[Federal Register Volume 72, Number 145 (Monday, July 30, 2007)]
[Rules and Regulations]
[Pages 41438-41441]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-14426]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26441; Directorate Identifier 2006-NM-204-AD; 
Amendment 39-15139; AD 2007-15-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 747 airplanes. This AD requires an inspection of the No. 2 
and No. 3 windows on the left and right sides of the airplane to 
determine their part numbers, and related investigative and corrective 
actions if necessary. This AD results from loss of a No. 3 window in-
flight. We are issuing this AD to detect and correct cracking in the 
fail-safe interlayer of certain No. 2 and No. 3 glass windows, which 
could result in loss of the window and consequent rapid loss of cabin 
pressure. Loss of the window could also result in crew communication 
difficulties or incapacitation of the crew.

DATES: This AD becomes effective September 4, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of September 4, 
2007.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue, SE., Washington, DC.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Steve Fox, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6425; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Examining the Docket

    You may examine the airworthiness directive (AD) docket on the 
Internet at http://dms.dot.gov or in person at the Docket Operations 
office between 9 a.m.

[[Page 41439]]

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 street address stated in the 
ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to all Boeing Model 747 
airplanes. That NPRM was published in the Federal Register on December 
8, 2006 (71 FR 71099). That NPRM proposed to require an inspection of 
the No. 2 and No. 3 windows on the left and right sides of the airplane 
to determine their part numbers, and related investigative and 
corrective actions if necessary.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Support for the NPRM

    Boeing supports the NPRM, and British Airways supports the intent 
of the NPRM.

Request To Extend Grace Period

    Qantas Airways states that the compliance times given in calendar 
time (units of years) in Tables 1, 2, and 3 of Boeing Alert Service 
Bulletin 747-56A2012, dated August 24, 2006, are not relevant for 
windows installed after the issue date of the service bulletin. As an 
example, the commenter states that a window installed on an airplane 5 
years from now will have already surpassed the compliance time at the 
time of installation. Qantas Airways, therefore, requests that the 
calendar times in Tables 1, 2, and 3 of the service bulletin be revised 
as follows: ``Within 2 (or 3) years after the date on this service 
bulletin, or after the window was installed, whichever occurs last.'' 
Qantas Airways asserts that this change will ensure that the inspection 
of newly installed windows is controlled by calendar and flight-hour 
constraints.
    We agree to clarify the compliance time for newly installed 
windows. If a discrepant window is replaced with a new window, then the 
initial detailed inspection of the new window must be accomplished 
within either 5,500 or 22,000 flight hours after installing the window, 
depending on the window part number. The inspection must be repeated at 
the interval stated in Table 2 or 3, as applicable, of the Boeing 
service bulletin. We have revised paragraph (g) of this AD to clarify 
the compliance time.

Request To Include Terminating Action

    GKN Aerospace states that it manufactures some of the affected 
windows identified in Boeing Alert Service Bulletin 747-56A2012, dated 
August 24, 2006. GKN Aerospace states that it is concerned about the 
potential removal rates of in-service airplanes to address the unsafe 
condition; therefore, it is working to certify an improved window 
design that incorporates a new, improved interlayer, which is less 
susceptible to the cracking experienced with the existing windows. We 
infer the commenter would like us to include a terminating action in 
this AD.
    We agree that improving the window design to prevent cracking is a 
preferable solution than requiring long-term repetitive inspections. In 
the preamble of the NPRM, we stated that we considered this action to 
be an interim action. When a final action is identified, we may 
consider further rulemaking. We have not changed this AD in this 
regard.

Request To Skip Inspection To Determine Part Number

    Boeing Aerospace Operations Engineering and Logistics Services 
requests that we allow operators to skip the window identification 
procedure and accomplish the rest of the service bulletin as though the 
part number could not be identified. The commenter states that since 
some airplanes are equipped with unique No. 2 and No. 3 windows, the 
window identification cannot be accomplished according to Part 1 of the 
Boeing Alert Service Bulletin 747-56A2012, dated August 24, 2006, or 
the replacement according to Part 2, step 4 of the service bulletin.
    We do not agree to delete the inspection to determine the part 
numbers of the windows. Operators who inspect and determine that the 
affected windows are not installed on an airplane are not required to 
accomplish the related investigative and corrective actions. Therefore, 
accomplishing the inspection to determine the window part numbers may 
relieve some operators of the on-condition requirements. However, under 
the provisions of paragraph (h) of this AD, we may consider requests 
for approval of an alternative method of compliance (AMOC) if 
sufficient data are submitted to substantiate that such a design change 
would provide an acceptable level of safety. We have not changed this 
AD in this regard.

Request To Revise Compliance Times

    British Airways states that the compliance times in Tables 2 and 3 
of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 2006, 
should be revised as follows:
     For part numbers (P/Ns) 65B27042-( ) and 65B27043-( ), the 
initial inspection should be extended from 5,500 flight hours to 9,000 
flight hours.
     For P/Ns 65B27046-( ) and 65B27047-( ), the initial 
inspection should be reduced from 22,000 flight hours to 15,000 flight 
hours, and the repetitive interval should be reduced from 7,500 flight 
hours to 3,000 flight hours (to match the repetitive interval for P/Ns 
65B27042-( ) and 65B27043-( )).
    British Airways asserts that, based on its experience, the longer 
compliance times for P/Ns 65B27046-( ) and 65B27047-( ), are not 
justified. British Airways also asserts that requiring different 
repetitive intervals for different windows does not make sense since 
many airlines use a mix of windows on their airplanes.
    We acknowledge British Airways' comments but disagree with revising 
the compliance times as proposed by the commenter. In developing the 
compliance time for this AD action, we considered not only the safety 
implications of the identified unsafe condition, but the 
recommendations of the manufacturer, known service experience, average 
utilization rate of the affected fleet, and the availability of 
required parts. British Airways refers to its service experience but 
does not provide any data to support its comment. We invite British 
Airways to submit, to Boeing, any data it has that supports its 
comments related to changing certain compliance times. We would 
consider further rulemaking should such data support changing the 
compliance times of this AD. To further delay this AD would be 
inappropriate considering the need to correct a known safety problem in 
a timely manner. Further, operators are always permitted to accomplish 
the requirements of an AD at an earlier time than the required 
compliance time; therefore, an operator may choose to inspect P/Ns 
65B27046-( ) and 65B27047-( ) at repetitive intervals of 3,000 flight 
hours. We have determined that the compliance times recommended in the 
service bulletin are appropriate for addressing the unsafe condition 
and we have not changed this AD in this regard.

Request To Delete Grace Period

    British Airways states that the grace period of 1,000 flight hours 
after the date on the service bulletin is obsolete, since this time 
period will have been exceeded by the time we issued an AD. We infer 
that the commenter would like us to delete the grace period from Tables

[[Page 41440]]

2 and 3 of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 
2006.
    We disagree with deleting the grace period. We would like to point 
out that in paragraph (g) of the NPRM, which is retained in this AD, we 
stated that the compliance times given in the service bulletin are to 
be counted from the effective date of this AD, not from the date on the 
service bulletin. We have not changed this AD in this regard.

Request To Rephrase Compliance Time

    British Airways requests that we delete the word ``or'' where the 
service bulletin compliance times are restated in the ``Relevant 
Service Information'' section of the NPRM. As justification, the 
commenter states that using the word ``or'' gives an operator the 
choice of choosing between two compliance times.
    We disagree with revising this AD, since the ``Relevant Service 
Information'' section is not retained in a final rule. We have reviewed 
the NPRM and find that the wording used throughout the NPRM is 
consistent with the service bulletin. Further, where we restated the 
service bulletin compliance times in the NPRM, the lead-in statements 
clearly specify doing the proposed actions at the earlier of the 
compliance times; therefore, the compliance time cannot be chosen at an 
operator's discretion. We have not changed this AD in this regard.

Request To Revise Costs of Compliance

     British Airways requests that we make the following 
changes to the ``Costs of Compliance'' section:
     Add the cost of replacing a cracked window. The commenter 
states that the ``Costs of Compliance'' section is wrong because it 
does not estimate the cost of replacing a cracked window.
     Include the cost of having to remove an airplane from 
service 40% more frequently to accomplish the repetitive actions.
     Revise the estimated work hours. The commenter asserts 
that it should take \1/2\ hour to inspect a window to determine its 
part number, and that the inspection for cracks would require 2 people 
and would take 1 hour.
    We do not agree to revise the ``Cost of Compliance'' section as the 
commenter proposes. The economic analysis of an AD is limited to the 
cost of actions that are actually required. The economic analysis does 
not consider the costs of conditional actions, such as repairing a 
crack detected during a required inspection (``repair, if necessary''). 
Such conditional repairs would be required--regardless of AD 
direction--to correct an unsafe condition identified in an airplane and 
to ensure that the airplane is operated in an airworthy condition, as 
required by the Federal Aviation Regulations. Furthermore, we do not 
consider it appropriate to attribute the costs associated with aircraft 
``down time'' to the AD. Also, we have determined the cost of 
compliance from information contained in the manufacturer's service 
information. We recognize that individual operators might incur costs 
less than or more than our estimate. It is impossible to estimate such 
individual variations. We have not changed this AD in this regard.

Request To Revise Service Bulletin

    British Airways submitted several comments on the accuracy and 
clarity of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 
2006. We infer that the commenter would like us delay issuance of the 
AD until the service bulletin is revised to incorporate its comments.
    We acknowledge the value of the information submitted by the 
commenter. British Airways' comments will be of benefit to any future 
revisions of the service bulletin. In this case, however, the service 
bulletin is acceptable for ensuring that the unsafe condition is 
addressed. Therefore, we do not agree to delay this action until the 
service bulletin has been revised. To do so would be inappropriate, 
since we have determined that an unsafe condition exists, and that 
inspections must be conducted to ensure continued safety. We have not 
changed this AD in this regard.

Clarification of AMOC Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the change described previously. 
We have determined that this change will neither increase the economic 
burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 949 airplanes of the affected design in the 
worldwide fleet. This AD affects about 153 airplanes of U.S. registry. 
The required inspection to determine the window part numbers takes 
about 4 work hours per airplane, at an average labor rate of $80 per 
work hour. Based on these figures, the estimated cost of the AD for 
U.S. operators is $48,960, or $320 per airplane.
    The detailed inspection, if necessary, takes about 1 work hour per 
airplane, at an average labor rate of $80 per work hour. Based on these 
figures, the estimated cost of the detailed inspection for U.S. 
operators is $80 per airplane, per inspection cycle, if necessary.

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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 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, Incorporation by 
reference, Safety.

[[Page 41441]]

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2007-15-10 Boeing: Amendment 39-15139. Docket No. FAA-2006-26441; 
Directorate Identifier 2006-NM-204-AD.

Effective Date

    (a) This AD becomes effective September 4, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, 747SR, and 747SP series airplanes, certificated in any 
category.

Unsafe Condition

    (d) This AD results from loss of a No. 3 window in-flight. We 
are issuing this AD to detect and correct cracking in the fail-safe 
interlayer of certain No. 2 and No. 3 glass windows, which could 
result in loss of the window and consequent rapid loss of cabin 
pressure. Loss of the window could also result in crew communication 
difficulties or incapacitation of the crew.

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.

Inspection, Related Investigative Actions, and Corrective Action

    (f) Inspect the No. 2 and No. 3 windows on the left and right 
sides of the airplane to determine their part numbers, and do all 
the applicable related investigative and corrective actions, by 
accomplishing all of the actions specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-56A2012, dated 
August 24, 2006, as applicable. Do all of these actions at the 
compliance times specified in Tables 1, 2, and 3 of paragraph 1.E. 
of the service bulletin, as applicable, except as provided by 
paragraph (g) of this AD. A review of airplane maintenance records 
is acceptable in lieu of the inspection if the part numbers of the 
windows can be conclusively determined from that review. Repeat the 
related investigative and corrective actions thereafter at the 
interval specified in Table 2 or 3 of the service bulletin, as 
applicable.

Exceptions to Compliance Times

    (g) Where Tables 1, 2, and 3 of paragraph 1.E. of Boeing Alert 
Service Bulletin 747-56A2012, dated August 24, 2006, specify 
counting the compliance time from ``. . . after the date on this 
service bulletin,'' this AD requires counting the compliance time 
from the effective date of this AD. After replacing a discrepant 
window with a new window, do the initial detailed inspection of the 
new window at the applicable compliance time: (1) within 5,500 
flight cycles after installing part number (P/N) 65B27042-( ) or 
65B27043-( ), or (2) within 22,000 flight cycles after installing P/
N 65B27046-( ) or 65B27047-( ).

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle Aircraft Certification Office, 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.

Material Incorporated by Reference

    (i) You must use Boeing Alert Service Bulletin 747-56A2012, 
dated August 24, 2006, to perform the actions that are required by 
this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, Washington; or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on July 18, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-14426 Filed 7-27-07; 8:45 am]
BILLING CODE 4910-13-P