Commonwealth legislation

AD/B737/15 Amdt 3 - Fuel Boost Pump Bypass Valve

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Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

4/10 complexity

This AD requires operators of the Boeing 737 models listed in Boeing Service Bulletin 737-28A1072 to fit improved fuel boost pump bypass valves, perform interim suction-feed checks about every 300 flight hours until the fix is fitted, and inspect for bracket preload on aircraft modified under earlier revisions. CASA enforces compliance; aircraft operators and their maintenance organisations pay for and schedule the inspections and modifications. The action responds to two flameouts traced to ice-blocked bypass valves (Background).

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Current sections

Direct links to the current provisions in AD/B737/15 Amdt 3 - Fuel Boost Pump Bypass Valve.

AD/B737/15 Amdt 3 - Fuel Boost Pump Bypass Valve

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Boeing 737 Series Aeroplanes

AD/B737/15

Amdt 3

Fuel Boost Pump Bypass Valve 11/90

Applicability: Model 737 series aeroplanes listed in Boeing Service Bulletin 737-28A1072 Revision 4.

Requirement: 1. Action in accordance with Part I of Boeing Service Bulletin 737-28A1072 Revision 4.

2. Unless already modified in accordance with Part II of Boeing Service Bulletin 737-28A1072 Revision 2 or 3, action in accordance with Part II of Boeing Service Bulletin 737-28A1072 Revision 4.

3. For those aircraft which exhibited bracket preload when previously modified in accordance with Boeing Service Bulletin 737-28A1072 Revision 2 or 3; unless already accomplished, conduct an inspection of the suction feed bypass system for preloading in accordance with Boeing Service Bulletin 737-28A1072 Revision 4.

Note: FAA AD 90-15-17 Amdt 39-6673 refers.

Compliance: 1. At each maintenance interval coinciding with approximately 300 hrs time in service, until improved bypass valves are installed in accordance with Requirement 2.

2. Prior to 31 March 1992.

3. Prior to 31 March 1992.

Background: The manufacturer has determined that two separate incidents of engine flame out during cruise conditions was caused by small accumulations of water freezing in the Fuel Boost Pump Bypass Valve, and preventing fuel flow to the engine while on suction feed. Amendment 3 is raised in response to a revision of the country of origin AD which required modification of those aircraft not previously modified and an inspection for bracket preload for aircraft modified prior to Revision 4 of the Service Bulletin.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/B737/15 Amdt 3 - Fuel Boost Pump Bypass Valve