Commonwealth legislation

AD/SWSA226/72 - Main Landing Gear Door Jamming

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legislative instrument

Plain English Summary

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This airworthiness directive requires operators of specified Fairchild (Swearingen) SA226/SA227 aeroplanes to remove particular main-landing-gear (MLG) door-stop bolts and jam nuts (when fitted per a named service bulletin) and to service the MLG struts per the maintenance manual. It responds to incidents where misaligned bolts and low hydraulic fluid in the strut caused MLG doors to jam and prevented gear extension.

Aircraft owners/operators pay for and perform the work within the stated 50‑hour windows; CASA enforces the requirement, changing maintenance practice and part configuration for affected aircraft.

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AD/SWSA226/72 - Main Landing Gear Door Jamming

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Fairchild (Swearingen) SA226 and SA227 Series Aeroplanes

AD/SWSA226/72 Main Landing Gear Door Jamming 12/95 DM

Applicability: Model SA226-T S/n T201 to T275, and T277 to T291; SA226-T(B) S/n T(B)276 and T(B)292 to T(B)417; SA226-AT S/n AT001 to AT074; and SA226-TC S/n TC201 to TC419.

Requirement: 1. For aircraft with the MLG door stop installed in accordance with Fairchild Aircraft SB SA226-32-043 Revised 6 September 1983:

- remove the four bolts P/N 27K51001-007 or the alternate P/N NAS 428-3-13 and four jam nuts P/N NAS509-3 from the P/N 27K51001-003 bracket assembly.

For all applicable aircraft: service the MLG struts in accordance with “Fluid Servicing - Landing Gear” instructions in SA-226 Maintenance Manual 32-00-00 Paragraph 1C.

Note: FAA AD 95-17-07 refers.

Compliance: 1. Within 50 hours time in service after the effective date of this Directive.

Unless carried out within the last 400 hours time in service, within 50 hours time in service after the effective date of this Directive.

This Directive has effect from 20 September 1995.

Background: There have been two incidents of aircraft making emergency MLG up landings when the MLG door stop bolts and striker plate hardware jammed and prevented the MLG from extending. Investigation revealed that misalignment of the bolts and the striker caused this jamming. This misalignment occurred because the strut did not fully extend upon gear retraction after the previous take off. This was caused by low hydraulic fluid in the strut.

Source text

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

1 AD/SWSA226/72 - Main Landing Gear Door Jamming