[Federal Register: July 30, 2007 (Volume 72, Number 145)]
[Proposed Rules]
[Page 41462-41465]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30jy07-14]
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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]
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: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all Boeing Model 707 airplanes and Model 720 and 720B series
airplanes. This proposed AD would 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. This proposed 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 proposing 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: We must receive comments on this proposed AD by September 13,
2007.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to http://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Fax: (202) 493-2251.
Hand Delivery: Room W12-140 on the ground floor of the
West Building, 1200 New Jersey Avenue, SE., 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 the service information identified in this
proposed AD.
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:
Comments Invited
We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
28811; Directorate Identifier 2006-NM-246-AD'' at the
[[Page 41463]]
beginning of your comments. We specifically invite comments on the
overall regulatory, economic, environmental, and energy aspects of the
proposed AD. We will consider all comments received by the closing date
and may amend the proposed AD in light of those comments.
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 proposed 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 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 Operations office between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The
Docket Operations office (telephone (800) 647-5527) is located on the
ground floor of the West 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.
Discussion
We have received a report indicating that stress corrosion cracking
of the elevator hinge support fittings (made of 7079-T6 material) of
the horizontal stabilizer trailing edge has been discovered on several
Model 707 airplanes. In some cases, multiple fittings on one stabilizer
were found to be cracked; excessive cracking at multiple rib locations
will reduce the elevator support stiffness. This condition, if not
corrected, could lead to in-flight airframe vibration, consequent
damage to the elevator and horizontal stabilizer, and reduced
controllability of the airplane.
Relevant Service Information
We have reviewed Boeing 707 Alert Service Bulletin A3518, dated
October 9, 2006. The alert service bulletin describes procedures for:
Repetitively verifying whether or not the elevator hinge
support fittings of the horizontal stabilizer trailing edge are made of
7079-T6 or 7075-T6 material;
Modifying certain rib web segments by fabricating and
installing nutplates to create access to the web area for inspection;
Doing initial and repetitive inspections for cracking of
hinge support fittings made of 7079-T6 or 7075-T6 material, and
corrective actions if necessary; and
Eventually replacing all affected hinge support fittings
with new, improved fittings made of 7075-T7351 material.
Corrective actions include repairing or replacing any cracked fitting
with a new or serviceable fitting made of 7079-T6 or 7075-T6 material,
or with a new, improved fitting. Replacing any affected fitting with a
new, improved fitting made of 7075-T7351 material eliminates the need
for the repetitive inspections for that fitting. Accomplishing the
actions specified in the service information is intended to adequately
address the unsafe condition.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously, except as discussed under
``Differences Between the Proposed AD and Service Bulletin.''
Differences Between the Proposed AD and Service Bulletin
The alert service bulletin specifies to contact Boeing for
instructions on how to repair certain conditions, but this proposed AD
would require repairing those conditions in one of the following ways:
Using a method that we approve; or
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.
The alert service bulletin does not specify a number of work hours
for modifying the rib web segments. However, we have confirmed with
Boeing that this action should take about 6 work hours and have
estimated the costs to accomplish this proposed AD accordingly.
The alert service bulletin specifies to repeat the verification of
the hinge material at intervals not to exceed 180 days after the date
on the alert service bulletin or before further flight after the
replacement of any hinge support fitting, whichever occurs first. We
have confirmed with Boeing that repetitive verification at intervals
not to exceed 180 days is not necessary. Therefore, this proposed AD
would only require repeat verification of the hinge material before
further flight after the replacement of any hinge support fitting.
Costs of Compliance
There are about 185 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 52 airplanes of
U.S. registry. The following table provides the estimated costs for
U.S. operators to comply with this proposed AD, at an average labor
rate of $80 per work hour.
Estimated Costs
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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............ $47,840, 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\.
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\1\ For Group 1 airplanes.
\2\ For Group 2 airplanes.
[[Page 41464]]
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 proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD 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.
For the reasons discussed above, I certify that the 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. 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 proposed 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, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2007-28811; Directorate Identifier 2006-NM-
246-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by September
13, 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.
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 of 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 of
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.
[[Page 41465]]
Issued in Renton, Washington, on July 18, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-14638 Filed 7-27-07; 8:45 am]
BILLING CODE 4910-13-P