Federal Register / Vol. 77, No. 57 / Friday, March 23, 2012 / Proposed Rules 16967 

[FR Doc. 2012–6992 Filed 3–22–12; 8:45 am] 

BILLING CODE 3410–02–C 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0079; Directorate 

Identifier 2012–NE–06–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Division Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for Pratt & 

Whitney PW4052, PW4152, PW4056, 

PW4156A, PW4060, PW4060A, 

PW4060C, PW4062, PW4062A, 

PW4158, PW4460, PW4462, PW4164, 

PW4164C, PW4164C/B, PW4168, and 

PW4168A turbofan engines with certain 

high-pressure turbine (HPT) stage 1 

front hubs installed. This proposed AD 

was prompted by Pratt & Whitney’s 

updated low-cycle-fatigue analysis that 

indicated certain HPT stage 1 front hubs 

could initiate a crack prior to the 

published life limit. This proposed AD 

would require removing the affected 

HPT stage 1 front hubs from service 

using a drawdown plan. We are 

proposing this AD to prevent failure of 

the HPT stage 1 front hub, which could 

lead to an uncontained engine failure 

and damage to the airplane. 

DATES: We must receive comments on 

this proposed AD by May 22, 2012. 

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 proposed AD, contact Pratt & 

Whitney, 400 Main St., East Hartford, 

CT 06108; phone: 860–565–7700; fax: 

860–565–1605. You may review copies 

of the referenced service information at 

the FAA, Engine & Propeller Directorate, 

12 New England Executive Park, 

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; 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: 

James Gray, Aerospace Engineer, Engine 

Certification Office, FAA, 12 New 

England Executive Park, Burlington, 

MA; phone: 781–238–7742; fax: 781– 

238–7199; email: james.e.gray@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– 

2012–0079; Directorate Identifier 2012– 

NE–06–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 

A PW2000 field event led Pratt & 

Whitney to re-evaluate the low-cycle 

fatigue analysis of the PW2000 engine 

and similar engine models, including 

the PW4000 engine. Pratt & Whitney’s 

updated analysis indicated that the 

original grain size requirement specified 

on the HPT stage 1 front hub design 

drawing was too large, and may not be 

sufficient to meet the published life 

limits. Although we have not received 

any reports of cracks, parts with the 

larger grain size may initiate a crack 

prior to the published life limits. This 

condition, if not corrected, could result 

in failure of the HPT stage 1 front hub, 

which could lead to an uncontained 

engine failure and damage to the 

airplane. 

Relevant Service Information 

We reviewed Pratt & Whitney Service 

Bulletin (SB) No. PW4ENG 72–795, 

Revision 2, dated April 5, 2011, and SB 

No. PW4G–100–72–220, Revision 4, 

dated September 30, 2011. The SBs list 

the serial numbers of HPT stage 1 front 

hubs with part number (P/N) 51L901 

that are NOT affected by this AD. 

However, all serial numbers of HPT 

stage 1 front hubs with P/N 51L201, 

P/N 51L201–001, P/N 51L601, and 

P/N 52L401 are affected. 

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 

removing the affected HPT stage 1 front 

hubs from service using a drawdown 

plan. 

Costs of Compliance 

We estimate that this proposed AD 

would affect 954 engines installed on 

airplanes of U.S. registry. About 605 

engines use a 20,000 cycles-since new 

(CSN) life limit for the HPT stage 1 front 

hub. For these engines, we estimate the 

lost part life to have a value of about 

$25,400 per engine. About 349 engines 

use a 15,000 CSN life limit. For these 

engines, we estimate the lost life to have 

a value of about $22,013 per engine. 

Based on these figures, we estimate the 

total cost of the proposed AD to U.S. 

operators is $23,049,537. 

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 


TKELLEY on DSK3SPTVN1PROD with PROPOSALS
16968 Federal Register / Vol. 77, No. 57 / Friday, March 23, 2012 / Proposed Rules 

because it addresses an unsafe condition 

that is likely to exist or develop on 

products identified in this rulemaking 

action. 

Regulatory Findings 

We determined that this proposed AD 

would not have federalism implications 

under Executive Order 13132. This 

proposed AD would not have a 

substantial direct effect on the States, on 

the relationship between the national 

Government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government. 

For the reasons discussed above, I 

certify this proposed regulation: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Is not a ‘‘significant rule’’ under 

the DOT Regulatory Policies and 

Procedures (44 FR 11034, February 26, 

1979), 

(3) Will not affect intrastate aviation 

in Alaska, and 

(4) Will not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

The Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 14 CFR part 

39 as follows: 

PART 39—AIRWORTHINESS 

DIRECTIVES 

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): 

Pratt & Whitney Division: Docket No. FAA– 

2012–0079; Directorate Identifier 2012– 

NE–06–AD. 

(a) Comments Due Date 

We must receive comments by May 22, 

2012. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to the following Pratt & 

Whitney Division turbofan engines: 

(1) PW4052, PW4152, and PW4056 

turbofan engines, including models with any 

dash number suffix, with the following highpressure turbine (HPT) stage 1 front hub part 

numbers (P/Ns) installed: 

(i) P/N 51L201, or P/N 51L201–001, or 

P/N 51L601, or P/N 52L401; or 

(ii) P/N 51L901 with a serial number (S/N) 

not listed in Table 9 of the Accomplishment 

Instructions of Pratt & Whitney Service 

Bulletin (SB) No. PW4ENG 72–795, Revision 

2, dated April 5, 2011. 

(2) PW4156A, PW4060, PW4060A, 

PW4060C, PW4062, PW4062A, PW4158, 

PW4460, and PW4462 turbofan engines, 

including models with any dash number 

suffix, with the following HPT stage 1 front 

hub P/Ns installed: 

(i) P/N 51L201, or P/N 51L201–001, or 

P/N 52L401; or 

(ii) P/N 51L901 with an S/N not listed in 

Table 9 of the Accomplishment Instructions 

of Pratt & Whitney SB No. PW4ENG 72–795, 

Revision 2, dated April 5, 2011. 

(3) PW4164, PW4164C, PW4164C/B, 

PW4168, and PW4168A turbofan engines 

with an HPT stage 1 front hub P/N 51L901 

installed with a S/N not listed in Table 27A 

of the Accomplishment Instructions of Pratt 

& Whitney SB No. PW4G–100–72–220, 

Revision 4, dated September 30, 2011. 

(d) Unsafe Condition 

This AD was prompted by Pratt & 

Whitney’s updated low-cycle-fatigue analysis 

that indicated certain HPT stage 1 front hubs 

could initiate a crack prior to the published 

life limit. This AD requires removing the 

affected HPT stage 1 front hubs from service 

using a drawdown plan. We are issuing this 

AD to prevent failure of the HPT stage 1 front 

hub, which could lead to an uncontained 

engine failure and damage to the airplane. 

(e) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(f) Removal of HPT Stage 1 Front Hubs From 

Service 

(1) For HPT stage 1 front hubs listed in 

paragraph (c)(1)(i) and (c)(1)(ii) of this AD, do 

the following: 

(i) If the HPT stage 1 front hub has 

accumulated 17,000 or fewer cycles-since 

new (CSN) on the effective date of this AD, 

remove the HPT stage 1 front hub from 

service before accumulating 18,000 CSN. 

(ii) If the HPT stage 1 front hub has 

accumulated more than 17,000 CSN on the 

effective date of this AD, remove the HPT 

stage 1 front hub from service before 

accumulating an additional 1,000 cycles-inservice (CIS), or at the next piece-part 

exposure after the effective date of this AD, 

whichever occurs first. 

(2) For HPT stage 1 front hubs listed in 

paragraphs (c)(2)(i), (c)(2)(ii), and (c)(3) of 

this AD, do the following: 

(i) If the HPT stage 1 front hub has 

accumulated 12,700 or fewer CSN on the 

effective date of this AD, remove the HPT 

stage 1 front hub from service before 

accumulating 13,700 CSN. 

(ii) If the HPT stage 1 front hub has 

accumulated more than 12,700 CSN on the 

effective date of this AD, remove the HPT 

stage 1 front hub from service before 

accumulating an additional 1,000 CIS, or at 

the next piece-part exposure after the 

effective date of this AD, whichever occurs 

first. 

(g) Installation Prohibition 

After the effective date of this AD, do not 

install or reinstall into any engine any HPT 

stage 1 front hubs listed in paragraph (c)(1)(i) 

and (c)(1)(ii) of this AD that are at piece-part 

exposure and exceed 18,000 CSN, or any 

HPT stage 1 front hubs listed in (c)(2)(i), 

(c)(2)(ii), and (c)(3) of this AD that are at 

piece-part exposure and exceed 13,700 CSN. 

(h) Definition 

For the purpose of this AD, piece-part 

exposure means that the part is completely 

disassembled and removed from the engine. 

(i) Alternative Methods of Compliance 

(AMOCs) 

The Manager, Engine Certification Office, 

may approve AMOCs for this AD. Use the 

procedures found in 14 CFR 39.19 to make 

your request. 

(j) Related Information 

(1) For more information about this AD, 

contact James Gray, Aerospace Engineer, 

Engine Certification Office, FAA, 12 New 

England Executive Park, Burlington, MA; 

phone: 781–238–7742; fax: 781–238–7199; 

email: james.e.gray@faa.gov. 

(2) For service information identified in 

this AD, contact Pratt & Whitney, 400 Main 

St., East Hartford, CT 06108; phone: 860– 

565–7700; fax: 860–565–1605. 

(3) You may review copies of the 

referenced service information at the FAA, 

Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA. For 

information on the availability of this 

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

Issued in Burlington, Massachusetts, on 

March 14, 2012. 

Peter A. White, 

Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

[FR Doc. 2012–6965 Filed 3–22–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0324; Directorate 

Identifier 2012–CE–008–AD] 

RIN 2120–AA64 

Airworthiness Directives; Burkhart 

GROB Luft- und Raumfahrt GmbH 

Powered Sailplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for 


TKELLEY on DSK3SPTVN1PROD with PROPOSALS