Commonwealth legislation

AD/ELECT/11 - Leach Relays - Control Terminal Insulation

RepealedCTH

This Act has been repealed and is no longer in force. It is retained for historical reference.

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Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

This airworthiness directive mandates a safety fix for specific electrical relays (Leach types 5038, 5039, 5058, 5059, 5060, and 5061) used in aircraft.

What it requires: Anyone installing these relays must first modify them to add extra insulation between the electrical coil terminals and the metal components of the relay. This prevents dangerous electrical short circuits or arcing.

Who must comply: Aircraft maintenance engineers, repair stations, and operators who handle these specific relay models.

How to comply: Before installing the relay in an aircraft, you must add a specially shaped piece of insulating material (a "hat section" made from 3 inch x 3 inch fibrous sheet at least 0.015 inches thick) around the terminal strip. The directive provides specific instructions for cutting, varnishing, and clamping this insulation in place.

Why it matters: Faulty insulation could cause electrical failures in critical aircraft systems, potentially compromising flight safety.

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AD/ELECT/11 - Leach Relays - Control Terminal Insulation

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Electrical Equipment

AD/ELECT/11 Leach Relays - Control Terminal Insulation NK

Applicability: All Leach type 5038, 5039, 5058, 5059, 5060, 5061 relays.

Requirement: Modify relays by increasing the insulation between the coil terminals and both the main contactor bar and the earthed metal yoke of the coil.

An approved method of compliance is as follows:

Remove the two coil terminal screw assemblies.

2. Form a piece of 3 in. x 3 in. fibrous insulating sheet of 0.015 inch minimum thickness into a hat section so that the hollow portion can fit over the existing insulated terminal strip, with the remaining portions bearing against the moulded cover and the metal yoke respectively, so as to provide an equal overhang of insulation at each end of the terminal strip. Cut a suitable hole to permit the passage of the coil end wires through the new insulation and cut appropriate holes in the hat section to correspond with the existing holes in the terminal strip. Varnish the formed strip.

3. Place the completed hat section in position and pass the coil wires through the appropriate hole. Replace the coil terminal assemblies at the same time connecting up the coil wires and clamping the new insulation firmly in place on each side of the terminal strip; or

ANO 107.2.6.2.1.

Compliance: Before installation in an aircraft.

Source text

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

1 AD/ELECT/11 - Leach Relays - Control Terminal Insulation