
[Federal Register Volume 82, Number 70 (Thursday, April 13, 2017)]
[Proposed Rules]
[Pages 17773-17776]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-07440]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0249; Directorate Identifier 2016-NM-138-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
The Boeing Company Model 757-200, -200PF, and -200CB series airplanes. 
This proposed AD was prompted by reports of slats disbonding on 
airplanes on which the terminating actions of AD 2005-07-08 had been 
performed. We have also received reports of slats disbonding on 
airplanes outside of the applicability of AD 90-23-06, AD 91-22-51, and 
AD 2005-07-08. This proposed AD would require determining the type of 
trailing edge slat wedges of the leading edge slats, repetitive 
inspections for disbonding on certain trailing edge slat wedges, and 
corrective actions, if necessary. This proposed AD would also provide 
an optional terminating action for the repetitive inspections. We are 
proposing this AD to address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by May 30, 2017.

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: Contractual & Data Services (C&DS), 
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; 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-2017-0249.

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-2017-
0249; 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: Lu Lu, 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: 
425-917-6478; email: lu.lu@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-2017-0249; 
Directorate Identifier 2016-NM-138-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

[[Page 17774]]

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 slats disbonding on airplanes on which 
the terminating actions of AD 2005-07-08, Amendment 39-14032 (70 FR 
16403, March 31, 2005), had been performed. We have also received 
reports of slats disbonding on airplanes outside of the applicability 
of AD 90-23-06, Amendment 39-6794 (55 FR 46499, November 5, 1990); AD 
91-22-51, Amendment 39-8129 (57 FR 781, January 9, 1992); and AD 2005-
07-08. Inspection of submitted damaged trailing edge slat wedges 
indicated that the panels had been contaminated with moisture 
ingression, as there was evidence of aluminum oxide powder on the core, 
and the adhesive had failed at the skin-to-core bondline. It is 
suspected that there was incomplete removal of moisture and honeycomb 
core corrosion during the repair of the trailing edge slat wedges or 
that moisture had previously migrated into the panel and was 
subsequently sealed inside.
    One operator reported major skin-to-core disbonding of a trailing 
edge slat wedge when the airplane had accumulated 42,603 total flight 
hours and 9,808 total flight cycles. Another operator reported the 
departure of a trailing edge slat wedge during flight when the airplane 
had accumulated 47,470 total flight hours and 17,579 total flight 
cycles. We are proposing this AD to prevent delamination of the 
trailing edge slat wedges of the leading edge slats. This delamination 
could cause loss of pieces of the trailing edge slat wedge assemblies 
during flight, reduction of the maneuver and stall margins, and 
consequent reduced controllability of the airplane.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Special Attention Service Bulletin 757-57-0066, 
Revision 1, dated June 7, 2016 (``SASB 757-57-0066, R1''). The service 
information describes procedures for doing inspections on trailing edge 
slat wedges of the leading edge slats for areas of skin-to-core and aft 
edge disbonding, and corrective actions including replacement of 
certain slat wedges. 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 and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

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-2017-0249.
    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 757-57-0066, R1, specifies to contact the manufacturer for 
certain instructions, but this proposed AD would require using 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 469 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
            Action                   Labor cost          Parts cost    Cost per product   Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Inspections..................  Up to 24                           $0   Up to $2,040 per  Up to $956,760 per
                                work[dash]hours x                       inspection        inspection cycle.
                                $85 per hour =                          cycle.
                                $2,040 per
                                inspection cycle.
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    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed 
inspections. We have no way of determining the number of aircraft that 
might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
              Action                       Labor cost              Parts cost             Cost per product
----------------------------------------------------------------------------------------------------------------
Wedge replacement (per wedge)....  43 work-hours x $85 per    Up to $84,636.......  Up to $88,291.
                                    hour = $3,655.
----------------------------------------------------------------------------------------------------------------

    The on-condition costs are an estimate of the cost of replacing a 
type A wedge with a type B wedge, which is a terminating action for the 
required inspections. There are up to 10 wedge assemblies per airplane, 
and the price range for a new assembly is $50,923 to $84,636 based on 
the information provided by Boeing.
    The cost of repairing a type A wedge cannot be estimated because 
damage type and size may vary widely.

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

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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:

    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-2017-0249; Directorate Identifier 
2016-NM-138-AD.

(a) Comments Due Date

    We must receive comments by May 30, 2017.

(b) Affected ADs

    This AD affects AD 90-23-06, Amendment 39-6794 (55 FR 46499, 
November 5, 1990) (``AD 90-23-06''); AD 91-22-51, Amendment 39-8129 
(57 FR 781, January 9, 1992) (``AD 91-22-51''); and AD 2005-07-08, 
Amendment 39-14032 (70 FR 16403, March 31, 2005) (``AD 2005-07-
08'').

(c) Applicability

    This AD applies to all The Boeing Company Model 757-200, -200PF, 
and -200CB series airplanes, certificated in any category.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of slats disbonding on airplanes 
on which the terminating actions of AD 2005-07-08 had been 
performed. We have also received reports of slats disbonding on 
airplanes outside of the applicability of AD 90-23-06, AD 91-22-51, 
and AD 2005-07-08. We are issuing this AD to prevent delamination of 
the trailing edge slat wedges of the leading edge slats. This 
delamination could cause loss of pieces of the trailing edge slat 
wedge assemblies during flight, reduction of the maneuver and stall 
margins, and consequent reduced controllability of the airplane.

(f) Compliance

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

(g) Inspection to Determine Slat Wedge Type

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 757-57-
0066, Revision 1, dated June 7, 2016 (``SASB 757-57-0066, R1''), 
except as specified in paragraph (j)(1) of this AD: Inspect each 
trailing edge slat wedge of the leading edge slats in accordance 
with Appendices A, B, C, and D of SASB 757-57-0066, R1, or review 
the airplane maintenance records, to determine whether the slat 
wedge is a type A or a type B. If a maintenance records review 
cannot conclusively determine a slat wedge is a type B, it must be 
assumed to be a type A slat wedge or a physical inspection must be 
done as specified in this paragraph.

(h) Type A Slat Wedge Repetitive Inspections, Related Investigative 
Actions, and Corrective Actions

    For each type A trailing edge slat wedge found during the 
inspection or records review required by paragraph (g) of this AD: 
At the applicable time specified in paragraph 1.E., ``Compliance,'' 
of SASB 757-57-0066, R1, except as specified in paragraph (j)(1) of 
this AD, do an ultrasonic low frequency bond test inspection, a tap 
test inspection, or a through transmission ultrasonic (TTU) 
inspection for skin-to-core disbonds of the honeycomb area of the 
trailing edge slat wedge; do a detailed inspection for aft edge 
disbonds of the aft edge of the trailing edge slat wedge; do a 
general visual inspection for any previously accomplished repair; 
and do all applicable related investigative and corrective actions; 
in accordance with the Accomplishment Instructions of SASB 757-57-
0066, R1, except as specified in paragraphs (i) and (j)(2) of this 
AD. Do all applicable related investigative and corrective actions 
at the applicable time specified in paragraph 1.E., ``Compliance,'' 
of SASB 757-57-0066, R1. Repeat the applicable inspections on each 
type A trailing edge slat wedge thereafter at the applicable 
intervals specified in paragraph 1.E., ``Compliance,'' of SASB 757-
57-0066, R1.

(i) Repaired Type A Slat Wedge Repetitive Inspections, Related 
Investigative Actions and Corrective Actions

    (1) For each type A trailing edge slat wedge with any class 1 
disbond repair or any previously accomplished repair subject to the 
Part 2 inspection as identified in SASB 757-57-0066, R1: At the 
applicable time specified in paragraph 1.E., ``Compliance,'' of SASB 
757-57-0066, R1, do an ultrasonic low frequency bond test 
inspection, a tap test inspection, or a TTU inspection for skin-to-
core disbonds in the repaired area of the trailing edge slat wedge; 
and do all applicable related investigative and corrective actions; 
in accordance with the Accomplishment Instructions of SASB 757-57-
0066, R1, except as specified in paragraph (j)(2) of this AD. Do all 
applicable related investigative and corrective actions before 
further flight. Repeat the applicable inspection on each type A 
trailing edge slat wedge thereafter at the applicable interval 
specified in paragraph 1.E., ``Compliance,'' of SASB 757-57-0066, 
R1.
    (2) For each type A trailing edge slat wedge with any time-
limited class 2 disbond repair as identified in SASB 757-57-0066, 
R1: At the applicable time specified in paragraph 1.E., 
``Compliance,'' of SASB 757-57-0066, R1, do a detailed inspection 
for any peeling or deterioration of the aluminum foil tape of the 
repaired area on the trailing edge slat wedge; and do all applicable 
related investigative and corrective actions; in accordance with the 
Accomplishment Instructions of SASB 757-57-0066, R1, except as 
specified in paragraph (j)(2) of this AD. Do all applicable related 
investigative and corrective actions before further flight. Repeat 
the applicable inspection on each type A trailing edge slat wedge 
thereafter at the applicable interval specified in paragraph 1.E., 
``Compliance,'' of SASB 757-57-0066, R1, until a permanent repair is 
done to complete the actions required for the time-limited class 2 
disbond repair, specified as corrective actions in paragraph (h) of 
this AD.
    (3) For each type A trailing edge slat wedge with any permanent 
class 2 disbond repair as identified in SASB 757-57-0066, R1: At the 
applicable time specified in paragraph 1.E., ``Compliance,'' of SASB 
757-57-0066, R1, do an ultrasonic low frequency bond test

[[Page 17776]]

inspection or a TTU inspection for any disbonding of the aft edge 
repaired areas; a detailed inspection for disbonds along the aft 
edge of the repaired areas; and do all applicable related 
investigative and corrective actions; in accordance with the 
Accomplishment Instructions of SASB 757-57-0066, R1, except as 
specified in paragraph (j)(2) of this AD. Do all applicable related 
investigative and corrective actions before further flight. Repeat 
the applicable inspection on each type A trailing edge slat wedge 
thereafter at the applicable interval specified in paragraph 1.E., 
``Compliance,'' of SASB 757-57-0066, R1.
    (4) For each type A trailing edge slat wedge with any class 3 or 
class 4 disbond repair, or any previously accomplished repair 
subject to Part 5 inspection as identified in SASB 757-57-0066, R1: 
At the applicable time specified in paragraph 1.E., ``Compliance,'' 
of SASB 757-57-0066, R1, do the applicable actions specified in 
paragraphs (i)(4)(i) and (i)(4)(ii) of this AD.
    (i) For any class 3 disbond repair with a repair doubler common 
to the aft edge of the trailing edge slat wedge; for any previously 
accomplished repair with a repair doubler common to the aft edge of 
the trailing edge slat wedge; and for any class 4 disbond repair: Do 
an ultrasonic low frequency bond test inspection or a TTU inspection 
for any disbonding of the aft edge repaired areas; a detailed 
inspection for disbonds along the aft edge of the repaired areas; 
and do all applicable related investigative and corrective actions; 
in accordance with the Accomplishment Instructions of SASB 757-57-
0066, R1, except as specified in paragraph (j)(2) of this AD. Do all 
applicable related investigative and corrective actions before 
further flight. Repeat the applicable inspection on each type A 
trailing edge slat wedge thereafter at the applicable interval 
specified in paragraph 1.E., ``Compliance,'' of SASB 757-57-0066, 
R1.
    (ii) For any class 3 disbond repair without a repair doubler 
common to the aft edge of the trailing edge slat wedge; and for any 
previously accomplished repair without a repair doubler common to 
the aft edge of the trailing edge slat wedge: Do an ultrasonic low 
frequency bond test inspection, a tap test inspection, or a TTU 
inspection for skin-to-core disbonds of the honeycomb area of the 
trailing edge slat wedge in the repaired area; and do all applicable 
related investigative and corrective actions; in accordance with the 
Accomplishment Instructions of SASB 757-57-0066, R1, except as 
specified in paragraph (j)(2) of this AD. Do all applicable related 
investigative and corrective actions before further flight. Repeat 
the applicable inspection on each type A trailing edge slat wedge 
thereafter at the applicable interval specified in paragraph 1.E., 
``Compliance,'' of SASB 757-57-0066, R1.

(j) Exceptions to Service Information

    (1) Where paragraph 1.E., ``Compliance,'' of SASB 757-57-0066, 
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 disbonding is found during any inspection required by 
this AD, and SASB 757-57-0066, R1, specifies to contact Boeing for 
appropriate action: Before further flight, repair the disbonding 
using a method approved in accordance with the procedures specified 
in paragraph (n) of this AD.

(k) Optional Terminating Action for Repetitive Inspections

    Replacing a type A trailing edge slat wedge with a type B 
trailing edge slat wedge in accordance with the Accomplishment 
Instructions of SASB 757-57-0066, R1, terminates the repetitive 
inspections required by this AD for the replaced wedge.

(l) Terminating Action for Certain Other ADs

    Accomplishing the initial inspections required by paragraphs (g) 
and (h) of this AD on a trailing edge slat wedge terminates all the 
requirements of AD 90-23-06, AD 91-22-51, and AD 2005-07-08 for that 
slat wedge.

(m) Parts Installation Limitation

    As of the effective date of this AD: A replacement type A wedge 
may be installed provided that the initial and repetitive 
inspections specified in paragraph (h) and (i) of this AD are done 
within the applicable compliance times specified in paragraph (h) 
and (i) of this AD and all applicable related investigative and 
corrective actions are done within the applicable compliance times 
specified in paragraphs (h) and (i) of this AD.

(n) Alternative Methods of Compliance (AMOCs)

    (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. 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 (o)(1) of this AD. 
Information may be emailed to: 9-ANM-LAACO-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.
    (4) Except as required by paragraph (j)(2) of this AD: For 
service information that contains steps that are labeled as Required 
for Compliance (RC), the provisions of paragraphs (n)(4)(i) and 
(n)(4)(ii) of this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. If a step or substep is labeled ``RC Exempt,'' then the 
RC requirement is removed from that step or substep. An AMOC is 
required for any deviations to RC steps, including substeps and 
identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(o) Related Information

    (1) For more information about this AD, contact Lu Lu, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind 
Avenue SW., Renton, WA 98057-3356; phone: 425-917-6478; fax: 425-
917-6590; email: lu.lu@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; 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 April 5, 2017.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-07440 Filed 4-12-17; 8:45 am]
 BILLING CODE 4910-13-P


