AIRWORTHINESS DIRECTIVE On the commencement date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below repeals Airworthiness Directive AD/INST/10 Amdt 1 and issues the following AD under subregulation 39.001 (1) of CASR and subsection 33 (3) of the Acts Interpretation Act 1901. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct an unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. Instruments and Automatic Pilots AD/INST/10Amdt 2 Mechanical Fatigue Meters 6/2019 Applicability: All Meggitt PLC, Mechanisms Ltd and Negretti and Zambra Ltd mechanical fatigue meters installed in aircraft. Requirement: The mechanical fatigue meters must be calibrated and overhauled. Compliance: The calibration and overhaul must be performed at intervals not exceeding the following time periods: Fatigue Meter Type Calibration Interval Overhaul Interval Single Spring Units Every Six months Every Two Years Dual Spring Units Every Twelve months Every Four Years Table 1 - Calibration and Overhaul Intervals. Note: Compliance with the requirement of AD/INST/10 or AD/INST/10 Amdt 1 constitutes compliance with a requirement of this AD. This AD commences on 22 March 2019. Background: Amendment 2 of this AD was issued to take into account a change of manufacturer's name. Amendment 2 of this AD: * updated the title, * updated the manufacturer's name, and * removed obsolete fatigue meter part number examples. Amendment 1 extended calibration and overhaul intervals for dual type spring meter units as experience showed they are more reliable and hold their calibration longer than the single spring units, and added fatigue meter part number examples. Pieter van Dijk Delegate of the Civil Aviation Safety Authority 12 March 2019