Airworthiness Directive · Amendment 39-16785 · Fuel
The Boeing Company Model 737-600, -700, -700C, -800, and -900 Series Airplanes
This AD applies to the airplanes, certificated in any category, identified in paragraphs (c)(1) and (c)(2) of this AD.
(1) The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes, identified in Boeing Alert Service Bulletin 737-28A1206, Revision 2, dated May 21, 2009.
(2) The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes, identified in Boeing Alert Service Bulletin 737-28A1248, Revision 2, dated August 28, 2009.
Note 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance (AMOC) according to paragraph (u) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires installation of an automatic shutoff system for the center tank fuel boost pumps, and installation of a placard in the airplane flight deck if necessary. This AD also requires revisions to the Limitations and Normal Procedures sections of the airplane flight manual to advise the flightcrew of certain operating restrictions for airplanes equipped with an automated center tank fuel pump shutoff control. This AD further requires installation of a secondary control relay for the electrical control circuit of each of the two center tank fuel boost pumps. Additionally, this AD requires a revision to the maintenance program to incorporate Airworthiness Limitation (AWL) No. 28-AWL-23. This AD also provides an option of installation and maintenance of universal fault interrupters using a certain supplemental type certificate, which terminates certain requirements of this AD. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent center tank fuel pump operation with continuous low pressure, which could lead to friction sparks or overheating in the fuel pump inlet that could create a potential ignition source inside the center fuel tank. These conditions, in combination with flammable fuel vapors, could result in a center fuel tank explosion and consequent loss of the airplane.
Comply with this AD within the compliance times specified, unless already done.
For airplanes identified in paragraph 1.A.1. of Boeing Alert Service Bulletin 737-28A1206, Revision 2, dated May 21, 2009: Within 36 months after the effective date of this AD, install an automatic shutoff system for the center tank fuel boost pumps, by accomplishing all of the actions specified in Part 1 and Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-28A1206, Revision 2, dated May 21, 2009, except that Figure 1 of this AD must be used in lieu of Sheet 2 of Figure 11 of Boeing Alert Service Bulletin 737-28A1206, Revision 2, dated May 21, 2009. If a placard has been previously installed on the airplane in accordance with paragraph (h) of this AD, the placard may be removed from the flight deck of only that airplane after the automatic shutoff system has been installed. Installing automatic shutoff systems on all airplanes in an operator's fleet, in accordance with this paragraph, terminates the placard installation required by paragraph (h) of this AD for all airplanes in an operator's fleet.
Note 2: Boeing Alert Service Bulletin 737-28A1206, Revision 2, dated May 21, 2009, refers to Boeing Component Service Bulletin 233A3202-28-03, dated January 12, 2006, as an additional source of guidance for replacing the left and right center boost pump switches of the P5-2 fuel control module assembly with new switches and changing the wiring of the P5-2 fuel control module assembly.
Prior to or concurrently with installing an automatic shutoff system on any airplane in an operator's fleet, as required by paragraph (g) of this AD, install a placard adjacent to the pilot's primary flight display on all airplanes in the operator's fleet that are not equipped with an automatic shutoff system for the center tank fuel boost pumps. The placard must read as follows (unless alternative placard wording is approved by an appropriate FAA Principal Operations Inspector):
“AD 2002-24-51 fuel usage restrictions required.”
Installing an automatic shutoff system, in accordance with paragraph (g) of this AD, terminates the placard installation required by this paragraph for only that airplane. Installing automatic shutoff systems on all airplanes in an operator's fleet, in accordance with paragraph (g) of this AD, terminates the placard installation required by this paragraph for all airplanes in an operator's fleet. If operation according to the fuel usage restrictions of AD 2002-24-51, Amendment 39-12992 (68 FR 10, January 2, 2003), and AD 2001-08-24, Amendment 39-12201 (66 FR 20733, April 25, 2001), is maintained until automatic shutoff systems are installed on all airplanes in an operator's fleet, the placard installation specified in this paragraph is not required. Installation of a placard in accordance with paragraph (e) of AD 2002-19-52, Amendment 39-12900 (67 FR 61253, September 30, 2002), is acceptable for compliance with the placard installation requirements of this paragraph; however, terminating action specified in paragraph (g) of AD 2002-19-52 and installation of an automatic shutoff system required by paragraph (g) of this AD must be accomplished on the airplane before the placard is removed from the airplane.
(i) For airplanes on which Boeing Alert Service Bulletin 737-28A1206, Revision 2, dated May 21, 2009, has been accomplished: At the applicable time specified in paragraph (i)(1) or (i)(2) of this AD, do the actions specified in paragraphs (i)(3) and (i)(4) of this AD.
(1) For airplanes on which the terminating action specified in paragraph (g) of AD 2002-19-52, Amendment 39-12900 (67 FR 61253, September 30, 2002), has been done: Concurrently with accomplishing the actions required by paragraph (g) of this AD.
(2) For airplanes on which the terminating action specified in paragraph (g) of AD 2002-19-52, Amendment 39-12900 (67 FR 61253, September 30, 2002), has not been done: Concurrently with accomplishing the terminating action specified in paragraph (g) of AD 2002-19-52.
(3) Revise Section 1 of the Limitations section of the Boeing 737-600/-700/-700C/-800/-900 AFM to include the following statement. This may be done by inserting a copy of this AD into the AFM.
Intentional dry running of a center tank fuel pump (low pressure light illuminated) is prohibited.”
Note 3: For clarification purposes, the AFM limitations required by AD 2002-19-52, Amendment 39-12900 (67 FR 61253, September 30, 2002), continue to be required until the optional terminating actions specified in paragraph (g) of AD 2002-19-52 have been done.
(4) Revise Section 3 of the Normal Procedures section of the Boeing 737-600/-700/-700C/-800/-900 AFM to include the following statements. This may be done by inserting a copy of this AD into the AFM. Alternative statements that meet the intent of the following requirements may be used if approved by an appropriate FAA Principal Operations Inspector.
