AD/B747/364 Water and Drain Line Heater Tapes (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.

Boeing 747 Series Aeroplanes

AD/B747/364 Water and Drain Line Heater Tapes 12/2007

Applicability:	Model 747 aeroplanes, as identified in Boeing Service Bulletin (SB) 747-30A2080, Revision 3, dated 14 June 2007.
Note 1:  For the purposes of this Directive, a cargo area that is not fully enclosed or not enclosed, as identified in SB 747-30A2080, Revision 3, is a floor without panels installed between all roller trays in the cargo compartment.
Requirement:	1.    Carry out a general visual inspection of the forward and aft cargo compartments, as applicable, for foreign object debris (FOD) or contamination on, near or around the potable water supply and gray water drain lines in accordance with SB 747-30A2080, Revision 3.
2.    Carry out a general visual inspection of the forward and aft cargo compartments, as applicable, for indications of heat damage, exposed foam insulation or missing or damaged protective tape of all heater tape on the potable water supply and gray water drain lines in accordance with SB 747-30A2080, Revision 3.
3.    Repair any discrepancies detected during the Requirement 1 and 2 inspections in accordance with SB 747-30A2080, Revision 3.
4.    Replace the heater tape on the potable water supply and gray water drain lines of the forward and aft cargo compartments, as applicable, with Adel Wiggins ribbon heaters, in accordance with the Accomplishment Instructions of SB 747-30A2080, Revision 3.
The replacement of the heater tape on the potable water supply and gray water drain lines terminates the Requirement 1 and 2 repetitive inspections.
Actions accomplished before the effective date of this Directive in accordance with:
a.     Boeing Alert Service Bulletin (ASB) 747-30A2080, either the original version dated 16 December 2004, or Revision 1, dated 18 August 2005, are acceptable for compliance with the corresponding requirements of this Directive; except, for Group 2, Configuration 2 and Configuration 3 aeroplanes, as defined in Revision 2 of the service bulletin, additional work is required in the forward cargo compartment, as specified in Parts 1, 2 and 3 of the service bulletin and required by this Directive.

b.    ASB 747-30A2080, Revision 2, dated 14 September 2006, are acceptable for compliance with the corresponding requirements of this Directive.
Later revisions of SB 747-30A2080, Revision 3, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-19-16, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note 2:  FAA AD 2007-19-16 Amdt 39-15207 refers.
Compliance:	For Requirement 1 - Either within 18 months after the date of issue of the original Certificate of Airworthiness, or within 18 months after the date of the issue of the original Export Certificate of Airworthiness, or within 90 days after the effective date of this Directive, whichever occurs later, and thereafter at intervals not to exceed 600 hours time in service (TIS) until Requirement 4 is accomplished.
For Requirement 2 - Either within 18 months after the date of issue of the original Certificate of Airworthiness, or within 18 months after the date of the issue of the original Export Certificate of Airworthiness, or within 90 days after the effective date of this Directive, whichever occurs later, and thereafter at intervals not to exceed 1,800 hours TIS until Requirement 4 is accomplished.
For Requirement 3 - Before further flight after the Requirement 1 or 2 inspections, as applicable.
For Requirement 4 - At the applicable time specified in Table 1.
Table 1
For aeroplanes on which the heater tape has:	Replace the heater tape at the later of:
(1) Not been replaced before the effective date of this Directive in accordance with Boeing ASB 747-30A2079, dated 12 December 2002; or Revision 1, dated 16 October 2003; or Revision 2, dated 16 December 2004	Within 42 months since the date of issue of the original Certificate of Airworthiness or the date of issue of the original Export Certificate of Airworthiness, whichever occurs first	24 months after the effective date of this Directive
(2) Been replaced before the effective date of this Directive in accordance with ASB 747-30A2079; or Revision 1; or Revision 2	Within 42 months after the heater tape was replaced	24 months after the effective date of this Directive.

This Airworthiness Directive becomes effective on 22 November 2007.
Background:	This Directive supersedes AD/B747/310, which has been cancelled.  That Directive required a one-time inspection for discrepancies of the potable water and drain lines in the cargo compartments and, if necessary, the accomplishment of corrective action.
This new Directive requires that the inspection be repetitively performed using new service information, until terminating action is accomplished.  The Directive also removes certain aeroplanes from the applicability.  The Directive results from a report from the FAA of a fire in the aft cargo compartment started by a potable water line heater tape and is issued to prevent overheating of the heater tape on potable water fill and drain lines, which could ignite accumulated debris or contaminants on or near the potable water fill and drain lines, resulting in a fire in the aeroplane.

David Punshon
Delegate of the Civil Aviation Safety Authority

2 October 2007