[Federal Register Volume 67, Number 78 (Tuesday, April 23, 2002)]
[Rules and Regulations]
[Pages 19641-19644]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-9570]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-69-AD; Amendment 39-12718; AD 2002-08-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

[[Page 19642]]


ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 747 series airplanes. This action 
requires a one-time inspection to identify all alloy steel bolts on the 
body station 1480 bulkhead splice, and corrective action if necessary. 
This action provides for optional terminating action for certain 
requirements of this AD. This action is necessary to detect and correct 
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: Effective May 8, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 8, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before June 24, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-69-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 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-69-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 this AD 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; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: 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.

SUPPLEMENTARY INFORMATION: The FAA has received reports of broken alloy 
steel bolts on the body station (BS) 1480 bulkhead splice on Boeing 
Model 747 series airplanes. This splice connects the upper and lower 
pieces of the BS 1480 bulkhead and the overwing longeron. The maximum 
number of broken bolts found on an airplane was 10; that airplane was 
shown to be unable to withstand limit load. Broken splice bolts were 
found on one airplane with only 6,229 total flight cycles and 37,440 
total flight hours. All of the broken splice bolts found on the 
airplanes were made from H11 alloy steel, which has been found to be 
susceptible to stress corrosion and consequent cracking and breakage. 
Cracked or broken bolts on the bulkhead splice, if not corrected, could 
result in structural damage and rapid depressurization of the airplane.

Related AD

    AD 2001-11-06, amendment 39-12248 (66 FR 31124, June 11, 2001), 
applicable to certain Boeing Model 747 series airplanes, requires, 
among other things, repetitive inspections to detect cracking of 
certain areas of the BS 1480 bulkhead. AD 2001-11-06 focuses more on 
the skin splice plate and outer chord splice fitting than the mating 
bolts. However, airplanes on which the bulkhead splice areas have been 
modified in accordance with AD 2001-11-06 are excluded from the 
applicability of this AD. Also, inspections of the bulkhead splice area 
in accordance with AD 2001-11-06 meet the inspection requirements of 
this AD, provided that the bolts are inspected using magnetic particle 
methods before they are reinstalled.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
747-53A2477, dated February 28, 2002, which describes procedures for a 
one-time inspection using a magnet to identify all alloy steel bolts on 
the BS 1480 bulkhead splice, and an inspection using torque test or 
ultrasonic methods of all alloy steel bolts to determine if any are 
cracked or broken. Corrective actions include replacement of any 
cracked or broken alloy steel bolts with Inconel 718 bolts; an 
ultrasonic inspection--if any bolt on the splice was found cracked--of 
any remaining alloy steel bolt that was inspected using torque test 
methods; and repetitive inspections of the remaining serviceable alloy 
steel bolts. The alert service bulletin specifies that replacement of 
all alloy steel bolts on the splice eliminates the need for the 
corrective actions for the alloy steel bolts.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to detect and correct cracked or broken bolts on the BS 
1480 bulkhead splice, which could result in structural damage and rapid 
depressurization of the airplane. This action is intended to address 
the identified unsafe condition. This AD requires accomplishment of the 
actions specified in the alert service bulletin described previously, 
except as described below.

Differences Between AD and Alert Service Bulletin

    Although the alert service bulletin specifies that the manufacturer 
may be contacted for disposition of certain repair conditions, this AD 
requires 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.

Interim Action

    This is considered to be interim action. The FAA is currently 
considering requiring the replacement of all alloy steel bolts on the 
BS 1480 bulkhead splice, which would terminate the torque tests and 
ultrasonic inspections required by this AD. However, the planned 
compliance time for this action is long enough to provide adequate 
notice and opportunity for prior public comment.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire.

[[Page 19643]]

Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    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 what specific change to the AD is 
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 rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket 2002-NM-69-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding the following new 
airworthiness directive:

2002-08-10  Boeing: Amendment 39-12718. Docket 2002-NM-69-AD.

    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 detect and correct cracked or broken alloy steel bolts on the 
body station (BS) 1480 bulkhead splice and consequent structural 
damage and rapid depressurization of the airplane, accomplish the 
following:

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 
visual methods, in accordance with Boeing Alert Service Bulletin 
747-53A2477, dated February 28, 2002.

    Note 2: For the purposes of this AD, a detailed visual 
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 the effective date of this AD: Inspect within 90 days 
after the effective date of this AD.
    (2) For airplanes on which the bulkhead splice inspection 
specified by AD 2001-11-06 HAS been accomplished within 15 months 
before the effective date of this AD: 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 optional 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.

[[Page 19644]]

Optional Terminating Action

    (d) Replacement of 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, 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 in 
accordance with 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 by the 
Manager, Seattle ACO, as required by this paragraph, the Manager's 
approval letter 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 a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (i) Except as required by paragraph (e) of this AD: The actions 
must be done in accordance with Boeing Alert Service Bulletin 747-
53A2477, dated February 28, 2002. This incorporation by reference 
was approved by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

Effective Date

    (j) This amendment becomes effective on May 8, 2002.

    Issued in Renton, Washington, on April 12, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-9570 Filed 4-22-02; 8:45 am]
BILLING CODE 4910-13-U