Commonwealth legislation

AD/PMTV/1 - Blade Root Lag Screws

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Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

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This airworthiness directive requires an immediate torque check of blade-root lag screws on specified MT propeller models (manufactured before 31 Dec 1998) installed on Vedeney M-14-P or M-14-PF engines, and repeating the check every 100 flight hours or 12 months until the lag screws are replaced per MT‑Propeller Service Bulletin (SB) 17 Rev A. Replacing the screws according to SB 17 is the terminating action for the checks. It affects aircraft owners/operators and maintenance providers because they must inspect, repeat inspections, and pay for parts and downtime in response to reported lag‑screw failures that can cause blade separation.

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AD/PMTV/1 - Blade Root Lag Screws

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Propellers - Variable Pitch - MT

AD/PMTV/1 Blade Root Lag Screws 4/99 DM

Applicability: MTV-3-B-C/L250-21 and MTV-9-B-C/CL250 or /CL260-27 model propellers manufactured prior to 31 December 1998 and installed on Vedeney M-14-P or M-14- PF engines.

Requirement: Check lag screw torque in accordance with MT-Propeller Service Bulletin (SB) 17, Revision A, dated 5 March 1999.

Incorporation of new blade root lag screws in accordance with SB 17, Revision A, constitutes terminating action for this check.

Note 1: LBA ADs 1999-081/2 and 1999-082/2 also refer.

Note 2: Propellers inspected per the original issue of SB 17 satisfy the intent of this Directive.

Compliance: Unless previously accomplished, prior to next flight after effective date of this airworthiness directive. Thereafter at intervals of 100 hours time in service or 12 months, whichever occurs first.

This Airworthiness Directive becomes effective on 17 March 1999.

Background: This airworthiness directive is prompted by reports of broken blade root lag screws in certain models of MT propellers installed on aerobatic aircraft. Lag screw breakage is attributed to loss of torque. Fractured lag screws can lead to blade separation and loss of control of the aircraft.

Source text

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

1 AD/PMTV/1 - Blade Root Lag Screws