accomplished.

To prevent failure of the Thermal Relief Valve installed in the No. 2 Auxiliary Hydraulic Power System, introduced by Modification PM 1653, and to provide an adequate thermal relief device in all airplanes, accomplish the following:

  (a) For Post Modification PM 1653 airplanes, within the next 200 hours' time in service after the effective date of this AD, and thereafter at intervals not to exceed 200 hours' time in service from the last inspection, check No. 2 Auxiliary Hydraulic System Thermal Relief Valve for satisfactory functioning in accordance with BAC One-Eleven Service Bulletin 29-A- PM 2758, Issue 2, or later ARB-approved issue, or FAA-approved equivalent.

  (b) For Post Modification PM 1653 airplanes, within the next 600 hours' time in service after the effective date of this AD, and thereafter at intervals not to exceed 600 hours' time in service from the date of the last inspection or when a low maximum pressure is indicated in the No. 2 Auxiliary Hydraulic System or emergency elevator power system, conduct a bench test of Thermal Relief Valve P/N AIR 91186/2 in accordance with British Aircraft Corporation, Ltd., BAC One-Eleven Alert Service Bulletin No. 29-A-PM 2758, Issue 2, or later ARB- approved issue, or FAA-approved equivalent.

  (c) If defective parts are found during the inspections provided for in paragraphs (a) and (b), either modify the hydraulic system in accordance with paragraph (d), or replace the defective part with a serviceable P/N AIR 91186/2 and continue the inspections required by paragraphs (a) an (b).

  (d) For Post Modification PM 1653 airplanes, within the next 1800 hours' time in service after the effective date of this AD, remove Thermal Relief Valve P/N AIR 91186/2, Conduit Guide P/N AB58A3967, and Pipe P/N AB58/48/2675, and rework Lockheed Non- Return Valve P/N 91178 to the standard of Choke Valve Assembly P/N AB48A1427 in accordance with British Aircraft Corporation, Ltd. BAC One-Eleven Service Bulletin No. 29-PM 2758, Part C, or FAA-approved equivalent.

  (e) For Pre Modification PM 1653 airplanes, within the next 1,800 hours' time in service after the effective date of this AD, rework Lockheed Non-Return Valve P/N AIR 91178 to the standard of Choke Valve Assembly P/N AB48A1427 in accordance with British Aircraft Corporation, Ltd., BAC One-Eleven Service Bulletin No. 29-PM 2758, Part B, or FAA-approved equivalent.

  (f) The repetitive inspections required by paragraphs (a) and (b) of this AD may be discontinued when modifications in accordance with paragraph (d) of this AD have been accomplished.

This amendment effective December 4, 1967.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A5EU](https://openairdocs.org/tcds/A5EU): Airbus SAS; names 1 of 2 models: BAC 1-11 200 Series

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

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