Document ID: chunk:federal_register_of_legislation:F2019L01314:body:0:p3
Version: federal_register_of_legislation:F2019L01314
Segment Type: other
Provision Reference: 
Character Range: 5790–7966

after the effective date of this AD:
                     (i) 100 heater hours;
                     (ii) 12 months' time in service (TIS); and
                  (b) at intervals not exceeding the earlier of the following:
                     (i) 100 heater hours;
                     (ii) 24 months' TIS.
                4. The action in Requirement 4 must be taken at intervals in accordance with the heater manufacturer's published Time Between Overhaul for the particular heater model.
                5. The action in Requirement 5 must be taken as required by Requirements 2 and 3 of this AD.
             Note 4:  If a heater hour meter is not installed, the aircraft hours may be divided by 2 to provide the heater TIS hours.
             This AD commences on 16 October 2019.
Background:  Two heater failures, one resulted in explosion and the other in fire of the baggage compartment prompted this AD action.
             AD/AIRCON/12 became effective on 2 January 1997.
             AD/AIRCON/12 Amdt 1 became effective on 13 June 2002.
             AD/AIRCON/12 Amdt 2, which became effective on 20 January 2005, removed the terminating action that was provided by the fitment of ceramic-coated combustion tubes. It has been demonstrated that ceramic-coated combustion tubes suffer from the same problems as uncoated combustion tubes.
             AD/AIRCON/12 Amdt 3, which became effective on 14 April 2005, changed the overhaul period to include an option to follow the manufacturer's recommended overhaul period and clarification of aspects relating to the disabling of the heater.
             AD/AIRCON/12 Amdt 4 made reference to the overhaul and maintenance manual for the B‑Series (EL) units and pertinent manufacturer's data relative to heater disabling and return to service. The overhaul compliance statement was simplified to reflect manufacturer requirements with minor editorial changes made throughout the text for readability.

   AD/AIRCON/12 Amdt 5 removes Note 1 from the applicability section of the AD. Note 1 referenced AD/AIRCON/9 which has been cancelled.

Pieter van Dijk
Delegate of the Civil Aviation Safety Authority
2 October 2019