Document ID: FAA-2010-0379-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Boeing Company Model 737-300, -400, and -500 Series Airplanes
Posted Date: 2010-04-08T04:00Z

[Federal Register Volume 75, Number 67 (Thursday, April 8, 2010)]
[Proposed Rules]
[Pages 17882-17884]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-7944]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0379; Directorate Identifier 2009-NM-210-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Model 737-300, -400, 
and -500 Series Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) that applies to all Model 737-300, -400, and -500 series 
airplanes. The existing AD currently requires inspecting to determine 
if certain carriage spindles are installed, repetitive inspections for 
corrosion and indications of corrosion on affected carriage spindles, 
and if necessary, related investigative and corrective actions. The 
existing AD also provides an optional terminating action. This proposed 
AD would mandate the optional terminating action, which would eliminate 
the need for the repetitive inspections. The proposed AD results from 
reports of corrosion found on carriage spindles that are located on the 
outboard trailing edge flaps. We are proposing this AD to detect and 
correct corrosion of the carriage spindle, which could result in 
fracture. Fracture of both the inboard and outboard carriage spindles, 
in the forward ends through the large diameters, on a flap, could 
adversely affect the airplane's continued safe flight and landing.

DATES: We must receive comments on this proposed AD by May 24, 2010.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     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.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; 
Internet https://www.myboeingfleet.com. You may review copies of the 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information 
on the availability of this material at the FAA, call 425-227-1221.

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 proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6440; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0379; 
Directorate Identifier 2009-NM-210-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On October 26, 2009, we issued AD 2009-23-10, Amendment 39-16084 
(74 FR 57564, November 9, 2009), for all Model 737-300, -400, and -500 
series airplanes. That AD requires inspecting to determine if certain 
carriage spindles are installed, repetitive inspections for corrosion 
and indications of corrosion on affected carriage spindles, and if 
necessary, related investigative and corrective actions. That AD also 
provides an optional terminating action. That AD resulted from reports 
of corrosion found on carriage spindles that are located on the 
outboard trailing edge flaps. We issued that AD to detect and correct 
corrosion of the carriage spindle, which could result in fracture. 
Fracture of both the inboard and outboard carriage spindles, in the 
forward ends through the large diameters, on a flap, could adversely 
affect the airplane's continued safe flight and landing.

Actions Since Existing AD Was Issued

    The preamble to AD 2009-23-10 explains that we consider the 
requirements ``interim action'' and were considering further 
rulemaking. We now have determined that further rulemaking is indeed 
necessary, and this proposed AD follows from that determination.
    Boeing Commercial Airplanes has received an Organization 
Designation Authorization (ODA), which replaces their previous 
designation as a Delegation Option Authorization (DOA) holder. We have 
revised paragraph (l)(3) of this AD to delegate the authority to 
approve an alternative method of

[[Page 17883]]

compliance for any repair required by this AD to the Boeing Commercial 
Airplanes ODA.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to develop on other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 2009-23-10 and would retain the requirements of the 
existing AD. This proposed AD would also mandate the optional 
terminating action, which would eliminate the need for the repetitive 
inspections.

Costs of Compliance

    There are about 482 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 150 airplanes of 
U.S. registry.
    The inspection that is required by AD 2009-23-10 and retained in 
this proposed AD takes about 2 work hours per airplane, at an average 
labor rate of $85 per work hour. Based on these figures, the estimated 
cost of the currently required inspection is $170 per airplane, per 
inspection cycle.
    The replacement of each affected carriage spindle that is proposed 
in this AD would take about 17 work hours per spindle (4 spindles per 
airplane), at an average labor rate of $85 per work hour. Required 
parts cost would be provided under warranty. Based on these figures, 
the estimated cost of the replacement specified in this proposed AD for 
U.S. operators is up to $5,780, or $1,445 per carriage spindle or up to 
$867,000.

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, Incorporation by 
reference, 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 FAA amends Sec.  39.13 by removing Amendment 39-16084 (74 FR 
57564, November 9, 2009) and adding the following new AD:

The Boeing Company: Docket No. FAA-2010-0379; Directorate Identifier 
2009-N-210-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by May 24, 
2010.

Affected ADs

    (b) This AD supersedes AD 2009-23-10, Amendment 39-16084.

Applicability

    (c) This AD applies to all The Boeing Company Model 737-300, -
400, and -500 series airplanes, certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 57: Wings.

Unsafe Condition

    (e) This AD results from reports of corrosion found on carriage 
spindles that are located on the outboard trailing edge flaps. The 
Federal Aviation Administration is issuing this AD to detect and 
correct corrosion of the carriage spindle, which could result in 
fracture. Fracture of both the inboard and outboard carriage 
spindles, in the forward ends through the large diameters, on a 
flap, could adversely affect the airplane's continued safe flight 
and landing.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

RESTATEMENT OF REQUIREMENTS OF AD 2008-15-05, AMENDMENT 39-15617: 
Inspection To Determine Affected Carriage Spindle

    (g) For all airplanes: Within 30 days after August 5, 2008 (the 
effective date of AD 2008-15-05), inspect the carriage sub-assembly 
to determine whether an affected carriage spindle with a high 
velocity oxy-fuel (HVOF) thermal coating is installed, in accordance 
with the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-57A1304, dated June 2, 2008. A review of airplane 
maintenance records is acceptable in lieu of this inspection if the 
part number and/or serial number of the carriage can be conclusively 
determined from that review. If no affected carriage spindle is 
installed, no further action is required by this paragraph.

Repetitive Inspections, Related Investigative Actions, and Corrective 
Action

    (h) For airplanes on which any affected carriage spindle was 
determined to be installed in accordance with Boeing Alert Service 
Bulletin 737-57A1304, dated June 2, 2008, as of August 5, 2008; and 
the spindle is identified in Table 2 of Boeing Service Bulletin 737-
57A1304, Revision 1, dated August 11, 2009: At the later of the 
times specified in paragraphs (h)(1) and (h)(2) of this AD, do a 
detailed inspection (or, as an option for the forward end of the 
spindle only, a borescope inspection technique may be used) of the 
spindle for corrosion and potential indications of corrosion of the 
carriage spindle, and do all applicable related investigative and 
corrective actions, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-57A1304, dated 
June 2, 2008; or Boeing Service Bulletin 737-57A1304, Revision 1, 
dated August 11, 2009. Do all applicable related investigative and 
corrective actions before further flight. Repeat the detailed 
inspection (or, as an option for the forward end of the spindle 
only, the borescope inspection) and certain related investigative 
actions (i.e., the gap-check or optional non-destructive test (NDT) 
ultrasonic inspection) at the applicable compliance times specified 
in paragraph 1.E. of Boeing Alert Service Bulletin 737-57A1304, 
dated June 2, 2008; or

[[Page 17884]]

Boeing Service Bulletin 737-57A1304, Revision 1, dated August 11, 
2009.
    (1) Within 30 days after August 5, 2008.
    (2) Within 90 days after the installation of a new HVOF-coated 
spindle.

    Note 1:  Boeing Alert Service Bulletin 737-57A1304, dated June 
2, 2008; and Boeing Service Bulletin 737-57A1304, Revision 1, dated 
August 11, 2009; reference Boeing Alert Service Bulletin 737-
57A1277, Revision 1, dated November 25, 2003; for further guidance 
on accomplishing the related investigative actions.

RESTATEMENT OF REQUIREMENTS OF AD 2009-23-10, AMENDMENT 39-16084: 
Repetitive Inspections, Related Investigative Actions, and Corrective 
Action for Certain Airplanes

    (i) For airplanes on which a carriage spindle having a serial 
number identified in Table 3 of Appendix A of Boeing Service 
Bulletin 737-57A1304, Revision 1, dated August 11, 2009, is 
installed: At the latest of the times specified in paragraphs 
(i)(1), (i)(2), and (i)(3) of this AD, as applicable, do a detailed 
inspection (or, as an option for the forward end of the spindle 
only, a borescope inspection technique may be used) of the spindle 
for corrosion and potential indications of corrosion of the carriage 
spindle, and do all applicable related investigative and corrective 
actions, in accordance with the Accomplishment Instructions of 
Boeing Service Bulletin 737-57A1304, Revision 1, dated August 11, 
2009. Do all applicable related investigative and corrective actions 
before further flight. Repeat the detailed inspection (or, as an 
option for the forward end of the spindle only, the borescope 
inspection) and related investigative actions (i.e., the gap-check 
or optional NDT ultrasonic inspection) at the applicable compliance 
times specified in paragraph 1.E. of Boeing Service Bulletin 737-
57A1304, Revision 1, dated August 11, 2009.
    (1) Within 30 days after November 24, 2009 (the effective date 
of AD 2009-23-10).
    (2) Within 90 days after the installation of a new HVOF-coated 
spindle identified in Table 3 of Appendix A of Boeing Service 
Bulletin 737-57A1304, Revision 1, dated August 11, 2009.
    (3) Within 90 days after doing an inspection in accordance with 
Boeing Alert Service Bulletin 737-57A1304, dated June 2, 2008.

Parts Installation

    (j) As of August 5, 2008, an HVOF-coated spindle without an `R' 
suffix on the serial number may be installed on an airplane provided 
the actions required by paragraph (h) or (i) of this AD, as 
applicable, are done on that spindle.

NEW REQUIREMENTS OF THIS AD: Terminating Action

    (k) Within 48 months after the effective date of this AD: 
Replace any HVOF-coated carriage spindle having a serial number 
identified in Table 2 or 3 of Appendix A of Boeing Service Bulletin 
737-57A1304, Revision 1, dated August 11, 2009, with a non-HVOF 
coated carriage spindle, or with a serviceable HVOF-coated carriage 
spindle with an `R' suffix on the serial number, in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-57A1304, dated June 2, 2008; or Boeing Service Bulletin 737-
57A1304, Revision 1, dated August 11, 2009. Replacing all affected 
carriage spindles terminates the repetitive inspections required by 
this AD.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
ATTN: Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6440; fax (425) 917-6590. Or, e-mail 
information to9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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 principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (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 the 
Boeing Commercial Airplanes Organization Delegation Authorization 
(ODA) that 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.

    Issued in Renton, Washington, on April 1, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-7944 Filed 4-7-10; 8:45 am]
BILLING CODE 4910-13-P