[Federal Register Volume 62, Number 180 (Wednesday, September 17, 1997)]
[Rules and Regulations]
[Pages 48754-48755]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24630]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-239-AD; Amendment 39-10136; AD 97-19-15]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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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.
DATES: Effective October 2, 1997.
Comments for inclusion in the rules docket must be received on or
before November 17, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-239-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
The information concerning this amendment may be obtained from or
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Larry Reising, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2683; fax (425) 227-1181.
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 the override 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
[[Page 48755]]
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 the following 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
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 the FAA-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.
Issued in Renton, Washington on September 11, 1997.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-24630 Filed 9-16-97; 8:45 am]
BILLING CODE 4910-13-U
