Airworthiness Directives; Boeing Model 720 and 720B Series Airplanes

[Federal Register Volume 71, Number 52 (Friday, March 17, 2006)]
[Rules and Regulations]
[Pages 13747-13749]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-2545]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24162; Directorate Identifier 2006-NM-031-AD; 
Amendment 39-14513; AD 2006-06-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 720 and 720B Series 
Airplanes

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

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 720 and 720B series airplanes. This AD requires repetitive 
inspections for any crack, corrosion, or sign of damage (e.g., finish 
scratches, blistering, or signs of fuel leaking) of the front spar 
upper chords under the fairing web, and repair if necessary. This AD 
results from a report that inspections required by a previous AD action 
are inadequate for Boeing Model 720 and 720B series airplanes. We are 
issuing this AD to detect and correct any crack, corrosion, or sign of 
damage of the front spar upper chords under the fairing web, which 
could result in structural failure of the wing.

DATES: This AD becomes effective April 3, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of April 3, 
2006.
    We must receive comments on this AD by May 16, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in This AD.

FOR FURTHER INFORMATION CONTACT: Candice Gerretsen, Aerospace Engineer, 
Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6428; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We previously issued AD 2004-22-24, amendment 39-13852 (69 FR 
64835, November 9, 2004), for all Boeing Model 707 and 720 series 
airplanes. That AD requires repetitive detailed and high frequency eddy 
current inspections for corrosion, signs of corrosion (e.g., blistering 
or signs of fuel leaks), and cracking, and certain related follow-on 
and investigative actions if necessary. That AD resulted from a report 
of a 31-inch crack found during a routine inspection. We issued that AD 
to find and fix corrosion and stress corrosion cracking of the upper 
and lower chords on the wing front and rear spars, which could result 
in reduced structural integrity of the wing.
    Since we issued that AD, Boeing has informed us that, for Model 720 
and 720B series airplanes, the repetitive inspections required by AD 
2004-22-24 do not adequately address the identified unsafe condition. 
The wing configuration of Model 720 and 720B series airplanes differs 
from that on Model 707 series airplanes. Model 720 series airplanes 
have an aerodynamic fairing that extends from the aircraft side of body 
to the inboard nacelle. This fairing prevents operators from doing the 
repetitive inspections intended by AD 2004-22-24. Cracks, corrosion, or 
signs of damage (e.g., finish scratches, blistering or signs of fuel 
leaking) of the front spar upper chords under the fairing web, if not 
detected and corrected, could result in structural failure of the wing.

Relevant Service Information

    We have reviewed Boeing Multi-Operator Message (MOM) 1-151636045-1, 
dated January 17, 2006. The MOM describes procedures for doing 
repetitive detailed and high-frequency eddy current (HFEC) inspections 
for any crack, corrosion, or scratch of the front spar upper chords 
under the fairing web, and repair if necessary. The HFEC inspection is 
in the area of the forward face of the vertical flange, from the side 
of the body to the inboard nacelle (front spar station 107 through 
383), from the upper fastener row to the upper edge of the chord 
flange, and the surface in between. The detailed inspection is of the 
forward face of the vertical flange from the upper edge of the chord 
flange to the lower edge of the chord flange. Accomplishing the actions 
specified in the service information is intended to adequately address 
the unsafe condition.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to detect and correct any crack, corrosion, or sign 
damage (e.g., finish scratches, blistering, or signs of fuel leaking) 
of the front spar upper chords under the fairing web, which could 
result in structural failure of the wing. This AD requires 
accomplishing the actions specified in the service information 
described previously, except as discussed under ``Differences Between 
the AD and the MOM.''

[[Page 13748]]

Differences Between the AD and the MOM

    Although the MOM specifies to contact the manufacturer for repair 
instructions, this proposed AD would require operators to do the repair 
using a method we approve.
    The MOM also specifies to contact the manufacturer for instructions 
on oversizing fasteners during restoration, but this proposed AD would 
require oversizing the fasteners in one of the following ways:
    <bullet> Using a method that we approve; or
    <bullet> Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists to make this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2006-
24162; Directorate Identifier 2006-NM-031-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it. 
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of that web 
site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov 
, or in person at the Docket Management Facility office between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays. The Docket 
Management Facility office (telephone (800) 647-5227) is located on the 
plaza level of the Nassif Building at the DOT street address stated in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after the Docket Management System receives them.

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 the 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. 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.

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):

2006-06-05 Boeing: Amendment 39-14513. Docket No. FAA-2006-24162; 
Directorate Identifier 2006-NM-031-AD.

Effective Date

    (a) This AD becomes effective April 3, 2006.

Affected ADs

    (b) Accomplishing the inspections in paragraph (f) of this AD 
terminates the repetitive inspection requirements of paragraph (c) 
of AD 2004-22-24, amendment 39-13852, for the front spar upper chord 
stations 107 through 383 only, for Boeing Model 720 and 720B series 
airplanes only.

Applicability

    (c) This AD applies to all Boeing Model 720 and 720B series 
airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report that inspections required by 
previous AD action are inadequate for Boeing Model 720 and 720B 
series airplanes. We are issuing this AD to detect and correct any 
crack, corrosion, or sign of damage (e.g., finish scratches, 
blistering, or signs of fuel leaking) of the front spar upper chords 
under the fairing web, which could result in structural failure of 
the wing.

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.

Repetitive Inspections

    (f) Within 30 days after the effective date of this AD: Do 
detailed and high-frequency eddy current (HFEC) inspections for any 
crack, corrosion, or sign of damage (e.g., finish scratches, 
blistering, or signs of fuel leaking) of the front spar upper chords 
under the fairing web; and repair if necessary; by accomplishing all 
the actions specified in Boeing Multi-Operator Message (MOM) 1-
151636045-1, dated January 17, 2006. If any

[[Page 13749]]

crack, corrosion, or sign of damage is found, do all applicable 
repairs before further flight. Repeat the inspections thereafter at 
intervals not to exceed 12 months. Where the MOM specifies to 
contact Boeing for repair instructions: Before further flight, 
repair using a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA. For a repair method to be approved 
by the Manager, Seattle ACO, as required by this paragraph, the 
Manager's approval letter must specifically refer to this AD.

    Note 1: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Instructions for Oversizing Fasteners

    (g) Where Boeing MOM 1-151636045-1, dated January 17, 2006, 
specifies to contact Boeing for appropriate action if it is 
necessary to oversize fasteners during restoration: Before further 
flight, oversize the fasteners using a method approved in accordance 
with a method approved by an Authorized Representative for the 
Boeing Commercial Airplanes Delegation Option Authorization 
Organization who has been authorized by the Manager, Seattle ACO, to 
make those findings. For a repair method to be approved, the repair 
must meet the certification basis of the airplane.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Material Incorporated by Reference

    (i) You must use Boeing Multi-Operator Message (MOM) 1-
151636045-1, dated January 17, 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 Docket Management Facility, U.S. Department 
of Transportation, 400 Seventh Street, SW., room PL-401, Nassif 
Building, Washington, DC; on the Internet at http://dms.dot.gov ; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at the NARA, call 
(202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html html .

    Issued in Renton, Washington, on March 7, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-2545 Filed 3-16-06; 8:45 am]
BILLING CODE 4910-13-U

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