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 39.1 (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/B747/310 Water and Drain Line Heaters 8/2004
Applicability: Model 747 series aeroplanes, certificated in any category, with lower cargo floors (floors in the lower cargo areas) that are not fully enclosed.
Note 1: For the purposes of this Directive, a fully enclosed cargo floor is a floor with panels installed between all roller trays in the cargo compartment and a cargo floor that is not fully enclosed is a floor without panels installed between all roller trays in the cargo compartment.
Requirement: 1. Perform a one-time general visual inspection for foreign object debris (FOD) and contamination on or near potable water and drain lines located below the cargo floor in the forward and aft cargo compartments, in areas not covered by floor panels or sidewall panels. Carry out the inspection in accordance with the Accomplishment Instructions of Boeing Service Bulletin (SB) 747-30A2079, Revision 1, dated 16 October 2003.
Note 2: For the purposes of this Directive, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, torch or droplight and may require removal or opening of access panels or doors. Stands, ladder, or platforms may be required to gain proximity to the area being checked."
2. Remove any FOD or contamination observed during the Requirement 1 inspection on or near the potable water or drain lines in accordance with SB 747- 30A2079 Revision 1.
3. Perform a general visual inspection for discrepancies of potable water and drain lines located below the cargo floor in the forward and aft cargo compartments, in areas not covered by floor panels or sidewall panels, in accordance with SB 747- 30A2079, Revision 1, as follows:
- Inspect potable water and drain lines for indications of overheating of the heater tape, including localized darkening of foam insulation or protective tape.
b. Inspect potable water and drain lines for exposed foam insulation and missing or damaged protective tape.
4. If overheating is observed during the Requirement 3.a. inspection, either:
- Replace the defective heater tape, removing floor panels as necessary, in accordance with the SB 747-30A2079, Revision 1;
b. Deactivate the heater tape in accordance with the provisions and limitations specified in the operator's Minimum Equipment List (MEL), or
c. Deactivate the heater tape in accordance with Figure 1 of SB 747-30A2079, Revision 1.
5. If the heater tape is deactivated in accordance with Requirements 4.b. or 4.c., replace the heater tape in accordance with SB 747-30A2079, Revision 1.
6. If exposed foam insulation is observed during the Requirement 3.b. inspection, cover the foam insulation with a continuous wrap of protective tape, in accordance with SB 747-30A2079, Revision 1.
7. If, during the Requirement 3.b inspection protective tape is found to be missing or damaged replace the protective tape in accessible areas in accordance with SB 747-30A2079, Revision 1.
Note 3: It is not necessary to remove floor panels to replace the protective tape.
Actions accomplished before the effective date of this Directive in accordance with Boeing Alert Service Bulletin 747-30A2079, dated 12 December 2002, are acceptable for compliance with the corresponding actions required by Requirements 1 through 7 of this Directive.
Note 4: FAA AD 2004-09-10 Amdt 39-13599 refers.
Compliance: For Requirement 1 - Either within 18 months since the date of manufacture of the aircraft (as per the aircraft data plate) or 90 days after the effective date of this Directive, whichever occurs last.
For Requirement 2 - Prior to further flight after the Requirement 1 inspection.
For Requirement 3 - Either within 18 months since the date of manufacture of the aircraft or 90 days after the effective date of this Directive, whichever occurs last.
For Requirement 4 - Prior to further flight after the Requirement 3.a. inspection.
For Requirement 5 - Within 90 days after the date of the Requirement 3.a. inspection.
For Requirements 6 and 7 - Within 90 days after the date of the Requirement 3.b. inspection.
This Airworthiness Directive becomes effective on 5 August 2004.
Background: This Directive requires a one-time inspection of the potable water and drain lines in the forward and aft cargo compartments for indications of overheating of the heater tape, exposed foam insulation, missing or damaged protective tape or debris around the potable water fill and drain lines together with any necessary corrective action. This action is necessary to prevent overheating of the heater tape on potable water fill and drain lines, which may ignite accumulated debris or contaminants on or near the potable water fill and drain lines, resulting in a fire in the aeroplane.
James Coyne
Delegate of the Civil Aviation Safety Authority 23 June 2004
The above AD is notified in the Commonwealth of Australia Gazette on 14 July 2004.