[Federal Register Volume 67, Number 103 (Wednesday, May 29, 2002)]
[Proposed Rules]
[Pages 37357-37361]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-12949]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-329-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200, -200CB, and -
200PF Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 757 
series airplanes, that currently requires repetitive inspections for 
excessive wear of the internal and external splines of the torque tube 
couplings of the trailing edge flaps, and replacement of the couplings, 
if necessary. That AD also provides an optional modification that, if 
installed, constitutes terminating action for the inspection 
requirements. This action would expand the applicability of the 
existing AD and require new inspections of the torque tube assemblies 
and certain gearbox assemblies and universal joints in the drive system 
for the inboard trailing edge flaps, and follow-on actions, if 
necessary. For certain airplanes, this action also would require the 
previously optional modification and/or a new modification, which would 
terminate certain inspections. The actions specified by the proposed AD 
are intended to prevent separations in the drive system for the inboard 
trailing edge flaps, which could cause a flap skew condition that could 
result in damage to the flaps or fuselage, and consequent reduced 
controllability of the airplane.

DATES: Comments must be received by July 15, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-329-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.

[[Page 37358]]

Comments may be inspected at this location between 9:00 a.m. and 3:00 
p.m., Monday through Friday, except Federal holidays. Comments may be 
submitted via fax to (425) 227-1232. Comments may also be sent via the 
Internet using the following address: [email protected]. 
Comments sent via fax or the Internet must contain ``Docket No. 2001-
NM-329-AD'' in the subject line and need not be submitted in 
triplicate. Comments sent via the Internet as attached electronic files 
must be formatted in Microsoft Word 97 for Windows or ASCII text.
    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: Technical Information: Douglas Tsuji, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1506; fax (425) 227-1181.
    Other Information: Judy Golder, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 227-1119, fax (425) 227-1232. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

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 action may be changed in 
light of the comments received.
    Submit comments using the following format:

    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.

    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-329-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. 2001-NM-329-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On November 9, 1992, the FAA issued AD 92-25-01, amendment 39-8416 
(57 FR 54298, November 18, 1992), applicable to certain Boeing Model 
757 series airplanes, to require visual inspections of the internal and 
external splines of the trailing edge flap drive torque tube coupling 
assembly for excessive wear, and replacement of the coupling, if 
necessary. That AD also provides an optional modification that, if 
installed, constitutes terminating action for the inspection 
requirements. That action was prompted by reports of excessive wear on 
the aft end of the trailing edge flap drive torque tube coupling. The 
requirements of that AD are intended to prevent damage caused by skewed 
flaps resulting from excessive wear of the splines of the trailing edge 
flap drive torque tube coupling.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has received several reports 
of separations in the drive system for the inboard trailing edge flaps 
on Boeing Model 757-200, -200CB, and -200PF series airplanes. These 
separations caused a flap skew condition, in which one end of a flap 
did not move to the commanded position. These separations have been 
attributed to various discrepancies in the drive system for the 
trailing edge flaps, including:
    [sbull] Worn splines in the torque tube assemblies;
    [sbull] Corroded and worn bearings from loss of lubricant, which 
permitted axial shaft movement and subsequent bevel gear separation 
inside angle gearbox assemblies; and
    [sbull] Worn universal joints (U-joints) caused by the loss of 
boots and subsequent wear on the drive shaft assembly between the 
inboard transmission of the inboard flaps and the angle tee gearbox 
assembly.
    These discrepancies could cause a flap skew condition, which could 
result in damage to the flaps or fuselage and consequent reduced 
controllability of the airplane.
    The existing AD applies to Model 757 series airplanes with line 
numbers 1 through 411 inclusive and 413 through 432 inclusive. Since 
the issuance of that AD, the FAA has determined that certain other 
Model 757 series airplanes (i.e., Model 757-200, -200CB, and -200PF 
series airplanes) may also be subject to the discrepancies described 
previously. Therefore, these additional airplanes also may be subject 
to the identified unsafe condition.
    Also, as stated previously, AD 92-25-01 provides for an optional 
modification per Boeing Service Bulletin 757-27-0099, dated March 12, 
1992, for airplanes that were delivered without coupling seals on 
torque tube assemblies 3 and 6. That modification includes replacement 
of torque tube assemblies 3 and 6 with improved torque tube assemblies 
and installation of a sealant plug in the shafts of four gearboxes. The 
FAA has now determined that long-term continued operational safety will 
be better assured by requiring installation of this modification (to 
remove the source of the problem), rather than by requiring repetitive 
inspections. In some instances, long-term inspections may not provide 
the degree of safety assurance necessary for the transport airplane 
fleet. This, coupled with a better understanding of the human factors 
associated with numerous continual inspections, has led the FAA to 
consider placing less emphasis on inspections and more emphasis on 
design improvements. Therefore, this proposed AD would require doing 
the previously optional modification. Doing this modification 
eliminates the need for the repetitive inspections for excessive wear 
of torque tube assemblies 3 and 6.

[[Page 37359]]

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
757-27A0125, Revision 1, including Appendices A and B, dated December 
2, 1999. That service bulletin describes procedures for inspecting 
certain torque tube assemblies, certain gearbox assemblies, and U-
joints on the drive shaft assembly in the drive system for the inboard 
trailing edge flaps. The inspection of the torque tube assemblies 
involves performing a general visual inspection for excessive wear of 
external splines and, if excessive wear is found, measuring the 
distance over pins, measuring the outer diameter, if necessary, and 
repeating the inspection or replacing the torque tube assembly, as 
necessary. The inspection of the gearbox assemblies involves measuring 
axial movement, and replacing the gearbox assembly with a new assembly, 
if necessary. The inspection of the U-joints on the drive shaft 
assembly involves measuring the maximum and minimum distance between 
the upper and lower yoke, and replacing the drive shaft assembly with a 
new assembly, if necessary. Doing the actions specified in the service 
bulletin is intended to adequately address the identified unsafe 
condition.
    The FAA also has reviewed and approved Boeing Service Bulletin 757-
27-0107, dated June 16, 1994. Among other actions, for airplanes 
delivered without coupling seals on torque tube assemblies 4 and 5, 
that service bulletin describes procedures for a modification that 
involves replacing torque tube assemblies 4 and 5 with new, improved 
torque tube assemblies, and changing related angle and tee gearbox 
assemblies of the drive system. The changes to the angle gearbox 
assembly involve replacing certain coupling halves with improved 
coupling halves, installing sealant, and changing the part number of 
the assembly. The changes to the tee gearbox assembly involve cleaning 
certain holes, installing sealant, and changing the part number of the 
assembly. Doing this modification eliminates the need for the 
repetitive inspections for excessive wear of torque tube assemblies 4 
and 5.

Explanation of Change to Existing Requirements

    In the ``Restatement of Requirements of AD 92-25-01'' in this 
proposed AD, the FAA has revised paragraph (a) of the existing AD to 
clarify that the visual inspection applies to the torque tube 3 and 6 
coupling splines. Also, the FAA has clarified the existing requirement 
to specify that the required inspection is a ``general visual 
inspection.'' A note has been added under the new requirements of this 
proposed AD to define that inspection.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 92-25-01 to continue to require 
repetitive inspections of the internal and external splines of the 
trailing edge flap drive torque tube coupling assemblies for excessive 
wear, and replacement of the couplings, if necessary. The proposed AD 
also would require accomplishment of the actions specified in Boeing 
Alert Service Bulletin 757-27A0125, Revision 1. For certain airplanes, 
the proposed AD also would require accomplishment of Boeing Service 
Bulletin 757-27-0099, and/or certain actions in Boeing Service Bulletin 
757-27-0107, as described previously.

Cost Impact

    There are approximately 979 airplanes of the affected design in the 
worldwide fleet.
    In AD 92-25-01, the FAA estimated that approximately 279 U.S.-
registered airplanes would be subject to the inspections in that AD. 
For these airplanes, the currently required inspections take 
approximately 2 work hours per airplane, at an average labor rate of 
$60 per work hour. Based on these figures, the cost impact of the 
currently required actions on U.S. operators is estimated to be 
$33,480, or $120 per airplane, per inspection cycle.
    The FAA estimates that approximately 283 U.S.-registered airplanes 
(Group 1 of Boeing Alert Service Bulletin 757-27A0125, Revision 1) 
would be subject to the proposed inspection of torque tube assemblies 3 
and 6. This inspection would take approximately 2 work hours per 
airplane, at an average labor rate of $60 per work hour. Based on these 
figures, the cost impact of these new proposed inspections on U.S. 
operators of Group 1 airplanes is estimated to be $33,960, or $120 per 
airplane, per inspection cycle.
    The FAA estimates that approximately 376 U.S.-registered airplanes 
(Groups 1 and 2 of Boeing Alert Service Bulletin 757-27A0125, Revision 
1) would be subject to the proposed inspection of torque tube 
assemblies 4 and 5. This inspection would take approximately 2 work 
hours per airplane, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of these new proposed 
inspections on U.S. operators of Group 2 airplanes is estimated to be 
$45,120, or $120 per airplane, per inspection cycle.
    The FAA estimates that 643 U.S.-registered airplanes (Groups 1, 2, 
and 3 of Boeing Alert Service Bulletin 757-27A0125, Revision 1) would 
be subject to the new proposed inspections of the gear box assemblies 
and U-joints of the drive shaft assembly. These inspections would take 
approximately 4 work hours per airplane, at an average labor rate of 
$60 per work hour. Based on these figures, the cost impact of these new 
proposed inspections on U.S. operators is estimated to be $154,320, or 
$240 per airplane, per inspection cycle.
    The FAA estimates that approximately 283 U.S.-registered airplanes 
(Group 1 of Boeing Alert Service Bulletin 757-27A0125, Revision 1) 
would be subject to the proposed modification that involves replacement 
of torque tube assemblies 3 and 6. This modification would take 
approximately 5 work hours per airplane, at an average labor rate of 
$60 per work hour. Required parts would cost approximately $4,550. 
Based on these figures, the cost impact of this proposed modification 
on U.S. operators is estimated to be $1,372,550, or $4,850 per 
airplane.
    The FAA estimates that approximately 376 U.S.-registered airplanes 
(Groups 1 and 2 of Boeing Alert Service Bulletin 757-27A0125, Revision 
1) would be subject to the proposed modification that involves 
replacement of torque tube assemblies 4 and 5. This modification would 
take approximately 5 work hours per airplane, at an average labor rate 
of $60 per work hour. Required parts will cost approximately $4,550. 
Based on these figures, the cost impact of this proposed modification 
on U.S. operators is estimated to be $1,823,600, or $4,850 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 proposed 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.

[[Page 37360]]

Regulatory Impact

    The regulations proposed herein would 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 proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) 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.


[sect] 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-8416 (57 FR 
54298, November 18, 1992), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2001-NM-329-AD. Supersedes AD 92-25-01, Amendment 39-
8416.

    Applicability: Model 757-200, -200CB, and -200PF series 
airplanes; line numbers (L/Ns) 1 through 979 inclusive; certificated 
in any category.

    Note 1:
    This AD applies to each airplane identified in the preceding 
applicability provision, regardless of whether it has been modified, 
altered, or repaired in the area subject to the requirements of this 
AD. For airplanes that have been modified, altered, or repaired so 
that the performance of the requirements of this AD is affected, the 
owner/operator must request approval for an alternative method of 
compliance in accordance with paragraph (h) 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 separations in the drive system for the inboard 
trailing edge flaps, which could cause a flap skew condition that 
could result in damage to the flaps or fuselage, and consequent 
reduced controllability of the airplane, accomplish the following:

Restatement of Requirements of AD 92-25-01:

Repetitive Visual Inspections and Corrective Actions

    (a) For airplanes with L/Ns 1 through 411 inclusive and 413 
through 432 inclusive: Prior to the accumulation of 2,000 total 
flight cycles, or within the next 200 flight cycles after April 30, 
1990 (the effective date of AD 90-08-16, amendment 39-6574), 
whichever occurs later, and thereafter at intervals not to exceed 
2,000 flight cycles, perform a general visual inspection of the 
torque tube 3 and 6 coupling splines, in accordance with Boeing 
Service Letter 757-SL-27-52-B, dated April 30, 1990.

    Note 2:
    Operators who have conducted inspections of the torque tube 
coupling splines prior to December 23, 1992 (the effective date of 
AD 92-25-01, amendment 39-8416), in accordance with Boeing Service 
Letter 757-SL-27-52, dated January 31, 1990, or Boeing Service 
Letter 757-SL-27-52-A, dated March 21, 1990, are considered to be in 
compliance with paragraph (a) of this AD.

    (1) If the measurement over the pin, as detailed in the service 
letter, is less than 1.8605 inches but equal to or greater than 
1.8533 inches, repeat the inspection within 1,000 flight cycles, 
until the requirements of paragraph (c) or (f) of this AD have been 
accomplished.
    (2) If the measurement over the pin, as detailed in the service 
letter, is less than 1.8533 inches, replace the coupling before 
further flight, in accordance with the service letter.

New Requirements of This AD:

    Note 3:
    For the purposes of this AD, a general visual inspection is 
defined as: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
enhance visual access to all exposed surfaces in the inspection 
area. This level of inspection is made under normally available 
lighting conditions such as daylight, hangar lighting, flashlight, 
or droplight 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.''

New Repetitive Inspections: Torque Tubes 3 and 6

    Note 4: If the requirements of paragraph (f) of this AD have 
been accomplished before the effective date of this AD, inspection 
per paragraph (b) of this AD is not required.

    (b) For airplanes with L/Ns 1 through 411 inclusive and 413 
through 432 inclusive, which are identified as Group 1 airplanes in 
Boeing Alert Service Bulletin 757-27A0125, Revision 1, including 
Appendices A and B, dated December 2, 1999: Do a general visual 
inspection for excessive wear of torque tube assemblies 3 and 6, per 
the service bulletin. Do the initial inspection at the time 
specified in paragraph (b)(1) or (b)(2) of this AD, as applicable. 
If no wear is found, repeat the inspection every 3,000 flight cycles 
or 24 months, whichever comes first, until paragraph (f) of this AD 
has been accomplished. Doing paragraph (b) of this AD terminates the 
requirements of paragraph (a) of this AD for torque tube assemblies 
3 and 6.
    (1) For airplanes on which the inspection in paragraph (a) of 
this AD has been done prior to the effective date of this AD: 
Inspect within 3,000 flight cycles after the most recent inspection 
done PRIOR to the effective date of this AD per paragraph (a) of 
this AD, or within 24 months after the effective date of this AD, 
whichever is first.
    (2) For airplanes on which the inspection in paragraph (a) of 
this AD has NOT been done prior to the effective date of this AD: 
Inspect prior to the accumulation of 3,000 total flight cycles, 
within 24 months since the airplane's date of manufacture, or within 
18 months after the effective date of this AD, whichever is latest.

    Note 5:
    Inspections, measurements, and replacements done prior to the 
effective date of this AD per Boeing Alert Service Bulletin 757-
27A0125, dated July 17, 1997, are considered acceptable for 
compliance with the corresponding requirements of paragraphs (b), 
(c), (d), and (e) of this AD.

New Repetitive Inspections: Torque Tubes 4 and 5

    Note 6:
    If the requirements of paragraph (g) of this AD have been 
accomplished before the effective date of this AD, inspection per 
paragraph (c) of this AD is not required.

    (c) For airplanes with L/Ns 1 through 411 inclusive and 413 
through 580 inclusive, which are identified as Groups 1 and 2 
airplanes in Boeing Alert Service Bulletin 757-27A0125, Revision 1, 
including Appendices A and B, dated December 2, 1999: Prior to the 
accumulation of 3,000 total flight cycles, within 24 months since 
the airplane's date of manufacture, or within 18 months after the 
effective date of this AD, whichever is latest, do a general visual 
inspection for excessive wear of torque tube assemblies 4 and 5, per 
the service bulletin. If no wear is found, repeat the inspection 
every 3,000 flight cycles or 24 months, whichever comes first, until 
paragraph (g) of this AD has been accomplished.

[[Page 37361]]

Corrective Actions: Torque Tubes 3, 4, 5, and 6

    (d) If any wear is found during any inspection required by 
paragraph (b) or (c) of this AD: Before further flight, measure the 
distance of the measurement over pins, per Boeing Alert Service 
Bulletin 757-27A0125, Revision 1, including Appendices A and B, 
dated December 2, 1999.
    (1) If the distance is 1.8337 inches or more, repeat the general 
visual inspection required by paragraph (b) or (c) of this AD at the 
applicable interval specified in Table 1 of Figure 7 of the service 
bulletin, until the actions in paragraphs (f) (for torque tube 
assemblies 3 and 6) and (g) (for torque tube assembles 4 and 5) have 
been done.
    (2) If the distance is less than 1.8337 inches, do the actions 
in paragraphs (d)(2)(i) and (d)(2)(ii) of this AD, per the service 
bulletin.
    (i) Before further flight, measure the distance of the outside 
diameter, as shown in Table 1 of Figure 7 of the service bulletin.
    (ii) Replace the affected torque tube assembly with a new torque 
tube assembly at the applicable time specified in Table 1 of Figure 
7 of the service bulletin.

New Repetitive Inspections: Gearbox Assemblies and Universal Joints

    (e) For airplanes with L/Ns 1 through 979 inclusive: Prior to 
the accumulation of 3,000 total flight cycles, within 24 months 
since the airplane's date of manufacture, or within 18 months after 
the effective date of this AD, whichever is latest, perform an 
inspection to measure the axial movement of the angle and tee 
gearbox assemblies and the distance between the upper and lower 
yokes of the universal joints (U-joints) of the drive shaft 
assemblies, per Boeing Alert Service Bulletin 757-27A0125, Revision 
1, including Appendices A and B, dated December 2, 1999. Repeat 
these measurements every 3,000 flight cycles or 24 months, whichever 
comes first, and do paragraphs (e)(1) and (e)(2) of this AD, as 
applicable.
    (1) If any measurement of the axial movement of the gearbox 
assembly is more than 0.015 inch, as specified in the service 
bulletin: Before further flight, replace the gearbox assembly with a 
new gearbox assembly, per the service bulletin.
    (2) If the distance between the upper and lower yokes of the U-
joints is more than 0.020 inch, as specified in Steps 3 and 6 of 
Figure 6 of the service bulletin: Before further flight, replace the 
drive shaft assembly with a new drive shaft assembly, per the 
service bulletin.

Terminating Action

    (f) For airplanes with L/Ns 1 through 411 inclusive and 413 
through 432 inclusive: Within 3 years after the effective date of 
this AD, modify the airplane by replacing torque tube assemblies 
number 3 and 6 with new, improved torque tube assemblies, and 
installing a sealant plug in the shafts of four gearboxes, according 
to Boeing Service Bulletin 757-27-0099, dated March 12, 1992. Doing 
this paragraph terminates the inspections required by paragraphs (a) 
and (b) of this AD.
    (g) For airplanes with L/Ns 1 through 580 inclusive: Within 3 
years after the effective date of this AD, modify the airplane by 
replacing torque tube assemblies number 4 and 5 with new, improved 
torque tube assemblies, and changing the related angle and tee 
gearbox assemblies, per Boeing Service Bulletin 757-27-0107, dated 
June 16, 1994. The changes for the related tee and angle gearbox 
assemblies are shown in Figures 6 and 7, respectively, of the 
service bulletin. Doing this paragraph terminates the inspections 
required by paragraph (c) of this AD.

    Note 7: No terminating action has been identified for the 
inspections specified in paragraph (e) of this AD.

Alternative Methods of Compliance

    (h) 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. 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 8: 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

    (i) 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.

    Issued in Renton, Washington, on May 15, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-12949 Filed 5-28-02; 8:45 am]
BILLING CODE 4910-13-P