AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AIRCON/9 Amdt 6 and issues the following AD under subregulation 39.1 (1) of CAR 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.
Airconditioning Equipment
AD/AIRCON/9
Amdt 7
Combustion Type Cabin Heaters 10/2002
Applicability: All Combustion type heaters other than the heaters for which AD/AIRCON/12 is applicable.
Requirement: | 1. | INSPECTION: |
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| a. Inspect the combustion heater installation including any airframe mounted components necessary for heater operation for general condition and security, |
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| b. Inspect the hot air outlet ducting adjacent to the heater for freedom from exhaust contamination and corrosion, |
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| c. Clean the heater fuel filter and check the heater fuel system for loose connections and leaks using system pressure, |
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| d. Inspect heater drain lines for freedom from obstructions, and |
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| e. Inspect and adjust spark plugs and contact breaker points where necessary. |
| 2. | FUNCTIONAL TEST: |
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| Carry out functional check during which carbon monoxide (CO) level is to be measured in the heated air entering the cabin. Quantitative CO measurement must be used to confirm CO level entering cabin is less than 1 part per 20,000 parts of |
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| air. |
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| If the heater fails this test, disable the heater per Requirement 4 or replace/repair |
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| the heater. |
| 3. | OVERHAUL: |
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| Overhaul the heater and the associated airframe mounted components necessary |
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| for the heater operation. |
Airconditioning Equipment
AD/AIRCON/9 Amdt 7 (continued)
4. DISABLE:
Disable the heater as follows subject to Minimum Equipment List (MEL) requirements or CAR (1988) 37 as applicable.
- Cap the fuel supply line,
b. Disconnect the electrical power and ensure that the connections are properly secured to reduce the possibility of electrical spark or structural damage,
c. Inspect and test to ensure that the cabin heater system is disabled and the cabin fans are operative,
d. Ensure that no other aircraft system is affected by this action,
e. Ensure there are no fuel leaks, and
f. Fabricate a placard with the words: “ System Inoperative “; install the placard at the heater control valve within the pilots clear view.
Note 1: Permanent deactivation of the heater will require approved modification data including internal inspection and functional tests before return to service.
Compliance: 1. Unless previously accomplished, within 100 heater hours or 12 calendar months time in service (TIS) which ever occurs first after the effective date of this AD and there after at interval not exceeding 100 heater hours or 24 months time in service which ever occurs first.
2. Unless previously accomplished, within 100 heater hours or 12 calendar months time in service (TIS) which ever occurs first after the effective date of this AD and there after at intervals not exceeding 100 heater hours or 24 months time in service which ever occurs first.
3. Per heater manufacturers recommendations. Where heater manufacturers recommendations are not available, at intervals not to exceed 500 heater hours since overhaul or 8 years since overhaul which ever occurs first.
4. As required per Requirement 2.
Note 2: If a heater hour meter is not installed, the aircraft hours may be divided in half to provide the heater TIS hours.
This Amendment becomes effective on 3 October 2002.
Airconditioning Equipment
AD/AIRCON/9 Amdt 7 (continued)
Background: This amendment deletes the calendar time overhaul requirements for heaters where the manufacturer has recommended overhaul periods. In addition, conditions are added to the disabling of heaters.
Amendment 5 of this Airworthiness directive became effective on 14 October 1993. Amendment 6 of this Airworthiness directive became effective on 13 June 2002.
The original issue of this Airworthiness Directive became effective on 31 January 1987.
James Coyne
Delegate of the Civil Aviation Safety Authority 23 August 2002
The above AD is notified in the Commonwealth of Australia Gazette on 11 September 2002.