AD/AIRCON/12 Amdt 3 Kelly Aerospace Power Systems Cabin Combustion Heaters (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AIRCON/12 Amdt 2 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.

Airconditioning Equipment

AD/AIRCON/12 Amdt 3 Kelly Aerospace Power Systems - Cabin Combustion Heaters 4/2005

Applicability:

Kelly Aerospace Power Systems (formerly Janaero Devices) B Series combustion heaters, Models B1500, B2030, B2500, B3040, B3500, B4050 and B4500 marked as meeting the standards of FAA TSO-C20.

Note 1:  For all other heaters refer to AD/AIRCON//9 at the latest amendment.

Requirement:

1.    INSPECTION

a.     Inspect the combustion heater installation including any airframe mounted components necessary for heater operation for general condition and security,

b.    Inspect the hot air outlet ducting adjacent to the heater for freedom from exhaust contamination and corrosion,

c.     Clean the heater fuel filter and check the heater fuel system for loose connections and leaks using system pressure,

d.    Inspect heater drain lines for freedom from obstructions, and

e.     Inspect and adjust spark plugs and contact breaker points where necessary.

2.    PRESSURE TEST:

a.     Carry out pressure decay test per Janitrol Maintenance and Overhaul Manual P/N 24E25-1, Section III; or

b.    Carry out functional check during which carbon monoxide (CO) level is to be measured in the heated air entering the cabin.  Quantitative CO must be used and the CO level entering the cabin must be less than 1 part in 20,000 parts of air.

c.     If the heater fails any part of this test, disable the heater per paragraph 5 of the requirement or replace/overhaul the heater.

3.    PRESSURE SWITCH TEST:

Conduct operational test of the combustion air pressure switch per Janitrol Maintenance and Overhaul Manual P/N 24E25-1, Section 4.  Replace the switch, or disable the heater per paragraph 5 of this Directive if the switch fails test.

Compliance per requirement 3 of this Directive is not required for combustion air pressure switch P/N 94E42.

4.    OVERHAUL:

Overhaul the heater and the associated airframe mounted components necessary for the heater operation.

5.    DISABLE:

Disable the heater as follows, subject to Minimum Equipment List (MEL) requirements or Permissible Unserviceabilities (PU) per the provisions of CAR 37 if applicable to the aircraft.

a.     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 pilot’s clear view.

Note 2:  Permanent deactivation of the heater will require approved modification data including internal inspection and functional tests before return to service.

Note 3:  FAA AD 2004-21-05 Amdt 39-13826 supersedes FAA AD 96-20-07 Amdt 39-9773.

For Requirements 1, 2 and 3:

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 Directive and thereafter at interval not exceeding 100 heater hours or 24 months TIS, which ever occurs first.

Compliance:

For Requirement 4:

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.

For Requirement 5:

As required per paragraphs 2 and 3 of the requirements.

Note 4:  If a heater hour meter is not installed, the aircraft hours may be divided by two to provide the heater TIS hours.

This Amendment becomes effective on 14 April 2005.

Background:

Two heater failures, one resulted in explosion and the other in fire of the baggage compartment prompted this Directive action.  Janaero Heaters were previously subject to AD/AIRCON/9 Amdt 5 and AD/AIRCON/12.

This amendment changes the overhaul period to include an option to follow the manufacturers recommended overhaul period and clarification of aspects relating to the disabling of the heater.

Amendment 1 simplified requirements such that heaters are subject to either AD/AIRCON/9 Amdt 7 or AD/AIRCON/12 Amdt 1 as applicable.

Amendment 2 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. 

Amendment 1 of this Directive became effective on 13 June 2002.

Amendment 2 of this Directive became effective on 20 January 2005.

The original issue of this Airworthiness Directive became effective on 2 January 1997.

James Coyne
Delegate of the Civil Aviation Safety Authority

4 March 2005