COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F100 (F28 Mk 100) Series Aeroplanes AD/F100/22 Passenger Service Units 4/99 Applicability: F.28 Mk.0100 aircraft, serial numbers 11244 through 11437, if equipped with Grimes Aerospace Passenger Service Units, Part Number (P/N) 10-1178-( ), all serial numbers. Requirement: Modify affected Grimes Aerospace Passenger Service Units in accordance with Fokker Service Bulletin (SB) F100-25-061 dated 8 March 1994, and Grimes Aerospace SB 10-1178-33-0036 dated 14 May 1993 and SB 10-1178-33-0039 Revision 1 dated 31 October 1193. Note: RLD BLA 94-078(A) refers. Compliance: Unless already accomplished, before 22 July 1999. This Airworthiness Directive becomes effective on 22 April 1999. Background: Through service experience with the F.28 Mk.0100 aircraft, it has been determined that the NO SMOKING and FASTEN SEATBELTS signs, installed in the overhead Passenger Service Units, may not be sufficiently readable to each seated passenger under all probable conditions of cabin illumination.