Document ID: FAA-2016-9068-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2016-09-08T04:00Z

[Federal Register Volume 81, Number 174 (Thursday, September 8, 2016)]
[Proposed Rules]
[Pages 62022-62024]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-21148]

 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 81, No. 174 / Thursday, September 8, 2016 / 
Proposed Rules  

[[Page 62022]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9068; Directorate Identifier 2016-NM-067-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 737-300, -400, and -500 series 
airplanes. This proposed AD was prompted by reports of cracks in 
horizontal stabilizer lower skins. This proposed AD would require 
repetitive inspections for cracking of the horizontal stabilizer lower 
skin, and corrective actions if necessary. This proposed AD also 
provides actions that would terminate certain repetitive inspections. 
We are proposing this AD to detect and correct cracks in horizontal 
stabilizer lower skins resulting in reduced local stiffness of the 
horizontal stabilizer, which can cause heavy vibration leading to loss 
of structural integrity of the horizontal stabilizer.

DATES: We must receive comments on this proposed AD by October 24, 
2016.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, 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: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Boeing 
Commercial Airplanes, Attention: Data & Services Management, P.O. Box 
3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, 
extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. 
You may view this referenced service information at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information 
on the availability of this material at the FAA, call 425-227-1221. It 
is also available on the Internet at http://www.regulations.gov by 
searching for and locating Docket No. FAA-2016-9068.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-
9068; 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 (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Gaetano Settineri, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6577; fax: 425-917-6590; email: gaetano.settineri@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2016-9068; 
Directorate Identifier 2016-NM-067-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

    We have received reports of approximately 90 cracks in horizontal 
stabilizer lower skins with most of them occurring between stabilizer 
station (SSTA) 111.10 and 166.30. Ten operators reported cracks on 18 
airplanes outside this range with 14 of them inboard of SSTA 111.10. 
The cracks range in length from 0.25 inch to 3.75 inches, and the 
airplanes had between 12,670 and 69,569 total flight cycles.
    The cracks started on the outer surface of the horizontal 
stabilizer lower skin where the chem-milled edge aligns with the edge 
of the lower flange of the rear spar. The cracks grew parallel to the 
rear spar. High secondary bending stresses due to compression buckling 
of the skins and sonic fatigue can cause the cracks to grow. Cracks 
have also started from the fastener line nearest the chem-milled step.
    This horizontal stabilizer lower skin cracking, if not corrected, 
could result in reduced local stiffness of the horizontal stabilizer, 
which can cause heavy vibration leading to loss of structural integrity 
of the horizontal stabilizer.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Special Attention Service Bulletin 737-55-1059, 
Revision 1, dated April 6, 2016 (``SASB 737-55-1059 R1''). The service 
information describes procedures for doing inspections of the 
horizontal stabilizer lower skin, and repairs. The service information 
also describes procedures for doing actions that would terminate 
certain repetitive inspections. This service information is reasonably 
available because the interested parties have access to it through 
their normal course of business or by the means identified in the 
ADDRESSES section.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information

[[Page 62023]]

and determined the unsafe condition described previously is likely to 
exist or develop in other products of these same type designs.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously, except as discussed 
under ``Differences Between this Proposed AD and the Service 
Information. For information on the procedures and compliance times, 
see this service information at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2016-9068.
    The phrase ``related investigative actions'' is used in this 
proposed AD. Related investigative actions are follow-on actions that 
(1) are related to the primary action, and (2) further investigate the 
nature of any condition found. Related investigative actions in an AD 
could include, for example, inspections.
    The phrase ``corrective actions'' is used in this proposed AD. 
Corrective actions correct or address any condition found. Corrective 
actions in an AD could include, for example, repairs.

Differences Between This Proposed AD and the Service Information

    SASB 737-55-1059 R1, specifies to contact the manufacturer for 
certain instructions, but this proposed AD would require accomplishment 
of repair methods, modification deviations, and alteration deviations 
in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Costs of Compliance

    We estimate that this proposed AD affects 270 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost     Cost per product         operators
----------------------------------------------------------------------------------------------------------------
Inspection.......................  4 work-hours x $85             $0   $340 per inspection   $91,800 per
                                    per hour = $340 per                 cycle.                inspection cycle.
                                    inspection cycle.
----------------------------------------------------------------------------------------------------------------

                                      Estimated Costs for Optional Actions
----------------------------------------------------------------------------------------------------------------
                 Action                            Labor cost             Parts cost        Cost per product
----------------------------------------------------------------------------------------------------------------
Modification...........................  Up to 51 work-hours per                $721   Up to $5,056 per
                                          stabilizer x $85 per hour =                   stabilizer.
                                          $4,335.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary repairs that 
would be required based on the results of the proposed inspection. We 
have no way of determining the number of aircraft that might need these 
repairs:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                  Action                            Labor cost           Parts cost        Cost per product
----------------------------------------------------------------------------------------------------------------
Skin slice repair........................  Up to 438 work-hours x $85            $0  Up to $37,230.
                                            per hour = $37,230.
External doubler repair..................  26 work-hours x $85 per               $0  $2,210.
                                            hour = $2,210.
----------------------------------------------------------------------------------------------------------------

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 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 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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

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

0
1. The authority citation for part 39 continues to read as follows:

[[Page 62024]]

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

The Boeing Company: Docket No. FAA-2016-9068; Directorate Identifier 
2016-NM-067-AD.

(a) Comments Due Date

    We must receive comments by October 24, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-300, -400, and -
500 series airplanes, certificated in any category, as identified in 
Boeing Special Attention Service Bulletin 737-55-1059, Revision 1, 
dated April 6, 2016 (``SASB 737-55-1059 R1'').

(d) Subject

    Air Transport Association (ATA) of America Code 55; Horizontal 
stabilizer.

(e) Unsafe Condition

    This AD was prompted by reports of cracks in horizontal 
stabilizer lower skins. We are issuing this AD to detect and correct 
cracks in horizontal stabilizer lower skins resulting in reduced 
local stiffness of the stabilizer, which can cause heavy vibration 
leading to loss of structural integrity of the horizontal 
stabilizer.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Inspections, Related Investigative Actions, and Corrective Actions 
for Group 1, Configuration 1 Airplanes

    For Group 1, Configuration 1 airplanes, as identified in SASB 
737-55-1059 R1: Except as specified in paragraph (i)(1) of this AD, 
at the applicable time specified in paragraph 1.E., ``Compliance,'' 
of SASB 737-55-1059 R1, do a detailed inspection for cracking of the 
horizontal stabilizer lower skin; and do all applicable related 
investigative and corrective actions; in accordance with the 
Accomplishment Instructions of SASB 737-55-1059 R1, except as 
specified in paragraph (i)(2) of this AD. Do all applicable related 
investigative and corrective actions before further flight. Repeat 
the inspection of the horizontal stabilizer lower skin, if 
applicable, thereafter at the applicable intervals specified in 
paragraph 1.E., ``Compliance,'' of SASB 737-55-1059 R1. Options 
specified in SASB 737-55-1059 R1, for accomplishing the inspections 
are acceptable for the corresponding requirements of this paragraph 
provided that the inspections are done at the applicable times in 
paragraph 1.E., ``Compliance,'' of the SASB 737-55-1059 R1.

(h) Inspections, Related Investigative Actions, and Corrective Actions 
for Group 1, Configuration 2 Airplanes

    For Group 1, Configuration 2 airplanes, as identified in SASB 
737-55-1059 R1: Except as specified in paragraph (i)(1) of this AD, 
at the applicable time specified in paragraph 1.E., ``Compliance,'' 
of SASB 737-55-1059 R1, do the actions specified in paragraphs 
(h)(1), (h)(2), and (h)(3) of this AD; and do all applicable related 
investigative and corrective actions; in accordance with the 
Accomplishment Instructions of SASB 737-55-1059 R1, except as 
specified in paragraph (i)(2) of this AD. Do all applicable related 
investigative and corrective actions before further flight. Repeat 
the inspections specified in paragraphs (h)(1), (h)(2), and (h)(3) 
of this AD, if applicable, thereafter at the applicable intervals 
specified in paragraph 1.E., ``Compliance,'' of SASB 737-55-1059 R1. 
Options specified in SASB 737-55-1059 R1, for accomplishing the 
inspections are acceptable for the corresponding requirements of 
this paragraph provided that the inspections are done at the 
applicable times in paragraph 1.E., ``Compliance,'' of SASB 737-55-
1059 R1.
    (1) Do a high frequency eddy current inspection for cracking of 
the skin around any repair done as specified in the structural 
repair manual or any external doubler repair, and a detailed 
inspection for any loose or any missing fastener of repaired 
doublers.
    (2) Do a detailed inspection for cracking of the inspar lower 
skin of the horizontal stabilizer in unrepaired areas.
    (3) Do a low frequency eddy current inspection for cracking of 
the forward fastener row of any external doubler repair.

(i) Service Information Exceptions

    (1) Where SASB 737-55-1059 R1, specifies a compliance time 
``after the Revision 1 date of this service bulletin,'' this AD 
requires compliance within the specified compliance time after the 
effective date of this AD.
    (2) If any cracking, corrosion, hole elongation, or loose or 
missing fastener is found during any inspection required by this AD, 
and SASB 737-55-1059 R1, specifies to contact Boeing for repair 
instructions: Before further flight, repair the cracking, corrosion, 
hole elongation, loose or missing fasteners using a method approved 
in accordance with the procedures specified in paragraph (j) of this 
AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office, FAA, has 
the authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the ACO, send it to the attention of the 
person identified in paragraph (k)(1) of this AD. Information may be 
emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO, to make those findings. To be approved, the 
repair method, modification deviation, or alteration deviation must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.

(k) Related Information

    (1) For more information about this AD, contact Gaetano 
Settineri, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, 
Seattle ACO, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 
425-917-6577; fax: 425-917-6590; email: gaetano.settineri@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, WA. For information on the availability of this 
material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on August 24, 2016.
John P. Piccola, Jr.,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-21148 Filed 9-7-16; 8:45 am]
 BILLING CODE 4910-13-P