[Federal Register: August 16, 2007 (Volume 72, Number 158)]
[Proposed Rules]
[Page 45961-45963]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16au07-21]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-28990; Directorate Identifier 2007-NM-033-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200, -200CB, and -300
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 certain Boeing Model 757-200, -200CB, and -300 series airplanes.
This proposed AD would require repetitive inspections for cracks of the
intercostal tee clips and attachment fasteners at the number 3 and
number 4 doorstops of the passenger door cutouts, or repetitive
inspections for cracks of the intercostal tee clips; and related
investigative/ corrective actions if necessary. This proposed AD also
provides an optional terminating action for the repetitive inspections.
This proposed AD results from reports of cracked intercostal tee clips
at the number 3 and number 4 doorstops of the passenger door cutouts.
We are proposing this AD to detect and correct cracking of the tee
clips, which could result in additional stress on the adjacent tee
clips, surrounding intercostals, edge frame, door structure and
doorstops. This additional stress could cause further cracking or
breaking of the tee clips, which could result in failure of the door to
seal and consequent rapid decompression of the airplane.
DATES: We must receive comments on this proposed AD by October 1, 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: Dennis Stremick, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6450; 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-
28990; Directorate Identifier 2007-NM-033-AD'' at the 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 eight reports indicating that cracked intercostal
tee clips were found at the number 3 and number 4 doorstops of the
passenger door cutouts on certain Boeing Model 757-200, -200CB, and -
300 series airplanes. These cracks were found during normal maintenance
checks on passenger doorway number 4, at the aft edge frame of body
station 1681.8 on the left and right sides. On two airplanes, cracks
were found on the intercostal tee clips at both the number 3 and number
4 doorstops. The cracks occurred in the radius area of the tee clip,
between the horizontal and vertical flange. The number of flight cycles
for these airplanes was between 22,700 and 25,000. The cracks in the
tee clips are attributed to a preload of the tee clip; continued flight
with cracks in the tee clips can place additional stress on the
adjacent tee clips, surrounding intercostals, edge frame, door
structure and doorstops. This additional stress, if not corrected,
could cause further cracking or breaking of the tee clips, which could
result in failure of the door to seal and consequent rapid
decompression of the airplane.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 757-53A0093, dated
November 8, 2006. The service bulletin describes procedures for
repetitive detailed inspections with a borescope for cracks of the
intercostal tee clips; or repetitive detailed inspections for cracks of
the intercostal tee clips and attachment fasteners at the number 3 and
number 4 doorstops of the passenger door cutouts after the galley/
lavatory has been removed; and related investigative and corrective
actions if necessary. The related investigative and corrective actions
include the following:
[[Page 45962]]
Condition 1: For airplanes on which any tee clip for only
door stop intercostal number 3 is cracked or broken; the procedures
specify replacing any cracked tee clip with a new tee clip and
contacting Boeing before further flight. In addition, the procedures
describe inspections of the door stop fittings on the forward side of
body station 1681.8 edge frame; the inner chord, web, and outer chord;
the number 4 door structure including the door stop fittings and stop
beams above and below the cracked tee clips; and the number 4 aft door
frame.
Condition 2: For airplanes on which any tee clip for only
door stop intercostal number 4 is cracked or broken; the procedures
specify replacing any cracked tee clip with a new tee clip and
contacting Boeing before further flight. In addition, the procedures
describe inspections of the tee clip and intercostal for cracking at
door stop intercostal number 5; and from door stop number 3 through
number 5: Inspecting the door stop fittings on the forward side of the
body station 1681.8 edge frame; the inner chord, web, and outer chord;
the number 4 door structure including the door stop fittings and stop
beams above and below the cracked tee clips; and the number 4 aft door
frame.
Condition 3: For airplanes on which both tee clips for
only door stop intercostal numbers 3 and 4 are cracked or broken; the
procedures specify replacing the cracked tee clip with a new tee clip
and contacting Boeing before further flight. In addition, the
procedures describe inspections of the fasteners; the door stop
fittings on the forward side of the body station 1681.8 edge frame; the
inner chord, web, and outer chord; the number 4 door structure
including the door stop fittings and stop beams above and below the
cracked tee clips; for airplanes with greater than 28,000 flight
cycles, the fasteners and the fillet radius of the stop fittings; and
the number 4 aft door frame.
If cracked or broken tee clips are found during any inspection, the
procedures describe inspecting the tee clip and intercostal for cracks
of the door stop intercostal number 2 and doing inspections from door
stop numbers 2 through 5. The additional inspections are for cracks of
the door stop fittings; the inner chord, web, and outer chord; and the
body station 1681.8 edge frame.
Replacing both tee clips on the left and right sides with new tee
clips would eliminate the need for the repetitive inspections.
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
``Difference Between the Proposed AD and Service Information.''
Difference Between the Proposed AD and Service Information
The service bulletin specifies to contact the manufacturer 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.
Costs of Compliance
There are about 912 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 324 airplanes of
U.S. registry.
The proposed detailed inspection, if accomplished, would take about
2 work hours per airplane, at an average labor rate of $80 per work
hour. Based on these figures, the estimated cost of the inspections
proposed by this AD is $51,840, or $160 per airplane, per inspection
cycle.
The proposed borescope inspection, if accomplished, would take
about 3 work hours per airplane, at an average labor rate of $80 per
work hour. Based on these figures, the estimated cost of the
inspections proposed by this AD is $77,760, or $240 per airplane, per
inspection cycle.
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-2007-28990; Directorate Identifier 2007-NM-
033-AD.
[[Page 45963]]
Comments Due Date
(a) The FAA must receive comments on this AD action by October
1, 2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 757-200, -200CB, and -300
series airplanes, certificated in any category; as identified in
Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006.
Unsafe Condition
(d) This AD results from reports of cracked intercostal tee
clips at the number 3 and number 4 doorstops of the passenger door
cutouts. We are issuing this AD to detect and correct cracking of
the tee clips, which could result in additional stress on the
adjacent tee clips, surrounding intercostals, edge frame, door
structure and doorstops. This additional stress could cause further
cracking or breaking of the tee clips, which could result in failure
of the door to seal and consequent rapid decompression 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.
Repetitive Inspections/Investigative and Corrective Actions
(f) Before the accumulation of 20,000 total flight cycles or
within 3,000 flight cycles after the effective date of this AD,
whichever is later: Do the applicable inspection specified in
paragraph (f)(1) or (f)(2) of this AD by doing all the actions
including all applicable related investigative (additional detailed
inspections if necessary) and corrective actions; except as provided
by paragraph (g) of this AD; in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 757-53A0093, dated
November 8, 2006. All related investigative and corrective actions
must be done before further flight.
(1) Do a detailed inspection for cracks of the intercostal tee
clips and attachment fasteners at the number 3 and number 4
doorstops of the passenger door cutouts. Repeat the inspection
thereafter at intervals not to exceed 3,000 flight cycles until
accomplishment of the terminating action specified in paragraph (h)
of this AD.
(2) Do a detailed inspection with a borescope for cracks of the
intercostal tee clips. Repeat the inspection thereafter at intervals
not to exceed 3,000 flight cycles until accomplishment of the
terminating action specified in paragraph (h) of this AD.
(g) If any cracked structure is found during any inspection
required by this AD, and the Accomplishment Instructions of Boeing
Alert Service Bulletin 757-53A0093, dated November 8, 2006, specify
to contact Boeing for appropriate action: Before further flight,
repair any cracked structure using a method approved in accordance
with the procedures specified in paragraph (i)(2) of this AD.
Optional Terminating Action
(h) Replacing both intercostal tee clips on the left and right
sides with new tee clips in accordance with Part 3 of the
Accomplishment Instructions of Boeing Alert Service Bulletin 757-
53A0093, dated November 8, 2006, terminates the repetitive
inspections required by this AD.
Alternative Methods of Compliance (AMOCs)
(i)(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) 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.
(3) 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.
Issued in Renton, Washington, on August 2, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-16103 Filed 8-15-07; 8:45 am]
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