Document ID: FAA-2007-0004-0038
Agency: faa
Document Type: Notice
Title: Airworthiness Directives; Boeing Model 747-100, 747-100B, 747- 100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR Series Airplanes
Posted Date: 2007-09-19T04:00Z

[Federal Register: September 19, 2007 (Volume 72, Number 181)]
[Proposed Rules]               
[Page 53498-53501]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19se07-25]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29227; Directorate Identifier 2007-NM-100-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR 
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 certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 
747-200C, 747-300, 747-400, 747-400D, and 747SR series airplanes. For 
certain airplanes, this proposed AD would require a material type 
inspection to determine if the lower forward corner reveal of the 
number 3 main entry doors (MEDs) is a casting. If the reveals are 
castings, this proposed AD would require repetitive inspection of the 
reveals for cracking, and corrective action if necessary. If the 
reveals are not castings, this proposed AD would require a detailed 
inspection of the reveals for a sharp edge and repetitive inspection of 
the reveals for cracking, and corrective action if necessary. For 
certain other airplanes, this AD would require only a detailed 
inspection of the reveals for a sharp edge and repetitive inspection of 
the reveals for cracking, and corrective action if necessary. For 
certain other airplanes, this AD would require repetitive inspection of 
the reveals for cracking only, and corrective action if necessary. This 
proposed AD results from reports of cracking and/or a sharp edge in the 
lower forward corner reveal of the number 3 MEDs. We are proposing this 
AD to detect and correct fatigue cracking of the lower forward corner 
reveal of the number 3 MEDs, which could lead to the door escape slide 
departing from the airplane when the door is opened and the slide is 
deployed, and consequent injuries to passengers and crew using the door 
escape slide during an emergency evacuation.

DATES: We must receive comments on this proposed AD by November 5, 
2007.

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 Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; 
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-
29227; Directorate Identifier 2007-NM-100-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

    On June 30, 2004, we issued an NPRM, Docket No. FAA-2004-18583, to 
address the identified unsafe condition. That NPRM was prompted by 
reports from eight operators indicating that cracking of the lower 
forward corner reveal of the number 3 main entry doors (MEDs) was found 
on several Model 747 airplanes. Of the twelve reveals that were 
cracked, eleven were made of cast 356 aluminum and one was made of 
machined 6061 aluminum. The cause of the cracking of the reveals made 
of cast 356 aluminum is fatigue. The cause of the cracking of the 
reveal made of machined 6061 aluminum was a manufacturing defect, which 
led to fatigue cracking.
    Subsequent to issuing the NPRM, we have been working with the 
manufacturer to ensure that the unsafe condition is adequately 
addressed and appropriate service instructions are available. We have 
also received new data showing other issues related to the unsafe 
condition. In addition to the comments received for that NPRM, the data 
include reports that forward corner reveals installed on certain 
airplanes have a ``sharp edge'' detail at the forward edge, which could 
lead to fatigue cracking, and that additional airplanes are affected by 
the identified unsafe condition. We have determined from these data 
that the corrective actions proposed by that NPRM are inadequate for 
addressing the identified unsafe condition; therefore, we have 
withdrawn that NPRM and are issuing this new proposed AD.

[[Page 53499]]

Explanation of Related AD

    We have previously issued AD 2007-12-11, amendment 39-15089 (72 FR 
31984, June 11, 2007), which applies to certain Boeing Model 747 series 
airplanes. That AD requires repetitive inspections to detect cracks 
and/or corrosion of the girt bar support fitting at certain main entry 
doors (MED), and repair or replacement of the support fitting. That AD 
also provides for various terminating actions for the repetitive 
inspections. That AD also requires an inspection, for certain 
airplanes, for correct installation of square and conical washers in 
the girt bar support fitting; an inspection, for certain other 
airplanes, to determine if the washers are installed; and related 
investigative and corrective action if necessary.
    Actions required by that AD are done in accordance with Boeing 
Service Bulletin 747-53A2378, Revision 1, dated March 10, 1994; or 
Boeing Service Bulletin 747-53A2378, Revision 3, dated August 11, 2005. 
Accomplishment of the applicable repair in this proposed AD would 
constitute compliance with the requirements of paragraph (q)(2)(ii) of 
AD 2007-12-11 for the repair of the lower forward corner casting 
(reveal) of the number 3 MEDs only.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 747-53-
2460, Revision 1, dated February 13, 2007. The service bulletin 
describes procedures for inspections of the lower forward corner reveal 
of the number 3 MEDs, depending on the configuration of the airplane.
    For airplanes identified as Group 3 airplanes: The service bulletin 
describes procedures for a repetitive detailed inspection for cracking 
of the lower forward corner reveals for cracking, and corrective action 
if necessary. Corrective action includes replacing the reveal with a 
new or reworked two-piece reveal, which would end the repetitive 
inspections; or replacing the reveal with a new or reworked one-piece 
machined aluminum reveal without a sharp edge, doing repetitive 
inspections at a new compliance time after the replacement, and doing 
corrective action if necessary.
    For airplanes identified as Group 2 airplanes and Group 1, 
Configuration 2 airplanes: The service bulletin describes procedures 
for a repetitive detailed inspection of the lower forward corner 
reveals for cracking, a one-time detailed inspection of the lower 
forward corner reveals for a sharp edge, and corrective action if 
necessary. The corrective actions include the following:
     If no cracking and no sharp edge are found: Replace the 
reveal with a new or reworked two-piece reveal, which would end the 
repetitive inspections; or do repetitive detailed inspections at a new 
compliance time, and corrective action if necessary (as specified above 
in procedures for Group 3 airplanes).
     If no cracking is found but a sharp edge is found: Replace 
the reveal with a new or reworked two-piece reveal, which would end the 
repetitive inspections; or replace the reveal with a new or reworked 
one-piece machined aluminum reveal without a sharp edge, do the 
repetitive detailed inspections at a new compliance time after doing 
the replacement, and do corrective action if necessary (as specified 
above in procedures for Group 3 airplanes).
     If cracking is found: Replace the reveal with a new or 
reworked two-piece reveal, which would end the repetitive inspection; 
or replace the reveal with a new or reworked one-piece machined 
aluminum reveal without a sharp edge, do the repetitive detailed 
inspections at a new compliance time after doing the replacement, and 
do corrective action if necessary (as specified above in procedures for 
Group 3 airplanes).
    For airplanes identified as Group 1, Configuration 1 airplanes: The 
service bulletin describes procedures for a one-time material type 
inspection to determine if the lower forward corner reveals are 
castings. If the forward corner reveal is not a casting: Do a one-time 
detailed inspection of the reveal for a sharp edge, repetitive 
inspection of the reveal for cracking, and corrective action if 
necessary (as specified above in procedures for Group 2 and Group 1, 
Configuration 2 airplanes). If the reveal is a casting: Do repetitive 
detailed inspections of the reveal for cracking, and corrective action 
if necessary. Corrective actions include the following: Weld repair the 
reveal and repeat the detailed inspection; replace the reveal with a 
new or reworked two-piece reveal, which ends the repetitive 
inspections; or replace the reveal with a new or reworked one-piece 
machined aluminum reveal without a sharp edge, do the repetitive 
inspections again at a new compliance time after the replacement, and 
do corrective action if necessary (as specified above in procedures for 
Group 2 and Group 1, Configuration 2 airplanes).
    Accomplishing the actions specified in the service information is 
intended to 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 service 
information described previously, except as discussed under 
``Difference Between the Proposed AD and the Service Bulletin.''

Difference Between the Proposed AD and the Service Bulletin

    Although Step 5 of Figure 8 of the service bulletin specifies that 
operators may accomplish the actions on forward corner reveals made of 
cast 356 aluminum in accordance with ``an operator's equivalent 
procedure,'' this proposed AD would require operators to accomplish 
Step 5 of Figure 8 only in accordance with the procedures specified in 
Boeing Standard Overhaul Practices Manual (SOPM) 20-20-02. An 
``operator's equivalent procedure'' may be used only if approved as an 
alternative method of compliance in accordance with paragraph (p) of 
this AD.
    The difference described above has been coordinated with the 
manufacturer.

Costs of Compliance

    There are about 715 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                 Number of U.S.-
            Action               Work hours     Average labor      Cost per        registered       Fleet cost
                                                rate per hour      airplane         airplanes
----------------------------------------------------------------------------------------------------------------
Inspections..................               4             $80  $320, per                    119  $38,080, per
                                                                inspection                        inspection
                                                                cycle.                            cycle.
----------------------------------------------------------------------------------------------------------------

[[Page 53500]]

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-2007-29227; Directorate Identifier 2007-NM-
100-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by November 
5, 2007.

Affected ADs

    (b) Certain requirements of this AD terminate certain 
requirements of AD 96-23-05, amendment 39-9810.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR 
series airplanes, certificated in any category, as identified in 
Boeing Special Attention Service Bulletin 747-53-2460, Revision 1, 
dated February 13, 2007, except airplanes that have been converted 
to an all-cargo configuration. The requirements of this AD also 
become applicable at the time when a converted airplane operating in 
an all-cargo configuration is converted back to a passenger or 
passenger/cargo configuration.

Unsafe Condition

    (d) This AD results from reports of cracking and/or a sharp edge 
in the lower forward corner reveal of the number 3 main entry doors 
(MEDs). We are issuing this AD to detect and correct fatigue 
cracking of the lower forward corner reveal of the number 3 MEDs, 
which could lead to the door escape slide departing from the 
airplane when the door is opened and the slide is deployed, and 
consequent injuries to passengers and crew using the door escape 
slide during an emergency evacuation.

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 ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2460, Revision 1, dated February 13, 2007.

Actions for Group 3 Airplanes

    (g) For airplanes identified as Group 3 airplanes in the service 
bulletin: Before the accumulation of 10,000 total flight cycles, or 
within 1,000 flight cycles after the effective date of this AD, 
whichever occurs later, do a detailed inspection for cracking of the 
lower forward corner reveals in accordance with Part 8 of the 
service bulletin.
    (1) If no cracking is found, repeat the inspection thereafter at 
intervals not to exceed 6,000 flight cycles until a new or reworked 
two-piece reveal is installed in accordance with Part 2 of the 
service bulletin. No further action is required by this paragraph 
for that location only after the replacement.

    Note 1: For the purpose of this AD, a one-piece machined 
aluminum reveal may be reworked into a two-piece reveal in 
accordance with Part 7 of the service bulletin after it was verified 
to be crack free and without a sharp edge in accordance with Part 5 
of the service bulletin, or after it was confirmed to be crack free 
in accordance with Part 5 of the service bulletin and reworked to 
remove a sharp edge in accordance with Part 6 of the service 
bulletin.

    (2) If cracking is found, do the replacement specified in 
paragraph (g)(2)(i) or (g)(2)(ii) of this AD.
    (i) Before further flight, replace the reveal with a new or 
reworked two-piece reveal in accordance with Part 2 of the service 
bulletin. No further action is required by this paragraph for that 
location only after the replacement.
    (ii) Before further flight, replace the reveal with a new or 
reworked one-piece machined aluminum reveal without a sharp edge in 
accordance with Part 3 of the service bulletin. Within 10,000 flight 
cycles after doing the replacement, do the inspection specified in 
paragraph (g) of this AD and repeat the inspection thereafter at 
intervals not to exceed 6,000 flight cycles until a new or reworked 
two-piece reveal is installed in accordance with Part 2 of the 
service bulletin. No further action is required by this paragraph 
for that location only after the replacement with a two-piece 
reveal.

    Note 2: For the purpose of this AD, a one-piece machined 
aluminum reveal with a sharp edge may be reworked into a one-piece 
machined aluminum reveal without a sharp edge in accordance with 
Part 6 of the service bulletin after it was confirmed to be crack 
free in accordance with Part 5 of the service bulletin. After the 
sharp edge was removed, the one-piece machined aluminum reveal 
without a sharp edge may be further reworked into a two-piece reveal 
in accordance with Part 7 of the service bulletin.

Actions for Group 2 Airplanes and Group 1, Configuration 2 Airplanes

    (h) For airplanes identified as Group 2 airplanes in the service 
bulletin: Before the accumulation of 1,500 total flight cycles, or 
within 1,000 flight cycles after the effective date of this AD, 
whichever occurs later, do the inspection specified in paragraph (j) 
of this AD.
    (i) For airplanes identified as Group 1, Configuration 2 
airplanes in the service bulletin: Within 1,500 flight cycles after 
the lower forward corner reveal was last replaced or 1,000 flight 
cycles after the effective date of this AD, whichever occurs later, 
do the inspection specified in paragraph (j) of this AD.
    (j) At the applicable times specified in paragraphs (h) and (i) 
of this AD: Do a detailed inspection of the lower forward corner 
reveals for cracking and a sharp edge in accordance with Part 5 of 
the service bulletin.
    (1) If no cracking and no sharp edge is found, before the 
accumulation of another

[[Page 53501]]

10,000 flight cycles on the lower forward corner reveal, do the 
detailed inspection for cracking specified in paragraph (j) of this 
AD and inspect thereafter at intervals not to exceed 6,000 flight 
cycles, until a new or reworked two-piece reveal is installed in 
accordance with Part 2 of the service bulletin. No further action is 
required by this paragraph for that location only after the 
replacement.
    (2) If no cracking is found but a sharp edge is found, do the 
action specified in paragraph (j)(2)(i) or (j)(2)(ii) of this AD.
    (i) Before further flight, replace the lower forward corner 
reveal with a new or reworked two-piece reveal, in accordance with 
Part 2 of the service bulletin. No further action is required by 
this paragraph for that location only after the replacement.
    (ii) Before further flight, replace the reveal with a new or 
reworked one-piece machined aluminum reveal without a sharp edge, in 
accordance with Part 3 of the service bulletin. Within 10,000 flight 
cycles after doing the replacement, do the actions specified in 
paragraph (j) of this AD, except for the inspection for a sharp 
edge.
    (3) If cracking is found, do the action specified in paragraph 
(j)(3)(i) or (j)(3)(ii) of this AD.
    (i) Before further flight, replace the reveal with a new or 
reworked two-piece reveal, in accordance with Part 2 of the service 
bulletin. No further action is required by this paragraph for that 
location only after the replacement.
    (ii) Before further flight, replace the lower forward corner 
reveal with a new or reworked one-piece machined aluminum reveal 
without a sharp edge, in accordance with Part 3 of the service 
bulletin. Within 10,000 flight cycles after doing the replacement, 
do the actions specified in paragraph (j) of this AD, except for the 
inspection for a sharp edge.

Actions for Group 1, Configuration 1 Airplanes

    (k) For airplanes identified as Group 1, Configuration 1 
airplanes in the service bulletin: Before the accumulation of 1,500 
total flight cycles, or within 1,000 flight cycles after the 
effective date of this AD, whichever occurs later, do a material 
type inspection to determine if the lower forward corner reveals are 
castings, in accordance with the service bulletin.
    (1) If the forward corner reveal is not a casting: Before 
further flight, do the actions specified in paragraph (j) of this 
AD, except for the inspection for a sharp edge.
    (2) If the forward corner reveal is a casting: Before the 
accumulation of 7,000 total flight cycles, within 2,000 flight 
cycles after the effective date of this AD, or within 3,000 flight 
cycles since the forward corner reveal was inspected in accordance 
with Boeing Service Bulletin 747-53A2378, whichever is later, do a 
detailed inspection for cracking of the lower forward corner reveal, 
in accordance with Part 1 of Boeing Special Attention Service 
Bulletin 747-53-2460, Revision 1, dated February 13, 2007.
    (i) If no cracking is found: Repeat the inspection specified in 
paragraph (k)(2) of this AD thereafter at intervals not to exceed 
3,000 flight cycles until a new or reworked two-piece lower forward 
corner reveal is installed in accordance with Part 2 of the service 
bulletin. No further action is required by this paragraph for that 
location only after the replacement.
    (ii) If cracking is found: Do the actions specified in paragraph 
(k)(2)(ii)(A), (k)(2)(ii)(B), or (k)(2)(ii)(C) of this AD.
    (A) Before further flight, weld repair the reveal in accordance 
with Part 4 of the service bulletin. Repeat the inspection specified 
in paragraph (k)(2) of this AD thereafter at intervals not to exceed 
3,000 flight cycles until a new or reworked two-piece reveal is 
installed in accordance with Part 2 of the service bulletin.
    (B) Before further flight, replace the reveal with a new or 
reworked two-piece reveal, in accordance with Part 2 of the service 
bulletin. No further action is required by this paragraph for that 
location only after the replacement.
    (C) Before further flight, replace the reveal with a new or 
reworked one-piece machined aluminum reveal without a sharp edge, in 
accordance with Part 3 of the service bulletin. Within 10,000 flight 
cycles after doing the replacement, do the actions specified in 
paragraph (j) of this AD, except for the inspection for a sharp 
edge.

Operator's Equivalent Procedure

    (l) Although Step 5 of Figure 8 of the service bulletin 
specifies that operators may accomplish the actions in accordance 
with ``an operator's equivalent procedure,'' this AD requires 
operators to accomplish Step 5 of Figure 8 in accordance with only 
the procedures specified in Boeing Standard Overhaul Practices 
Manual (SOPM) 20-20-02 as given in the service bulletin. An 
``operator's equivalent procedure'' may be used only if approved as 
an alternative method of compliance in accordance with paragraph (p) 
of this AD.

Compliance With AD 2007-12-11 for MED 3 Only

    (m) Accomplishment of the applicable repair required by this AD 
constitutes compliance with the repair of the lower forward corner 
casting (reveal) of the number 3 MEDs only, as required by paragraph 
(q)(2)(ii) of AD 2007-12-11 (which specifies the actions be done in 
accordance with Boeing Service Bulletin 747-53A2378, Revision 1, 
dated March 10, 1994; or Boeing Service Bulletin 747-53A2378, 
Revision 3, dated August 11, 2005). Accomplishment of the actions of 
this AD does not terminate the remaining requirements of AD 2007-12-
11.

Parts Installation

    (n) As of the effective date of this AD, no person may install a 
door lower forward corner reveal made of cast 356 aluminum on any 
airplane at a location specified by this AD.
    (o) As of the effective date of this AD, no person may install a 
door lower forward corner reveal made of machined 6061 aluminum on 
any airplane at a location specified by this AD, unless it has been 
confirmed/reworked to be without a sharp edge in accordance with the 
service bulletin.

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 September 10, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-18420 Filed 9-18-07; 8:45 am]

BILLING CODE 4910-13-P