Airworthiness Directives; Boeing Model 707 Airplanes and Model 720 and 720B Series Airplanes

[Federal Register Volume 72, Number 199 (Tuesday, October 16, 2007)]
[Rules and Regulations]
[Pages 58495-58497]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-20219]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28811; Directorate Identifier 2006-NM-246-AD; 
Amendment 39-15233; AD 2007-21-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 Airplanes and Model 
720 and 720B Series Airplanes

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 707 airplanes and Model 720 and 720B series airplanes. 
This AD requires identifying the material used in the elevator hinge 
support fittings of the horizontal stabilizer trailing edge, doing 
repetitive detailed inspections for cracking of the fittings and 
corrective actions if necessary, and doing an eventual terminating 
action. This AD results from a report that stress corrosion cracking of 
the elevator hinge support fittings has been discovered on several 
Model 707 airplanes. We are issuing this AD to prevent cracking of the 
elevator hinge support fittings, which could reduce the elevator 
support stiffness and lead to in-flight airframe vibration, consequent 
damage to the elevator and horizontal stabilizer, and reduced 
controllability of the airplane.

DATES: This AD becomes effective November 20, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of November 20, 
2007.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Duong Tran, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6452; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to all Boeing Model 707 
airplanes and Model 720 and 720B series airplanes. That NPRM was 
published in the Federal Register on July 30, 2007 (72 FR 41462). That 
NPRM proposed to require identifying the material used in the elevator 
hinge support fittings of the horizontal stabilizer trailing edge, 
doing repetitive detailed inspections for cracking of the fittings and 
corrective actions if necessary, and doing an eventual terminating 
action.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We received no comments on the NPRM or on the 
determination of the cost to the public.

Clarification of Costs of Compliance

    In the NPRM, the estimated cost per airplane for the proposed 
detailed inspections was correct, but the fleet cost was erroneously 
calculated to be $47,840 per inspection cycle. We have

[[Page 58496]]

corrected that amount to $99,840 per inspections cycle.

Conclusion

    We have carefully reviewed the available data and determined that 
air safety and the public interest require adopting the AD with the 
change described previously. We have determined that this change will 
neither increase the economic burden on any operator nor increase the 
scope of the AD.

Costs of Compliance

    There are about 185 airplanes of the affected design in the 
worldwide fleet. This AD affects about 52 airplanes of U.S. registry. 
The following table provides the estimated costs for U.S. operators to 
comply with this AD, at an average labor rate of $80 per work hour.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
             Action                   Work hours             Parts        Cost per  Airplane      Fleet cost
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Material verification...........  1.................  No parts needed...  $80...............  $4,160.
Detailed inspections............  24, per inspection  No parts needed...  $1,920............  $99,840, per
                                   cycle.                                                      inspection cycle.
Modification (fabrication and     6.................  Operator supplied.  $480..............  $24,960.
 installation of nutplates).
Terminating action..............  132...............  $53,078 \1\ or      $63,638 \1\ or      Up to $5,112,120.
                                                       $87,750 \2\.        $98,310 \2\.
----------------------------------------------------------------------------------------------------------------
\1\ for Group 1 airplanes.
\2\ for Group 2 airplanes.

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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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):

2007-21-15 Boeing: Amendment 39-15233. Docket No. FAA-2007-28811; 
Directorate Identifier 2006-NM-246-AD.

Effective Date

    (a) This AD becomes effective November 20, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Model 707-100 long body, -200, -100B 
long body, and -100B short body series airplanes; Model 707-300, -
300B, -300C, and -400 series airplanes; and Model 720 and 720B 
series airplanes; certificated in any category.

Unsafe Condition

    (d) This AD results from a report that stress corrosion cracking 
of the elevator hinge support fittings of the horizontal stabilizer 
trailing edge has been discovered on several Model 707 airplanes. We 
are issuing this AD to prevent cracking of the elevator hinge 
support fittings, which could reduce the elevator support stiffness 
and lead to in-flight airframe vibration, consequent damage to the 
elevator and horizontal stabilizer, and reduced controllability of 
the airplane.

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.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing 707 Alert Service Bulletin 
A3518, dated October 9, 2006.

Material Identification

    (g) Within 180 days after the effective date of this AD or 
before further flight after any horizontal stabilizer is replaced: 
Verify the type of material used in the elevator hinge support 
fittings of the horizontal stabilizer trailing edge, in accordance 
with Part 1 of the Accomplishment Instructions of the service 
bulletin, then do the requirements of paragraph (g)(1) or (g)(2) of 
this AD, as applicable. Repeat the verification before further 
flight after the replacement of any hinge support fitting.
    (1) For any hinge support fitting made of 7075-T7351 material: 
No further action is required by paragraph (h) or (i) of this AD.
    (2) For any hinge support fitting made of 7079-T6 or 7075-T6 
material: Do the actions required by paragraph (h) of this AD.

[[Page 58497]]

Repetitive Inspections, One-time Modification, and Corrective Actions

    (h) Before further flight after doing paragraph (g) of this AD, 
do a detailed inspection for cracking of the hinge support fittings 
and modify certain segments of the rib webs, in accordance with Part 
2 of the Accomplishment Instructions of the service bulletin. For 
any hinge support fitting found to be cracked or damaged, before 
further flight, do the actions required by paragraph (h)(1) or 
(h)(2) of this AD; in accordance with Part 3 of the Accomplishment 
Instructions of the service bulletin. Do all actions in accordance 
with the Accomplishment Instructions of the service bulletin; except 
where the service bulletin specifies to contact the manufacturer for 
repair procedures, this AD requires repair using a method approved 
in accordance with the procedures specified in paragraph (k) of this 
AD.
    (1) Replace the fitting with a serviceable fitting made of 7079-
T6 or 7075-T6 material. Repeat the detailed inspection thereafter at 
intervals not to exceed 180 days, until the terminating action 
required by paragraph (i) of this AD has been done.
    (2) Replace the fitting with a new, improved fitting made of 
7075-T7351 material.

Terminating Action

    (i) For all airplanes: Within 48 months after the effective date 
of this AD, replace all hinge support fittings made of 7079-T6 or 
7075-T6 material with new, improved fittings made of 7075-T7351 
material, in accordance with Part 4 of the Accomplishment 
Instructions of the service bulletin. Doing this action terminates 
all requirements of paragraphs (g) and (h) of this AD.

Parts Installation

    (j) As of the effective date of this AD, no person may install, 
on any airplane, a new or serviceable hinge support fitting made of 
7079-T6 or 7075-T6 material, unless the requirements of paragraph 
(h)(1) of this AD are accomplished.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is 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 and the approval must specifically refer to this AD.

Material Incorporated by Reference

    (l) You must use Boeing 707 Alert Service Bulletin A3518, dated 
October 9, 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 
FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington; or at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on October 5, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-20219 Filed 10-15-07; 8:45 am]
BILLING CODE 4910-13-P

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