[Federal Register Volume 67, Number 120 (Friday, June 21, 2002)]
[Proposed Rules]
[Pages 42204-42207]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-15662]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-84-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 supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 747 
series airplanes, that currently requires a one-time inspection to 
identify all alloy steel bolts on the body station 1480 bulkhead 
splice, and corrective action if necessary; and provides for optional 
terminating action for certain requirements of that AD. This proposed 
AD would require accomplishment of the previously optional terminating 
action. The actions specified by this proposed AD are intended to 
prevent cracked or broken bolts, which could result in structural 
damage and rapid depressurization of the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by August 5, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-84-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-84-AD'' in the subject line and need not 
be submitted

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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: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 687-4248. 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:
     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.
     For each issue, state the specific change to the proposed 
AD being requested.
     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-84-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-84-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On April 12, 2002, the FAA issued AD 2002-08-10, amendment 39-12718 
(67 FR 19641, April 23, 2002), applicable to certain Boeing Model 747 
series airplanes, to require a one-time inspection to identify all 
alloy steel bolts on the body station (BS) 1480 bulkhead splice, and 
corrective action if necessary. That action also provides for optional 
terminating action for certain requirements. That action was prompted 
by reports of broken alloy steel bolts on the BS 1480 bulkhead splice. 
Alloy steel bolts have been found to be susceptible to stress corrosion 
and consequent cracking and breakage. The requirements of that AD are 
intended to detect and correct cracked or broken bolts, which could 
result in structural damage and rapid depressurization of the airplane.

Actions Since Issuance of Previous Rule

    In the preamble to AD 2002-08-10, the FAA indicated that the 
actions required by that AD were considered ``interim action'' and that 
further rulemaking action was being considered. The FAA now has 
determined that further rulemaking action is indeed necessary, and this 
proposed AD follows from that determination.

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 supersede AD 2002-08-10 to continue to require a one-
time inspection to identify all alloy steel bolts on the BS 1480 
bulkhead splice, and corrective action if necessary and to require the 
previously optional replacement of all alloy steel bolts on the splice, 
which would terminate the requirements of the AD. The actions would be 
required to be accomplished in accordance with Boeing Alert Service 
Bulletin 747-53A2477, described previously, except as discussed below.

Differences Between Proposed AD and Alert Service Bulletin

    Although the alert service bulletin specifies that the manufacturer 
may be contacted for disposition of certain repair conditions, this 
proposed AD would require the repair of those conditions to be 
accomplished in accordance with a method approved by the FAA, or per 
data meeting the type certification basis of the airplane approved by a 
Boeing Company Designated Engineering Representative who has been 
authorized by the Manager, Seattle Aircraft Certification Office, to 
make such findings.

Explanation of Change Made to Existing Requirements

    The FAA has clarified the inspection requirement contained in AD 
2002-08-10. Whereas that AD specifies a detailed visual inspection, 
this proposed AD specifies a detailed inspection. Additionally, a note 
is included in this proposed AD to define that inspection.

Cost Impact

    There are approximately 582 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 178 airplanes of U.S. registry 
would be affected by this proposed AD.
    The inspection that is currently required by AD 2002-08-10 takes 
approximately 58 work hours per airplane to accomplish (including 
access and close), at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of the currently required actions on 
U.S. operators is estimated to be $619,440, or $3,480 per airplane.
    The terminating action proposed in this AD action would take 
approximately 86 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts could cost as much as 
approximately $1,414 per airplane. Based on these figures, the cost 
impact of the proposed requirements of this AD on U.S. operators is 
estimated to be $1,170,172, or $6,574 per airplane.
    The cost impact figures discussed above are 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.

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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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-12718 (67 FR 
19641, April 23, 2002), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2002-NM-84-AD. Supersedes AD 2002-08-10, Amendment 
39-12718.

    Applicability: Model 747 series airplanes, certificated in any 
category, line numbers 1 through 750 inclusive, excluding airplanes 
on which the bulkhead splice areas have been modified in accordance 
with Plan ``B'' of AD 2001-11-06, amendment 39-12248.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (g) 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 prevent cracked or broken bolts, which could result in 
structural damage and rapid depressurization of the airplane, 
accomplish the following:

Restatement of Certain Requirements of AD 2002-08-10

Inspection

    (a) At the applicable time specified by paragraph (a)(1) or 
(a)(2) of this AD: Inspect the BS 1480 bulkhead splice to identify 
all alloy steel bolts by using a magnet or, if applicable, detailed 
methods, in accordance with Boeing Alert Service Bulletin 747-
53A2477, dated February 28, 2002.

    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.''

    (1) For airplanes on which the bulkhead splice inspection 
specified by AD 2001-11-06 has NOT been accomplished within 15 
months before May 8, 2002 (the effective date of AD 2002-08-10, 
amendment 39-12718): Inspect within 90 days after May 8, 2002.
    (2) For airplanes on which the bulkhead splice inspection 
specified by AD 2001-11-06 HAS been accomplished within 15 months 
before May 8, 2002: Inspect within 18 months since the most recent 
inspection.

Corrective Actions

    (b) For each alloy steel bolt found during the inspection 
required by paragraph (a) of this AD: Before further flight, inspect 
those bolts using torque test or ultrasonic methods to detect cracks 
or breakage, in accordance with Boeing Alert Service Bulletin 747-
53A2477, dated February 28, 2002, except as required by paragraph 
(e) of this AD.
    (1) For each uncracked and unbroken alloy steel bolt found: 
Repeat the inspection specified by paragraph (b) of this AD 
thereafter at least every 18 months, until the terminating action of 
paragraph (d) of this AD is accomplished.
    (2) For any cracked or broken bolt found: Before further flight, 
replace it with an Inconel 718 bolt. Such replacement terminates the 
requirements of this AD for that bolt only.
    (3) If any cracked or broken bolt is found anywhere along the 
splice during any inspection required by paragraph (b) of this AD: 
Before further flight, reinspect, using ultrasonic methods, any 
remaining alloy steel bolts that were initially inspected using 
torque test methods, and replace any cracked or broken bolt with an 
Inconel 718 bolt. Such replacement terminates the requirements of 
this AD for that bolt only.

Magnetic Particle Inspection

    (c) Plan ``A'' inspections required by AD 2001-11-06 are 
acceptable for compliance with the inspection requirements of 
paragraph (b) of this AD, provided a magnetic particle inspection 
and applicable corrective actions are performed on any alloy steel 
bolt removed during any Plan ``A'' inspection before the bolt is 
reinstalled. The magnetic particle inspection and corrective actions 
must be performed in accordance with Boeing Alert Service Bulletin 
747-53A2477, dated February 28, 2002, except as required by 
paragraph (e) of this AD.

New Requirements of this AD

Terminating Action

    (d) Within 6 years after the effective date of this AD: Replace 
all alloy steel bolts in the BS 1480 bulkhead splice with Inconel 
718 bolts, in accordance with Boeing Alert Service Bulletin 747-
53A2477, dated February 28, 2002, except as required by paragraph 
(e) of this AD. Replacement of all alloy steel bolts terminates the 
requirements of this AD.

Exceptions to Service Information

    (e) If Boeing Alert Service Bulletin 747-53A2477, dated February 
28, 2002, specifies to contact Boeing for appropriate action: Before 
further flight, repair in accordance with a method approved by the 
Manager, Seattle Aircraft Certification Office (ACO), FAA; or per 
data meeting the type certification basis of the airplane approved 
by a Boeing Company Designated Engineering Representative who has 
been authorized by the Manager, Seattle ACO, to make such findings. 
For a repair method to be approved, the approval must specifically 
reference this AD.

Spares

    (f) As of the effective date of this AD, no person may install 
an alloy steel bolt on the BS 1480 bulkhead splice on any airplane.

Alternative Methods of Compliance

    (g) 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 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

    (h) 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

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a location where the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on June 14, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-15662 Filed 6-20-02; 8:45 am]
BILLING CODE 4910-13-P