COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters AD/HU 369/83 Amdt 1 Tail Rotor Blades 7/91 Applicability: All model 369 Series Helicopters equipped with a Tail Rotor Blade Assembly in the following Part number/Serial Number range: Part Number Blade Serial Numbers 369A1613 (all dash numbers) Prior to 7959 369D21613 (all dash numbers) Prior to 6482 369D21615 (all dash numbers) Prior to 1358 369D21606 (all dash numbers) Prior to 0538 421-088 ( all dash numbers) Prior to 0218 Requirement: 1. Visually inspect in accordance with part I of Service Information Notice HN- 230.1, DN-177.1, EN-68.1, or FN-55.1, as applicable. 2. Action in accordance with Part II of Service Information Notice HN-230.1, DN- 177.1, EN-68.1, or FN-55.1, as applicable. Note 1: This Directive shall be entered on the Maintenance Release as maintenance required. The visual inspection required by Para 1 may be performed by the Pilot in command, in which case certification is to be made by entering AD/HU36/83 against the daily inspection certification of the Maintenance Release. A copy of this Airworthiness Directive is to be kept in the aircraft. Note 2: FAA AD 91-08-02 Amdt 39-6963 refers. Compliance: 1. Before the first flight of each day, after 18 January 1991. 2. Within 100 hours Time in Service after 18 January 1991 or before 1 March 1991; whichever occurs first. The compliance dates of the original issue of this Directive are as stated. This reissue is effective from 11 July 1991. Background: Due to a failure of a tail rotor blade root fitting, McDonnell Douglas Helicopter Company (MDHC) is requiring operators to perform an inspection of all aluminium tail rotor blades to ensure that no crack exists in the tail rotor blade root fitting and that the tail rotor blade root fitting has proper wall thickness. Thin wall thickness in the tail rotor blade root fitting can lead to tail rotor blade failure. MDHC Mandatory Service Documents listed above are considered to be of sufficient Safety of Flight importance, that this Airworthiness Directive was raised without the support of a Country of Origin AD. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Amdt 1 is raised to introduce a revision to the Requirement documents, and the issue of the FAA AD that now confirms support for this Directive.