[Federal Register: October 13, 2005 (Volume 70, Number 197)]
[Rules and Regulations]
[Page 59644-59647]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13oc05-11]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-20137; Directorate Identifier 2004-NM-96-AD;
Amendment 39-14338; AD 2005-20-41]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200, -200PF, and -300
Series Airplanes, Powered by Pratt & Whitney PW2000 Series Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Boeing Model 757-200, -200PF, and -300 series airplanes,
powered by Pratt & Whitney PW2000 series engines. This AD requires
repetitive inspections for loose or damaged components of the support
brackets and associated fasteners for the hydraulic lines located in
the nacelle struts, and any related investigative and corrective
actions. This AD results from reports of damage and subsequent failure
of the support brackets and associated fasteners for the hydraulic
lines located internal to the upper fairing cavity of the nacelle
struts. We are issuing this AD to prevent such failure, which, in
conjunction with sparking of electrical wires, failure of seals that
would allow flammable fluids to migrate to compartments with ignition
sources, or overheating of the pneumatic ducts beyond auto-ignition
temperatures, could result in an uncontained fire.
DATES: This AD becomes effective November 17, 2005.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of November 17,
2005.
ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov
or in person at the Docket Management Facility, U.S.
Department of Transportation, 400 Seventh Street SW., Nassif Building,
Room PL-401, Washington, DC.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for service information identified in this AD.
FOR FURTHER INFORMATION CONTACT: Tom Thorson, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone
(425) 917-6508; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Examining the Docket
You may examine the AD docket in person at the Docket Management
Facility office between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The Docket Management Facility office
(telephone (800) 647-5227) is located on the plaza level of the Nassif
Building at the street address stated in the ADDRESSES section. This
docket number is FAA-2005-20137; the directorate identifier for this
docket is 2004-NM-96-AD.
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to include an AD that would apply to certain Boeing Model
757 series airplanes. That NPRM was published in the Federal Register
on January 28, 2005 (70 FR 4052). That NPRM proposed to require
repetitive inspections for loose or damaged components of the support
brackets and associated fasteners for the hydraulic lines located in
the nacelle struts, and any related investigative and corrective
actions.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments on the NPRM
that have been received.
Support for Proposed AD
Two commenters concur with the proposed AD as written.
Requests To Extend Compliance Time
Two commenters ask that the compliance time for the initial and
repetitive inspections specified in the proposed AD be extended.
One commenter asks that the compliance time for the initial and
repetitive inspections be extended to 6,000 flight hours or 24 months,
whichever is first. The proposed AD specifies initial and repetitive
inspections at intervals not to exceed 6,000 flight hours or 18 months.
The commenter adds that, based on access, labor hour requirements, and
the nature of the detailed inspections, this type of work aligns with
the airline's heavy maintenance program, which is calendar-based and
FAA-approved at 24-month intervals. The commenter states that, because
the proposed inspections are fatigue-related, an equivalent level of
safety is maintained by extending the proposed calendar compliance
time.
A second commenter asks that the compliance time for the repetitive
inspections be changed to 7,500 flight hours or 24 months. The
commenter states that the proposed AD requires the initial inspection
to be accomplished within 18 months or 6,000 flight hours, regardless
of total flight cycles/hours on the airplane. The commenter adds that
the safety concern addressed by the proposed AD appears to be age-
related. Additionally, consideration should be given to whether or not,
and when, the work described in Boeing Service Bulletin 757-29-0043,
dated June 21, 1990 (the concurrent service bulletin referenced in the
proposed AD) was accomplished. The commenter also states that the
initial and repetitive inspection interval in the proposed AD coincides
with the published Material Review Board's most conservative periodic
check (PCK) interval; several operators, including the commenter, have
escalated that PCK interval to 24 months. The commenter concludes that
attempting to accomplish the proposed actions within the proposed
compliance time would be expensive; extending the compliance time would
allow operators who have escalated the PCK interval to accomplish the
inspections during maintenance checks.
We agree to extend the compliance time for the initial and
repetitive inspections to 6,000 flight hours or 24 months, whichever is
first. The fatigue-related failures are a function of airplane flight
hours and flight cycles, not a direct function of calendar time.
Extending the compliance time will continue to provide an equivalent
level of safety, as noted by the commenter. However, we do not agree to
extend the compliance time to 7,500 flight hours or 24 months; the
6,000-flight-hour compliance time was based on service history of part
failures and an engineering fatigue analysis by the original equipment
manufacturer (OEM). We have changed paragraph (f) of this AD to reflect
the revised compliance time.
Request To Change Costs of Compliance Section
Two commenters ask for changes to the Costs of Compliance section.
One commenter states that the estimate in the cost section in the
proposed AD specifies that it would
[[Page 59645]]
take 35 work hours to accomplish the inspection required by paragraph
(f) of the proposed AD, but the commenter estimates that it would take
47 work hours to accomplish that inspection. The commenter adds that
the proposed AD also requires accomplishing the concurrent actions
specified in paragraph (g) of the proposed AD and referenced in Boeing
Service Bulletin 757-29-0043, dated June 21, 1990; however, the cost
for those actions is not included in the Costs of Compliance section.
The commenter concludes that the cost for the inspections was
underestimated and the cost for the concurrent actions was omitted.
A second commenter asks that we change the Costs of Compliance
section in the proposed AD to specify that the number of work hours
necessary to accomplish the proposed inspection and the concurrent
actions would be determined by operators on a case-by-case basis.
We do not agree to change the work hours in this AD or specify that
operators will determine the number of work hours necessary for
accomplishing the actions. The number of work hours represent the time
necessary to perform only the actions actually required by the AD. The
actions in an AD normally reflect only the costs of the specific
required action (inspection) based on the best data available from the
manufacturer; however, this AD also includes the time required to gain
access and close up. The cost analysis in AD rulemaking actions
typically does not include incidental costs such as the time necessary
for planning, or time necessitated by other administrative actions.
Those incidental costs, which may vary significantly among operators,
are almost impossible to calculate. We have made no change to the AD in
this regard.
We do agree to add the cost for the concurrent actions since those
actions were inadvertently omitted from the NPRM. We have added a new
paragraph to the Costs of Compliance section which estimates the work
hours and cost per airplane for accomplishing the concurrent actions.
Request To Change Statement of Unsafe Condition
One commenter, the OEM, asks that we change the statement of unsafe
condition specified in the proposed AD. The statement of unsafe
condition is as follows: ``We are proposing this AD to prevent
flammable fluids from leaking into the interior compartment of the
nacelle struts where ignition sources exist, which could result in the
ignition of flammable fluids and an uncontained fire.'' The commenter
states that the damage to the Pratt & Whitney strut has not caused any
damage to barriers between the upper strut compartment and any other
compartment; the hydraulic tube is clamped to frames, not to a vapor
barrier. The commenter adds that the upper strut compartment is
designated as a flammable leakage zone, and therefore, to the greatest
extent possible, all ignition sources have been eliminated. The
commenter notes that the unsafe condition addressed by the referenced
service information does not result in any zone barriers being damaged.
The commenter concludes that any leakage of flammable fluids will not
come in contact with ignition sources; additionally, the upper strut
compartment has drainage provisions to prevent the accumulation of
flammable fluids.
We agree to change the description of the unsafe condition. The
commenter is accurate in the statement that any leakage of flammable
fluids will not come in contact with ignition sources because the upper
strut compartment has drainage provisions to prevent the accumulation
of flammable fluids. Due to the design of the system installations in
the strut compartments, an additional failure would have to occur to
result in the ignition of flammable fluids. Additional failures include
shorting and sparking of electrical wires in either the strut upper
fairing cavity or torque box, failure of seals that would allow
flammable fluids to migrate to compartments with ignition sources, or
overheating of the pneumatic ducts beyond auto-ignition temperatures.
The description of the unsafe condition has been changed throughout the
AD.
Request To Clarify Acceptable Part Numbers
One commenter states that the proposed AD requires accomplishing
the actions specified in two different service bulletins, which are
referenced in paragraphs (f) and (g) of the proposed AD. The commenter
is concerned because the part numbers specified in those two bulletins
are different. The commenter recommends that the proposed AD be revised
to specify that the part numbers listed in either service bulletin are
acceptable configurations and fully comply with the actions specified
in the proposed AD.
We acknowledge and provide clarification for the commenter's
concern. The OEM verified with us that the different part numbers
specified in the referenced service bulletins are due to one series of
parts having pilot holes and the other series not having pilot holes.
Therefore, the part numbers identified in either service bulletin are
acceptable configurations and fully comply with the AD requirements for
the modifications. We have added a note to the AD for clarification. In
addition, once a revision to the service bulletins has been issued by
the manufacturer, and reviewed and accepted by us, we will approve the
use of either series of part numbers as an acceptable alternative
method of compliance (AMOC) according to paragraph (j) of this AD.
Request To Clarify the Repair Approval Specified in Paragraph (i)
One commenter asks that paragraph (i) of the proposed AD, titled
``Repair Information,'' be clarified concerning the requirement to
obtain repair approval per the Manager, Seattle Aircraft Certification
Office (ACO). The commenter questions if this approval is required for
all Boeing-assisted repairs to the engine strut frames, or if the
approval is only required for Boeing-assisted repairs found during the
inspections required by the proposed AD.
We interpret the commenter's question to be whether damage found
inside the strut that is not found during the inspection required by
the AD requires Seattle ACO approval of the repair method. Our response
is that only repairs of hardware damage found during the inspection
required by the AD for which the service bulletin specifies a Boeing-
assisted repair per the referenced service information need be
submitted to the Seattle ACO for approval. If specific cases develop
and the repair method is not apparent to the operator, contact the
Seattle ACO for guidance. We have not changed the AD in this regard.
Request To Resolve Parts Issues
One commenter states that the following parts issues represent an
undue burden on operators by needlessly restricting operator action,
and asks that these issues be resolved. Those issues and our responses
are as follows:
1. The commenter asks that the proposed AD be changed to allow
dimensional drawings or provisions for operators to fabricate
acceptable substitute brackets. The commenter states that, since parts
are not available from the OEM, operators must fabricate the brackets
and re-use the fasteners and rubber blocks, as necessary.
We do not agree that operators can be allowed to fabricate their
own parts. Operators would be required to fabricate parts by using an
approved design, and we cannot authorize this without
[[Page 59646]]
reviewing the operators' design data. The manufacturer has indicated
that the parts required are readily available; therefore, obtaining
them should not be a problem. However, should parts not be available in
a timely manner, operators may provide the design data to us and
request approval of an AMOC per paragraph (j) of this AD.
2. The commenter asks that we revise Section II of Boeing Service
Bulletin 757-29-0064 (referenced in the proposed AD as the appropriate
source of service information for accomplishing the inspections for
Model 757-200 and -200PF series airplanes) to add a provision for
providing brackets and hardware for all stations. The commenter states
that Section II of the service bulletin contains material information
that is inadequate. The commenter has found that only parts necessary
for station 149.5 are included in that section; however, the service
bulletin specifies inspecting and replacing parts at stations 102.1,
128.0, 149.5, 161.35, and 180.0 on the left and right sides of the
airplane. In addition, the commenter found damaged/worn parts at other
stations.
3. The commenter asks that we require brackets and hardware to be
stocked and provided by Boeing until terminating action is developed.
The commenter states that parts for all stations are not readily
available from the OEM or other suppliers.
We do not agree to advise Boeing to revise Section II of the
referenced service bulletin, or to require that Boeing provide parts
until terminating action is developed. The technical content of the
referenced service bulletin is correct and contains adequate
information and procedures to accomplish the repetitive inspections.
Therefore, we have determined that it is not necessary for the
manufacturer to revise the service bulletin before issuance of this AD.
In addition, we have no regulatory basis to require the type
certificate holder to provide the parts necessary to comply with the
corrective action specified in the AD. The manufacturer has indicated
that the parts required are readily available; therefore, obtaining
them should not be a problem. However, under the provisions of
paragraph (j) of this AD, affected operators may request approval of an
AMOC.
Request To Approve Future Service Information
One commenter, the OEM, asks that the appropriate sections in the
proposed AD be changed to reference Revision 1 of Boeing Service
Bulletins 757-29-0064 and 757-29-0065. (Boeing Service Bulletins 757-
29-0064 and 757-29-0065, both dated February 29, 2004, are referenced
in the NPRM as the appropriate sources of service information for
accomplishing the repetitive inspections.) The commenter states that
those service bulletins are currently being revised and are expected to
be released soon.
We cannot accept as-yet unpublished service documents for
compliance with the requirements of an AD. Referring to an unavailable
service bulletin in an AD violates Office of the Federal Register
regulations for approving materials that are incorporated by reference.
We have not changed the AD regarding this issue because the service
bulletins have not been revised and we cannot delay the final rule to
wait for revisions to be issued. However, under the provisions of
paragraph (j) of this AD, affected operators may request approval to
use a later revision of the referenced service bulletin as an AMOC.
Clarification of Alternative Method of Compliance (AMOC) Paragraph
We have changed this AD to clarify the appropriate procedure for
notifying the principal inspector before using any approved AMOC on any
airplane to which the AMOC applies.
Conclusion
We have carefully reviewed the available data, including the
comments that we received, and determined that air safety and the
public interest require adopting the AD with the changes described
previously. These changes will neither increase the economic burden on
any operator nor increase the scope of the AD.
Costs of Compliance
This AD affects about 432 airplanes worldwide and 377 airplanes of
U.S. registry.
The inspection/test takes about 35 work hours per airplane
(including access and close-up), at an average labor rate of $65 per
work hour. Based on these figures, the estimated cost of the
inspection/test for U.S. operators is $857,675, or $2,275 per airplane,
per inspection/test cycle.
The concurrent actions would take about 38 work hours per airplane,
at an average labor rate of $65 per work hour. Required parts cost is
minimal. Based on these figures, the estimated cost of the concurrent
actions is $2,470 per airplane.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
subtitle VII, part A, subpart III, section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD 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.
For the reasons discussed above, I certify that this AD:
(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 impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket. See the ADDRESSES
section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the FAA amends 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. The Federal Aviation Administration (FAA) amends Sec. 39.13
[[Page 59647]]
by adding the following new airworthiness directive (AD):
2005-20-41 Boeing: Amendment 39-14338. Docket No. FAA-2005-20137;
Directorate Identifier 2004-NM-96-AD.
Effective Date
(a) This AD becomes effective November 17, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 757-200, -200PF, and -300
series airplanes; certificated in any category; powered by Pratt &
Whitney PW2000 series engines.
Unsafe Condition
(d) This AD was prompted by reports of damage and subsequent
failure of the support brackets and associated fasteners for the
hydraulic lines located internal to the upper fairing cavity of the
nacelle struts. We are issuing this AD to prevent such failure,
which, in conjunction with sparking of electrical wires, failure of
seals that would allow flammable fluids to migrate to compartments
with ignition sources, or overheating of the pneumatic ducts beyond
auto-ignition temperatures, could result in an uncontained fire.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Repetitive Inspections
(f) Within 6,000 flight hours or 24 months after the effective
date of this AD, whichever is first: Do a detailed inspection for
loose or damaged components of the support brackets and associated
fasteners for the hydraulic lines located in the nacelle struts by
accomplishing all of the actions specified in Part 1, Part 2, and
Part 3 of the Accomplishment Instructions of Boeing Service Bulletin
757-29-0064 (for Model 757-200 and -200PF series airplanes) or
Boeing Service Bulletin 757-29-0065 (for Model 757-300 series
airplanes), both dated February 29, 2004; as applicable. Repeat the
inspection thereafter at intervals not to exceed 6,000 flight hours
or 24 months, whichever is first.
Note 1: 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.''
Concurrent Service Bulletin
(g) Prior to or concurrently with the accomplishment of
paragraph (f) of this AD: Accomplish all of the actions specified in
the Accomplishment Instructions of Boeing Service Bulletin 757-29-
0043, dated June 21, 1990.
Note 2: The part numbers identified in Boeing Service Bulletins
757-29-0064 or 757-29-0065, both dated February 29, 2004; or Boeing
Service Bulletin 757-29-0043, dated June 21, 1990; are acceptable
configurations and fully comply with the AD requirements for the
actions required by paragraphs (f) and (g) of this AD.
Related Investigative and Corrective Actions
(h) Except as required by paragraph (i) of this AD: If any loose
or damaged part is found during any inspection required by paragraph
(f) of this AD, before further flight, do all of the related
investigative and corrective actions specified in Part 1 and Part 2
of the Accomplishment Instructions of Boeing Service Bulletin 757-
29-0064, or Boeing Service Bulletin 757-29-0065, both dated February
29, 2004; as applicable.
Repair Information
(i) If any damage is found during any inspection required by
this AD, and the service bulletin specifies contacting Boeing for
appropriate action: Before further flight, repair per a method
approved by the Manager, Seattle Aircraft Certification Office
(ACO), FAA. For a repair method to be approved, the approval letter
must specifically refer to this AD.
Note 3: There is no terminating action currently available for
the repetitive inspections required by paragraph (f) of this AD.
Alternative Methods of Compliance (AMOCs)
(j)(1) The Manager, Seattle ACO, has the authority to approve
AMOCs for this AD, if requested in accordance with the procedures
found in 14 CFR 39.19.
(2) Before using any AMOC approved in accordance with Sec.
39.19 on any airplane to which the AMOC applies, notify the
appropriate principal inspector in the FAA Flight Standards
Certificate Holding District Office.
Material Incorporated by Reference
(k) You must use Boeing Service Bulletin 757-29-0064, dated
February 29, 2004, or Boeing Service Bulletin 757-29-0065, dated
February 29, 2004; and Boeing Service Bulletin 757-29-0043, dated
June 21, 1990; as applicable, to perform the actions that are
required by this AD, unless the AD specifies otherwise. The Director
of the Federal Register approved the incorporation by reference of
these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for a copy of this service information. You
may review copies at the Docket Management Facility, U.S. Department
of Transportation, 400 Seventh Street SW., Room PL-401, Nassif
Building, Washington, DC; on the Internet at http://dms.dot.gov; or
at the National Archives and Records Administration (NARA). For
information on the availability of this material at the NARA, call
(202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html
.
Issued in Renton, Washington, on September 30, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-20264 Filed 10-12-05; 8:45 am]
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