[Federal Register Volume 64, Number 175 (Friday, September 10, 1999)]
[Proposed Rules]
[Pages 49105-49109]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23478]
========================================================================
Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
========================================================================
Federal Register / Vol. 64, No. 175 / Friday, September 10, 1999 /
Proposed Rules
[[Page 49105]]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-323-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200, -200PF, and -
200CB Series Airplanes Powered by Rolls-Royce RB211-535C/E4/E4B
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking; reopening of
comment period.
-----------------------------------------------------------------------
SUMMARY: This document revises an earlier proposed airworthiness
directive (AD), applicable to certain Boeing Model 757-200, -200PF, and
-200CB series airplanes, that would have required modification of the
engine thrust control cable installation, and repetitive inspections to
detect certain discrepancies of the cables, pulleys, pulley brackets,
and cable travel; and repair, if necessary. That proposal was prompted
by reports of failure of certain engine thrust control cables. This new
action would revise the proposed rule by extending the compliance time
for certain actions, revising certain inspection procedures, and adding
a requirement for a one-time inspection to determine the part number of
thrust control cable pulleys and replacement of existing pulleys with
new pulleys, if necessary. The actions specified by this new proposed
AD are intended to prevent failure of certain engine thrust control
cables, which could result in a severe asymmetric thrust condition
during landing, and consequent reduced controllability of the airplane.
DATES: Comments must be received by October 5, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-323-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Kathrine Rask, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-1547; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-NM-323-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 98-NM-323-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to add an airworthiness directive (AD), applicable to
certain Boeing Model 757-200, -200PF, and -200CB series airplanes, was
published as a notice of proposed rulemaking (NPRM) in the Federal
Register on February 17, 1999 (64 FR 7822). That NPRM would have
required modification of the engine thrust control cable installation,
and repetitive inspections to detect certain discrepancies of the
cables, pulleys, pulley brackets, and cable travel; and repair, if
necessary. That NPRM was prompted by reports of failure of certain
engine thrust control cables. That condition, if not corrected, could
result in a severe asymmetric thrust condition during landing, and
consequent reduced controllability of the airplane.
Actions Since Issuance of Previous Proposal
Due consideration has been given to the comments received in
response to the NPRM. Certain of these comments and the information
they provided have led the FAA to consider making certain significant
changes to the proposal. These comments and the changes prompted by
them are explained below.
Request to Extend Compliance Time
One commenter requests that the compliance time for the thrust
control cable inspection [specified in paragraph (a) of the NPRM] be
extended from 18 months or 6,000 flight hours after the effective date
of this AD (whichever occurs first) to 24 months or 6,000 flight hours
after the effective date of this AD (whichever occurs first). The
commenter states that, for some operators, 6,000 flight hours would not
closely correspond to 18 months.
The FAA concurs with the commenter's request to extend the
compliance time somewhat. The FAA's intent is that the inspection
specified in the proposal be performed during a regularly scheduled
maintenance visit,
[[Page 49106]]
when the airplane is at a base where special equipment and trained
personnel are readily available, if necessary. The FAA has determined
that an interval of 24 months better corresponds to operators' normal
maintenance schedules than an interval of 18 months. The FAA does not
consider that such an extension of the compliance time to 24 months
would adversely affect safety. Therefore, as the commenter requests,
paragraph (a) of this supplemental NPRM has been revised accordingly.
Similarly, the repetitive interval for the inspection specified in
paragraph (a) of this supplemental NPRM has been revised from the
earlier of 18 months or 6,000 flight hours to the earlier of 24 months
or 6,000 flight hours, and paragraphs (c) and (d) of this supplemental
NPRM [i.e., paragraphs (b) and (c) of the original NPRM] have been
revised to incorporate a compliance time of 24 months or 6,000 flight
hours after the effective date of this AD, whichever occurs first.
Request To Revise Inspection Procedure
Two commenters request that the ``Thrust Control Cable Inspection
Procedure,'' specified in paragraph (a) and described in Appendix 1 of
the proposal, be revised to focus on minimizing the possibility of
failure of an engine thrust control cable. One of the commenters
suggests that the procedure be revised to eliminate all steps that
don't contribute to the intent of the AD. The same commenter also
suggests that the inspection procedure would be enhanced by adding an
inspection of the cable joints.
The FAA concurs with the commenters' request, and the ``Thrust
Control Cable Inspection Procedure'' specified in Appendix 1 of this
supplemental NPRM has been revised accordingly.
Request To Add Requirement for Pulley Replacement
One commenter, the airplane manufacturer, suggests that the intent
of the proposed AD would be enhanced by inclusion of a requirement for
replacement of existing phenolic thrust control cable pulleys in the
struts with aluminum pulleys. The commenter states that phenolic
pulleys have seized due to delamination and loss of bearing
lubrication, which would result in chafing of the engine thrust control
cables. The commenter notes that this replacement is described in
Boeing Service Letter 757-SL-76-004-A, dated July 21, 1997.
The FAA concurs with the commenter's request. Therefore, a new
paragraph (b) has been added to this supplemental NPRM, which would
require, for airplanes having line numbers 1 through 636 inclusive, a
one-time inspection of the thrust control cable pulleys in the struts
to determine the part number of the pulleys, and replacement of
phenolic pulleys with new aluminum pulleys. Such replacement would be
required to be accomplished in accordance with the Boeing 757 Airplane
Maintenance Manual. A new Note 2 also has been added to this
supplemental NPRM to provide references for the location of the pulleys
to be inspected in accordance with paragraph (b) of this proposed AD.
Request To Revise Cost Impact
One commenter, the airplane manufacturer, requests that the ``Cost
Impact'' section of the proposal be revised to remove the statement
that the manufacturer will provide certain parts at no cost to the
operators. The FAA concurs with the commenter's request and has revised
the Cost Impact section of this supplemental NPRM in accordance with
new cost data provided by the manufacturer.
Explanation of Additional Change to the Original NPRM
The Cost Impact section in this supplemental NPRM has been revised
to increase the number of affected airplanes in the worldwide fleet as
well as on the U.S. Register from the numbers stated in the original
NPRM. Since the issuance of the NPRM, more airplanes have been
delivered by the manufacturer; thus the number of affected airplanes
has increased. No change to the applicability statement of the AD has
been made or is necessary.
Conclusion
Since these changes expand the scope of the originally proposed
rule, the FAA has determined that it is necessary to reopen the comment
period to provide additional opportunity for public comment.
Cost Impact
There are approximately 483 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 248 airplanes of U.S. registry
would be affected by this proposed AD.
It would take approximately 3 work hours per airplane to accomplish
the proposed inspection to verify the integrity of the thrust control
cables, at an average labor rate of $60 per work hour. Based on these
figures, the cost impact of this inspection proposed by this AD on U.S.
operators is estimated to be $44,640, or $180 per airplane, per
inspection cycle.
It would take approximately 1 work hour per airplane to accomplish
the proposed inspection to determine the part number of the thrust
control cable pulleys, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of this inspection proposed by
this AD on U.S. operators is estimated to be $14,880, or $60 per
airplane, per inspection cycle.
For airplanes identified in Boeing Service Bulletin 757-76-1 (8
U.S.-registered airplanes), it would take approximately 2 work hours
per airplane to accomplish the proposed guide bracket removal, at an
average labor rate of $60 per work hour. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$960, or $120 per airplane.
For airplanes identified in Boeing Service Bulletin 757-76-0005 (14
U.S.-registered airplanes), it would take approximately 14 work hours
per airplane to accomplish the proposed replacement, at an average
labor rate of $60 per work hour. Required parts would cost
approximately $1,410 per airplane. Based on these figures, the cost
impact of the proposed AD on U.S. operators is estimated to be $31,500,
or $2,250 per airplane.
For airplanes identified in Boeing Alert Service Bulletin 757-
30A0018, Revision 1 (167 U.S.-registered airplanes), it would take
approximately 2 work hours per airplane to accomplish the proposed
installation and adjustment, at an average labor rate of $60 per work
hour. Required parts would cost approximately $192 per airplane. Based
on these figures, the cost impact of the proposed AD on U.S. operators
is estimated to be $52,104, or $312 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed requirements
of this AD action, and that no operator would accomplish those actions
in the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
regulation (1)
[[Page 49107]]
is not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under the DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated,
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. A copy of the draft regulatory evaluation
prepared for this action is contained in the Rules Docket. A copy of it
may be obtained by contacting the Rules Docket at the location provided
under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 adding the following new
airworthiness directive:
Boeing: Docket 98-NM-323-AD.
Applicability: Model 757-200, -200PF, and -200CB series
airplanes powered by Rolls-Royce RB211-535C/E4/E4B turbofan 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 (f) 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 engine thrust control cable failure, which could
result in a severe asymmetric thrust condition during landing, and
consequent reduced controllability of the airplane, accomplish the
following:
Inspections and Corrective Actions
(a) Within 24 months or 6,000 flight hours after the effective
date of this AD, whichever occurs first: Accomplish the ``Thrust
Control Cable Inspection Procedure'' specified in Appendix 1.
(including Figure 1) of this AD to verify the integrity of the
thrust control cables. Prior to further flight, repair any
discrepancy found in accordance with the procedures described in the
Boeing 757 Maintenance Manual. Repeat the inspection thereafter at
intervals not to exceed 24 months or 6,000 flight hours, whichever
occurs first.
(b) For airplanes having line numbers 1 through 636 inclusive:
Within 24 months or 6,000 flight hours after the effective date of
this AD, whichever occurs first, perform a one-time inspection of
the 8 engine thrust control cable pulleys in the struts (4 in each
strut) to determine the part number (P/N) of each pulley. If any
pulley having P/N 65B80977-1 is installed, prior to further flight,
replace it with a pulley having P/N 255T1232-7, in accordance with
the procedures described in the Boeing 757 Airplane Maintenance
Manual.
Note 2: The location of the pulleys to be inspected in
accordance with paragraph (b) of this AD is specified in Chapters
53-11-53-04, 76-11-52-01, and 76-11-52-02 of the Boeing 757
Illustrated Parts Catalog.
Modifications
(c) For airplanes identified in Boeing Service Bulletin 757-76-
1, dated May 18, 1984: Within 24 months or 6,000 flight hours after
the effective date of this AD, whichever occurs first, remove the
guide bracket of the engine thrust control cable located on the
front spar of the right wing in accordance with the service
bulletin.
(d) For airplanes identified in Boeing Service Bulletin 757-76-
0005, dated May 5, 1988: Within 24 months or 6,000 flight hours
after the effective date of this AD, whichever occurs first, remove
the engine thrust control cable breakaway stop assemblies, and
replace sections of the engine thrust control cables with smaller
diameter cables in accordance with the service bulletin.
(e) For airplanes identified in Boeing Alert Service Bulletin
757-30A0018, Revision 1, dated September 17, 1998: Within 60 days
after the effective date of this AD, install a support bracket
assembly between the window heat wire bundle and the engine thrust
control cable; and adjust the wire bundle clearance, as necessary,
to parallel the minimum clearance specified in the alert service
bulletin.
Alternative Method of Compliance
(f) 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 (ACO), 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.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Appendix 1.--Thrust Control Cable Inspection Procedure
Special Flight Permits
(g) 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 acomplished. Issued in Renton,
Washington, on September 2, 1999.
1. General
A. Clean the cables, if necessary, for the inspection, in
accordance with Boeing 757 Maintenance Manual 12-21-31.
B. Use these procedures to verify the integrity of the thrust
control cable system. The procedures must be performed along the
entire cable run for each engine. To ensure verification of the
portions of the cables which are in contact with pulleys and
quadrants, the thrust control must be moved by operation of the
thrust and/or the reverse thrust levers to expose those portions of
the cables.
C. The first task is an inspection of the control cable wire
rope. The second task is an inspection of the control cable
fittings. The third task is an inspection of the pulleys.
Note: These three tasks may be performed concurrently at one
location of the cable system on the airplane, if desired, for
convenience.
2. Inspection of the Control Cable Wire Rope
A. Perform a detailed visual inspection to ensure that the cable
does not contact parts other than pulleys, quadrants, cable seals,
or grommets installed to control the cable routing. Look for
evidence of contact with other parts. Correct the condition if
evidence of contact is found.
Note: For the purposes of this procedure, a detailed visual
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.''
B. Perform a detailed visual inspection of the cable runs to
detect incorrect routing, kinks in the wire rope, or other damage.
Replace the cable assembly if:
(1) One cable strand had worn wires where one wire cross section
is decreased by more than 40 percent (see Figure 1),
(2) A kink is found, or
(3) Corrosion is found.
C. Perform a detailed visual inspection of the cable: To check
for broken wires, rub a cloth along the length of the cable. The
cloth catches on broken wires.
(1) Replace the 7x7 cable assembly if there are two or more
broken wires in 12 continuous inches of cable or there are three or
more broken wires anywhere in the total cable assembly.
(2) Replace the 7x19 cable assembly if there are four or more
broken wires in 12 continuous inches of cable or there are six or
more broken wires anywhere in the total cable assembly.
3. Inspection of the Control Cable Fittings
A. Perform a detailed visual inspection to ensure that the means
of locking the joints
[[Page 49108]]
are intact (wire locking, cotter pins, turnbuckle clips, etc.).
Install any missing parts.
B. Perform a detailed visual inspection of the swaged portions
of swaged end fittings to detect surface cracks or corrosion.
Replace the cable assembly if cracks or corrosion are found.
C. Perform a detailed visual inspection of the unswaged portion
of the end fitting. Replace the cable assembly if a crack is
visible, if corrosion is present, or if the end fitting is bent more
than 2 degrees.
D. Perform a detailed visual inspection of the turnbuckle.
Replace the turnbuckle if a crack is visible or if corrosion is
present.
4. Inspection of Pulleys
A. Perform a detailed visual inspection to ensure that pulleys
are free to rotate. Replace pulleys which are not free to rotate.
BILLING CODE 4910-13-P
[[Page 49109]]
[GRAPHIC] [TIFF OMITTED] TP10SE99.000
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-23478 Filed 9-9-99; 8:45 am]
BILLING CODE 4910-13-C
