- Effective
- October 2, 1997
- Published
- September 17, 1997 · 62 FR 48754–48755
- Superseded by
- AD2001-15-08
- Model
- 767 Series (all)
- Product
- Aircraft · Large airplane
- Amendment
- 39-10136
- Docket
- 97-NM-239-AD
- Issued as
- Final rule; request for comments
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. Only the govinfo PDF is the legal edition. DRS record last changed August 7, 2025.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| Official PDF | 116 KB | a64754b7…df85f48 | 97-24630.pdf on govinfo.gov |
| FAA DRS HTML | 59 KB | f18b4c89…a54abee | FAA DRS (API key needed) |
| Federal Register text | 15 KB | 0f1f69ed…3529a39 | 97-24630.txt on federalregister.gov |
On this page
Summary
This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 767 series airplanes. This action requires revising the Airplane Flight Manual (AFM) to include procedures that will ensure that the center tank fuel pumps are not operated with less than 1,000 pounds of fuel in the center tank. This amendment is prompted by a report indicating that a fuel pump failed due to damage to an impeller unit and pumping unit housing caused by a loose diffuser ring in the fuel pump assembly. The actions specified in this AD are intended to ensure the flight crew is advised of procedures that will ensure that the center tank fuel pumps are not operated with less than 1,000 pounds of fuel, which will prevent ignition of fuel vapors due to the generation of sparks and a potential ignition source inside the fuel tank caused by metal-to- metal contact during dry fuel pump operation.
The airworthiness directive
97-19-15 BOEING: Amendment 39-10136. Docket 97-NM-239-AD.
Applicability: All Model 767 series airplanes, certificated in any category.
NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent the generation of sparks and a potential ignition source inside the fuel tank caused by metal-to-metal contact during dry fuel pump operation, accomplish the following:
(a) Within 14 days after the effective date of this AD, accomplish paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this AD.
(1) Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following procedures. This may be accomplished by inserting a copy of this AD in the AFM.
"If the center tank fuel pumps are to be used, there must be at least 5,000 pounds (2,267 kilograms) of fuel in the center tank prior to engine start.
The center fuel pumps must be selected "OFF" at or greater than 1,000 pounds (453 kilograms) of fuel in the center tank. For airplanes not equipped with a center tank scavenge system, this 1,000 pounds (453 kilograms) of center tank fuel must be considered unusable.
NOTE: On all Model 767-200ER/300ER series airplanes and some Model 767-200/300 series airplanes, a scavenge system, operating with fuel pressure from the main wing tank pumps, will operate automatically to transfer any fuel remaining in the center tank to the main tanks. Fuel transfer begins when the main tanks are approximately half empty."
(2) Revise the Limitations Section of the FAA-approved AFM entitled "FUEL SYSTEM, FUEL USAGE II (fuel in center tank)," to include the following procedures. This may be accomplished by inserting a copy of this AD in the AFM.
"Use the center tank fuel for all operations with all operable fuel pumps "ON" and the cross feed valve(s) closed until the center tank fuel quantity is 1,000 pounds (453 kilograms) or greater, then use FUEL USAGE I.
Do not operate the center tank fuel pumps with less than 1,000 pounds (453 kilograms) of fuel in the center tank.
NOTE: The crossfeed valve(s) is open for minimum fuel operation, and may be opened to correct fuel imbalance."
(3) Revise the Normal Procedures Section of theFAA-approved AFM to include the following procedure. This may be accomplished by inserting a copy of this AD in the AFM.
"USE OF FUEL FROM THE CENTER TANK
When the center tank approaches "EMPTY" during normal use or fuel transfer, select both center tank fuel pump switches "OFF" with the first occurrence of any of the following:
* The center tank fuel reaches 1,000 pounds (453 kilograms); * Either of the center tank fuel pump "PRESS" lights illuminate; or * Either the "CTR L FUEL PUMP" or "CTR R FUEL PUMP" EICAS message is displayed."
(4) Revise the Non-Normal Procedures Section of the FAA-approved AFM to include the following procedures. This may be accomplished by inserting a copy of this AD in the AFM.
"CENTER TANK FUEL PUMP FAULTS
A center tank fuel pump failure may have occurred if a fuel pump pressure light illuminates when there is ample fuel in the tank. If a fault is suspected, select the affected pump "OFF" and do not re-select "ON." If the affected circuit breaker is tripped, do not reset. Select fuel crossfeed valve(s) "OPEN."
Attempted operation of a faulted center tank pump could ignite fuel tank vapors in an empty or nearly empty tank."
(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Operations Inspector, who may add comments and then send it to the Manager, Seattle ACO.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.
(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.
(d) This amendment becomes effective on October 2, 1997.
Rule preamble
The FAA’s background, reasoning and cost estimate, published with the AD.
Supplementary information
The FAA has received a report of failure of an override and jettison fuel pump on a Boeing Model 767 series airplane. Investigation revealed that the screws that attach the inlet diffuser assembly to the pumping unit housing became loose and were ingested into the fuel pump assembly. Loose screws caused the diffuser ring to become loose and contact the impeller, which damaged the impeller and pumping unit housing and caused the fuel pump to seize. During dry fuel pump operation, a loose diffuser ring also could cause metal-to-metal contact. This condition, if not corrected, could result in the generation of sparks and a potential ignition source inside the fuel tank.
Other Relevant Rulemaking
The conditions described previously were addressed in AD 94-11-05, amendment 39-8921 (59 FR 27970, May 31, 1994), which is applicable to Boeing Model 767-200 and 767-300 series airplanes. That AD requires repetitive inspections of the pumping unit assembly on the override and jettison fuel boost pump assemblies to detect looseness of the screws that attach the inlet diffuser assembly to the pumping unit housing, and repair or replacement of the pumping unit assembly with a serviceable assembly, if necessary. For certain airplanes, that AD also provides for deactivation of the center wing fuel tank as an alternative to the repetitive inspections. The actions specified by that AD are intended to prevent the generation of sparks and a potential ignition source inside the fuel tank caused by metal-to-metal contact during dry fuel pump operation.
FAA's Findings
Since the issuance of AD 94-11-05, an alternative method of compliance was granted that entailed fuel pump modifications, which alleviated the need for repetitive inspections of the fuel pump. However, the previously described report of failure of an override fuel pump occurred on a unit that had incorporated those modifications. The FAA has determined that, even if theoverride fuel pump fails, operation of the center tank fuel pumps with no less than 1,000 pounds of fuel will prevent ignition of fuel vapors due to the generation of sparks inside the fuel tank due to metal-to-metal contact. Therefore, the FAA has determined that a revision to the FAA-approved Airplane Flight Manual (AFM) for Model 767 series airplanes is necessary to ensure that the center tank fuel pumps are not operated with less than 1,000 pounds of fuel in the center tank.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other Boeing Model 767 series airplanes of the same type design, this AD is being issued to prevent the generation of sparks and a potential ignition source inside the fuel tank caused by metal-to-metal contact during dry fuel pump operation. This AD requires revising the AFM to include procedures that will ensure that the center tank fuel pumps are not operated with less than 1,000 pounds of fuel in the center tank.
Interim Action
This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which thefollowing statement is made: "Comments to Docket Number 97-NM-239-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 - (Amended) 2. Section 39.13 is amended by adding the following new airworthiness directive: