[Federal Register Volume 68, Number 227 (Tuesday, November 25, 2003)]
[Proposed Rules]
[Pages 66028-66030]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-29341]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-334-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 and 720 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 all Boeing Model 707 and 720 
series airplanes. This proposed AD would require inspection of the bolt 
forward of the wing front spar upper chord on the overwing support 
fittings of the inboard and outboard nacelle struts to verify that 
BACB30US type bolts are installed. If any other type of bolt is found, 
this proposed AD would require replacement with a new BACB30US type 
bolt. This action is necessary to prevent separation of the engine from 
the airplane due to stress corrosion cracking and consequent fracturing 
of the bolts. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by January 9, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-334-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-334-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 or 2000 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: Candice Gerretsen, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6428; fax (425) 917-6590.

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,

[[Page 66029]]

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-334-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-334-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that several fractured H-11 
steel bolts have been found on the underwing strut attachment fitting 
on Boeing Model 767 series airplanes. The cause of the H-11 steel bolt 
fracture was due to stress corrosion. This condition, if not corrected, 
could result in separation of the engine from the airplane due to 
stress corrosion cracking and consequent fracturing of the bolts.
    The H-11 steel bolts forward of the wing front spar upper chord on 
the overwing support fittings of the inboard and outboard nacelle 
struts on certain Boeing Model 707 and 720 series airplanes are 
identical to those on the affected Boeing Model 767 series airplanes. 
Therefore, all these airplanes may be subject to the same unsafe 
condition.

Other Relevant Rulemaking

    The FAA has previously issued AD 2000-10-51, amendment 39-11770 (65 
FR 37011, June 13, 2000), applicable to certain Boeing Model 767 series 
airplanes. That AD requires an inspection of the 767 underwing strut 
attachment fitting to determine whether H-11 steel tension bolts are 
installed in the side load underwing fittings on both struts. This 
proposed AD would not affect the current requirements of that AD.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing 707/720 Service Bulletin 
A3502, dated February 21, 2002, which describes procedures for 
performing a general visual inspection of the bolt forward of the wing 
front spar upper chord on the overwing support fittings of the inboard 
and outboard nacelle struts to verify that BACB30US type bolts are 
installed, and performing corrective actions if any other type bolt is 
found. The corrective actions consist of performing a high frequency 
eddy current inspection of the hole bore for corrosion and cracks; 
measuring the hole to verify the diameter is within the specified 
dimensions; contacting the manufacturer for corrective action if any 
crack or corrosion is found or if hole diameter is not within the 
specified dimensions; and replacing non-BACB30US type bolts with new 
BACB30US type bolts. The new BACB30US bolts are made from nickel alloy 
718 material and are not subject to stress corrosion. Accomplishment of 
the actions specified in the service bulletin is intended to adequately 
address the identified unsafe condition.

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, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that, although the service bulletin specifies 
that reviewing records is another way to verify if a BACB30US type bolt 
is installed, this proposed AD would require performing a general 
visual inspection as the only way to verify if a BACB30US type bolt is 
installed. The FAA has determined that even if a BACB30US type bolt had 
been installed as shown on the records, the BACB30US type bolt could 
have been replaced at a later time with a bolt other than a BACB30US 
type bolt. Therefore, a general visual inspection is the only way to 
verify if a BACB30US type bolt is installed.
    Operators should note that, although the 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 per 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 FAA to make such findings.

Cost Impact

    There are approximately 230 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 42 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 $65 per work hour. Based on these figures, 
the cost impact of the proposed AD on U.S. operators is estimated to be 
$2,730, or $65 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. 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.

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

[[Page 66030]]

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 adding the following new 
airworthiness directive:

Boeing: Docket 2002-NM-334-AD.

    Applicability: All Model 707 and 720 series airplanes, as listed 
in Boeing 707/720 Service Bulletin A3502, dated February 21, 2002; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent separation of the engine from the airplane due to 
stress corrosion cracking and consequent fracturing of the bolts, 
accomplish the following:

Service Bulletin References

    (a) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing 707/720 Service Bulletin 
A3502, dated February 21, 2002.

Inspection and Corrective Action

    (b) Except as provided by paragraph (c) of this AD, within 12 
months from the effective date of this AD, perform a general visual 
inspection of the bolts forward of the wing front spar upper chord 
on the overwing support fittings of the inboard and outboard nacelle 
struts to verify that BACB30US type bolts are installed, per Figure 
1 of the service bulletin.

    Note 1: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

    (c) The service bulletin specifies that reviewing records is 
another way to verify if a BACB30US type bolt is installed. However, 
this AD does not allow that alternative. The general visual 
inspection required by paragraph (b) of this AD must be accomplished 
to verify if BACB30US type bolts are installed.
    (d) If any bolt other than the BACB30US type bolts specified in 
Figure 1 of the service bulletin is found during the inspection 
required by paragraph (b) of this AD or if any bolt cannot be 
identified: Prior to further flight, do the actions specified in 
paragraphs (d)(1) and (d)(2) of this AD, per Figure 2 of the service 
bulletin.
    (1) Perform a high frequency eddy current (HFEC) inspection of 
the hole bore for cracks and corrosion and measure the hole to 
verify the diameter is within the specified dimensions. If any 
corrosion or cracking is found or if the measured hole diameter is 
not within the specified dimensions, and the service bulletin 
specifies to contact Boeing for appropriate action: Prior to further 
flight, repair per 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.
    (2) Replace the bolt with a new BACB30US type bolt per Figure 2 
of the service bulletin.

Parts Installation

    (e) As of the effective date of this AD, no person shall install 
any bolt other than a BACB30US type bolt in the locations specified 
in this AD, on any airplane.

Alternative Methods of Compliance

    (f) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Issued in Renton, Washington, on November 17, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-29341 Filed 11-24-03; 8:45 am]
BILLING CODE 4910-13-P