Document ID: FAA-2016-9067-0009
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2017-11-09T05:00Z

[Federal Register Volume 82, Number 216 (Thursday, November 9, 2017)]
[Proposed Rules]
[Pages 52015-52021]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-21223]

 ========================================================================
 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. 82, No. 216 / Thursday, November 9, 2017 / 
Proposed Rules  

[[Page 52015]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9067; Product Identifier 2016-NM-043-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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

SUMMARY: We are revising an earlier notice of proposed rulemaking 
(NPRM), which applies to all The Boeing Company Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 
747-400D, 747-400F, 747SR, and 747SP series airplanes. This action 
revises the NPRM by adding a reporting requirement. We are proposing 
this airworthiness directive (AD) to address the unsafe condition on 
these products. Since these actions impose an additional burden over 
that proposed in the NPRM, we are reopening the comment period to allow 
the public the chance to comment on these changes.

DATES: The comment period for the NPRM published in the Federal 
Register on September 8, 2016 (81 FR 62031), is reopened.
    We must receive comments on this SNPRM by December 26, 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: 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 SNPRM, 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 service information at the FAA, Transport Standards Branch, 
1601 Lind Avenue SW., Renton, WA. 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 by searching for and locating Docket No. FAA-2016-
9067; 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 SNPRM, 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: Bill Ashforth, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 1601 Lind Avenue SW., 
Renton, WA 98057-3356; phone: 425-917-6432; fax: 425-917-6590; email: 
[email protected].

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-2016-9067; 
Product Identifier 2016-NM-043-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this SNPRM. We will consider all 
comments received by the closing date and may amend this SNPRM 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 SNPRM.

Discussion

    We issued an NPRM to amend 14 CFR part 39 by adding an AD that 
would apply to all The Boeing Company Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes. The NPRM published in the 
Federal Register on September 8, 2016 (81 FR 62031). The NPRM was 
prompted by a report of fatigue cracking in airplanes that are 
approaching or have exceeded their design service objective and a 
structural reevaluation that identified additional structural elements 
that qualify as structural significant items (SSIs). The NPRM proposed 
to require revising the maintenance or inspection program to include 
inspections that will give no less than the required damage tolerance 
rating (DTR) for certain SSIs, inspecting for cracks of all SSI 
structure, and repairing any cracked structure.

Actions Since the NPRM Was Issued

    Since we issued the NPRM, we have determined that reporting must be 
required in order to ensure the continuing structural airworthiness of 
The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 
747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 
747SP series airplanes with a high number of flight cycles. All cracks 
involving an SSI or related structure in close vicinity to the SSI must 
be reported to Boeing in order to evaluate the effectiveness of the 
supplemental structural inspections. We have revised paragraph (h) of 
this proposed AD to include reporting as part of the inspection 
program.

Comments

    We gave the public the opportunity to comment on the NPRM. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Support for the NPRM

    United Airlines stated that it concurs with the NPRM and has no 
further comments.

[[Page 52016]]

Requests To Revise Certain Compliance Times

    Boeing and United Parcel Service (UPS) requested that we include a 
compliance time of ``1,000 flight cycles measured from 12 months after 
the effective date of the AD'' instead of a compliance time of ``within 
1,000 flight cycles or 12 months after the effective date of this AD, 
whichever occurs later'' as specified in paragraphs (i)(1)(ii), 
(i)(2)(ii), (j)(1)(ii), and (j)(2)(ii) of the proposed AD (in the 
NPRM). Boeing stated that it is not realistic to incorporate the 
proposed inspections within 12 months, as specified in paragraph (h) of 
the proposed AD (in the NPRM), while simultaneously performing 
inspections as specified in paragraphs (i) and (j) of the proposed AD 
(in the NPRM). Boeing noted that the related AD, AD 2004-07-22 R1, 
Amendment 39-15326 (73 FR 1052, January 7, 2008; corrected February 14, 
2008 (73 FR 8589)) (``AD 2004-07-22 R1''), increases the compliance 
time up to 1,000 flight cycles, after allowing 12 months to implement 
the new program. UPS stated that the proposed AD (in the NPRM) should 
include a 1,000-flight-cycle grace period similar to that provided in 
paragraphs (i)(1)(ii) and (i)(2)(ii) of AD 2004-07-22 R1. UPS stated 
that the proposed AD (in the NPRM) creates a situation for airplanes 
that are already over a threshold to have inspections due almost 
immediately upon the revision of the maintenance or inspection program.
    In addition, KLM Royal Dutch Airlines requested that we provide a 
grace period for SSI items for which the inspection interval has to be 
lowered due to a flight-hour/flight-cycle ratio of 7.0 or more. British 
Airways stated that a suitable grace period should be introduced given 
that certain inspection intervals could be reduced from 6 years to 2 
years.
    We agree with the requests to revise the compliance time. The 
revised compliance time proposed by Boeing and UPS is consistent with 
the compliance time in AD 2004-07-22 R1, and will not adversely affect 
safety. This revised compliance time provides an adequate grace period 
for reduced intervals. We have revised paragraphs (i)(1)(ii), 
(i)(2)(ii), (j)(1)(ii), and (j)(2)(ii) of this proposed AD accordingly.

Requests To Clarify Compliance Times for Components

    Boeing and KLM Royal Dutch Airlines requested that we clarify the 
compliance times for removable structural components. The commenters 
noted that for inspections of removable structural components, the 
accumulated flight cycles and flight hours on the component should be 
used instead of flight cycles and flight hours on the airframe. Boeing 
noted that some SSI details are replaced, such as when installing 
removable structural components or installing used structural parts in 
a repair. The commenters recommended we add a note to paragraphs (i) 
and (j) of the proposed AD (in the NPRM) to address this issue.
    We agree because an SSI can be removed from the airframe and 
replaced, and have different flight cycles and flight hours than the 
airframe. Boeing Document D6-35022, ``Supplemental Structural 
Inspection Document for Model 747 Airplanes,'' Revision H, dated 
September 2013; and Boeing Document D6-35022-1, ``747-400 LCF 
Supplemental Structural Inspection Document--Appendix A,'' dated 
November 2015; state the following:

    The initial inspection (threshold) and intervals are measured in 
flight cycles or flight hours that a particular SSI detail has 
accumulated regardless of what the airframe as a whole has 
accumulated. Most SSI details have never been replaced and therefore 
have accumulated the same flight cycles and flight hours as the 
airframe. Some SSI details are replaced, such as when installing 
removable structural components (repairable/rotable/expendables) or 
installing used structural parts as a repair. In these cases the SSI 
details have accumulated flight cycles and flight hours that may be 
different than the airframe. The operator must account for this in 
determining when inspections must be done.

    We have added new content to paragraph (l) to this proposed AD 
(replacing the content in paragraph (l) of the proposed AD (in the 
NPRM)) to state that for compliance times that specify total flight 
cycles and total flight hours, and the SSI is a removable structural 
component, those compliance times must be measured on the SSI since its 
installation, regardless of what the airframe as a whole has 
accumulated. If the total flight cycles and total flight hours on the 
SSI are not available or cannot be determined, the airframe total 
flight cycles and total flight hours are to be used for the compliance 
times identified in paragraphs (i) and (j) of this proposed AD. We have 
also added a reference to ``paragraph (l) of this AD'' to paragraphs 
(i) and (j) of this proposed AD.

Request To Add Explanation To Continue Inspections

    Boeing requested that we add an explanation to the NPRM regarding 
the continuation of the inspections in AD 2004-07-22 R1 until the start 
of the new inspections specified in the NPRM. Boeing recommended that 
we add the following text to the ``Proposed AD Requirements'' section 
in the preamble of the NPRM:

    Note it is required to start and continue inspections per D6-
35022 Rev G, as required by AD 2004-07-22 R1; until inspections per 
D6-35022 Rev H, dated Sept. 2013, and if required also D6-35022-1 
Appendix A, dated Nov. 2015, are accomplished as required by the new 
AD.

    We agree with the statement that Boeing provided. Inspections 
required by AD 2004-07-22 R1 are terminated only after accomplishment 
of the corresponding inspections required by this AD, as specified in 
paragraphs (i) and (j) of this proposed AD. However, the ``Proposed AD 
Requirements'' section is not restated in this proposed AD. Therefore, 
we have not changed this proposed AD in this regard.

Request To Clarify Affected Airplanes in Paragraph (i) of the Proposed 
AD (in the NPRM)

    Boeing requested that we revise the header and first sentence of 
paragraph (i) of the proposed AD (in the NPRM) to clarify the affected 
airplanes. Boeing stated that the text ``all Model 747 airplanes'' 
should be revised so that the paragraph excludes Model 747-8 and 747-8F 
airplanes. Boeing noted those models are not included in the 
applicability specified in paragraph (c) of the proposed AD (in the 
NPRM).
    We agree to clarify the language for the affected airplanes for 
paragraph (i) of this proposed AD. When we use the term ``all 
airplanes'' in the regulatory text of an AD, we mean all airplanes 
identified in paragraph (c) of the AD. Model 747-8 and 747-8F airplanes 
are not identified in paragraph (c) of this proposed AD. We have 
revised the header and first sentence of paragraph (i) of this proposed 
AD by specifying ``all airplanes except . . .'' instead of ``all Model 
747 airplanes except . . . .''

Request To Clarify Alternative Methods of Compliance (AMOCs) for AD 
2004-07-22 R1

    Boeing requested that we revise paragraph (m)(3) of the proposed AD 
(in the NPRM) to clarify that AMOCs are no longer needed for AD 2004-
07-22 R1 after the requirements of the proposed AD (in the NPRM) are 
implemented. Boeing stated that both ADs should not be required to be 
reported on FAA Form 8100-9.
    We agree to clarify the AMOC requirements, but we do not agree to 
revise paragraph (p)(3) of this proposed AD (paragraph (m)(3) of the 
proposed AD (in the NPRM)). Paragraphs (i) and (j) of this proposed AD 
state that doing

[[Page 52017]]

the actions in paragraph (i) or (j) of this proposed AD terminates the 
corresponding action required by AD 2004-07-22 R1. Thus, an AMOC for AD 
2004-07-22 R1 is no longer needed for a given SSI once the inspection 
for that SSI is done as required by this proposed AD. We have not 
changed this proposed AD in this regard.

Request To Clarify Approval of Previous AMOCs

    Qantas Airways requested that we clarify paragraph (m)(4) of the 
proposed AD (in the NPRM), which approves previous AMOCs for the 
actions specified in paragraphs (h), (i), and (j) of the proposed AD 
(in the NPRM), except for any SSI that has an expanded inspection area 
identified in Boeing Document D6-35022, ``Supplemental Structural 
Inspection Document for Model 747 Airplanes,'' Revision H, dated 
September 2013; or Boeing Document D6-35022-1, ``747-400 LCF 
Supplemental Structural Inspection Document--Appendix A,'' dated 
November 2015. Qantas Airways requested that previous AMOCs also be 
approved for the actions required by paragraph (k) of the proposed AD 
(in the NPRM), which specifies repairing any cracked structure.
    We agree and have added a reference to paragraph (k) in paragraph 
(p)(4) of this proposed AD (paragraph (m)(4) of the proposed AD (in the 
NPRM)).

Request for Relief From Certain Requirements

    UPS requested that we revise paragraph (k) of the proposed AD (in 
the NPRM) to match the wording in paragraph (j) of AD 2004-07-22 R1 in 
order to avoid an unnecessary burden for Boeing, operators, and the 
FAA. UPS stated that paragraph (k) of the proposed AD (in the NPRM) 
specifies repairs to be done in accordance with AMOC-approved methods. 
UPS noted that previous repairs have been approved as AMOCs to 
paragraph (j) of AD 2004-07-22 R1, which corresponds to paragraph (k) 
of the proposed AD (in the NPRM). UPS further stated that paragraph 
(m)(4) of the proposed AD (in the NPRM) states that AMOCs approved for 
AD 2004-07-22 R1 are approved as AMOCs for the corresponding provisions 
of paragraphs (h), (i), and (j) of the proposed AD (in the NPRM). UPS 
noted that paragraph (j) of AD 2004-07-22 R1 requires repairs to be 
done in accordance with FAA-approved methods. UPS concluded that a 
requirement to have all repairs be AMOC-approved creates an unnecessary 
burden.
    We agree to revise paragraph (k) of this proposed AD. Paragraph (j) 
of AD 2004-07-22 R1 allows repairs to be performed using an FAA-
approved method. This is because the original intent of the 
supplemental structural inspection document (SSID) program was to 
perform damage-tolerant-type inspections of SSIs that had no 
significant prior fatigue crack history on pre-14 CFR 25.571 amendment 
45 airplanes. In accordance with the SSID program, when cracking was 
found, Boeing would remove the SSI from the SSID, produce a separate 
service bulletin to address the cracking, and the FAA would then 
mandate the inspections specified in that service bulletin. These 
repairs would then need an AMOC to the corresponding AD when 
inspections were due. Since AD 2004-07-22 R1 was issued, the FAA and 
Boeing have determined that in many cases it is not necessary to create 
a separate service bulletin and AD, provided the cracks are found in an 
SSI and the existing inspections in the SSID are sufficient to maintain 
airworthiness and detect cracks in a timely manner. This is similar to 
how airworthiness limitations programs are managed on post-14 CFR 
25.571 amendment 45 airplanes. We have revised paragraph (k) of this 
proposed AD to state that repairs are to be performed using an FAA-
approved method.
    We also acknowledge that AMOCs to AD 2004-07-22 R1 have been 
issued, but these were issued to paragraph (l)(3) of that AD, rather 
than to paragraph (j) of that AD as discussed by UPS. These AMOCs were 
issued because operators could not inspect the SSI in accordance with 
the SSID and required alternate inspections or inspection intervals. We 
have determined that the guidance on when AMOCs are needed relative to 
the SSID program is not clear. Therefore, we have discussed this in the 
``Proposed Requirements of this SNPRM'' section in this document and 
added new content to paragraph (m) to this proposed AD to clarify when 
operators must request an AMOC.

Request for Approval of Alternative Determination of Utilization

    British Airways and UPS requested that we approve an alternative 
determination of airplane utilization (i.e., an airplane's average 
flight hours/flight cycles). The commenters stated that section 5.1.3. 
of Boeing Document D6-35022, ``Supplemental Structural Inspection 
Document for Model 747 Airplanes,'' Revision H, dated September 2013, 
specifies that the utilization is an average of flight hours per flight 
for each airplane and that the utilization should be determined since 
the last D-check. British Airways recommended that utilization be 
considered from the delivery of the airplane. British Airways stated 
the proposed change is a more realistic average over the life of the 
airplane, makes it easier for operators to determine future 
utilization, and reduces the possibility of missing inspections due to 
minor changes in utilization between D-checks.
    UPS recommended that an option be included to allow operators to 
use projected utilizations. UPS stated that the following terminology 
in Boeing Document D6-35022, ``Supplemental Structural Inspection 
Document for Model 747 Airplanes,'' Revision H, dated September 2013, 
can be contradictory and cannot be complied with: ``for determining 
utilization, use flight hours and cycles accumulated since the last D 
check or its equivalent. If future utilization is known, use the new 
average flight hours.'' UPS stated that the option would allow the 
operator to determine utilization from its maintenance program.
    We disagree that future airplane utilization (unless known through 
scheduled maintenance) or airplane utilization based on the delivery 
date of the airplane is acceptable. The terminology used in Boeing 
Document D6-35022, ``Supplemental Structural Inspection Document for 
Model 747 Airplanes,'' Revision H, dated September 2013, is:

    After implementing the FLS [Flight Length Sensitive] inspections 
and to account for utilization changes over time, it is recommended 
the operator re-assess the airplane's utilization at least every D 
check or its equivalent. As a result of a re-assessment, SSIs which 
require inspection more frequently should be inspected within the 
new interval since the last inspection or at the next C check, 
whichever is later.

    Future airplane utilization or airplane utilization from the 
delivery date would not, in general, be conservative in assessing the 
aircraft structure and is not equivalent. We have not changed this 
proposed AD in this regard.
    We also disagree that the terminology that UPS cited in Boeing 
Document D6-35022, ``Supplemental Structural Inspection Document for 
Model 747 Airplanes,'' Revision H, dated September 2013, is 
contradictory. If the utilization that is used to set up the 
maintenance program changes over time, then the maintenance program 
schedule should be updated based on the new utilization. For example, 
if the average flight hours increase over the assessment period, then 
that operator should revise its maintenance program in consideration of 
the new average

[[Page 52018]]

flight hours. We have not changed this proposed AD in this regard.

Requests To Allow a Tolerance for Selecting Forms

    UPS and British Airways requested that we provide a tolerance for 
selecting the appropriate DTR forms. UPS recommended a tolerance of +/-
0.1 hour be allowed for selecting DTR forms. UPS stated that the 
historic utilization of its fleet is slightly less than 7 flight hours 
per flight cycle since delivery of the airplane and over the most 
recent D-check interval. UPS stated that current utilization 
projections show an average over 7 flight hours per flight cycle. UPS 
concluded that since it would have no knowledge ahead of time which 
airplane will be under or over 7, a tolerance in selecting the 
appropriate DTR form would provide a significant benefit to 
incorporating the program change without affecting the level of safety. 
British Airways recommended a tolerance of +/-0.2 hour for the 7-hour 
utilization threshold and +/-0.25 hour for 9- or 11-hour utilization 
thresholds. British Airways noted that if the utilization increases 
during the next interval, then the interval is significantly reduced, 
causing difficulty in providing the correct maintenance. The commenters 
noted that no tolerance is provided in Boeing Document D6-35022, 
``Supplemental Structural Inspection Document for Model 747 
Airplanes,'' Revision H, dated September 2013.
    We do not find it necessary to include the requested tolerance in 
this AD, because section 5.1.3 of Boeing Document D6-35022, 
``Supplemental Structural Inspection Document for Model 747 
Airplanes,'' Revision H, dated September 2013, states, ``DTR values can 
be read to the nearest two significant figures (0.1),'' and section 7.3 
of that document provides the following example on how to determine 
what the average flight hours per flight cycle without the use of 
additional tolerances:

    For Wing SSIs, the initial step is to check to see if the SSI if 
Flight Length Sensitive (FLS). If so, the operator uses the average 
flight length to select the DTR Check Form that the airplane's 
average flight length fits under. For example, at the SSID 
threshold, the airplane's average flight length is 8.6 hours. For 
this SSID item, there may be forms for <7 hours and >7 hours. In 
this case, the operator is to use the >7 hour DTR check form.

Therefore, an operator will be able to determine if its average flight 
hours are either <7 hours or >=7 hours without needing the aid of an 
additional tolerance. We have not changed this proposed AD in this 
regard.

Request To Clarify if a Reassessment Is Required

    UPS requested that we clarify whether a reassessment of utilization 
is required. UPS stated that Boeing Document D6-35022, ``Supplemental 
Structural Inspection Document for Model 747 Airplanes,'' Revision H, 
dated September 2013, states, ``it is recommended the operator re-
assess the airplane's utilization at least every D check or 
equivalent,'' but it is not clear if this recommendation is a 
requirement of the proposed AD (in the NPRM) or an option.
    We agree to clarify. Boeing Document D6-35022, ``Supplemental 
Structural Inspection Document for Model 747 Airplanes,'' Revision H, 
dated September 2013, is for an exploratory program. When that document 
calls out recommendations on re-assessing the airplane's utilization, 
this should be done at the operator's own discretion. The reassessment 
is not a requirement of this proposed AD. We have not changed this 
proposed AD in this regard.

Request To Provide Guidelines for Adjusting Certain Intervals

    KLM Royal Dutch Airlines (KLM) requested that we provide guidance 
for adjusting certain intervals. KLM stated that no information is 
given on how to adjust repeat flight length sensitive (FLS) tasks for 
airplanes with a flight-hour/flight-cycle ratio of 7.0 or more once the 
initial inspection is performed. KLM stated that chapter 5.0 of Boeing 
Document D6-35022, ``Supplemental Structural Inspection Document for 
Model 747 Airplanes,'' Revision H, dated September 2013, does not give 
clear guidelines. KLM stated that FLS tasks in Boeing Document D6-
35022, ``Supplemental Structural Inspection Document for Model 747 
Airplanes,'' Revision H, dated September 2013, will result in a 
significant decrease of the repetitive interval of complex inspections 
for a flight-hour/flight-cycle ratio of 7.0 or more.
    In reviewing Boeing Document D6-35022, ``Supplemental Structural 
Inspection Document for Model 747 Airplanes,'' Revision H, dated 
September 2013, we have determined that it adequately addresses 
adjustment of the repetitive FLS tasks in sections 5.1.3 and 7.3. In 
addition, under the provisions of paragraph (p) of this AD, we will 
consider requests for alternate approaches to compliance time changes 
if sufficient data are submitted to substantiate that the approach and 
compliance time changes would provide an acceptable level of safety. We 
have not changed this proposed AD in this regard.

Request To Fix Typographical Error

    Boeing and KLM requested that we revise a typographical error in 
paragraph (j)(2) of the proposed AD (in the NPRM), which refers to 
paragraph (i)(2)(ii) of the proposed AD (in the NPRM). The commenters 
stated that the correct reference is paragraph (j)(2)(ii) of the 
proposed AD (in the NPRM).
    We agree with the request. We have revised paragraph (j)(2) of this 
proposed AD accordingly.

Removal of Inspection Program for Transferred Airplanes

    We have determined that the requirements specified in paragraph (l) 
of the proposed AD (in the NPRM) are not necessary. The inspection 
program for transferred airplanes was included in early SSID programs 
that involved a ``candidate fleet'' (a specific group of airplanes that 
was inspected instead of all airplanes). Therefore, we have removed 
those requirements from this proposed AD.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Document D6-35022, ``Supplemental Structural 
Inspection Document for Model 747 Airplanes,'' Revision H, dated 
September 2013. This service information describes procedures for 
inspections to detect cracks of all structure identified as SSIs, and 
includes six new SSIs since the last revision.
    We also reviewed Boeing Document D6-35022-1, ``747-400 LCF 
Supplemental Structural Inspection Document--Appendix A,'' dated 
November 2015. This service information describes procedures for 
inspections of the wings, fuselage, and empennage SSIs for Model 747-
400 LCF airplanes.
    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 these same type design. 
Certain changes described above expand the scope of the NPRM. As a 
result, we have determined that it is necessary to reopen the comment

[[Page 52019]]

period to provide additional opportunity for the public to comment on 
this SNPRM.

Proposed Requirements of This SNPRM

    This SNPRM would require revising the maintenance or inspection 
program to include inspections that will give no less than the required 
damage tolerance rating (DTR) for certain SSIs, inspecting for cracks 
of all SSI structure, and repairing any cracked structure. This 
proposed AD also would require reporting all cracks involving an SSI or 
related structure in close vicinity to the SSI to Boeing.
    This SNPRM would require revisions to certain operator maintenance 
documents to include new inspections. Compliance with these inspections 
is required by 14 CFR 91.403(c). For airplanes that have been 
previously modified, altered, or repaired in the areas addressed by 
these inspections, the operator may not be able to accomplish the 
actions described in the revisions. In this situation, to comply with 
14 CFR 91.403(c), the operator must request approval for an alternative 
method of compliance according to paragraph (p) of this proposed AD. 
The request should include a description of changes to the required 
inspections that will ensure the continued damage tolerance of the 
affected airplane.

Costs of Compliance

    We estimate that this proposed AD affects 118 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Revision of maintenance or inspection   1 work-hour x $85 per                 $0             $85         $10,030
 program.                                hour = $85.
----------------------------------------------------------------------------------------------------------------

    We have not specified cost estimates for the inspection and repair 
specified in this proposed AD. Compliance with this proposed AD 
constitutes a method of compliance with the FAA aging airplane safety 
final rule (AASFR) (70 FR 5518, February 2, 2005) for certain baseline 
structure of Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 
747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series 
airplanes. The AASFR requires certain operators to incorporate damage 
tolerance inspections into their maintenance inspection programs. These 
requirements are described in 14 CFR 121.1109(c)(1) and 14 CFR 
129.109(b)(1). Accomplishment of the actions specified in this proposed 
AD will meet the requirements of these regulations for certain baseline 
structure. The costs for accomplishing the inspection portion of this 
proposed AD were accounted for in the regulatory evaluation of the 
AASFR for airplanes affected by that rule. For airplanes not affected 
by the AASFR, we have received no definitive data that would enable us 
to provide cost estimates for the inspection portion of this proposed 
AD.
    We estimate the following costs to do any necessary reporting that 
would be required based on the results of the proposed inspections in 
the maintenance inspection program. We have no way of determining the 
number of aircraft that might need this action:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                 Action                           Labor cost            Parts cost         Cost per product
----------------------------------------------------------------------------------------------------------------
Reporting...............................  1 work-hour x $85 per hour              $0  $85 per inspection cycle.
                                           = $85.
----------------------------------------------------------------------------------------------------------------

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a current valid OMB control number. The control 
number for the collection of information required by this proposed AD 
is 2120-0056. The paperwork cost associated with this proposed AD has 
been detailed in the Costs of Compliance section of this document and 
includes time for reviewing instructions, as well as completing and 
reviewing the collection of information. Therefore, all reporting 
associated with this proposed AD is mandatory. Comments concerning the 
accuracy of this burden and suggestions for reducing the burden should 
be directed to the FAA at 800 Independence Ave. SW., Washington, DC 
20591, ATTN: Information Collection Clearance Officer, AES-200.

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.
    This proposed AD is issued in accordance with authority delegated 
by the Executive Director, Aircraft Certification Service, as 
authorized by FAA Order 8000.51C. In accordance with that order, 
issuance of ADs is normally a function of the Compliance and 
Airworthiness Division, but during this transition period, the 
Executive Director has delegated the authority to issue ADs applicable 
to transport category airplanes to the Director of the System Oversight 
Division.

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

[[Page 52020]]

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-2016-9067; Product Identifier 
2016-NM-043-AD.

(a) Comments Due Date

    We must receive comments by December 26, 2017.

(b) Affected ADs

    This AD affects AD 2004-07-22 R1, Amendment 39-15326 (73 FR 
1052, January 7, 2008; corrected February 14, 2008 (73 FR 8589)) 
(``AD 2004-07-22 R1'').

(c) Applicability

    This AD applies to all The Boeing Company Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 
747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated 
in any category.

    Note 1 to paragraph (c) of this AD: A Model 747-400 LCF airplane 
is a Model 747-400 series airplane that has been modified from a 
passenger airplane to a freighter configuration, as specified in 
Boeing Service Bulletin 747-00-2084.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage; 
54, Nacelles/Pylons; 55, Stabilizers; 57, Wings.

(e) Unsafe Condition

    This AD was prompted by a report of incidents involving fatigue 
cracking in transport category airplanes that are approaching or 
have exceeded their design service objective, and a structural 
reevaluation by the manufacturer that identified additional 
structural elements that qualify as structural significant items 
(SSIs). We are issuing this AD to ensure the continued structural 
integrity of all The Boeing Company Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, 747SR, and 747SP series airplanes.

(f) Compliance

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

(g) Definition of SSI

    For the purposes of this AD, an SSI is defined as a principal 
structural element (PSE). A PSE is a structural element that 
contributes significantly to the carrying of flight, ground, or 
pressurization loads, and whose integrity is essential in 
maintaining the overall structural integrity of the airplane.

(h) Maintenance or Inspection Program Revision for All Airplanes

    Prior to reaching the compliance times specified in paragraph 
(i)(1)(i), (i)(2)(i), (j)(1)(i), or (j)(2)(i) of this AD, as 
applicable, or within 12 months after the effective date of this AD, 
whichever occurs later: Incorporate a revision into the maintenance 
or inspection program, as applicable, that provides no less than the 
required damage tolerance rating (DTR) for each SSI listed in the 
applicable service information specified in paragraph (h)(1) or 
(h)(2) of this AD. The revision to the maintenance or inspection 
program must include, and must be implemented in accordance with, 
the procedures in Section 5.0, ``Damage Tolerance Rating (DTR) 
System Application,'' and Section 6.0, ``SSI Discrepancy Reporting'' 
of Boeing Document D6-35022, ``Supplemental Structural Inspection 
Document for Model 747 Airplanes,'' Revision H, dated September 
2013; and Boeing Document D6-35022-1, ``747-400 LCF Supplemental 
Structural Inspection Document--Appendix A,'' dated November 2015; 
as applicable. Accomplishing the revision required by this paragraph 
terminates the actions required by paragraphs (f), (g), and (h) of 
AD 2004-07-22 R1.
    (1) For all airplanes except Model 747-400 LCF airplanes: SSIs 
listed in Boeing Document D6-35022, ``Supplemental Structural 
Inspection Document for Model 747 Airplanes,'' Revision H, dated 
September 2013.
    (2) For Model 747-400 LCF airplanes: SSIs listed in Boeing 
Document D6-35022, ``Supplemental Structural Inspection Document for 
Model 747 Airplanes,'' Revision H, dated September 2013; and SSIs 
listed in Boeing Document D6-35022-1, ``747-400 LCF Supplemental 
Structural Inspection Document--Appendix A,'' dated November 2015. 
For SSIs listed in both Boeing Document D6-35022-1, ``747-400 LCF 
Supplemental Structural Inspection Document--Appendix A,'' dated 
November 2015; and Boeing Document D6-35022, ``Supplemental 
Structural Inspection Document for Model 747 Airplanes,'' Revision 
H, dated September 2013: Incorporate the SSIs listed in Boeing 
Document D6-35022-1, ``747-400 LCF Supplemental Structural 
Inspection Document--Appendix A,'' dated November 2015.

(i) Inspections for All Airplanes Except Model 747-400 LCF Airplanes

    For all airplanes except Model 747-400 LCF airplanes: Perform 
inspections to detect cracks of all structure identified in Boeing 
Document D6-35022, ``Supplemental Structural Inspection Document for 
Model 747 Airplanes,'' Revision H, dated September 2013, at the 
times specified in paragraph (i)(1), (i)(2), or (i)(3) of this AD, 
as applicable, except as required by paragraph (l) of this AD. Once 
the initial inspection has been performed, in order to remain in 
compliance with the maintenance or inspection program, as required 
by paragraph (h) of this AD, repetitive inspections are required at 
the intervals specified in Boeing Document D6-35022, ``Supplemental 
Structural Inspection Document for Model 747 Airplanes,'' Revision 
H, dated September 2013. Doing an inspection required by this 
paragraph terminates the corresponding inspection required by 
paragraph (i) of AD 2004-07-22 R1.
    (1) For wing structure, except as provided by paragraph (i)(3) 
of this AD: Inspect at the times specified in paragraph (i)(1)(i) or 
(i)(1)(ii) of this AD, whichever occurs later.
    (i) Within the applicable compliance time specified in paragraph 
(i)(1)(i)(A) or (i)(1)(i)(B) of this AD.
    (A) For all Model 747-100, 747-100B, 747-100B SUD, 747-200B, 
747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes: 
Prior to the accumulation of 20,000 total flight cycles or 100,000 
total flight hours, whichever occurs first.
    (B) For all Model 747-400, 747-400D, and 747-400F series 
airplanes: Prior to the accumulation of 20,000 total flight cycles 
or 115,000 total flight hours, whichever occurs first.
    (ii) Within 1,000 flight cycles measured from 12 months after 
the effective date of this AD.
    (2) For all structure other than wing structure, except as 
provided by paragraph (i)(3) of this AD: At the time specified in 
paragraph (i)(2)(i) or (i)(2)(ii) of this AD, whichever occurs 
later.
    (i) Prior to the accumulation of 20,000 total flight cycles.
    (ii) Within 1,000 flight cycles measured from 12 months after 
the effective date of this AD.
    (3) For any portion of an SSI that has been replaced with new 
structure: Inspect at the later of the times specified in paragraphs 
(i)(3)(i) and (i)(3)(ii) of this AD.

[[Page 52021]]

    (i) At the time specified in paragraph (i)(1) or (i)(2) of this 
AD, as applicable.
    (ii) Within 10,000 flight cycles after the replacement of the 
part with a new part.

(j) Inspections for Model 747-400 LCF Airplanes

    For Model 747-400 LCF airplanes: Perform inspections to detect 
cracks of all structure identified in Boeing Document D6-35022, 
``Supplemental Structural Inspection Document for Model 747 
Airplanes,'' Revision H, dated September 2013; and Boeing Document 
D6-35022-1, ``747-400 LCF Supplemental Structural Inspection 
Document--Appendix A,'' dated November 2015; at the times specified 
in paragraph (j)(1) or (j)(2) of this AD, as applicable, except as 
required by paragraph (l) of this AD. Once the initial inspection 
has been performed, in order to remain in compliance with the 
maintenance or inspection program, as required by paragraph (h) of 
this AD, repetitive inspections are required at the intervals 
specified in Boeing Document D6-35022, ``Supplemental Structural 
Inspection Document for Model 747 Airplanes,'' Revision H, dated 
September 2013; and Boeing Document D6-35022-1, ``747-400 LCF 
Supplemental Structural Inspection Document--Appendix A,'' dated 
November 2015. For SSIs listed in both Boeing Document D6-35022, 
``Supplemental Structural Inspection Document for Model 747 
Airplanes,'' Revision H, dated September 2013; and Boeing Document 
D6-35022-1, ``747-400 LCF Supplemental Structural Inspection 
Document--Appendix A,'' dated November 2015; the SSIs listed in 
Boeing Document D6-35022-1, ``747-400 LCF Supplemental Structural 
Inspection Document--Appendix A,'' dated November 2015, take 
precedence (i.e., the SSIs in the latter document prevail). Doing an 
inspection required by this paragraph terminates the corresponding 
inspection required by paragraph (i) of AD 2004-07-22 R1.
    (1) For wing structure: Inspect at the times specified in 
paragraph (j)(1)(i) or (j)(1)(ii) of this AD, whichever occurs 
later.
    (i) Prior to the accumulation of 20,000 total flight cycles or 
115,000 total flight hours, whichever occurs first.
    (ii) Within 1,000 flight cycles measured from 12 months after 
the effective date of this AD.
    (2) For all structure other than wing structure: At the time 
specified in paragraph (j)(2)(i) or (j)(2)(ii) of this AD, whichever 
occurs later.
    (i) At the earlier of the times specified in paragraphs 
(j)(2)(i)(A) and (j)(2)(i)(B) of this AD.
    (A) Prior to the accumulation of 20,000 total flight cycles.
    (B) Within the applicable initial compliance time specified in 
Boeing Document D6-35022, ``Supplemental Structural Inspection 
Document for Model 747 Airplanes,'' Revision H, dated September 
2013; and Boeing Document D6-35022-1, ``747-400 LCF Supplemental 
Structural Inspection Document--Appendix A,'' dated November 2015. 
For SSIs are listed in both Boeing Document D6-35022, ``Supplemental 
Structural Inspection Document for Model 747 Airplanes,'' Revision 
H, dated September 2013; and Boeing Document D6-35022-1, ``747-400 
LCF Supplemental Structural Inspection Document--Appendix A,'' dated 
November 2015; the SSIs listed in Boeing Document D6-35022-1, ``747-
400 LCF Supplemental Structural Inspection Document--Appendix A,'' 
dated November 2015, take precedence (i.e., the SSIs in the latter 
document prevail).
    (ii) Within 1,000 flight cycles measured from 12 months after 
the effective date of this AD.

(k) Repair

    If any cracked structure is found during any inspection required 
by paragraph (i) or (j) of this AD, repair before further flight 
using an FAA-approved method.

(l) Compliance Time Clarification

    For compliance times identified in paragraphs (i) and (j) of 
this AD that specify total flight cycles and total flight hours, and 
the SSI is a removable structural component, those compliance times 
must be measured on the SSI since its first installation on any 
airplane, regardless of what the airframe as a whole has 
accumulated. If the total flight cycles and total flight hours on 
the SSI are not available or cannot be determined, use the airframe 
total flight cycles and total flight hours for the compliance times 
identified in paragraphs (i) and (j) of this AD.

(m) No Alternative Inspections and Inspection Intervals

    After accomplishing the revision required by paragraph (h) of 
this AD, no alternative inspections or inspection intervals may be 
used unless the alternative inspection or inspection interval is 
approved as an alternative method of compliance (AMOC) in accordance 
with the procedures specified in paragraph (p) of this AD.

(n) Terminating Action for AD 2004-07-22 R1

    Accomplishing the revision required by paragraph (h) of this AD 
and all of the initial inspections required by paragraph (i) or (j) 
of this AD, as applicable, terminates all requirements of AD 2004-
07-22 R1.

(o) Paperwork Reduction Act Burden Statement

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty 
for failure to comply with a collection of information subject to 
the requirements of the Paperwork Reduction Act unless that 
collection of information displays a current valid OMB Control 
Number. The OMB Control Number for this information collection is 
2120-0056. Public reporting for this collection of information is 
estimated to be approximately 5 minutes per response, including the 
time for reviewing instructions, completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Comments concerning the accuracy of this 
burden and suggestions for reducing the burden should be directed to 
the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: 
Information Collection Clearance Officer, AES-200.

(p) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, 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 certification office, send it to the attention of the 
person identified in paragraph (q)(1) of this AD. Information may be 
emailed to: [email protected]
    (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 Branch, 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) AMOCs approved for AD 2004-07-22 R1 are approved as AMOCs 
for the corresponding provisions of paragraphs (h), (i), (j), and 
(k) of this AD for the SSIs identified in the AMOC, except for any 
SSI that has an expanded inspection area identified in Boeing 
Document D6-35022, ``Supplemental Structural Inspection Document for 
Model 747 Airplanes,'' Revision H, dated September 2013; or Boeing 
Document D6-35022-1, ``747-400 LCF Supplemental Structural 
Inspection Document--Appendix A,'' dated November 2015, as 
applicable.

(q) Related Information

    (1) For more information about this AD, contact Bill Ashforth, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 1601 
Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6432; fax: 
425-917-6590; email: [email protected].
    (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 Standards Branch, 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 September 25, 2017.
Dionne Palermo,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2017-21223 Filed 11-8-17; 8:45 am]
 BILLING CODE 4910-13-P