Federal Register / Vol. 82, No. 164 / Friday, August 25, 2017 / Proposed Rules 40511 

including substeps and identified figures, can 

still be done as specified, and the airplane 

can be put back in an airworthy condition. 

(k) Related Information 

(1) For more information about this AD, 

contact Muoi Vuong, Aerospace Engineer, 

Airframe Section, FAA, Los Angeles ACO 

Branch, 3960 Paramount Boulevard, 

Lakewood, CA 90712–4137; phone: 562–627– 

5205; fax: 562–627–5210; email: 

Muoi.Vuong@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 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 August 

10, 2017. 

Dionne Palermo, 

Acting Director, System Oversight Division, 

Aircraft Certification Service. 

[FR Doc. 2017–17538 Filed 8–24–17; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2017–0779; Product 

Identifier 2017–NM–040–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 787–8 

airplanes. This proposed AD was 

prompted by reports of degraded bondline performance of co-bonded upper 

wing stringer-to-skin joints. This 

proposed AD would require repetitive 

inspections of certain upper wing 

stringers for any disbond and corrective 

actions, if necessary; and a terminating 

preventative modification of installing 

disbond arrestment (DBA) fasteners. 

This proposed AD would also require 

revising the inspection or maintenance 

program to incorporate an airworthiness 

limitation. We are proposing this AD to 

address the unsafe condition on these 

products. 

DATES: We must receive comments on 

this proposed AD by October 10, 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 Standards Branch, 

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–2017–0779. 

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– 

0779; 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: 

Allen Rauschendorfer, Aerospace 

Engineer, Airframe Branch, FAA, Seattle 

ACO Branch, 1601 Lind Avenue SW., 

Renton, WA 98057–3356; phone: 425– 

917–6487; fax: 425–917–6590; email: 

allen.rauschendorfer@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– 

2017–0779; Product Identifier 2017– 

NM–040–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 degraded 

bond-line performance of co-bonded 

upper wing stringer-to-skin joints. The 

co-bonded upper wing stringer-to-skin 

joints were determined to have 

degraded bond-line performance due to 

the exposure of the bond surface with 

the use of BMS 8–308 peel ply to cure 

times that exceeded 4 hours at a 

temperature of 345 degrees Fahrenheit 

(F) plus or minus 10 F. The upper wing 

stringer-to-skin joint disbonding can 

reduce the structural capability to where 

it cannot sustain limit load, which 

could adversely affect the structural 

integrity of the airplane. 

Related Service Information Under 1 

CFR Part 51 

We have reviewed Boeing Alert 

Service Bulletin B787–81205– 

SB570030–00, Issue 001, dated March 

17, 2017 (‘‘ASB B787–81205– 

SB570030–00, Issue 001’’). This service 

information describes procedures for 

inspection of certain upper wing 

stringers for any disbond and repairs; 

and for a preventative modification 

which consists of, depending on 

airplane configuration, applying copper 

foil to the upper wing at certain stringer 

and rib bay locations, installing DBA 

fasteners on the upper flanges of the 

upper wing stringers at the stringer and 

rib bay locations, applying cap seals to 

the DBA fasteners, and applying edge 

sealant to the stringers at the DBA 

fastener installation locations. 

We have also reviewed Airworthiness 

Limitation (AWL) 57–AWL–13, 

‘‘Inspection Requirements for In-Tank 

Fasteners and Edge Seal near Disbond 

Arrestment (DBA) Fastener Installations 

of Lightning Zone 2,’’ of Boeing 787 

Special Compliance Items/ 

Airworthiness Limitations, D011Z009– 

03–04, dated February 2017. This 

service information describes tasks for 

inspecting in-tank fasteners and edge 

seals near DBA fastener installations of 

lightning zone 2. 


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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 in ASB B787–81205– 

SB570030–00, Issue 001, see this service 

information at http://

www.regulations.gov by searching for 

and locating Docket No. FAA–2017– 

0779. 

This AD requires revisions to certain 

operator maintenance documents to 

include new actions (e.g., inspections). 

Compliance with these actions is 

required by 14 CFR 91.403(c). For 

airplanes that have been previously 

modified, altered, or repaired in the 

areas addressed by this proposed AD, 

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 (l) of this proposed AD. The 

request should include a description of 

changes to the required actions that will 

ensure the continued damage tolerance 

of the affected structure. 

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 

ASB B787–81205–SB570030–00, 

Issue 001, 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. 

Explanation of Applicability 

In the applicability of this proposed 

AD, we refer to the airplanes identified 

in ASB B787–81205–SB570030–00, 

Issue 001. In addition, we have included 

line numbers 10, 13, 15, 16, 17, 18, and 

19 in the applicability of this proposed 

AD because those line numbers are 

included in the applicability for AWL 

57–AWL–13. Those line numbers are 

not listed in ASB B787–81205– 

SB570030–00, Issue 001, and the actions 

specified in ASB B787–81205– 

SB570030–00, Issue 001 are not 

required for those line numbers because 

the actions in the service information 

were completed during production. 

Costs of Compliance 

We estimate that this proposed AD 

affects 24 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 

Inspection ............................................... 49 work-hours × $85 per hour = $4,165 

per inspection cycle.

$0 $4,165 per inspection cycle.$99,960 per inspection cycle. 

Modification ............................................ Up to 352 work-hours × $85 per hour = 

$29,920.

1,902 Up to $31,822 ........ Up to $763,728. 

Maintenance or Inspection Program Revision.1 work-hour × $85 per hour = $85 ........ 0 $85 ......................... $2,040. 

We have received no definitive data 

that would enable us to provide cost 

estimates for the on-condition actions 

specified in this proposed AD. 

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 

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. 


pmangrum on DSK3GDR082PROD with PROPOSALS
Federal Register / Vol. 82, No. 164 / Friday, August 25, 2017 / Proposed Rules 40513 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

The Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 14 CFR part 

39 as follows: 

PART 39—AIRWORTHINESS 

DIRECTIVES 

■ 1. The authority citation for part 39 

continues to read as follows: 

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

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive (AD): 

The Boeing Company: Docket No. FAA– 

2017–0779; Product Identifier 2017– 

NM–040–AD. 

(a) Comments Due Date 

We must receive comments by October 10, 

2017. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to The Boeing Company 

Model 787–8 airplanes, certificated in any 

category, as identified in Boeing Alert 

Service Bulletin B787–81205–SB570030–00, 

Issue 001, dated March 17, 2017 (‘‘ASB 

B787–81205–SB570030–00, Issue 001’’), and 

line numbers 10, 13, 15, 16, 17, 18, and 19. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 57; Wings. 

(e) Unsafe Condition 

This AD was prompted by reports of 

degraded bond-line performance of cobonded upper wing stringer-to-skin joints. 

We are issuing this AD to prevent upper wing 

stringer-to-skin joint disbonding, which can 

reduce the structural integrity of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Inspections and Corrective Actions 

For airplanes identified in ASB B787– 

81205–SB570030–00, Issue 001: Except as 

specified in paragraph (k)(1) of this AD, at 

the applicable time specified in paragraph 5., 

‘‘Compliance,’’ of ASB B787–81205– 

SB570030–00, Issue 001: Do an ultrasonic 

inspection for any disbond on the left side 

and right side upper wing stringers; and do 

all applicable corrective actions; in 

accordance with the Accomplishment 

Instructions of ASB B787–81205–SB570030– 

00, Issue 001, except as specified in 

paragraph (k)(2) of this AD. Do all applicable 

corrective actions before further flight. 

Repeat the inspection of the upper wing 

stringers thereafter at the applicable intervals 

specified in paragraph 5., ‘‘Compliance,’’ of 

ASB B787–81205–SB570030–00, Issue 001 

until the actions required by paragraph (j) of 

this AD are done. 

(h) Maintenance or Inspection Program 

Revision 

(1) For airplanes identified in ASB B787– 

81205–SB570030–00, Issue 001: Prior to or 

concurrently with accomplishing the actions 

required by paragraph (g) of this AD, revise 

the inspection or maintenance program, as 

applicable, to incorporate Airworthiness 

Limitation (AWL) 57–AWL–13. ‘‘Inspection 

Requirements for In-Tank Fasteners and Edge 

Seal near Disbond Arrestment (DBA) 

Fastener Installations of Lightning Zone 2,’’ 

of Boeing 787 Special Compliance Items/ 

Airworthiness Limitations, D011Z009–03–04, 

dated February 2017. The initial compliance 

time for accomplishing the tasks specified in 

AWL 57–AWL–13 is within 24,000 flight 

cycles or 12 years, whichever occurs first, 

after accomplishing the actions specified in 

ASB B787–81205–SB570030–00, Issue 001. 

(2) For airplanes having line numbers 10, 

13, and 15 through 19 inclusive: Within 60 

days after the effective date of this AD, revise 

the inspection or maintenance program, as 

applicable, to incorporate AWL 57–AWL–13, 

‘‘Inspection Requirements for In-Tank 

Fasteners and Edge Seal near Disbond 

Arrestment (DBA) Fastener Installations of 

Lightning Zone 2,’’ of Boeing 787 Special 

Compliance Items/Airworthiness 

Limitations, D011Z009–03–04, dated 

February 2017. The initial compliance time 

for accomplishing the tasks specified in AWL 

57–AWL–13 is prior to the accumulation of 

24,000 total flight cycles or within 12 years 

after the date of issuance of the original 

airworthiness certificate or date of issuance 

of the original export certificate of 

airworthiness, whichever occurs first. 

(i) No Alternative Actions or Intervals 

After the action required by paragraph (h) 

of this AD has been done, no alternative 

actions (e.g., inspections) or intervals may be 

used unless the actions or intervals are 

approved as an AMOC in accordance with 

the procedures specified in paragraph (l) of 

this AD. 

(j) Inspection and Modification 

For airplanes identified in ASB B787– 

81205–SB570030–00, Issue 001, that have not 

done ‘‘PART 3: PREVENTIVE 

MODIFICATION’’ of the Accomplishment 

Instructions of ASB B787–81205–SB570030– 

00, Issue 001, at all of the unrepaired areas 

of the upper wing stringers: At the applicable 

time specified in paragraph 5., 

‘‘Compliance,’’ of ASB B787–81205– 

SB570030–00, Issue 001, do the actions 

specified in paragraphs (j)(1) and (j)(2) of this 

AD, in accordance with the Accomplishment 

Instructions of ASB B787–81205–SB570030– 

00, Issue 001, except as specified in 

paragraph (k)(2) of this AD. Doing the actions 

required by this paragraph terminates the 

repetitive inspections required by paragraph 

(g) of this AD. 

(1) Do an ultrasonic inspection for any 

disbond on the left side and right side upper 

wing stringers, and do all applicable 

corrective actions. Do all applicable 

corrective actions before further flight. 

(2) Do the preventative modification in 

accordance with ‘‘PART 3: PREVENTIVE 

MODIFICATION’’ of the Accomplishment 

Instructions of ASB B787–81205–SB570030– 

00, Issue 001. 

(k) Exceptions to Service Information 

(1) Where paragraph 5., ‘‘Compliance,’’ of 

ASB B787–81205–SB570030–00, Issue 001, 

specifies a compliance time ‘‘after the Issue 

001 date of this service bulletin,’’ this AD 

requires compliance within the specified 

compliance time after the effective date of 

this AD. 

(2) Although ASB B787–81205–SB570030– 

00, Issue 001, specifies to contact Boeing for 

repair instructions, and specifies that action 

as ‘‘RC’’ (Required for Compliance), this AD 

requires repair before further flight using a 

method approved in accordance with the 

procedures specified in paragraph (l) of this 

AD. 

(l) 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 (m)(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 

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) Except as required by paragraph (k)(2) 

of this AD: For service information that 

contains steps that are labeled as Required 

for Compliance (RC), the provisions of 

paragraphs (l)(4)(i) and (l)(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 


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40514 Federal Register / Vol. 82, No. 164 / Friday, August 25, 2017 / Proposed Rules 

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. 

(m) Related Information 

(1) For more information about this AD, 

contact Allen Rauschendorfer, Aerospace 

Engineer, Airframe Branch, FAA, Seattle 

ACO Branch, 1601 Lind Avenue SW., 

Renton, WA 98057–3356; phone: 425–917– 

6487; fax: 425–917–6590; email: 

allen.rauschendorfer@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 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 August 

9, 2017. 

Dionne Palermo, 

Acting Director, System Oversight Division, 

Aircraft Certification Service. 

[FR Doc. 2017–17543 Filed 8–24–17; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2017–0719; Product 

Identifier 2017–NE–22–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Division 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for all Pratt 

& Whitney Division (PW) PW4074, 

PW4074D, PW4077, PW4077D, 

PW4084D, PW4090, and PW4090–3 

turbofan engines. This proposed AD was 

prompted by the discovery of multiple 

cracked outer diffuser cases. This 

proposed AD would require initial and 

repetitive inspections to detect cracks in 

the outer diffuser case and removal from 

service of cases that fail inspection. We 

are proposing this AD to address the 

unsafe condition on these products. 

DATES: We must receive comments on 

this proposed AD by September 25, 

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 Pratt & Whitney 

Division, 400 Main St., East Hartford, 

CT 06118; phone: 800–565–0140; fax: 

860–565–5442. You may view this 

service information at the FAA, Engine 

and Propeller Standards Branch, Policy 

and Innovation Division, 1200 District 

Avenue, Burlington, MA. For 

information on the availability of this 

material at the FAA, call 781–238–7125. 

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– 

0719; 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 NPRM, 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: JoAnn Theriault, Aerospace Engineer, 

FAA, ECO Branch, Compliance and 

Airworthiness Division,1200 District 

Avenue, Burlington, MA 01803; phone: 

781–238–7105; fax: 781–238–7199; 

email: jo-ann.theriault@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– 

2017–0719; Directorate Identifier 2017– 

NE–22–AD’’ at the beginning of your 

comments. We specifically invite 

comments on the overall regulatory, 

economic, environmental, and energy 

aspects of this NPRM. We will consider 

all comments received by the closing 

date and may amend this NPRM 

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 NPRM. 

Discussion 

We were notified of the discovery of 

multiple cracked outer diffuser cases. 

This proposed AD requires initial and 

repetitive inspections to detect cracks in 

the outer diffuser case and removal from 

service of cases that fail inspection. This 

condition, if not corrected, could result 

in failure of the outer diffuser case, 

uncontained case release, damage to the 

engine, and damage to the airplane. 

Related Service Information Under 1 

CFR Part 51 

We reviewed PW Service Bulletin 

(SB) No. PW4G–112–A72–347, dated 

March, 31, 2017. This PW SB provides 

guidance on performing outer diffuser 

case fluorescent penetrant inspections 

(FPI). 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. 

Other Related Service Information 

We reviewed PW4000 Series (112 

Inch) Engine Cleaning, Inspection and 

Repair (CIR) Manual, Part Number 

51A750, Revision Number 74, section 

72–41–13, Inspection/Check-02, dated 

July 15, 2017. This manual section 

provides guidance on performing the 

high sensitivity FPI of the outer diffuser 

case at piece-part exposure. 

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 

initial and repetitive inspections to 

detect cracks in the outer diffuser case 

and removal from service of cases that 

fail inspection. 

Costs of Compliance 

We estimate that this proposed AD 

affects 121 engines installed on 

airplanes of U.S. registry. 

We estimate the following costs to 

comply with this proposed AD: 


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