[Federal Register Volume 64, Number 129 (Wednesday, July 7, 1999)]
[Rules and Regulations]
[Pages 36563-36565]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-17062]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-112-AD; Amendment 39-11215; AD 99-08-02 R1]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; correction.
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SUMMARY: This amendment corrects and clarifies an existing
airworthiness directive (AD), applicable to certain Boeing Model 747
series airplanes, that currently requires a one-time inspection to
detect discrepancies of the center fuel tank wiring and components, and
corrective action, if necessary; and a one-time electrical bonding test
of the center fuel tank components, and rework, if necessary. For
certain airplanes, the existing AD also requires a one-time insulation
resistance test and a one-time inspection to detect discrepancies of
the wiring and components of the fuel quantity indication system
(FQIS), and corrective actions, if necessary; replacement of certain
FQIS probes with certain newer probes; a system adjustment and system
operational test; and modification (installation of a flame arrestor)
of the inlet line of the scavenge pump of the center fuel tank. This
amendment corrects an inadvertent omission to reference a specific
section of the appropriate service information, and clarifies certain
other requirements. This amendment is prompted by a comment received
subsequent to issuance of the existing final rule, requesting
clarification of certain requirements of the existing AD. The actions
specified in this AD are intended to prevent ignition sources and
consequent fire/explosion in the center fuel tank.
DATES: Effective May 11, 1999.
The incorporation by reference of certain publications listed in
the regulations was approved previously by the Director of the Federal
Register as of May 11, 1999 (64 FR 16625, April 6, 1999).
FOR FURTHER INFORMATION CONTACT: Dionne Stanley, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2250; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: On March 29, 1999, the FAA issued AD 99-08-
02, amendment 39-11106 (64 FR 16625, April 6, 1999), applicable to
certain Boeing Model 747 series airplanes, to require a one-time visual
inspection to detect discrepancies of the center fuel tank wiring and
components, and corrective action, if necessary; and a one-time
electrical bonding test of the center fuel tank components, and rework,
if necessary. For certain airplanes, that AD also requires a one-time
insulation resistance test and a one-time visual inspection to detect
discrepancies of the wiring and components of the fuel quantity
indication system (FQIS), and corrective actions, if necessary;
replacement of certain FQIS probes with certain newer probes; a system
adjustment and system operational test; and modification (installation
of a flame arrestor) of the inlet line of the scavenge pump of the
center fuel tank. That action was prompted by design review and testing
results obtained in support of an accident investigation. The actions
required by that AD are intended to prevent ignition sources and
consequent fire/explosion in the center fuel tank.
Actions Since Issuance of AD 99-08-02
Since the issuance of AD 99-08-02, the FAA has become aware of
certain errors in Boeing Alert Service Bulletin 747-28A2208, dated May
14, 1998. That service bulletin is cited as the source of service
information for paragraph (b) of that AD, which requires replacement of
``series 3'' (or earlier series) FQIS probes with new ``series 4'' (or
subsequent series) probes. The term ``probes,'' as used in the AD,
applies generically to either ``tank units'' or ``compensators.'' The
intent of the requirement of AD 99-08-02 to replace ``series 3'' (or
earlier series) FQIS probes is to purge the Boeing Model 747 fleet of
those FQIS probes (both tank units and compensators) that utilize a
knurled surface terminal block, which contribute to the chafing
problem.
The Background and Reason sections of Alert Service Bulletin 747-
28A2208 state that ``series 3'' or earlier FQIS tank units and
compensators have a knurled surface. With respect to the tank units,
Figure 5 of the Accomplishment Instructions of that alert service
bulletin recommends replacement of ``series 3'' (or earlier)
configurations with ``series 4'' (or later) configurations. However,
with respect to the compensators, Figure 5 recommends removal of series
1, 2, 3, 4, 11, 12, 13, or 14 configurations of certain compensator
part numbers and replacement with series 1, 5, 6, 15, or 16 of certain
other compensator part numbers. Because of inconsistencies in Alert
Service Bulletin 747-28A2208 that were included in AD 99-08-02,
paragraph (b) of this AD has been revised to clarify that the
replacement of FQIS probes (tank units and compensators) with new or
serviceable components be accomplished in accordance with Figure 5 of
the alert service bulletin.
Clarification of Inspection Types
In paragraphs (a) and (b) of this AD, the FAA has added a
definition of the type of inspection required by those paragraphs.
Clarification of Note 2
Clarification of NOTE 2 of AD 99-08-02 may be helpful to operators
required to comply with the paragraph (a) of AD 99-08-02. Actions
performed in accordance with Boeing Service Bulletin 747-28-2205, dated
June 27, 1997, accomplished prior to the effective date of this AD, are
considered acceptable for compliance only with the corresponding
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applicable actions specified in this AD. This excludes actions that are
not described in that bulletin, such as inspection and testing of the
body fuel tank components that are described in Revision 1 of Boeing
Service Bulletin 747-28-2205. Additionally, the requirements of this AD
to repair and to replace apply equally to discrepancies detected under
either version of Boeing Service Bulletin 747-28-2205. NOTE 2 of this
AD has been revised accordingly.
Clarification of Note 3
Airplanes affected by paragraph (b) of AD 99-08-02 include only
certain Boeing Model 747-100, -200, -300, -SP, and -SR series
airplanes, but no -400 series airplanes. NOTE 3 of that AD exempts
airplanes affected by paragraph (b) from accomplishing steps 1, 2, and
4 through 9 in Figure 11 of Boeing Service Bulletin 747-28-2205,
Revision 1, dated April 16, 1998 [the source of service information for
accomplishment of paragraph (a) of that AD]; the only step required is
step 3. However, since the issuance of AD 99-08-02, the FAA has
determined that step 3 applies only to Boeing Model 747-400
airplanes'--which are not affected by the requirements of paragraph
(b). Therefore, step 3 has been included with the steps that are exempt
from the requirement to accomplish the inspection in NOTE 3 of this
final rule. This change is for clarification purposes only and does not
affect the actual implementation of the requirements of that AD.
Clarification of Affected Airplanes for Paragraph (c)
Operators should note that paragraph (c) of AD 99-08-02 identifies
certain airplanes by their line ``positions.'' In the context of the
service information cited for paragraph (c), the term ``line
positions'' refers to airplane line numbers, rather than manufacturer's
tracking numbers for production airplanes. To clarify the identity of
the affected airplanes, paragraph (c) of this AD identifies those
airplanes by line ``numbers.''
Clarification of the Applicability of the AD
Although the Summary page of Boeing Service Bulletin 747-28A2208,
dated May 14, 1998, does not have the Boeing Model 747-SR listed in the
Effectivity section, the Effectivity listing in the text of that
service bulletin does list the appropriate applicable airplane
identification numbers, which include Boeing Model 747-100, -200, -300,
SP, and SR series airplanes. No change to this AD is necessary because
paragraph (b) of the AD requires action for ``those airplanes listed in
Boeing Alert Service Bulletin 747-28A2208, dated May 14, 1998,'' which
does include all of the appropriate airplanes. This information is
provided for clarification so that no confusion would exist due to the
inconsistency identified in the Boeing service bulletin. There is no
change to this final rule as a result of this clarification.
Action is taken herein to clarify these requirements of AD 99-08-02
and to correctly add the AD as an amendment to Sec. 39.13 of the
Federal Aviation Regulations (14 CFR 39.13).
The final rule is being reprinted in its entirety for the
convenience of affected operators. The effective date remains May 11,
1999.
Since this action only corrects and clarifies the current
requirements, it has no adverse economic impact and imposes no
additional burden on any person. Therefore, notice and public
procedures hereon are unnecessary.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Correction
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 removing amendment 39-11106 (64 FR
16625, April 4, 1999), and by adding a new airworthiness directive
(AD), amendment 39-11215, to read as follows:
99-08-02 R1 Boeing: Amendment 39-11215. Docket 99-NM-112-AD.
Revises AD 99-08-02, Amendment 39-11106.
Applicability: Model 747 series airplanes having line numbers 1
through 1124 inclusive, 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 (d)(1)
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 ignition sources and consequent fire/explosion in the
center fuel tank, accomplish the following:
Fuel Tank Inspection and Bonding Test
(a) For those airplanes listed in Boeing Service Bulletin 747-
28-2205, Revision 1, dated April 16, 1998: Within 24 months after
the effective date of this AD, accomplish paragraphs (a)(1) and
(a)(2) of this AD, in accordance with the service bulletin.
(1) Perform a one-time visual inspection of the center fuel tank
wiring and components to detect discrepancies (damage, disbonding,
and incorrect installation). For the purposes of this AD, a visual
inspection is considered to be a general visual inspection, which is
defined as: ``A visual examination of an interior or exterior area,
installation or assembly to detect obvious damage, failure or
irregularity. This level of inspection is made under normally
available lighting conditions such as daylight, hangar lighting,
flashlight, or drop-light and may require removal or opening of
access panels or doors. Stands, ladders, or platforms, may be
required to gain proximity to the area being checked.'' If any
discrepancy is detected, prior to further flight, repair the
discrepant component, or replace it with a new or serviceable
component. And
(2) Perform a one-time electrical bonding test of the center
fuel tank components. If any measured resistance exceeds the limits
specified by the service bulletin, prior to further flight, rework
the discrepant component.
Note 2: Actions performed in accordance with Boeing Service
Bulletin 747-28-2205, dated June 27, 1997, accomplished prior to the
effective date of this AD, are considered acceptable for compliance
only with the corresponding applicable actions specified in this AD.
This excludes certain actions that are not described in that
bulletin, such as inspection and testing of the body fuel tank
components that are described in Revision 1 of Boeing Service
Bulletin 747-28-2205. Regardless of which version of the service
bulletin is used to detect any discrepancies, the repair and
replacement requirements of this AD apply.
Note 3: Airplanes required to accomplish paragraph (b) of this
AD are exempt from accomplishing steps 1 through 9 in Figure 11 of
Boeing Service Bulletin 747-28-2205, Revision 1, dated April 16,
1998.
FQIS Testing and Probe Replacement
(b) For those airplanes listed in Boeing Alert Service Bulletin
747-28A2208, dated May 14, 1998: Within 24 months after the
effective date of this AD, perform a one-time insulation resistance
test of the fuel quantity indication system (FQIS), a one-time
visual inspection of the FQIS wiring and components to detect
discrepancies (chafing
[[Page 36565]]
damage to the wiring and incorrect configuration of the terminal
blocks), replacement of FQIS probes (tank units and compensators)
with new or serviceable components in accordance with Figure 5 of
the alert service bulletin, and system adjustment and system
operational test; in accordance with the alert service bulletin. For
the purposes of this AD, a visual inspection is considered to be a
general visual inspection, which is defined as: ``A visual
examination of an interior or exterior area, installation or
assembly to detect obvious damage, failure or irregularity. This
level of inspection is made under normally available lighting
conditions such as daylight, hangar lighting, flashlight, or drop-
light and may require removal or opening of access panels or doors.
Stands, ladders, or platforms, may be required to gain proximity to
the area being checked.'' If any discrepancy is detected, prior to
further flight, perform corrective actions in accordance with the
alert service bulletin.
Note 4: For airplanes on which steps 1 through 9 in Figure 11 of
Boeing Service Bulletin 747-28-2205, dated June 27, 1997, or
Revision 1, dated April 16, 1998, were accomplished prior to the
effective date of this AD, steps 1 through 6 in Figure 16 of Boeing
Alert Service Bulletin 747-28A2208, dated May 14, 1998, are not
required.
Flame Arrestor Installation
(c) For airplanes having line numbers 1 through 971 inclusive:
Within 24 months after the effective date of this AD, install a
flame arrestor in the inlet line of the electrical motor-operated
scavenge pump of the center fuel tank, in accordance with Boeing
Alert Service Bulletin 747-28A2210, dated May 14, 1998.
Alternative Methods of Compliance
(d)(1) 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, FAA, Transport Airplane Directorate. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
(d)(2) Alternative methods of compliance, approved previously in
accordance with AD 99-08-02, amendment 39-11106, are approved as
alternative methods of compliance with paragraph (a) of this AD.
Note 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(e) Special flight permits may be issued in accordance with
Secs. 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.
Incorporation by Reference
(f) The actions shall be done in accordance with Boeing Service
Bulletin 747-28-2205, Revision 1, dated April 16, 1998; Boeing Alert
Service Bulletin 747-28A2208, dated May 14, 1998; and Boeing Alert
Service Bulletin 747-28A2210, dated May 14, 1998. This incorporation
by reference was approved previously by the Director of the Federal
Register as of May 11, 1999 (64 FR 16625, April 6, 1999). Copies may
be obtained from Boeing Commercial Airplane Group, P.O. Box 3707,
Seattle, Washington 98124-2207. Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
(g) The effective date of this amendment remains May 11, 1999.
Issued in Renton, Washington, on June 29, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-17062 Filed 7-6-99; 8:45 am]
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