[Federal Register: March 4, 2003 (Volume 68, Number 42)]
[Proposed Rules]
[Page 10188-10190]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04mr03-17]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-219-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to all Boeing Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes, that currently
requires repetitive inspections to find cracks, fractures, or corrosion
of each carriage spindle of the left and right outboard mid-flaps; and
corrective action, if necessary. This action would mandate the
previously optional overhaul or replacement of the carriage spindles,
which would end the repetitive inspections required by the existing AD.
The actions specified by the proposed AD are intended to prevent severe
flap asymmetry due to fractures of the carriage spindles on an outboard
mid-flap, which could result in reduced control or loss of
controllability of the airplane. This action is intended to address the
identified unsafe condition.
DATES: Comments must be received by April 18, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2002-NM-219-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:
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must
contain ``Docket No. 2002-NM-219-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 for Windows 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: Sue Lucier, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6438; 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, 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-219-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-219-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On October 22, 2002, the FAA issued AD 2002-22-05, amendment 39-
12929 (67 FR 66316, October 31, 2002), applicable to all Boeing Model
737-100, -200, -200C, -300, -400, and -500 series airplanes, to require
repetitive inspections to find cracks, fractures, or corrosion of each
carriage spindle of the left and right outboard mid-flaps; and
corrective action, if necessary. That action also provides for an
optional action of overhaul or replacement of the carriage spindles,
which would extend the repetitive inspection interval. The requirements
of that AD are intended to prevent severe flap asymmetry due to
fractures of the carriage spindles on an outboard mid-flap, which could
result in reduced control or loss of controllability of the airplane.
Actions Since Issuance of Previous Rule
In the preamble to AD 2002-22-05, we specified that the actions
required by that AD were considered ``interim action'' and that we were
considering requiring the optional overhaul or replacement of the
carriage spindles. We have now determined that it is necessary to
require the overhaul or replacement of the carriage spindles, and this
proposed AD follows from that determination.
[[Page 10189]]
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
737-57A1218, Revision 3, dated July 25, 2002. (Boeing Alert Service
Bulletin 737-57A1277, dated July 25, 2002, was referenced in the
existing AD as the appropriate source of service information for
accomplishment of the inspections to find discrepancies of each
carriage spindle, and corrective action, if necessary.) Service
Bulletin 737-57A1218 describes procedures for replacement or overhaul
of each carriage spindle (two on each flap) of the left and right
outboard mid-flaps. Such replacement or overhaul would end the
repetitive inspections specified in Service Bulletin 737-57A1277.
Accomplishment of the actions specified in Service Bulletin 737-57A1218
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 supersede AD 2002-22-05 to continue to require
repetitive inspections to find cracks, fractures, or corrosion of each
carriage spindle of the left and right outboard mid-flaps; and
corrective action, if necessary. This new action would mandate the
previously optional overhaul or replacement of the carriage spindles,
which would end the repetitive inspections required by the existing AD.
The actions would be required to be accomplished in accordance with
Service Bulletin 737-57A1218, Revision 3, except as discussed below.
Difference Between Service Information and Proposed AD
The service bulletin references Boeing 737 Overhaul Manual, chapter
57-53-35 (for Model 737-100, -200, and -200C series airplanes), and
chapter 57-53-36 (for Model 737-300, -400, and -500 series airplanes),
for the procedures for the overhaul specified in the proposed AD. Those
chapters reference Boeing 737 Standard Overhaul Practices Manual (SOPM)
chapter 20-42-09, titled, ``Electro-deposited Nickel Plating,'' for the
nickel plating procedures. The amount of nickel plating required to
restore functional capability and part geometry have made certain
processing steps critical within the plating process for the spindle
region of the flap carriage. The processing steps are specified in
paragraph (d) of this AD, and are necessary to prevent structural
failures of the carriage spindle due to hydrogen embrittlement. These
processing steps have been identified by the manufacturer as critical
details of the plating process, and Boeing Alert Service Bulletin 737-
57A1218, Revision 3, is being revised to reflect these requirements.
Cost Impact
There are approximately 3,132 airplanes of the affected design in
the worldwide fleet. The FAA estimates that 1,384 airplanes of U.S.
registry would be affected by this proposed AD.
The inspections that are currently required by AD 2002-22-05 take
approximately 10 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the currently required inspections on U.S. operators is
estimated to be $830,400, or $600 per airplane.
It would take approximately 2 work hours per airplane to accomplish
the new detailed inspection, at an average labor rate of $60 per work
hour. Based on these figures, the cost impact of the inspection
proposed by this AD on U.S. operators is estimated to be $166,080, or
$120 per airplane, per inspection cycle.
Should an operator be required to accomplish the overhaul, it would
take approximately 32 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Based on these figures, the
cost impact of the overhaul proposed by this AD is estimated to be
$1,920 per airplane.
Should an operator be required to accomplish the replacement, it
would take approximately 32 work hours per airplane to accomplish, at
an average labor rate of $60 per work hour. Required parts would cost
approximately $45,000 per carriage spindle. Based on these figures, the
cost impact of the replacement proposed by this AD is estimated to be
$46,920 per spindle, per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the current or proposed
requirements of this AD action, and that no operator would accomplish
those actions in the future if this 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 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 removing amendment 39-12929 (67 FR
66316, October 31, 2002), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 2002-NM-219-AD. Supersedes AD 2002-22-05, Amendment
39-12929.
Applicability: All Model 737-100, -200, -200C, -300, -400, and -
500 series airplanes; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
[[Page 10190]]
alternative method of compliance in accordance with paragraph (f) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent severe flap asymmetry due to fractures of the
carriage spindles on an outboard mid-flap, which could result in
reduced control or loss of controllability of the airplane,
accomplish the following:
Restatement of Requirements of AD 2002-22-05
Repetitive Inspections
(a) Do general visual and nondestructive test (NDT) inspections
of each carriage spindle (two on each flap) of the left and right
outboard mid-flaps to find cracks, fractures, or corrosion at the
later of the times specified in paragraphs (a)(1) and (a)(2) of this
AD, as applicable, per the Work Instructions of Boeing Alert Service
Bulletin 737-57A1277, dated July 25, 2002. Repeat the inspections at
least every 180 days until paragraph (b) or (c) of this AD is done,
as applicable.
(1) Before the accumulation of 12,000 total flight cycles or 8
years in-service on new or overhauled carriage spindles, whichever
is first.
(2) Within 90 days after November 15, 2002 (the effective date
of AD 2002-22-05, amendment 39-12929).
Note 2: 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.''
Corrective Action
(b) If any crack, fracture, or corrosion is found during any
inspection required by paragraph (a) of this AD: Before further
flight, do the applicable actions for that spindle as specified in
paragraph (b)(1) or (b)(2) of this AD, per the Work Instructions of
Boeing Alert Service Bulletin 737-57A1277, dated July 25, 2002. Then
repeat the inspections required by paragraph (a) of this AD every
12,000 flight cycles or 8 years, whichever is first, on the
overhauled or replaced spindle only.
(1) If any corrosion is found in the carriage spindle, overhaul
the spindle.
(2) If any crack or fracture is found in the carriage spindle,
replace with a new or overhauled carriage spindle.
Note 3: Although Boeing Alert Service Bulletin 737-57A1277,
dated July 25, 2002, recommends that operators report inspection
findings of any crack or fracture in the carriage spindle to the
manufacturer, this AD does not contain such a reporting requirement.
New Requirements of This AD
Overhaul or Replacement
(c) Overhaul or replace, as applicable, all four carriage
spindles (two on each flap) of the left and right outboard mid-flaps
at the applicable time specified in paragraph (c)(1) or (c)(2) of
this AD, per the Work Instructions of Boeing Alert Service Bulletin
737-57A1218, Revision 3, dated July 25, 2002. Then repeat the
applicable overhaul or replacement every 12,000 flight cycles or 8
years, whichever is first. Accomplishment of this paragraph ends the
repetitive inspections required by paragraphs (a) and (b) of this
AD.
(1) For Model 737-100, -200, and -200C series airplanes,
overhaul or replace at the later of the times specified in
paragraphs (c)(1)(i) and (c)(1)(ii) of this AD.
(i) Before the accumulation of 12,000 total flight cycles on the
carriage spindle, or within 8 years since overhaul of the spindle or
installation of a new spindle, whichever is first.
(ii) Within 1 year after the effective date of this AD.
(2) For Model 737-300, -400, and -500 series airplanes, overhaul
or replace at the later of the times specified in paragraphs
(c)(2)(i) and (c)(2)(ii) of this AD.
(i) Before the accumulation of 12,000 total flight cycles on the
carriage spindle, or within 8 years since overhaul of the spindle or
installation of a new spindle, whichever is first.
(ii) Within 2 years after the effective date of this AD.
(d) During accomplishment of any overhaul required by paragraph
(c) of this AD, use the procedures specified in paragraphs (d)(1)
and (d)(2) of this AD during application of the nickel plating of
the carriage spindle in addition to those specified in Boeing 737
Standard Overhaul Practices Manual, Chapter 20-42-09.
(1) Begin the hydrogen embrittlement relief bake within 10 hours
after application of the plating, or less than 24 hours after the
current was first applied to the part, whichever is first.
(2) The maximum thickness of the nickel plating that is
deposited in any one plating/baking cycle must not exceed 0.020
inch.
(e) Overhauling or replacing the carriage spindles before the
effective date of this AD, in accordance with Boeing Alert Service
Bulletin 737-57A1277, dated July 25, 2002, is considered acceptable
for compliance with the overhaul or replacement specified in
paragraph (c) of this AD.
Alternative Methods of Compliance
(f) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle ACO. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
Note 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(g) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on February 26, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-4990 Filed 3-3-03; 8:45 am]
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