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) AD/CESSNA 150/31 Amdt 4 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. Textron Aviation (Cessna) 150, F150, 152 & F152 Series Aeroplanes AD/CESSNA 150/31 Amdt 5 Vertical Fin Attach Brackets, 7/2022 Nutplates and Fittings Applicability: Textron Aviation (formerly Cessna/Reims) aircraft models listed below: Models 150F, 150G, 150H, 150J, 150K, 150L and 150M with serial numbers 15061533 through 15079405; Models A150K, A150L and A150M, with serial numbers A1500001 through A1500734; Model 152 aircraft, with serial numbers 15279406 through 15284541; Model A152 aircraft, with serial numbers A1520735 through A1520943; Models F150F, F150G, F150H and F150J, with serial numbers F150-0001 through F150-0529; Models F150K, F150L and F150M, with serial numbers F15000530 through F15001428; Models FA150K and FA150L, with serial Numbers FA1500001 through FA1500120; Model F152 aircraft with serial numbers F15201429 through F15201828; Model FA152 aircraft with serial numbers FA1520337 through FA1520372; Model FRA150L and FRA150M aircraft, with serial numbers FRA1500121 through FRA1500336. Requirement: 1. Inspect the attach bracket and nutplates using the method detailed in Cessna SIL No. SE 79-49 Revision 1, or Reims Aviation Service Bulletin No. 24 Revision 1, both as in force on the commencement date of this AD, as applicable. 2. a. Remove paint from both base radii on each of the port and starboard rear attach fittings; b. Visually check the radius area, inspecting for cracking and/or corrosion. If there are indications of either condition the brackets must be replaced; c. Re-protect the subject area with an approved protective treatment. Note 1: United States of America Federal Aviation Administration (FAA) AD 80‑11‑04 is the basis for this AD. European Aviation Safety Agency (EASA) AD 2006-0267 also refers. Note 2: The inspection requirements of this Directive are not required if the part number NAS 1068A4 nutplates are replaced with AN365-428, MS20365-428, MS21042L4, or MS21044N4 nuts. Compliance: For FRA150L and FRA150M aircraft, inspect within 100 hours' time in service after 26 October 2006, and thereafter at intervals not exceeding 100 hours' time in service until the affected nutplates are replaced (See Requirement Note 2). For all other aircraft, inspect within 100 hours' time in service after 31 November 1984, and thereafter at intervals not exceeding 100 hours' time in service until the affected nutplates are replaced (See Requirement Note 2). The compliance time for these aircraft is unchanged. This AD commences on 11 April 2022. Background: Cracked vertical fin attachment nutplates have been found on in-service aircraft. Undetected cracking could result in structural failure and consequent separation of the vertical or vertical and horizontal tail assembly from the aircraft. Amendment 3 corrected aircraft applicability so as to only include aircraft fitted with the fabricated attach bracket. Amendment 4 was issued to introduce optional terminating action to the inspection requirements of this Directive, as specified in EASA AD 2006-0267 and FAA AD 80-11-04; and to include Models FRA150L and FRA150M aircraft. Amendment 5 is issued to exclude pre 1966 aircraft from the AD effectivity to align with Cessna SIL SE79-49 Revision 1 and FAA AD 80-11-04. David Punshon Delegate of the Civil Aviation Safety Authority 1 April 2022