Airworthiness Directive · Amendment 39-16532 · Fuel
The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP Series Airplanes
This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes, certificated in any category; as identified in Boeing Service Bulletin 747-28A2288, Revision 1, dated January 21, 2010.
Note 1: This AD requires revisions to certain operator maintenance documents to include a new inspection. Compliance with this inspection is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by this inspection, 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 (l) of this AD. The request should include a description of changes to the required inspection 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 adding two new indicator lights on a certain panel to inform the captain and first officer of a low pressure condition in the left and right override/jettison pumps of the center wing tanks. This AD also requires replacing the left and right override/jettison switches on the M154 fuel control module on the P4 panel with improved switches and doing the associated wiring changes. This AD also requires, for certain airplanes, installation of a mounting bracket for the new indicator lights. This AD also requires a revision to the maintenance program to incorporate airworthiness limitation No. 28-AWL-22. This AD also requires a revision to the airplane flight manual to advise the flightcrew what to do in the event that the pump low pressure light on the flight engineer's panel does not illuminate when the pump is selected off. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent uncommanded operation of the override/jettison pumps of the center wing tanks, and failure to manually shut off the override/ jettison pumps at the correct time, either of which could lead to an ignition source inside the center wing tank. This condition, in combination with flammable fuel vapors, could result in a center fuel tank explosion and consequent loss of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 36 months after the effective date of this AD: For airplanes with a P10 panel installed, add two new indicator lights on the P10 panel to inform the captain and first officer of a low pressure condition in the left and right override/jettison pumps of the center wing tanks, and, for airplanes that do not have the warning panel (P10 panel) installed, add a mounting bracket and two new indicator lights to the Autopilot Flight Director panel; and replace the left and right override/jettison switches on the M154 fuel control module on the P4 panel with improved switches; and do the associated wiring changes. Accomplish these actions by doing all of the applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 747-28A2288, Revision 1, dated January 21, 2010, except where that service bulletin states “20-60-00,” the correct sub-section number is “28-60-06,” and except as described in Table 1 of this AD.
| Part name | Part number specified in Figures 22 through 32 of Boeing Service Bulletin 747-28A2288, Revision 1, dated January 21, 2010 | Part name of correct part | Correct part number |
|---|---|---|---|
| Nut | BACN10JC06CD | Nut | BACN10NW1 |
| Bolt | BACS12HN06-10 | Screw | BACS12HN04-6 |
| Washer | NAS1149D0632J | Washer | NAS1149DN416J |
Note 2: For airplanes equipped with certain M154 fuel control modules, paragraph 2.C.2 of Boeing Service Bulletin 747-28A2288, Revision 1, dated January 21, 2010, refers to the BAE Systems service bulletins identified in Table 2 of this AD, as applicable, as additional sources of guidance for replacing the switches.
| Service bulletin | Date |
|---|---|
| BAE Systems Service Bulletin 65B46124-28-01 | February 16, 2006. |
| BAE Systems Service Bulletin 65B46124-28-02 | March 28, 2007. |
| BAE Systems Service Bulletin 65B46124-28-03 | March 28, 2007. |
| BAE Systems Service Bulletin 65B46214-28-01 | February 16, 2006. |
| BAE Systems Service Bulletin 65B46214-28-02 | March 28, 2007. |
| BAE Systems Service Bulletin 65B46214-28-03 | March 28, 2007. |
Concurrently with accomplishing the actions required by paragraph (g) of this AD, revise the maintenance program by incorporating Airworthiness Limitation (AWL) No. 28-AWL-22 of Section D of the Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), D6-13747-CMR, Revision March 2008. Where the AWL states “28-31-00,” the correct section number is “28-42-00.”
(i) Concurrently with accomplishing the actions required by paragraph (g) of this AD, revise Section 1, “Certificate Limitations,” of the applicable Boeing 747 AFM to include the following statement. This may be done by inserting a copy of this AD into the AFM.
“When the center tank override jettison pumps are selected off, the amber pump low pressure lights on the Flight Engineer's panel should illuminate and remain on. If a pump low pressure light on the Flight Engineer's panel does not illuminate, open the associated pump circuit breaker.”
Note 3: When a statement identical to that in paragraph (i) of this AD has been included in the general revisions of the AFM, the general revisions may be inserted into the AFM, and the copy of this AD may be removed from the AFM.
After accomplishing the action specified in paragraph (h) of this AD, no alternative inspections or inspection intervals may be used unless the inspections or inspection intervals are approved as an AMOC in accordance with the procedures specified in paragraph (l) of this AD.
Incorporating AWL No. 28-AWL-22 into the maintenance program in accordance with paragraph (g) of AD 2008-10-07, Amendment 39-15513, or AD 2008-10-07 R1, Amendment 39-16070, terminates the action required by paragraph (h) of this AD.
