Document ID: FAA-2007-0004-0063
Agency: faa
Document Type: Notice
Title: Airworthiness Directives; Boeing Model 737-100, -200, -200C, - 300, -400, and -500 Series Airplanes
Posted Date: 2007-08-31T04:00Z

[Federal Register: August 31, 2007 (Volume 72, Number 169)]
[Proposed Rules]               
[Page 50278-50282]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr31au07-18]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29062; Directorate Identifier 2007-NM-020-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. For certain airplanes, this proposed AD would require 
replacing the outboard stabilizing fitting and certain adjacent 
components of the main landing gear (MLG) support beam. This proposed 
AD would also require repetitive inspections for discrepancies of the 
outboard stabilizing fitting, walking beam hanger, and rear spar 
attachment, and corrective actions if necessary. For certain airplanes, 
this proposed AD would provide an alternative one-time inspection of 
the outboard stabilizing fitting for discrepancies and corrective 
actions if necessary, which would extend the compliance time for the 
replacement of the outboard stabilizing fitting. For certain other 
airplanes, this proposed AD would also require performing a torque 
check of the aft pin of the outboard stabilizing fitting, and 
corrective actions if necessary. This proposed AD results from reports 
of findings of fatigue cracking of the outboard stabilizing fitting and 
stress corrosion cracking of the bolts attaching the fitting to the 
wing rear spar. We are proposing this AD to detect and correct that 
cracking, which could result in disconnection of the MLG actuator from 
the rear spar and support beam, and consequent damage to the hydraulic 
system causing hydraulic fluid leakage and loss of control of the 
airplane.

DATES: We must receive comments on this proposed AD by October 15, 
2007.

[[Page 50279]]

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (425) 
917-6440; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
29062; Directorate Identifier 2007-NM-020-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://
dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://
dms.dot.gov, or in person at the Docket Operations office between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The 
Docket Operations office (telephone (800) 647-5527) is located on the 
ground floor of the West Building at the DOT street address stated in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after the Docket Management System receives them.

Discussion

    We have received several reports indicating findings of fatigue 
cracking of the outboard stabilizing fitting and stress corrosion 
cracking of the bolts attaching the fitting to the wing rear spar and 
certain adjacent components of the main landing gear (MLG) support beam 
on Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. Those reports include the following: Cracking of the 
outboard stabilizing fitting attributed to fatigue, loose or missing 
forward pins that attach the stabilizing fitting to the stud assembly; 
a fractured aft pin that attaches the tube assembly to the aft 
stabilizing fitting, and fractured H-11 bolts that attach the inboard 
and outboard stabilizing fittings to the wing rear spar. These failures 
could result in disconnection of the MLG actuator from the rear spar 
and support beam, and consequent damage to the hydraulic system fluid 
supply tube causing hydraulic fluid leakage and loss of control of the 
airplane.

Other Relevant Rulemaking

    On December 30, 1998, we issued AD 98-11-04 R1, amendment 39-10984 
(64 FR 987, January 7, 1999), for all Boeing Model 737-100 and -200 
series airplanes. That AD supersedes AD 91-14-20 to continue to require 
that the FAA-approved maintenance program be revised to include 
inspections that will give no less than the required damage tolerance 
rating for each Structural Significant Item (SSI). AD 98-11-04 R1 also 
requires additional and expanded inspections, and repair of cracked 
structure. That AD was prompted by a structural re-evaluation by the 
manufacturer which identified additional structural elements where, if 
damage were to occur, supplemental inspections may be required for 
timely detection. We issued that AD to ensure the continued structural 
integrity of the Boeing Model 737-100 and -200 fleet.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 737-57A1266, 
Revision 1, dated January 3, 2007. For certain airplanes, the service 
bulletin describes procedures for replacing the outboard stabilizing 
fitting and certain adjacent components of the MLG support beam. The 
replacement procedures and configuration group to which the airplane 
belongs, are as follows.
     For airplanes identified in the service bulletin as Groups 
1, 2, 3, 4, and 5, the procedures describe replacing the outboard 
stabilizing fitting with a new titanium fitting and replacing the H-11 
bolts that attach the fitting to the wing rear spar with new Inconel 
718 bolts. In addition, the procedures describe replacing the aft pin 
that attaches the tube assembly to the aft outboard stabilizing fitting 
with a titanium bolt, replacing the forward pin, and replacing the H-11 
bolts for the inboard stabilizing fitting with new Inconel 718 bolts. 
As part of the replacement of the H-11 bolts, the service bulletin 
recommends contacting Boeing if corrosion damage is found which cannot 
be removed. The service bulletin also recommends prior or concurrent 
accomplishment of Part IV of Boeing Service Bulletin 737-57-1052, 
Revision 4, dated October 24, 1980, for Group 1 and 3 airplanes. Part 
IV describes procedures for replacing the existing tube assembly of the 
MLG support beam with a new assembly. For airplanes that had the aft 
pin of the aft outboard stabilizing fitting replaced per Boeing Alert 
Service Bulletin 737-57A1266, dated May 8, 2003, the procedures specify 
performing a torque check of the aft pin of the aft outboard 
stabilizing fitting and corrective actions if necessary. If the torque 
is greater than 570 in. lbs., the corrective action is replacing the 
aft pin and aft outboard stabilizing fitting. If the torque is less 
than 570 in. lbs., the corrective action is replacing the aft pin.
     For airplanes identified in the service bulletin as Groups 
6 and 7, the procedures describe replacing the outboard stabilizing 
fitting with a titanium fitting and replacing the H-11 bolts that 
attach the fitting to the wing rear spar with new Inconel 718 bolts. In 
addition, the procedures describe replacing the forward pin that 
attaches the stud assembly to the outboard stabilizing fitting with a 
titanium pin. The procedures also describe replacing the H-11 bolts for 
the inboard stabilizing fitting with new Inconel 718 bolts for Group 6 
only.

[[Page 50280]]

     For airplanes identified in the service bulletin as Group 
8, the procedures describe replacing the outboard stabilizing fitting 
with a titanium fitting, and replacing the forward pin that attaches 
the stud assembly to the outboard stabilizing fitting with new 
components.
     For airplanes identified in the service bulletin as Group 
9, the procedures describe doing a general visual inspection of the 
outboard stabilizing fitting and fasteners for discrepancies, and 
corrective actions if necessary. The corrective action is contacting 
Boeing if any discrepancies are found.
    For airplanes identified in the service bulletin as Group 8, and 
Groups 1 through 7 on which the existing H-11 bolts were previously 
replaced with Inconel 718 bolts, the procedures describe an alternative 
magnetic test of the attach bolts to determine if inspections could be 
done that may extend the compliance time for the replacement of the 
outboard stabilizing fitting. If any bolt is magnetic, do not do the 
alternative inspection. If none of the bolts are magnetic, do a one-
time general visual inspection of the stabilizing fitting for 
discrepancies (damage, failure, or irregularity), and a high frequency 
eddy current (HFEC) inspection for cracking of the fitting inboard and 
outboard lug faces, the fillet radii, and the fitting lug hole, and 
verify the fitting hole is within limits, and corrective actions if 
necessary. Performing the alternative inspection extends the compliance 
time from 36 to 60 months for replacing the fitting if no cracking is 
found.
    The corrective actions for the alternative inspections are as 
follows:
     If cracking is found during the alternative inspection, 
the service bulletin specifies doing the replacement of the fitting as 
specified in Part II of the service bulletin. If no cracking is found, 
the service bulletin specifies doing an installation of replacement 
bushings and reaming the bushing holes to final size, replacing the 
forward pin, and for Groups 1 through 5, replacing the aft pin. If any 
other damage is found or if the fitting hole is beyond the hole size 
limits, the service bulletin recommends contacting Boeing for repair 
instructions.
    For all airplanes, the service bulletin describes procedures for 
repetitive inspections for discrepancies of the outboard stabilizing 
fitting, walking beam hanger, and rear spar attachment fitting, and 
corrective actions if necessary. The corrective action is contacting 
Boeing if any discrepancies are found.
    Service Bulletin 737-57A1266 refers to the following service 
bulletins as acceptable sources of service information:
    Boeing Service Bulletin 737-57-1231, dated December 1, 1994, is an 
acceptable source of service information for accomplishment of the 
replacement of the H-11 attachment bolts of the inboard stabilizing 
fitting with new components for some airplane groups.
    Boeing Service Bulletin 737-57-1073, Revision 4, dated April 12, 
1985, is an acceptable source of service information for previous 
accomplishment of the replacement of the MLG support beam.
    We have determined that accomplishment of the actions specified in 
Service Bulletin 737-57A1266 will adequately address the unsafe 
condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the Boeing 
Alert Service Bulletin 737-57A1266, Revision 1, except as discussed 
under ``Differences Between the Proposed AD and Alert Service Bulletin 
737-57A1266.''

Differences Between the Proposed AD and Alert Service Bulletin 737-
57A1266

    For airplanes identified in the service bulletin as Groups 1 
through 5 on which the aft pin of the outboard stabilizing fitting has 
been replaced in accordance with the original issue of the service 
bulletin: The service bulletin recommends accomplishing the torque 
check of the aft pin within 36 months after the original issue date of 
the service bulletin, and, if the aft pin does not pass the torque 
check, replacing the aft pin and aft outboard stabilizing fitting 
within an additional 36 months after the torque check. However, we have 
determined that interval would not address the identified unsafe 
condition soon enough to ensure an adequate level of safety for the 
affected fleet. We find that a compliance time of within 36 months 
after accomplishing the replacement, or 36 months after the effective 
date of this AD, whichever is later, for doing the torque check and 
doing all applicable corrective actions before further flight, 
represents an appropriate interval of time for affected airplanes to 
continue to operate without compromising safety. This difference has 
been coordinated with the manufacturer.
    Certain sections in Parts I, II, and V of the Accomplishment 
Instructions of the service bulletin specify ``For 737-100 and -200 
airplanes'' and ``For 737-300 and -500 airplanes.'' Those sections are 
applicable to Model 737-100, -200, and -200C airplanes, and Model 737-
300, -400, and -500 airplanes, respectively. Model 737-200C and -400 
airplanes were inadvertently excluded from those sections.
    The service bulletin also specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing those conditions in one of the following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Costs of Compliance

    There are about 3,130 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 1,380 airplanes of 
U.S. registry.
    For all airplanes: The proposed replacement would take between 20 
and 24 work hours per airplane to do, depending on the airplane's 
configuration, at an average labor rate of $80 per work hour. Required 
parts would cost between $3,658 and $4,272 per airplane, depending on 
the airplane's configuration. Based on these figures, the estimated 
cost of the proposed replacement is estimated to be up to between 
$7,256,040 and $8,544,960, or between $5,258 and $6,192 per airplane, 
depending on the airplane's configuration.
    For Groups 1 through 8 airplanes: The alternative inspection, if 
done, would take about 12 work hours per airplane to do, at an average 
labor rate of $80 per work hour. Based on these figures, the estimated 
cost of the alternative inspection is estimated to be up to $1,324,800, 
or $960 per airplane.
    For Group 9 airplanes: The general visual inspection would take 
about 2 work hours per airplane to do, at an average labor rate of $80 
per work hour. Based on these figures, the estimated cost of the 
general visual inspection is estimated to be up to $220,800, or $160 
per airplane.
    For Groups 1 through 5 airplanes that had steel pins replaced per 
the original issue of the service bulletin: The torque check would take 
about 7 work hours

[[Page 50281]]

per airplane to do, at an average labor rate of $80 per work hour. 
Based on these figures, the estimated cost of the torque check is 
estimated to be up to $772,800, or $560 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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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 proposed 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, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-29062; Directorate Identifier 2007-NM-
020-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by October 
15, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Model 737-100, -200, -200C, -300, -
400, and -500 series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from reports of findings of fatigue cracking 
of the outboard stabilizing fitting and stress corrosion cracking of 
the bolts attaching the fitting to the wing rear spar. We are 
issuing this AD to detect and correct that cracking, which could 
result in disconnection of the main landing gear (MLG) actuator from 
the rear spar and support beam, and consequent damage to the 
hydraulic system causing hydraulic fluid leakage and loss of control 
of the airplane.

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.

Service Bulletin Reference

    (f) The term ``alert service bulletin'' as used in this AD, 
means the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-57A1266, Revision 1, dated January 3, 2007.

Replacement/Repetitive Inspections

    (g) For airplanes identified as Groups 1 through 8, as specified 
in the alert service bulletin, except as provided by paragraphs (h) 
and (k) of this AD: Within 36 months after the effective date of 
this AD, replace the outboard stabilizing fitting, H-11 bolts, 
forward pin, and aft pin, as applicable, with new components by 
doing all the applicable actions in accordance with Part II of the 
alert service bulletin, except as provided by paragraph (j) of this 
AD. Within 120 months after accomplishing the replacement, do a 
general visual inspection for discrepancies of the outboard 
stabilizing fitting, walking beam hanger, and rear spar attachment 
fitting, and do all applicable corrective actions, by doing all the 
actions, except as provided by paragraph (j) of this AD, in 
accordance with Part V of the alert service bulletin. Do all 
corrective actions before further flight. Repeat the inspection at 
intervals not to exceed 120 months.

Alternative Inspection

    (h) For airplanes identified as Groups 1 through 8, as specified 
in the alert service bulletin, on which the existing H-11 bolts were 
replaced before the effective date of this AD with Inconel 718 
bolts, in lieu of doing the actions required by paragraph (g) of 
this AD: Within 4,500 flight cycles or 36 months after the effective 
date of this AD, whichever is later, do a magnetic test of the 
attach bolts in accordance with the alert service bulletin. If any 
bolt is magnetic, discontinue the alternative inspection specified 
in the alert service bulletin and accomplish the actions required by 
paragraph (g) before further flight. If none of the bolts are 
magnetic, do all the applicable actions in accordance with Part I of 
the alert service bulletin before further flight.
    (1) If any crack is found: Stop the inspection and before 
further flight do the actions required by paragraph (g) of this AD. 
Repetitive inspections must be done after replacing the fitting at 
the interval specified in paragraph (g) of this AD.
    (2) If no crack is found: Before further flight, replace the 
forward pin and aft pin, as applicable, in accordance with the alert 
service bulletin, and within 60 months after the effective date of 
this AD, do the remaining replacement required by paragraph (g) of 
this AD. Repetitive inspections must be done after replacing the 
fitting at the interval specified in paragraph (g) of this AD.
    (3) If damage other than cracking is found, or if the fitting 
lug hole is beyond hole size limits, before further flight, repair 
using a method approved in accordance with the procedures specified 
in paragraph (p) of this AD.

General Visual Inspection

    (i) For airplanes identified as Group 9, as specified in the 
alert service bulletin: Within 36 months or 4,500 flight cycles 
after the effective date of this AD, whichever occurs later, do a 
general visual inspection of the outboard stabilizing fitting and 
fasteners for discrepancies, and do all applicable corrective 
actions in accordance with Part IV of the alert service bulletin, 
except as provided by paragraphs (j) and (k) of this AD. Within 120 
months after the inspection specified in Part IV has been done, do a 
general visual inspection for discrepancies of the outboard 
stabilizing fitting, walking beam hanger and rear spar attachment 
fitting in accordance with Part V of the alert service bulletin, and 
do all applicable corrective actions in accordance with Part V of 
the alert service bulletin, except as provided by paragraphs (j) and 
(k). Do all applicable corrective actions before further flight. 
Repeat the Part V inspection at intervals not to exceed 120 months.

Exceptions to Alert Service Bulletin Specifications

    (j) During any inspection required by this AD, if any corrosion 
damage is found that cannot be removed, or if any damage is found

[[Page 50282]]

that is outside the limits specified in the alert service bulletin, 
or if any discrepancy is found and the alert service bulletin 
specifies contacting the manufacturer for disposition of certain 
repair conditions: Before further flight, repair using a method 
approved in accordance with the procedures specified in paragraph 
(p) of this AD.
    (k) Certain sections in Parts I, II, and V of the Accomplishment 
Instructions of the alert service bulletin specify ``For 737-100 and 
-200 airplanes'' and ``For 737-300 and -500 airplanes.'' However, 
those sections are applicable to Model 737-100, -200, and -200C 
airplanes, and Model 737-300, -400, and -500 airplanes, 
respectively.

Torque Check

    (l) For airplanes identified as Groups 1 through 5, as specified 
in the alert service bulletin, on which the aft pin of the aft 
outboard stabilizing fitting was replaced before the effective date 
of this AD, in accordance with Boeing Alert Service Bulletin 737-
57A1266, dated May 8, 2003: Within 36 months after the effective 
date of this AD, do a torque check to determine whether the aft pin 
is correctly installed. Do all applicable corrective actions before 
further flight. Do the actions in accordance with Part III of the 
alert service bulletin.

Concurrent Requirements

    (m) For airplanes identified as Groups 1 and 3, as specified in 
the alert service bulletin: Prior to or concurrently with 
accomplishment of paragraph (g) of this AD, do the replacement of 
the existing tube assembly of the outboard stabilizing fitting as 
specified in Part IV of Boeing Service Bulletin 737-57-1052, 
Revision 4, dated October 24, 1980.

Credit for Previously Accomplished Actions

    (n) Replacement of the tube assembly before the effective date 
of this AD in accordance with Boeing Service Bulletin 737-57-1073, 
Revision 4, dated April 12, 1985, is acceptable for compliance with 
the replacement specified in paragraph (l) of this AD.
    (o) For Groups 1 through 4, as specified in the alert service 
bulletin: Replacement of the H-11 bolts for the inboard stabilizing 
fitting before the effective date of this AD, in accordance with 
Boeing Service Bulletin 737-57-1231 dated December 1, 1994, is 
acceptable for compliance with the replacement specified in 
paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

    (p)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane and the approval must specifically refer to this AD.

    Issued in Renton, Washington, on August 17, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-17290 Filed 8-30-07; 8:45 am]

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