[Federal Register Volume 67, Number 104 (Thursday, May 30, 2002)]
[Proposed Rules]
[Pages 37734-37735]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-13424]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-85-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 747 series 
airplanes. This proposal would require repetitive inspections to detect 
evidence of wear damage in the area at the interface between the 
vertical stabilizer and fuselage skin, and corrective actions, if 
necessary. This proposal also would provide for an optional terminating 
action for the repetitive inspections. This action is necessary to 
detect and correct wear damage of the fuselage skin, which could result 
in thinning and cracking of the fuselage skin, and consequent in-flight 
depressurization of the airplane. This action is intended to address 
the identified unsafe condition.

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

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-85-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-85-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Technical Information: Rick Kawaguchi, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-1153; fax (425) 227-1181.
    Other Information: Judy Golder, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 227-1119, fax (425) 227-1232. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-85-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2002-NM-85-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of wear damage at the 
interface area of the vertical stabilizer and fuselage skin in section 
46 and section 48 on certain Boeing Model 747 series airplanes. The 
damage has been attributed to movement of the adjacent vertical 
stabilizer blade seal and subsequent wear through the enamel coating on 
the fuselage skin. Such wear damage of the fuselage skin in the area at 
the interface between the vertical stabilizer and fuselage skin, if 
left undetected, could result in thinning and cracking of the fuselage 
skin, and consequent in-flight depressurization of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
(ASB) 747-53A2478, dated February 7, 2002, which describes procedures 
for repetitive detailed inspections to detect wear damage of the 
fuselage skin at the interface areas of the vertical stabilizer seal 
and fuselage skin, and corrective actions, if necessary. The ASB 
describes the corrective actions that include removal of the exterior 
surface finish and measurement of the wear depth if wear exists on the 
fuselage skin. If wear damage is detected, the ASB refers operators to 
the Structural Repair Manual (SRM). If no wear damage is found, the ASB 
describes procedures for refinishing the fuselage skin with BMS 10-86 
Teflon-filled coating, which would eliminate the need for repetitive 
inspections. Accomplishment of the actions specified in the service 
bulletin is intended to adequately address the identified unsafe 
condition.

[[Page 37735]]

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the service bulletin described previously.

Cost Impact

    There are approximately 1,104 Boeing Model 747 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 253 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 1 work hour per airplane to accomplish the 
proposed inspection, and that the average labor rate is $60 per work 
hour. Based on these figures, the cost impact of the proposed AD on 
U.S. operators is estimated to be $15,180, or $60 per airplane, per 
inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.
    Should an operator elect to accomplish the proposed optional 
terminating action per paragraph (b) of this AD, it would take 
approximately 6 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the optional termination action would be $360 per airplane.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect on the States, on the relationship between the national 
Government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


[sect] 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 2002-NM-85-AD.
    Applicability: Model 747 series airplanes, as listed in Boeing 
Alert Service Bulletin 747-53A2478, dated February 7, 2002; 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct wear damage of the fuselage skin in the 
area at the interface between the vertical stabilizer and fuselage 
skin, which could result in thinning and cracking of the fuselage 
skin, and consequent in-flight depressurization of the airplane; 
accomplish the following:

Inspections for Damage

    (a) Prior to the accumulation of 15,000 total flight cycles or 
within 1,200 flight cycles after the effective date of this AD, 
whichever occurs later: Perform a detailed inspection to detect 
evidence of wear damage of the fuselage skin at the interface area 
of the vertical stabilizer seal and fuselage skin, per Boeing Alert 
Service Bulletin 747-53A2478, dated February 7, 2002.
    (1) If no wear damage of the fuselage skin is detected or any 
existing blendout is within the structural repair manual (SRM) 
allowable damage limits: Repeat the detailed inspection at intervals 
not to exceed 6,000 flight cycles.
    (2) If any wear damage of the fuselage skin is detected or any 
existing blendout exceeds the allowable damage limits specified in 
the SRM: Before further flight, repair the vertical stabilizer seal 
interface and refinish the skin with BMS 10-86 Teflon filled 
coating, per the alert service bulletin. Accomplishment of the 
repair and refinishing is terminating action for the repetitive 
inspections required by paragraph (a) of this AD.

    Note 2: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Optional Terminating Action

    (b) Refinishing the fuselage skin with BMS 10-86 Teflon-filled 
coating, per Boeing Alert Service Bulletin 747-53A2478, dated 
February 7, 2002, terminates the repetitive inspections required by 
paragraph (a) of this AD.

Alternative Methods of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on May 22, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-13424 Filed 5-29-02; 8:45 am]
BILLING CODE 4910-13-P