[Federal Register: August 8, 2003 (Volume 68, Number 153)]
[Rules and Regulations]
[Page 47213-47216]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08au03-8]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-232-AD; Amendment 39-13259; AD 2003-16-06]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
Equipped with General Electric CF6-45 or CF6-50 Series Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to all Boeing Model 747 series airplanes equipped with
General Electric CF6-45 and CF6-50 series engines. This amendment
requires an inspection to detect chafing of the fuel line or incorrect
clearance between the fuel line and pneumatic duct insulation blanket;
a fuel leak check and strut drain test; corrective action if necessary;
replacement of the outboard strut fuel line coupling O-rings and
retaining rings with new parts; replacement of the pneumatic duct boot
with a new part; and, for certain airplanes, installation of a flame
arrestor and drain line entry screens. The actions specified by this AD
are intended to prevent leaking fuel line couplings, chafed fuel lines,
restricted or clogged strut drain lines, migrating fluids or vapors
toward ignition sources, and flashback of external flame into the
strut; these conditions could result in an uncontained engine strut
fire. This action is intended to address the identified unsafe
condition.
DATES: Effective September 12, 2003. The incorporation by reference of
certain publications listed in the regulations is approved by the
Director of the Federal Register as of September 12, 2003.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Dan Kinney, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone
(425) 917-6499; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to all Boeing Model 747 series
airplanes equipped with General Electric CF6-45 and CF6-50 series
engines was published in the Federal Register on January 29, 2003 (68
FR 4398). That action proposed to require an inspection to detect
chafing of the fuel line or incorrect clearance between the fuel line
and pneumatic duct insulation blanket; a fuel leak check and strut
drain test; corrective action if necessary; replacement of the outboard
strut fuel line coupling O-rings and retaining rings with new parts;
replacement of the pneumatic duct boot with a new part; and, for
certain airplanes, installation of a flame arrestor and drain line
entry screens.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request To Correct Service Bulletin Citations
Two commenters state that there are typographical errors in two of
the service bulletin citations specified in the section in the preamble
titled ``Explanation of Relevant Service Information.'' The first
commenter states that the reference to Boeing Service Bulletin 747-28-
2155 should be 747-71-2155. The second commenter states that the
reference to Boeing Service Bulletin 747-36-2122 should be 747-54-2122.
While the FAA agrees with these corrections and acknowledges that the
service bulletin citations were incorrect in the proposed AD, that
section of the preamble is not restated in the final rule.
Request To Clarify Certain Paragraphs
One commenter asks that paragraph (e) of the proposed AD be
changed, for clarification, to add that the fiberglass fabric pneumatic
duct boot is replaced with a new, NOMEX fabric duct boot. We agree and
have added the language requested by the commenter to paragraph (e) of
this final rule.
The same commenter asks that paragraphs (b) and (f) of the proposed
AD be changed, for clarification, to add the term ``outboard'' to
define which strut is affected by those paragraphs. We agree and have
added the term requested by the commenter to paragraphs (b) and (f) of
this final rule.
Replace Pneumatic Boot Only if Damage Found
One commenter states that it performs the repetitive detailed
visual inspections of the pneumatic duct boot at every 1C-check, with
replacement of the duct boot if it is damaged. The commenter asks that
it be allowed to continue to perform the inspections at every 1C-check,
and replace the duct boot only if damaged, instead of replacing the
duct boot at the time specified in paragraph (e) of the proposed AD.
The commenter asks that its program be included as an alternative
method of compliance (AMOC) to the proposed AD, if possible.
We do not agree with the commenter. Early replacement of the
original boot configuration with a NOMEX boot is critical to having a
reliable seal in place. The flight-hour intervals used for maintenance
checks may not ensure replacement of the original boot within 12
months. However, if maintenance records indicate that the original boot
has been replaced with the new NOMEX fabric part, it is not necessary
to repeat that action. Paragraph (e)(2) of this final rule is a
continuing requirement which specifies that whenever a damaged boot of
the original boot configuration is found it must be replaced before
further flight, or within 5 days following detection if there are no
leaks. The commenter may submit substantiating data that support a
request for an AMOC per paragraph (i) of this AD. No change to the
final rule is necessary in this regard.
[[Page 47214]]
Request To Change Compliance Time
Two commenters ask that the compliance time for the repetitive
replacement of the O-rings and retaining rings, as specified in
paragraph (d) of the proposed AD, be changed, as follows: One commenter
states that it performs the repetitive replacement of the O-rings and
retaining rings every 5 years.
We infer that the commenter wants to continue the replacement every
5 years, in lieu of the compliance time of every 21,000 flight hours or
5 years, whichever is earlier (unless a coupling is disassembled).
The same commenter states that it performs the fuel pressure leak
check every 5 years when it replaces the O-rings and retaining rings,
and would like to be allowed to continue at that interval in lieu of
the 3-year interval specified in Boeing Service Bulletin 747-28-2230,
dated September 30, 1999 (referenced in the proposed AD as the source
of service information for accomplishment of the fuel leak check and
strut drain inspection).
We acknowledge that the service bulletin specified recommends
repeating the leak check every 3 years; however, the proposed AD does
not require repetitive fuel pressure leak checks; only a one-time check
within 12 months after the effective date of the AD.
Another commenter states that it performs the repetitive
replacement of the O-rings and retaining rings during its D-check, and
asks that all operators be allowed to perform the replacement at that
time. The commenter also provides some statistics on cases of fuel
leakage found and the corrective actions taken; and noted that there
were more fuel leaks that occurred after maintenance of the fuel line
coupling O-rings if specially trained mechanics did not do the
maintenance, due to the necessity of using delicate installation
procedures that are specific to that type of couplings.
We do not agree with the requests to extend the compliance time.
The chronological age of the O-rings combined with flight hours
produces the deterioration and fuel leaks. With regard to extending the
compliance time to allow the replacement to be accomplished at a D-
check or every 5 years, we have already considered factors such as
operators' maintenance schedules in setting a compliance time for the
required replacement and determined that 21,000 flight hours or 5
years, whichever is earlier (unless a coupling is disassembled), is an
appropriate compliance time in which the replacement may be
accomplished during scheduled airplane maintenance for the majority of
affected operators. Since maintenance schedules vary from operator to
operator, it would not be possible to guarantee that all affected
airplanes could be modified during scheduled maintenance. In any event,
we find that the specified compliance time represents the maximum time
wherein the affected airplanes may continue to operate without
compromising safety. No change to the final rule is necessary in this
regard.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Changes to 14 CFR Part 39/Effect on the Proposed AD
On July 10, 2002, the FAA issued a new version of 14 CFR part 39
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness
directives system. This regulation now includes material that relates
to altered products, special flight permits, and AMOCs. Because we have
now included this material in part 39, only the office authorized to
approve AMOCs is identified in each individual AD. However, for clarity
and consistency in this final rule, we have retained the language of
the NPRM regarding that material.
Change to Labor Rate Estimate
We have reviewed the figures we have used over the past several
years to calculate AD costs to operators. To account for various
inflationary costs in the airline industry, we find it necessary to
increase the labor rate used in these calculations from $60 per work
hour to $65 per work hour. The cost impact information, below, reflects
this increase in the specified hourly labor rate.
Cost Impact
The following table provides the cost estimates to accomplish the
required actions:
----------------------------------------------------------------------------------------------------------------
Number of
Boeing service information for required Work Hourly Parts Per- U.S. U.S.
actions hours per labor cost per airplane airplanes fleet
airplane rate airplane cost affected cost
----------------------------------------------------------------------------------------------------------------
Service Bulletin 747-36-2111.................. 10 $65 $0 $650 32 $20,800
Service Bulletin 747-28-2230.................. 4 65 0 260 32 8,320
Service Letter 747-SL-28-052-B................ 4 65 0 260 32 8,320
Service Bulletin 747-36-2118.................. 10 65 1,269 1,919 32 61,408
Service Bulletin 747-54-2137.................. 48 65 3,047 6,167 30 185,010
Service Bulletin 747-54-2122.................. 56 65 2,590 6,230 30 186,900
----------------------------------------------------------------------------------------------------------------
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the requirements of this
AD action, and that no operator would accomplish those actions in the
future if this AD were not adopted. The cost impact figures discussed
in AD rulemaking actions represent only the time necessary to perform
the specific actions actually required by the AD. These figures
typically do not include incidental costs, such as the time required to
gain access and close up, planning time, or time necessitated by other
administrative actions.
Regulatory Impact
The regulations adopted herein will not have a substantial direct
effect 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, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a
significant economic
[[Page 47215]]
impact, positive or negative, on a substantial number of small entities
under the criteria of the Regulatory Flexibility Act. A final
evaluation has been prepared for this action and it is contained in the
Rules Docket. A copy of it 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, Incorporation by
reference, Safety.
Adoption of the Amendment
0
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
0
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]
0
2. Section 39.13 is amended by adding the following new airworthiness
directive:
2003-16-06 Boeing: Amendment 39-13259. Docket 2001-NM-232-AD.
Applicability: Model 747 series airplanes equipped with General
Electric CF6-45 or CF6-50 series engines, 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 (i) 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 leaking fuel line couplings, chafed fuel lines,
restricted or clogged strut drain lines, fluids or vapors migrating
to ignition sources, and flashback of external flame into the strut,
which could result in uncontained engine strut fire, accomplish the
following:
Inspection for Chafing and Clearance
Note 2: Paragraph (a) of this AD refers to certain portions of
Boeing Service Bulletin 747-36-2111, dated February 20, 1992, for
information regarding inspection and measurement actions. Further,
paragraph (a) of this AD requires replacement of the fuel tube as
corrective action for certain repair conditions; that action is not
included in the service bulletin. Where this AD and Service Bulletin
747-36-2111 differ, the AD prevails.
(a) Within 1,000 flight hours after the effective date of this
AD, perform a detailed inspection to detect chafing of the fuel line
and measure the clearance between the fuel line and the insulation
blanket on the pneumatic duct, in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 747-36-2111, dated February
20, 1992. Before further flight, accomplish all applicable
corrective actions (including reworking the fuel line, remeasuring
the clearance between the fuel line and the insulation blanket,
adjusting the pneumatic duct and fuel line positions, adjusting the
insulation blanket installation, and inspecting and cleaning the
strut and strut drain ports/screens); and, if applicable, repeat the
fuel line inspection at the applicable time in the Accomplishment
Instructions of the service bulletin. Do the corrective and follow-
on actions in accordance with Service Bulletin 747-36-2111. If,
after corrective actions have been performed, a clearance of at
least 0.40 inch on the number 4 strut cannot be achieved: Before
further flight, replace the fuel tube with a new part in accordance
with Boeing Service Bulletin 747-28-2162, dated July 30, 1992.
Note 3: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation, or assembly to detect damage,
failure, or irregularity. Available lighting is normally
supplemented with a direct source of good lighting at intensity
deemed appropriate by the inspector. Inspection aids such as mirror,
magnifying lenses, etc., may be used. Surface cleaning and elaborate
access procedures may be required.''
Fuel Leak Check and Outboard Strut Drain Inspection
(b) Within 12 months after the effective date of this AD,
perform a fuel pressure leak check of the fuel line in the outboard
strut area, and perform an outboard strut drain test for the aft
strut drain tubes to detect blockage; in accordance with the
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 747-28-2230, dated September 30, 1999. If any discrepancy
is found, before further flight, perform applicable corrective
actions (including performing the fuel pressure check procedure,
clearing the strut drain tubes, and repairing seal leaks) in
accordance with the service bulletin.
Replacement of O-Rings and Retaining Rings
(c) At the earliest of the times specified by paragraphs (c)(1),
(c)(2), and (c)(3) of this AD, replace the fuel line coupling O-
rings and retaining rings in the outboard strut positions with new
Nitrile O-rings, part number MS29513-330, in accordance with Boeing
Service Letter 747-SL-28-052-B, dated August 30, 1998. Replace the
rings thereafter at the time specified by paragraph (d) of this AD.
(1) Within 21,000 flight hours after the effective date of this
AD.
(2) Within 5 years after the effective date of this AD.
(3) Before further flight after a coupling has been disassembled
for any reason.
Repetitive Ring Replacement
(d) Replace the rings as required by paragraph (c) of this AD at
intervals not to exceed the earliest of the times specified by
paragraphs (d)(1), (d)(2), and (d)(3) of this AD.
(1) Every 21,000 flight hours.
(2) Every 5 years.
(3) Before further flight after a coupling has been disassembled
for any reason.
Replacement of Pneumatic Duct Boot
(e) At the earlier of the times specified in paragraphs (e)(1)
and (e)(2) of this AD: Replace the fiberglass fabric pneumatic duct
boot with a new NOMEX fabric part, in accordance with Boeing Service
Bulletin 747-36-2118, dated January 28, 1993.
(1) Within 12 months after the effective date of this AD; or
(2) Before further flight following detection of any torn boot;
or within 5 days following detection of any torn boot, provided
there are no leaks, liquid fuel, or vapors in the affected strut
compartment.
Installation of Flame Arrestor
(f) For airplanes identified in Boeing Service Bulletin 747-54-
2137, dated February 6, 1992: Within 24 months after the effective
date of this AD, install a flame arrestor in each aft condensate
drain hole of the outboard engine struts, in accordance with the
Accomplishment Instructions of the service bulletin.
Installation of Drain Screen
(g) For Group 2 and Group 4 airplanes listed in Boeing Service
Bulletin 747-54-2122, Revision 4, dated August 29, 1991, as revised
by Notice of Status Change 747-54-2122 NSC 2, dated May 14, 1992;
and Information Notice 747-54-2122 IN 03, dated August 19, 1999:
Within 24 months after the effective date of this AD, install a
drain line entry screen at each drain tube entry at the outboard
strut positions, in accordance with the Accomplishment Instructions
of the service bulletin. Where the service bulletin specifies that
certain actions may be accomplished in accordance with an operator's
``equivalent procedure': Those actions must be accomplished in
accordance with the applicable Boeing 747 Airplane Maintenance
Manual subject specified in the service bulletin.
(h) Installation of drain screens before the effective date of
this AD is also acceptable for compliance with the requirements of
paragraph (g) of this AD if accomplished in accordance with Boeing
Service Bulletin 747-54-2122, Revision 1, dated December 14, 1989;
Revision 2, dated May 3, 1990; or Revision 3, dated October 4, 1990.
Alternative Methods of Compliance
(i) 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
[[Page 47216]]
Aircraft Certification Office (ACO), FAA. 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.
Note 4: 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
(j) 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.
Incorporation by Reference
(k) Unless otherwise specified in this AD, the actions shall be
done in accordance with Boeing Service Bulletin 747-36-2111, dated
February 20, 1992; Boeing Service Bulletin 747-28-2162, dated July
30, 1992; Boeing Special Attention Service Bulletin 2 747-28-2230,
dated September 30, 1999; Boeing Service Letter 747-SL-28-052-B,
dated August 30, 1998; Boeing Service Bulletin 747-36-2118, dated
January 28, 1993; Boeing Service Bulletin 747-54-2137, dated
February 6, 1992; and Boeing Service Bulletin 747-54-2122, Revision
4, dated August 29, 1991, as revised by Notice of Status Change 747-
54-2122 NSC 2, dated May 14, 1992, and Information Notice 747-54-
2122 IN 03, dated August 19, 1999; as applicable.
This incorporation by reference was approved by the Director of
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. 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.
Effective Date
(l) This amendment becomes effective on September 12, 2003.
Issued in Renton, Washington, on July 31, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-19981 Filed 8-7-03; 8:45 am]
BILLING CODE 4910-13-P