Commonwealth legislation

AD/JETSTREAM/14 Amdt 4 - Flap Torque Tube Universal Joints

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What this does: Operators of British Aerospace Jetstream HP137 Mk1 and Series 200/3100/3200 aircraft (except those fitted with the improved flap torque shaft assembly) must identify whether Type F or Type M universal joints are fitted to each flap torque shaft and, if Type F is present, inspect it (visual and eddy‑current) and replace it with a Type M in accordance with the cited British Aerospace service bulletin.

Why it matters: Type F joints have a shorter fatigue life; the AD sets inspection frequencies and replacement deadlines to manage that risk while exempting aircraft already fitted with the improved assembly.

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AD/JETSTREAM/14 Amdt 4 - Flap Torque Tube Universal Joints

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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British Aerospace BAe 3100 (Jetstream) Series Aeroplanes

AD/JETSTREAM/14

Amdt 4

Flap Torque Tube Universal Joints 13/94

Applicability: All HP137 Mk1, Jetstream Series 200, 3100 and 3200 aircraft, except those which have the improved flap torque shaft assemblies introduced by Jetstream Service Bulletin 27-JA920340.

Note: The improved flap torque shaft assemblies were factory fitted beginning with constructor’s number 957.

Requirement: In accordance with British Aerospace Jetstream Alert Service Bulletin 27-A-JA 900544 Revision 3, or 4:

Identify whether Type F or Type M universal joints are fitted to the LH and to the RH flap torque shaft assemblies.

2. Inspect Type F universal joints for cracks, visually, and using eddy currents.

3. Replace Type F universal joints with Type M universal joints.

Compliance: 1. Identify joint type before 15000 landings, or before exceeding 100 landings after 30 June 1990, whichever occurs later.

2. If a type F joint has been in service more than 15000 landings when identified, inspect before further flight after identification, and thereafter at intervals not exceeding 400 landings.

3. Replace not later than 15000 landings, or before exceeding 400 landings after 30 June 1990, whichever occurs later.

The provisions of the previous amendments are unchanged, this Amendment is effective from 8 December 1994.

Background: Two types of universal joints were fitted to the flap torque shaft assemblies. One, known as Type F, has a much shorter fatigue life than the other, known as Type M. This Directive first requires an inspection to determine which type is fitted to the aircraft. No further action is required for Type M joints, but Type F joints must be replaced before 15000 landings. For Type F joints that have already exceeded 15000 landings, safety is maintained by inspection for a short period to allow scheduling for the replacement.

Amendment 4 exempts aircraft which have the later, improved flap torque shaft assemblies. The wording of this Directive has also been revised, without changing the intent.

Source text

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

1 AD/JETSTREAM/14 Amdt 4 - Flap Torque Tube Universal Joints