AD/ROTAX/21 Amdt 1 - Coolant "Evans NPG+" or Conventional Water-Glycol Coolant (Cth)

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ROTAX/21 and issues the following AD under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the 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.

Rotax Piston Engines AD/ROTAX/21 Amdt 1 Coolant "Evans NPG+" or Conventional 3/2005 Water-Glycol Coolant

Applicability: Bombardier Rotax 912 A, 912 F, 912 S and 914 F series reciprocating aircraft engines. Requirement: 1. Exchange current conventional engine coolant with a new coolant liquid type "Evans NPG+" per provisions of Bombardier Rotax Mandatory Service Bulletin SB-912-043 / SB-914-029 initial issue dated September 2004 or later revision approved by European Aviation Safety Agency (EASA). Operate the engine per Cylinder Head Temperature (CHT) limits specified in requirement 2 of this AD.

OR

Continue the use of conventional glycol / water coolant (mixing ratio 50/50). If you use this option, check the open-up pressure of the coolant pressure vessel cap. The open-up pressure is marked on the cap. If marked open-up pressure is any pressure other than "1.2 bar" or if marking is not legible or missing altogether, replace the cap with a new pressure vessel cap Rotax Part number 922.070. Operate the engine per CHT limits specified in requirement 2 of this AD.