[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

[[Page 36564]]

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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