Document ID: chunk:federal_register_of_legislation:F2008L00532:body:0:p1
Version: federal_register_of_legislation:F2008L00532
Segment Type: other
Provision Reference: 
Character Range: 0–3098

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/B747/370  Heat Exchanger Shells  3/2008

Applicability:  Boeing Model 747-400 series aeroplanes, as identified in Boeing Service Bulletin (SB) 747-21A2439, Revision 2, dated 24 May 2007.
Requirement:       1. Do the actions sspecified in 1a) and 1b) of this AD by accomplishing all the actions specified in the Accomplishment Instructions of the service bulletin.

                     a) Do repetitive general visual inspections to detect discrepancies (i.e., cracks, creases, deformation, deflection, and interference with the rudder and/or elevator cables) of the forward and rear heat exchanger shells of the air distribution system of the crew rest area, and do the applicable corrective actions, until the actions required by 1b) of this AD are done.

                     b) Do an inspection to identify the part number, shop code, and build date of the forward and rear heat exchanger shells of the air distribution system of the crew rest area, and do the applicable corrective actions.

                Accomplishing the actions in Requirement 1b) ends the repetitive inspections as detailed in Requirement 1a) of this AD.

                Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-21A2439, dated 3 November 2005; or Boeing Service Bulletin 74721A2439, Revision 1, dated 24 July 2006; are acceptable for compliance with the corresponding actions specified in this AD.

                If a forward heat exchanger shell, part number 65B41601-52, is found installed during the replacement required by AD/B747/232 Amdt 1, or was installed during the inspection required by AD/B747/232 Amdt 1 (AD/B747/232 Amdt 1 refers to Boeing Alert Service Bulletin 747-21A2412, dated 20 January 2000; or Revision 2, dated
                30 November 2000; as the appropriate sources of service information for accomplishing the required actions): Actions detailed in Requirements 1a) and 1b) of this AD are not required for that forward heat exchanger shell only.

                   2. Do not install a heat exchanger shell having a part number identified in the "Existing Part Number" column of the table specified in paragraph 2.C. of Boeing Service Bulletin 747-21A2439, Revision 2, on any aeroplane.

                Note:  FAA AD 2007-25-19 Amdt 39-15301 dated 30 November 2007 refers.

Compliance:     1. At the applicable