Document ID: FAA-2007-29227-0008
Agency: faa
Document Type: Rule
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: 2008-05-22T04:00Z

[Federal Register: May 22, 2008 (Volume 73, Number 100)]
[Proposed Rules]               
[Page 29716-29720]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22my08-13]                         

========================================================================
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.

========================================================================

[[Page 29716]]

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), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

-----------------------------------------------------------------------

SUMMARY: We are revising an earlier proposed 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, the original NPRM would have required 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, the original NPRM would have required repetitive inspections 
of the reveals for cracking, and corrective action if necessary. If the 
reveals are not castings, the original NPRM would have required a 
detailed inspection of the reveals for a sharp edge and repetitive 
inspections of the reveals for cracking, and corrective action if 
necessary. For certain other airplanes, the original NPRM would have 
required only a detailed inspection of the reveals for a sharp edge and 
repetitive inspections of the reveals for cracking, and corrective 
action if necessary. For certain other airplanes, the original NPRM 
would have required repetitive inspections of the reveals for cracking 
only, and corrective action if necessary. The original NPRM resulted 
from reports of cracking and/or a sharp edge in the lower forward 
corner reveal of the number 3 MEDs. This action revises the original 
NPRM by reducing the compliance times for doing certain inspections and 
allowing a certain replacement as an optional action for the material 
type inspection for certain airplanes. We are proposing this 
supplemental NPRM 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 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 supplemental NPRM by June 16, 
2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     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.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

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 send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. 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 this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We issued a notice of proposed rulemaking (NPRM) (the ``original 
NPRM'') to amend 14 CFR part 39 to include an airworthiness directive 
(AD) that would apply to certain Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR 
series airplanes. That original NPRM was published in the Federal 
Register on September 19, 2007 (72 FR 53498). For certain airplanes, 
that original NPRM proposed to 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, that original 
NPRM proposed to require repetitive inspections of the reveals for 
cracking, and corrective action if necessary. If the reveals are not 
castings, that original NPRM proposed to require a detailed inspection 
of the reveals for a sharp edge and repetitive inspections of the 
reveals for cracking, and corrective action if necessary. For certain 
other airplanes, that original NPRM proposed to require only a detailed 
inspection of the reveals for a sharp edge and repetitive inspections 
of the reveals for cracking, and corrective action if necessary. For 
certain other airplanes,

[[Page 29717]]

that original NPRM proposed to require repetitive inspections of the 
reveals for cracking only, and corrective action if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received from the commenter.

Request To Clarify No Further Action Statement

    Boeing requests that we clarify the statement ``No further action 
is required by this paragraph for that location only after the 
replacement'' specified in paragraphs (g)(1), (j)(1), (j)(2)(i), 
(j)(3)(i), (k)(2)(i), and (k)(2)(ii)(B) of the NPRM. Boeing suggests 
that we add the phrase ``with a two-piece reveal'' to the statement. 
Boeing states that the referenced service bulletin (Boeing Special 
Attention Service Bulletin 747-53-2460, Revision 1, dated February 13, 
2007) gives two options for the replacement, with either a one-piece 
reveal or a two-piece reveal. Boeing states that only a replacement 
with a two-piece reveal terminates the inspections for that location.
    We agree that only replacement with a two-piece reveal would 
terminate the inspections for that location. However, we do not agree 
that clarification is necessary for all paragraphs. In paragraphs 
(j)(2)(i), (j)(3)(i), and (k)(2)(ii)(B) of the supplemental NPRM, we 
specify replacing the reveal with a new or reworked two-piece reveal in 
accordance with Part 2 of Boeing Special Attention Service Bulletin 
747-53-2460, Revision 1. We do not mention installation of a one-piece 
reveal as an option in these paragraphs. Part 2 of the service bulletin 
describes procedures for installing two-piece reveals. Therefore, in 
paragraphs (j)(2)(i), (j)(3)(i), and (k)(2)(ii)(B) of the supplemental 
NPRM where we state that no further action is required after the 
replacement, the replacement is the two-piece reveal replacement 
specified in those paragraphs. No change is necessary for paragraphs 
(j)(2)(i), (j)(3)(i), and (k)(2)(ii)(B) of this supplemental NPRM in 
regard to this issue.
    Also, for paragraphs (g)(1) and (k)(2)(i) of this supplemental 
NPRM, we specify to repeat inspections until a new or re-worked two-
piece reveal is installed. The replacement is the two-piece reveal 
installation specified in those paragraphs. No change is necessary for 
paragraphs (g)(1) and (k)(2)(i) of this supplemental NPRM in regard to 
this issue.
    However, we have revised paragraph (j)(1) of this supplemental NPRM 
for clarity as suggested by the commenter.

Request To Allow Optional Action for Material Type Inspection

    Boeing requests that we allow doing a replacement with a new two-
piece reveal as an optional action for the material type inspection 
specified in paragraph (k) of the original NPRM. Boeing states that if 
an existing reveal is to be reworked to a two-piece reveal, the 
material type inspection is necessary; however, if the reveal is 
replaced with a new two-piece reveal, a material type inspection is not 
necessary. Boeing states if an operator replaces all the reveals with 
new two-piece reveals, the original NPRM would still require that the 
material type inspection be done.
    We agree to allow replacing the reveal with a new two-piece reveal 
as an option for the reasons stated by the commenter. In addition, we 
have determined it is acceptable to replace the reveal with a re-worked 
reveal as an option to doing the material type inspection; re-worked 
reveals are machined from 6061 aluminum. We have revised paragraph (k) 
of this supplemental NPRM accordingly.

Request To Reduce Compliance Time in Paragraph (j)(1) of the Original 
NPRM

    Boeing requests that we reduce the compliance time ``before the 
accumulation of another 10,000 flight cycles on the lower forward 
corner reveal'' to `` before the accumulation of 10,000 flight cycles 
on the lower forward corner reveal since new (for Group 2 airplanes) or 
since replacement (for Group 1 Configuration 2 airplanes).'' Boeing 
states that the first inspection should be at 1,500 flight cycles and 
then the interval should be 6,000 flight cycles.
    We agree with the commenter that the next repeat inspection after 
the initial inspection done in accordance with paragraph (j) of the 
supplemental NPRM should be reduced. We intended to match the 
compliance times specified in the service bulletin but the compliance 
times in the service bulletin are unclear. Figure 16 of the service 
bulletin specifies a compliance time of ``10,000 flight cycles after 
the reveal was last replaced'' but does not refer to a compliance time 
of 10,000 flight cycles on the reveal since new. In addition, the 
commenter gives conflicting statements. The commenter's statement that 
the interval should be 6,000 flight cycles after the first 1,500 flight 
cycle inspection conflicts with its statement that the compliance time 
should be revised to state 10,000 flight cycles on the reveal since new 
or replaced. We have revised paragraph (j)(1) to reduce the compliance 
time as follows: Before the accumulation of 10,000 flight cycles on the 
lower forward corner reveal since new, or within 6,000 flight cycles 
after doing the inspection required by paragraph (j) of this AD, 
whichever occurs later.
    In addition, we have revised paragraphs (g)(2)(ii), (j)(2)(ii), 
(j)(3)(ii), and (k)(2)(ii)(C) of the supplemental NPRM to clarify the 
10,000-flight-cycle compliance time is on the replacement reveal 
instead of since replacement of the reveal.

Request To Revise Reference

    Boeing requests that we revise the reference for doing the detailed 
inspection specified in paragraph (j)(1) of the original NPRM. Boeing 
states that instead of doing the detailed inspection as specified in 
paragraph (j) of the original NPRM, the paragraph should specify doing 
the detailed inspection in accordance with Part 5 of the service 
bulletin. Boeing notes that paragraph (j) refers to paragraphs (h) and 
(i) of the original NPRM for compliance times. Boeing contends that 
because paragraphs (h) and (i) include a compliance time of ``before 
the accumulation of 1,500 total flight cycles'' operators may interpret 
that the inspection interval is 1,500 flight cycles.
    We disagree with the commenter's assertion that the compliance time 
interval can be interpreted as 1,500 flight cycles because the 
compliance time is specified in paragraph (j)(1) of the supplemental 
NPRM and the reference to paragraph (j) of the supplemental NPRM is for 
the details of how to do the inspection. However, we have revised 
paragraph (j)(1) of the supplemental NPRM for clarity. Although the 
commenter suggests pointing to Part 5 of the service bulletin for doing 
the inspection, Part 5 of the service bulletin refers to Part 8 of the 
service bulletin for doing the inspection. Therefore, we have revised 
paragraph (j)(1) of the supplemental NPRM to refer directly to Part 8 
of the service bulletin. We have also revised paragraph (j)(1) of the 
supplemental NPRM to refer to paragraph (j)(3) of the supplemental NPRM 
for doing corrective action if any cracking is found.
    In addition, we have revised paragraphs (g)(2)(ii), (j)(2)(ii), 
(j)(3)(ii), and (k)(2)(ii)(C) of the supplemental NPRM to clarify the 
references for doing the inspections.

[[Page 29718]]

FAA's Determination and Proposed Requirements of the Supplemental NPRM

    We are proposing this supplemental NPRM because we evaluated all 
pertinent information and determined an unsafe condition exists and is 
likely to exist or develop on other products of the same type design. 
Certain changes described above expand the scope of the original NPRM. 
As a result, we have determined that it is necessary to reopen the 
comment period to provide additional opportunity for the public to 
comment on this supplemental NPRM.

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 supplemental NPRM.

                                                 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.
----------------------------------------------------------------------------------------------------------------

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 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 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. 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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

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 FAA amends Sec.  39.13 by adding the following new AD:

Boeing: Docket No. FAA-2007-29227; Directorate Identifier 2007-NM-
100-AD.

Comments Due Date

    (a) We must receive comments by June 16, 2008.

Affected ADs

    (b) Certain requirements of this AD terminate certain 
requirements of AD 2007-12-11, amendment 39-15089.

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 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.

[[Page 29719]]

    (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. Before the 
accumulation of 10,000 flight cycles on the replacement reveal since 
new, do the inspection for cracking specified in Part 8 of the 
service bulletin 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. If any cracking is found during any inspection required by 
this paragraph, before further flight, do the action specified in 
paragraph (g)(2) of this AD. 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 is confirmed to be crack 
free in accordance with Part 5 of the service bulletin. After the 
sharp edge is 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 are found, before the 
accumulation of 10,000 flight cycles on the lower forward corner 
reveal since new, or within 6,000 flight cycles after doing the 
inspection required by paragraph (j) of this AD, whichever occurs 
later, do the detailed inspection for cracking in accordance with 
Part 8 of the service bulletin 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. If any cracking is found during any inspection required by 
this paragraph, before further flight, do the action specified in 
paragraph (j)(3) of this AD. No further action is required by this 
paragraph for that location only after the replacement with a two-
piece reveal.
    (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. Before the 
accumulation of 10,000 flight cycles on the replacement reveal since 
new, do the inspection for cracking in accordance with Part 8 of the 
service bulletin 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. If any 
cracking is found during any inspection required by this paragraph, 
before further flight, do the action required by paragraph (j)(3) of 
this AD. No further action is required by this paragraph for that 
location only after the replacement with a two-piece reveal.
    (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. Before the accumulation of 10,000 flight cycles on the 
replacement reveal since new, do the inspection for cracking in 
accordance with Part 8 of the service bulletin 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. If any cracking is found during any 
inspection required by this paragraph, before further flight, do the 
action required by paragraph (j)(3) of this AD. No further action is 
required by this paragraph for that location only after the 
replacement with a two-piece reveal.

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. As an alternative 
to the material type inspection, replacing a reveal with a new or 
reworked two-piece lower forward corner reveal in accordance with 
Part 2 of the service bulletin is terminating action for the 
requirements of this paragraph for that location only.
    (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 latest, 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. No 
further action is required by this paragraph for that location only 
after the replacement.
    (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. Before the 
accumulation of 10,000 flight cycles on the replacement reveal since 
new, do the inspection for cracking in accordance with Part 8 of the 
service bulletin 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. If any 
cracking is found during any inspection required by this paragraph, 
before further flight, do the action required by paragraph 
(k)(2)(ii)(B) or (k)(2)(ii)(C) of this AD. No further action is 
required by this paragraph for that location only after the 
replacement with a two-piece reveal.

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-

[[Page 29720]]

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, Amendment 39-15089, 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 May 7, 2008.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-11474 Filed 5-21-08; 8:45 am]

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