This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents.

Rules and Regulations Federal Register

36061 

Vol. 86, No. 128 

Thursday, July 8, 2021 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2021–0191; Project 

Identifier AD–2020–01492–E; Amendment 

39–21633; AD 2021–14–06] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is superseding 

Airworthiness Directive (AD) 2019–21– 

11 and AD 2020–07–02. AD 2019–21–11 

applied to all Pratt & Whitney (PW) 

PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, PW1524G–3, 

PW1525G, PW1525G–3, PW1919G, 

PW1921G, PW1922G, PW1923G, and 

PW1923G–A model turbofan engines. 

AD 2020–07–02 applied to all PW 

PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, PW1524G–3, 

PW1525G, and PW1525G–3 model 

turbofan engines. AD 2019–21–11 

required initial and repetitive borescope 

inspections (BSIs) of the low-pressure 

compressor (LPC) rotor 1 (R1) and, 

depending on the results of the 

inspections, replacement of the LPC. AD 

2020–07–02 required the removal from 

service of certain electronic engine 

control (EEC) full authority digital 

electronic control (FADEC) software and 

the installation of a software version 

eligible for installation. This AD 

continues to require repetitive BSIs of 

certain LPC R1s until replacement of 

EEC FADEC software with the updated 

software. This AD also requires a BSI 

after installation of the updated EEC 

FADEC software if certain Onboard 

Maintenance Message fault codes are 

displayed and meet specified criteria. 

The FAA is issuing this AD to address 

the unsafe condition on these products. 

DATES: This AD is effective August 12, 

2021. 

ADDRESSES: For service information 

identified in this final rule, contact Pratt 

& Whitney, 400 Main Street, East 

Hartford, CT 06118; phone: (800) 565– 

0140; email: help24@pw.utc.com; 

website: http://fleetcare.pw.utc.com. 

You may view this service information 

at the Airworthiness Products Section, 

FAA, 1200 District Avenue, Burlington, 

MA 01803. For information on the 

availability of this material at the FAA, 

call (781) 238–7759. It is also available 

at https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0191. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2021–0191; or in person at Docket 

Operations between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal 

holidays. The AD docket contains this 

final rule, any comments received, and 

other information. The address for 

Docket Operations is U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: 

Nicholas Paine, Aviation Safety 

Engineer, ECO Branch, FAA, 1200 

District Avenue, Burlington, MA 01803; 

phone: (781) 238–7116; fax: (781) 238– 

7199; email: nicholas.j.paine@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The FAA issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 to supersede AD 2019–21–11, 

Amendment 39–19777 (84 FR 57813, 

October 29, 2019), (AD 2019–21–11) and 

AD 2020–07–02, Amendment 39–21106 

(85 FR 17742, March 31, 2020), (AD 

2020–07–02). AD 2019–21–11 applied 

to certain PW PW1519G, PW1521G, 

PW1521GA, PW1524G, PW1525G, 

PW1521G–3, PW1524G–3, PW1525G–3, 

PW1919G, PW1921G, PW1922G, 

PW1923G, and PW1923G–A model 

turbofan engines. AD 2020–07–02 

applied to all PW PW1519G, PW1521G, 

PW1521G–3, PW1521GA, PW1524G, 

PW1524G33, PW1525G, and 

PW1525G33 model turbofan engines. 

The NPRM published in the Federal 

Register on March 26, 2021 (86 FR 

16137). The NPRM was prompted by 

reports of in-flight shutdowns due to 

failure of the LPC R1 and by subsequent 

findings of cracked LPC R1s during 

inspection. Additionally, the 

manufacturer performed further root 

cause analysis of the LPC R1 failures 

and determined the need to update the 

EEC FADEC software to automate rotor 

speed management and limit the 

maximum climb and maximum 

continuous thrust ratings. In the NPRM, 

the FAA proposed to retain certain 

requirements of AD 2019–21–11 and 

none of the requirements of AD 2020– 

07–02. In the NPRM, the FAA proposed 

to continue to require a BSI of certain 

LPC R1s for damage and cracks and, 

depending on the results of the BSI, 

replacement of the LPC R1. In the 

NPRM, the FAA proposed to continue to 

require repetitive BSIs of certain LPC 

R1s until replacement of the EEC 

FADEC software with the updated 

software. In the NPRM, the FAA also 

proposed to require a BSI of the LPC R1 

after installation of the updated EEC 

FADEC software if certain Onboard 

Maintenance Message fault codes are 

displayed and meet specified criteria. 

Discussion of Final Airworthiness 

Directive 

Comments 

The FAA received comments from 

two commenters. The commenters were 

Air Line Pilots Association, 

International (ALPA) and Delta Air 

Lines, Inc. (DAL). ALPA supported the 

proposal without change. DAL 

supported the proposal but 

recommended certain changes. The 

following presents the comments 

received on the NPRM and the FAA’s 

response to each comment. 

Request To Correct the Effective Date of 

AD 2019–19–11 

DAL requested that the FAA correct 

the reference to the effective date of AD 

2019–19–11, in paragraph (g)(1)(i) of 

this AD from October 29, 2019, to 

September 26, 2019 (the effective date of 

AD 2019–19–11). 

The FAA agrees and has revised 

paragraph (g)(1)(i) of this AD as 

requested. This change adds no 

additional burden on any operator who 

is required to comply with this AD. 


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36062 Federal Register / Vol. 86, No. 128 / Thursday, July 8, 2021 / Rules and Regulations 

Request To Allow Use of Later 

Revisions of Service Information 

DAL requested that the FAA add the 

phrase ‘‘or later’’ after PW Section 

PW1000G–A–72–00–00–02A–0B5A–A 

of PW Engine Maintenance Manual 

(EMM), Issue No. 016, dated January 15, 

2021, and PW Section PW1000G–A–72– 

31–00–00A–312A–D of PW EMM, Issue 

No. 016, dated January 11, 2021, 

referenced in Notes 2 and 3 to paragraph 

(g)(6) of this AD. DAL stated that if a 

maintenance technician were 

troubleshooting Onboard Maintenance 

Message fault code 7100F0029 or 

7100F0030, the maintenance technician 

would be guided to the latest issue of 

the publication. 

The FAA disagrees to add the phrase 

‘‘or later’’ to the required actions section 

as requested by DAL. Notes 2 and 3 to 

paragraph (g)(6) of this AD, which 

contain references to the sections of the 

EMM specified by DAL, provide 

guidance for both determining the N1 

Exceedance duration and for performing 

the BSI. This AD does not mandate the 

use of specific manual revisions for 

purposes of compliance with the 

required actions. 

Conclusion 

The FAA reviewed the relevant data, 

considered any comments received, and 

determined that air safety requires 

adopting the AD as proposed. 

Accordingly, the FAA is issuing this AD 

to address the unsafe condition on these 

products. Except for minor editorial 

changes, and any other changes 

described previously, this AD is 

adopted as proposed in the NPRM. 

None of the changes will increase the 

economic burden on any operator. 

Related Service Information 

The FAA reviewed Pratt & Whitney 

Service Bulletin (SB) PW1000G–A–72– 

00–0125–00A–930A–D, Issue No. 002, 

dated October 24, 2019; Pratt & Whitney 

SB PW1000G–A–72–00–0075–00B– 

930A–D, Issue No. 003, dated October 

24, 2019; Pratt & Whitney SB 

PW1000G–A–73–00–0044–00A–930A– 

D, Issue No. 004, dated February 23, 

2021; and Pratt & Whitney SB 

PW1000G–A–73–00–0023–00B–930A– 

D, Issue No. 002, dated February 22, 

2021. The FAA also reviewed Section 

PW1000G–A–72–00–00–02A–0B5A–A 

of Pratt & Whitney EMM, Issue No. 016, 

dated January 15, 2021; and Section 

PW1000G–A–72–31–00–00A–312A–D 

of Pratt & Whitney EMM, Issue No. 016, 

dated January 11, 2021. 

Pratt & Whitney SBs PW1000G–A– 

72–00–0125–00A–930A–D, Issue No. 

002, dated October 24, 2019, and 

PW1000G–A–72–00–0075–00B–930A– 

D, Issue No. 003, dated October 24, 

2019, describe procedures for 

performing initial and repetitive BSI of 

certain LPC R1s. Pratt & Whitney SB 

PW1000G–A–73–00–0044–00A–930A– 

D, Issue No. 004, dated February 23, 

2021, describes procedures for replacing 

or modifying the EEC to incorporate 

EEC FADEC software version 

V2.11.10.4. Pratt & Whitney SB 

PW1000G–A–73–00–0023–00B–930A– 

D, Issue No. 002, dated February 22, 

2021, describes procedures for replacing 

or modifying the EEC to incorporate 

EEC FADEC software version V9.5.6.7. 

Section PW1000G–A–72–00–00–02A– 

0B5A–A of Pratt & Whitney EMM, Issue 

No. 016, dated January 15, 2021, 

describes procedures for inspecting the 

engine for possible engine damage after 

receiving notification of an N1 or N2 

overspeed operation. Section 

PW1000G–A–72–31–00–00A–312A–D 

of Pratt & Whitney EMM, Issue No. 016, 

dated January 11, 2021, describes 

procedures for performing a BSI of the 

LPC. 

Interim Action 

The FAA considers this AD to be an 

interim action. If final corrective action 

is later identified, the FAA might 

consider additional rulemaking. 

Costs of Compliance 

The FAA estimates that this AD 

affects 94 engines installed on airplanes 

of U.S. registry. 

The FAA estimates the following 

costs to comply with this AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

Replace EEC FADEC software ...................... 2 work-hours × $85 per hour = $170 ............. $0 $170 $15,980 

BSI per inspection cycle ................................. 2 work-hours × $85 per hour = $170 ............. 0 170 15,980 

The FAA estimates the following 

costs to do any necessary replacements 

that would be required based on the 

results of the inspection. The agency has 

no way of determining the number of 

aircraft that might need this 

replacement: 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Replace LPC R1 ........................................................... 40 work-hours × $85 per hour = $3,400 ...................... $156,000 $159,400 

BSI of the LPC R1 if Onboard Maintenance Message 

fault codes are displayed.

2 work-hours × $85 per hour = $170 ........................... 0 170 

The FAA has included all known 

costs in its cost estimate. According to 

the manufacturer, however, some of the 

costs of this AD may be covered under 

warranty, thereby reducing the cost 

impact on affected individuals. 

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. 

The FAA is 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 


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Federal Register / Vol. 86, No. 128 / Thursday, July 8, 2021 / Rules and Regulations 36063 

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 

The FAA has determined that this AD 

will not have federalism implications 

under Executive Order 13132. This AD 

will not have a substantial direct effect 

on the States, on the relationship 

between the national government and 

the States, or on the distribution of 

power and responsibilities among the 

various levels of government. 

For the reasons discussed above, I 

certify that this AD: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Will not affect intrastate aviation 

in Alaska, and 

(3) Will not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

The Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA amends 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: 

■ a. Removing Airworthiness Directive 

AD 2019–21–11, Amendment 39–19777 

(84 FR 57813, October 29, 2019); and 

AD 2020–07–02, Amendment 39–21106 

(85 FR 17742, March 31, 2020); and 

■ b. Adding the following new 

airworthiness directive: 

2021–14–06 Pratt & Whitney: Amendment 

39–21633; Docket No. FAA–2021–0191; 

Project Identifier AD–2020–01492–E. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective August 12, 2021. 

(b) Affected ADs 

This AD replaces AD 2019–21–11, 

Amendment 39–19777 (84 FR 57813, October 

29, 2019); and AD 2020–07–02, Amendment 

39–21106 (85 FR 17742, March 31, 2020). 

(c) Applicability 

This AD applies to Pratt & Whitney (PW) 

PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, PW1524G–3, 

PW1525G, PW1525G–3, PW1919G, 

PW1921G, PW1922G, PW1923G, and 

PW1923G–A model turbofan engines. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7230, Turbine Engine Compressor 

Section. 

(e) Unsafe Condition 

This AD was prompted by reports of inflight shutdowns due to failure of the lowpressure compressor (LPC) rotor 1 (R1) and 

by subsequent findings of cracked LPC R1s 

during inspection. The FAA is issuing this 

AD to prevent failure of the LPC R1. The 

unsafe condition, if not addressed, could 

result in uncontained release of the LPC R1, 

damage to the engine, damage to the airplane, 

and loss of control of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

(1) Except for those model turbofan engines 

identified in paragraph (g)(2) of this AD, 

perform a borescope inspection (BSI) of the 

LPC R1 for damage and cracks as follows: 

(i) For engines that have accumulated 

fewer than 300 flight cycles since new (CSN), 

perform a BSI within 50 flight cycles (FCs) 

from September 26, 2019 (the effective date 

of AD 2019–19–11), or before further flight, 

whichever occurs later. 

(ii) For engines that have accumulated 

fewer than 300 FCs since installation of 

V2.11.7 or V2.11.8 electronic engine control 

(EEC) full authority digital electronic control 

(FADEC) software, perform a BSI within 50 

FCs from October 29, 2019 (the effective date 

of AD 2019–21–11), or before further flight, 

whichever occurs later. 

(iii) Thereafter, at intervals not to exceed 

50 FCs until the engine accumulates 300 

flight CSN or accumulates 300 FCs since the 

installation of V2.11.7 or V2.11.8 EEC FADEC 

software, whichever occurs later, repeat the 

BSI for damage and cracks. 

(iv) Perform the BSI required by paragraphs 

(g)(1)(i) through (iii) of this AD at the 

following LPC R1 locations: 

(A) The blade tip; 

(B) The leading edge; 

(C) The leading edge fillet to rotor platform 

radius; and 

(D) The airfoil convex side root fillet to 

rotor platform radius. 

(2) For any affected PW model turbofan 

engine installed as a ‘‘zero time spare,’’ 

except for PW1519G, PW1521GA, PW1919G, 

and PW1922G model turbofan engines, 

within 15 FCs from the effective date of this 

AD, and thereafter at intervals not to exceed 

15 FCs until the engine accumulates 300 

flight CSN, perform a BSI of the LPC R1 for 

damage and cracks at the locations in 

paragraph (g)(1)(iv) of this AD. 

(3) Based on the results of the BSIs 

required by paragraphs (g)(1) and (2) of this 

AD, before further flight, remove and replace 

the LPC R1 if: 

(i) There is damage on an LPC R1 that 

exceeds serviceable limits; or 

(ii) Any crack in the LPC R1 exists. 

Note 1 to paragraph (g)(3): Guidance on 

determining the serviceable limits in 

paragraph (g)(3) of this AD can be found in 

PW Service Bulletin (SB) PW1000G–A–72– 

00–0125–00A–930A–D, Issue No. 002, dated 

October 24, 2019, and PW SB PW1000G–A– 

72–00–0075–00B–930A–D, Issue No. 003, 

dated October 24, 2019. 

(4) For PW PW1519G, PW1521G, 

PW1521G–3, PW1521GA, PW1524G, 

PW1524G–3, PW1525G, and PW1525G–3 

model turbofan engines, within 120 days 

from the effective date of this AD, remove the 

EEC FADEC software if the version is earlier 

than EEC FADEC software version V2.11.10.4 

and install EEC FADEC software that is 

eligible for installation. 

(5) For PW PW1919G, PW1921G, 

PW1922G, PW1923G, and PW1923G–A 

model turbofan engines, within 120 days of 

the effective date of this AD, remove the EEC 

FADEC software if the version is earlier than 

EEC FADEC software version V9.5.6.7 and 

install EEC FADEC software that is eligible 

for installation. 

(6) For PW PW1519G, PW1521G, 

PW1521G–3, PW1521GA, PW1524G, 

PW1524G–3, PW1525G, and PW1525G–3 

model turbofan engines with EEC FADEC 

software version V2.11.10.4 or later installed, 

within 15 FCs after receipt of Onboard 

Maintenance Message fault code 7100F0029 

or 7100F0030, perform a BSI of the LPC R1 

for damage and cracks at the locations in 

paragraph (g)(1)(iv) of this AD if the fault 

code is displayed on the ‘‘Active Failure 

Messages’’ and meets the following criteria: 

(i) N1 Exceedance is above 95.2%; 

(ii) N1 Exceedance occurred above 29,100 

feet; and 

(iii) N1 Exceedance occurs for a duration 

of 40 seconds (15 seconds of cockpit display) 

or more during any flight. 

Note 2 to paragraph (g)(6): Guidance on 

determining the N1 Exceedance duration can 

be found in PW Section PW1000G–A–72–00– 

00–02A–0B5A–A of PW Engine Maintenance 

Manual (EMM), Issue No. 016, dated January 

15, 2021. 

Note 3 to paragraph (g)(6): Guidance on 

performing the BSI can be found in PW 

Section PW1000G–A–72–31–00–00A–312A– 

D of PW EMM, Issue No. 016, dated January 

11, 2021. 

(7) As the result of the BSI of the LPC R1 

required by paragraph (g)(6) of this AD, 

before further flight, remove and replace the 

LPC R1 if: 

(i) There is damage on an LPC R1 that 

exceeds serviceable limits; or 

(ii) Any crack in the LPC R1 exists. 

(h) Terminating Actions 

(1) For PW1519G, PW1521G, PW1521G–3, 

PW1521GA, PW1524G, PW1524G–3, 

PW1525G, and PW1525G–3 model turbofan 

engines, the installation of EEC FADEC 

software required by paragraph (g)(4) of this 

AD terminates the repetitive BSI 

requirements of paragraphs (g)(1) and (2) of 

this AD. 


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36064 Federal Register / Vol. 86, No. 128 / Thursday, July 8, 2021 / Rules and Regulations 

(2) For PW1919G, PW1921G, PW1922G, 

PW1923G, and PW1923G–A model turbofan 

engines, the installation of EEC FADEC 

software required by paragraph (g)(5) of this 

AD terminates the repetitive BSI 

requirements of paragraphs (g)(1) and (2) of 

this AD. 

(i) Installation Prohibition 

After the effective date of this AD, do not 

install EEC FADEC software earlier than 

version V2.11.10.4 or version V9.5.6.7 onto 

any engine identified in paragraph (c) of this 

AD. 

(j) Definitions 

(1) For the purpose of this AD, a ‘‘zero time 

spare’’ is an engine that had zero flight hours 

time-in-service when it was installed on an 

airplane after the airplane had entered 

service. 

(2) For the purpose of this AD, ‘‘EEC 

FADEC software that is eligible for 

installation’’ is EEC FADEC software version 

V2.11.10.4 or later for PW1519G, PW1521G, 

PW1521G–3, PW1521GA, PW1524G, 

PW1524G–3, PW1525G, PW1525G–3 model 

turbofan engines and EEC FADEC software 

version V9.5.6.7 or later for PW1919G, 

PW1921G, PW1922G, PW1923G, and 

PW1923G–A model turbofan engines. 

(k) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, ECO 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 Related Information. You may 

email your request to ANE-AD-AMOC@

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) AMOCs approved for AD 2019–21–11 

(84 FR 57813, October 29, 2019) are approved 

as AMOCs for the corresponding provisions 

of this AD except for paragraphs (g)(1)(i) 

through (iv) and (g)(3)(i) and (ii) of this AD. 

(l) Related Information 

For more information about this AD, 

contact Nicholas Paine, Aviation Safety 

Engineer, ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: (781) 

238–7116; fax: (781) 238–7199; email: 

nicholas.j.paine@faa.gov. 

(m) Material Incorporated by Reference 

None. 

Issued on June 23, 2021. 

Lance T. Gant, 

Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2021–13873 Filed 7–7–21; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2020–1174; Project 

Identifier MCAI–2019–00135–E; Amendment 

39–21594; AD 2021–12–07] 

RIN 2120–AA64 

Airworthiness Directives; Rolls-Royce 

Deutschland Ltd & Co KG (Type 

Certificate Previously Held by RollsRoyce Deutschland GmbH, Formerly 

BMW Rolls-Royce GmbH) Turbofan 

Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for certain 

Rolls-Royce Deutschland Ltd & Co KG 

(RRD) BR700–710A1–10, BR700– 

710A2–20 and BR700–710C4–11 model 

turbofan engines. This AD was 

prompted by an investigation by RRD, 

which revealed a quality escape during 

the high-pressure turbine (HPT) stage 1 

disk rim cooling air hole manufacturing 

process. This AD requires removing 

affected HPT disks from service prior to 

reaching specified compliance times or 

at the next engine shop visit, whichever 

occurs first. The FAA is issuing this AD 

to address the unsafe condition on these 

products. 

DATES: This AD is effective August 12, 

2021. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of August 12, 2021. 

ADDRESSES: For service information 

identified in this AD, contact RollsRoyce Deutschland Ltd & Co KG, 

Eschenweg 11, Dahlewitz 15827, 

Germany; phone: +49 33 7086 4040; 

email: rrd.techhelp@rolls-royce.com. 

You may view this service information 

at the FAA, Airworthiness Products 

Section, Operational Safety Branch, 

1200 District Avenue, Burlington, MA 

01803. For information on the 

availability of this material at the FAA, 

call (781) 238–7759. It is also available 

at https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2020–1174. 

Examining the AD Docket 

You may examine the AD docket at 

https://www.regulations.gov by 

searching for and locating Docket No. 

FAA–2020–1174; or in person at Docket 

Operations between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal 

holidays. The AD docket contains this 

final rule, the mandatory continuing 

airworthiness information (MCAI), any 

comments received, and other 

information. The address for Docket 

Operations is U.S. Department of 

Transportation, Docket Operations, 

M–30, West Building Ground Floor, 

Room W12–140, 1200 New Jersey 

Avenue SE, Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: 

Wego Wang, Aviation Safety Engineer, 

ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: 

(781) 238–7134; fax: (781) 238–7199; 

email: wego.wang@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The FAA issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 by adding an AD that would 

apply to certain RRD BR700–710A1–10, 

BR700–710A2–20 and BR700–710C4–11 

model turbofan engines. The NPRM 

published in the Federal Register on 

January 21, 2021 (86 FR 6271). The 

NPRM was prompted by an 

investigation by RRD, which revealed a 

quality escape during the HPT stage 1 

disk rim cooling air hole manufacturing 

process. In the NPRM, the FAA 

proposed to require removing affected 

HPT disks from service prior to reaching 

specified compliance times or at the 

next engine shop visit, whichever 

occurs first. The FAA is issuing this AD 

to address the unsafe condition on these 

products. 

The European Union Aviation Safety 

Agency (EASA), which is the Technical 

Agent for the Member States of the 

European Community, has issued EASA 

AD 2019–0299, dated December 10, 

2019 (referred to after this as ‘‘the 

MCAI’’), to address the unsafe condition 

on these products. The MCAI states: 

An occurrence was reported of an HPT 

stage 1 disc burst on an industrial gas turbine 

engine. Subsequent investigation revealed a 

quality escape during HPT stage 1 disc rim 

cooling air hole manufacturing process. A 

review revealed that 28 HPT stage 1 discs 

were subject to a similar quality escape, two 

of which have been recovered and removed 

from service. The consequence of this 

manufacturing error is that the affected parts 

can no longer safely reach their Declared Safe 

Cyclic Life (DSCL). 

This condition, if not corrected, may lead 

to failure of an affected part, possibly 

resulting in release of high-energy debris, 

with consequent damage to, and/or reduced 

control of, the aeroplane. To address this 

potentially unsafe condition, RRD issued the 

NMSB, providing instructions to remove the 

engine from service for in-shop replacement 

of the affected part. 

For the reasons described above, this 

[EASA] AD reduces the DSCL for the affected 


lotter on DSK11XQN23PROD with RULES1