[Federal Register: October 26, 2005 (Volume 70, Number 206)]
[Rules and Regulations]
[Page 61716-61720]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26oc05-3]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-20473; Directorate Identifier 2004-NM-156-AD;
Amendment 39-14351; AD 2005-22-07]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200, -200PF, and -300
Series Airplanes
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. This
AD requires inspecting for damage of the ground brackets, ground wires,
and terminal lugs of the auxiliary power unit (APU) battery and the APU
start transformer rectifier unit (TRU) as applicable; and
[[Page 61717]]
corrective and related investigative actions. This AD results from
reports indicating that during inspections on two airplanes, the ground
brackets for the APU battery were found damaged. We are issuing this AD
to detect and correct a damaged electrical bonding surface of the APU
battery and APU start TRU ground connections, which could cause
overheating of the ground connections and lead to possible consequent
ignition of the adjacent insulating blankets.
DATES: This AD becomes effective November 30, 2005.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of November 30,
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: Elias Natsiopoulos, Aerospace
Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6478; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Examining the Docket
You may examine the airworthiness directive (AD) docket on the
Internet at http://dms.dot.gov or 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.
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
757-200, -200PF, and -300 series airplanes. That NPRM was published in
the Federal Register on March 3, 2005 (70 FR 10344). That NPRM proposed
to require inspecting for damage of the ground brackets, ground wires,
and terminal lugs of the auxiliary power unit (APU) battery and the APU
start transformer rectifier unit (TRU) as applicable; and corrective
and related investigative actions.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Support for the Proposed Rule
Two commenters have reviewed the subject NPRM and concur with the
content and 18 month compliance timetable of the proposed AD.
Request for Deferral of Corrective Actions
One commenter requests that we allow a deferral of 30 to 60 days,
not to exceed the compliance time of 18 months from the issue date of
the AD, to accomplish any required repair or replacement of damaged
parts discovered during the required inspection. The commenter is
concerned that additional time may be needed after the inspection to
accomplish the corrective actions and states that the NPRM does not
specify when the applicable corrective actions and related
investigative actions should be accomplished, only that they must be
accomplished within 18 months after the effective date of the AD.
We agree with the intent of the commenter's request. We have
determined that, in this case, safety will not be compromised if the
applicable corrective actions and related investigative actions are not
accomplished immediately after the inspection, provided such actions
are accomplished within the 18 month compliance time specified in
paragraph (f) of the AD. It is not necessary to change the AD to meet
the intent of the commenter's request.
Request to Cite Affected AD
Two commenters request that paragraph (b) of the NPRM be revised to
refer to AD 97-15-09, amendment 39-10083 (July 17, 1997, 62 FR 38204),
as an affected rule, and request that the proposed AD be revised to
clarify how it is affected by AD 97-15-09 and FAA Alternate Means of
Compliance (AMOC) 98-130S-149R1, dated August 6, 1998. One commenter
believes that the proposed AD should supersede AD 97-15-09, which is
applicable to all Model 757 airplanes.
We agree that AD 97-15-09 is related to this AD because AD 97-15-09
applies to the same APU battery and TRU ground assemblies as this AD,
and because AD 97-15-09 is applicable to all Model 757 airplanes.
However, we do not agree that this AD should supersede AD 97-15-09,
because the failure conditions addressed by AD 97-15-09 are not the
same as the failure condition addressed by this AD. For Model 757
airplanes having line number (L/N) 1 through 777 inclusive, the AMOC
and terminating action for AD 97-15-09 are specified in Boeing Service
Bulletin 757-24A0080, dated April 23, 1998--as well as Revision 1,
dated May 20, 1999, Revision 2, dated March 29, 2001, or Revision 3,
dated November 4, 2004--which specifies, among other things, replacing
the ground brackets. Model 757 airplanes having L/N 778 and subsequent
were in production when AD 97-15-09 was issued. The AMOC and
terminating action for AD 97-15-09 resulted from design changes made
during production of Model 757 airplanes having L/N 778 and subsequent,
and those design changes were approved in FAA AMOC 98-130S-149R1, dated
August 6, 1998. However, the production process used to clean the
electrical bonding surfaces of the grounding bracket and frame of Model
757 airplanes having L/N 778 and subsequent was incorrect and did not
reflect the actions specified in Service Bulletin 757-24A0080,
resulting in overheating of the ground assemblies. This AD applies only
to Model 757 airplanes having L/N 778 and subsequent; Model 757
airplanes having L/N 1 through 777 inclusive require no further action
according to this AD, provided those airplanes are repetitively
inspected per AD 97-15-09, or the terminating actions specified in
Service Bulletin 757-24A0080 have been correctly incorporated.
Therefore, although AD 97-15-09 is related to this AD, it is not
affected by this AD. We have not changed this AD in this regard.
Request to Clarify Applicability of Proposed AD to Certain Service
Information
One commenter requests that we clarify how the actions in the NPRM
apply to the actions specified by Alert Service Bulletin 757-24A0080,
which provides the terminating action for AD 97-15-09. The commenter
states that accomplishing Alert Service Bulletin 757-24A0080 may result
in the same unsafe condition that occurred in airplanes having L/N 778
and subsequent, that were modified in accordance with Boeing Production
Revision Record (PRR) 54530-186. The commenter asserts that the AD
should address this possibility.
We agree with the commenter's concern, since the unsafe condition
that is the subject of this AD was detected on airplanes produced in
accordance with PRR 54530-186. Certain production type design changes
were the same (for airplanes having L/N 778 and subsequent) as those
specified in Alert
[[Page 61718]]
Service Bulletin 757-24A0080--which provides the terminating action in
AD 97-15-09 for airplanes L/N 1 through 777 inclusive. However, as
already discussed, the unsafe condition addressed by this AD resulted
from using an incorrect method to clean the bonding surfaces of the
ground bracket and frame during the production of certain airplanes
having L/N 778 and subsequent. The manufacturer advises that the
bonding surface cleaning process specified in Alert Service Bulletin
757-24A0080 is the correct process. Therefore, no change is needed to
the AD in this regard. Operators should note that the manufacturer has
informed us that Model 757 airplanes having L/N 1029 and subsequent
received the design change in production using the correct bonding
surface cleaning process; therefore, only airplanes having L/N 778
through 1028 inclusive are affected by this AD.
Request to Include Electrical Check
One commenter requests that we revise the NPRM--as well as Figure 1
and the associated Work Instructions of Boeing Alert Service Bulletin
757-24A0099, dated March 25, 2004--to allow an initial detailed visual
inspection (DVI) for discoloration and signs of overheating of the
ground bracket and terminal, followed by a bonding resistance check
between the ground bracket and terminal lug, rather than disconnecting
the ground wire from the terminal bracket for the initial inspection.
The commenter contends that, if the DVI discloses no evidence of
discoloration or overheating, and the measured resistance does not
exceed 0.0001 ohm, the ground connection is acceptable for service and
further inspection or action is unnecessary and shouldn't be required
for the ground components. Further, the commenter asserts that adding
the DVI step will make the NPRM consistent with AD 97-15-09 and Alert
Service Bulletin 757-24A0080.
We do not agree with this request. The unsafe condition results
from the incorrect process used to clean the bonding surfaces of the
ground bracket and wire terminal, which failed to remove an anodized
finish that reduces conductivity from those ground components. We have
determined that it may be possible for those anodized ground components
to display no evidence of discoloration or overheating during a DVI and
to pass the bonding resistance check, but to deteriorate with time and
service, resulting in the unsafe condition this AD intends to correct.
Therefore, the inspections and actions specified in the applicable
service bulletins must be accomplished to correct the unsafe condition
addressed by this AD, which, as discussed earlier, is not the same as
the unsafe condition addressed by AD 97-15-09 and Alert Service
Bulletin 757-24A0080. We have not changed the AD in this regard.
Request to Replace Reference to Standard Overhaul Practices Manual
The same commenter requests that we revise the service bulletins by
replacing the references to the cleaning method of faying bonding
surfaces specified in the Standard Overhaul Practices Manual (SOPM),
section 20-11-03, with the method specified by the Standard Wiring
Practices Manual (SWPM), section 20-20-00. The commenter provided no
justification for this request.
We do not agree with this request. We have examined the specified
methods and have determined that SOPM section 20-11-03 provides the
correct method for cleaning faying surface bond. We have not changed
the AD in this regard.
Request to Identify Service Bulletins in Costs of Compliance
One commenter requests that we revise the Costs of Compliance
section of the NPRM to specify which airplane groups are affected by
Boeing Alert Service Bulletin 757-24A0099, and which airplane groups
are affected groups by Boeing Alert Service Bulletin 757-24A0100, both
dated March 25, 2004. The commenter gave no justification for this
request.
We partially agree with this request. Though costs are determined
in part from the estimated number of work hours specified in the
applicable service bulletins for each group of airplanes, specifying
which service bulletin provided the information for which group(s) of
airplanes would have no effect on the total costs of the AD. However,
to minimize any possible confusion, we have revised the Costs of
Compliance in the AD as requested.
Request to Revise Cost Estimate
One commenter requests that we revise the Cost of Compliance
section of the NPRM to agree with the work hours specified by the
service bulletins. The commenter states that the cost of the work hours
estimated by the manufacturer is considerably higher than the cost
specified in the NPRM. The commenter also requests that we include the
costs for materials and parts needed to repair any damaged ground
components. The commenter states that materials and parts form a
significant part of the costs of any airplane modification.
We do not agree with this request. The economic analysis of an AD
is limited to the cost of actions that are actually required by the AD.
The economic analysis does not consider the costs of conditional
actions, such as the work hours that might be needed to repair a broken
ground bracket detected during a required inspection (``repair, if
necessary''), or the costs for parts and materials needed to accomplish
such a repair. Such conditional repairs would be required--whether or
not the AD directs such repairs--to correct an unsafe condition
discovered in an airplane and to ensure that the airplane is operated
in an airworthy condition, as required by the Federal Aviation
Regulations. No change is needed to the AD in this regard.
Request to Supply Torque Information
One commenter requests that we revise the NPRM, or the applicable
service bulletin, to explicitly specify the torque required to tighten
the screw/nut used to secure the ground wire terminal lug to the ground
bracket. The commenter contends that SWPM section 20-30-00, which is
specified as the source information for determining the applicable
torque, lists a range of torque values for various stud sizes and
states that the proper torque value is critical to the proper function
of these components.
We agree that the correct torque is critical for proper
accomplishment of this AD. Improper torque will affect the electrical
conductivity of the ground terminals and could result in another unsafe
condition. However, we do not agree that it is necessary for the AD to
specify an exact torque value. Torque limits for specific stud sizes
are specified in the SWPM, which is controlled and maintained by the
manufacturer. We have not changed the AD in this regard.
Clarification of Alternative Method of Compliance (AMOC) Paragraph
We have revised this action 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 received, and determined that air safety and the public
interest require adopting the AD with the changes described previously.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
[[Page 61719]]
Costs of Compliance
There are about 251 airplanes of the affected design in the
worldwide fleet. This AD will affect about 159 airplanes of U.S.
registry.
For about 89 Group 1 airplanes as identified in Alert Service
Bulletin 757-24A0099 and Alert Service Bulletin 757-24A0100, as
applicable: The inspection and cleaning of the ground connections will
take about 2 work hours per airplane, at an average labor rate of $65
per work hour. Based on these figures, the estimated cost of the AD for
U.S. operators is $11,570, or $130 per airplane.
For about 64 Group 2 airplanes as identified in Alert Service
Bulletin 757-24A0099: The inspection and cleaning of the ground
connection will take about 1 work hour per airplane, at an average
labor rate of $65 per work hour. Based on these figures, the estimated
cost of the AD for U.S. operators is $4,160, or $65 per airplane.
For about 6 Group 3 airplanes as identified in Alert Service
Bulletin 757-24A0099: The inspection and cleaning of the ground
connections will take about 2 work hours per airplane, at an average
labor rate of $65 per work hour. Based on these figures, the estimated
cost of the AD for U.S. operators is $780, or $130 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 by
adding the following new airworthiness directive (AD):
2005-22-07 Boeing: Amendment 39-14351. Docket No. FAA-2005-20473;
Directorate Identifier 2004-NM-156-AD.
Effective Date
(a) This AD becomes effective November 30, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 757-200, -200PF, and -300
series airplanes, certificated in any category; as identified in
Boeing Alert Service Bulletin 757-24A0099 and Boeing Alert Service
Bulletin 757-24A0100, both dated March 25, 2004.
Unsafe Condition
(d) This AD was prompted by reports indicating that during
inspections on two airplanes, the ground brackets for the auxiliary
power unit (APU) battery were found damaged. We are issuing this AD
to detect and correct a damaged electrical bonding surface of the
APU battery and APU start transformer rectifier unit (TRU) ground
connections, which could cause overheating of the ground connections
and lead to possible consequent ignition of the adjacent insulating
blankets.
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.
Inspection of Ground Connections
(f) Within 18 months after the effective date of this AD,
perform a general visual inspection for damage of the ground
brackets, ground wires, and terminal lugs of the APU battery and APU
start TRU, and do any corrective and related investigative actions;
by doing all the actions specified in the Accomplishment
Instructions of Boeing Alert Service Bulletin 757-24A0099 (for Model
757-200 and -200PF series airplanes) or Boeing Alert Service
Bulletin 757-24A0100 (for Model 757-300 series airplanes), both
dated March 25, 2004, as applicable.
Note 1: For the purposes of this AD, a general visual inspection
is ``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 from within touching
distance unless otherwise specified. A mirror may be necessary to
ensure visual access to all surfaces in the inspection area. This
level of inspection is made under normal 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.''
Alternative Methods of Compliance (AMOCs)
(g)(1) The Manager, Seattle Aircraft Certification Office, FAA,
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 14 CFR
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
(h) You must use Boeing Alert Service Bulletin 757-24A0099,
dated March 25, 2004; or Boeing Alert Service Bulletin 757-24A0100,
dated March 25, 2004; 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
[[Page 61720]]
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 October 18, 2005.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-21311 Filed 10-25-05; 8:45 am]
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