Federal Register / Vol. 77, No. 173 / Thursday, September 6, 2012 / Rules and Regulations 54791 

fitting is installed using the same size bolts, 

repetitive thereafter inspect every 16,600 

flight cycles. 

If cracks are found during the initial 

inspection or during any subsequent 

repetitive inspection required by this AD and 

the replacement wing-to-fuselage attach 

fitting is installed using the oversized bolts, 

repetitive thereafter inspect every 13,100 

flight cycles. 

Issued in Kansas City, Missouri, on August 

24, 2012. 

Earl Lawrence, 

Manager, Small Airplane Directorate, Aircraft 

Certification Service. 

[FR Doc. 2012–21536 Filed 9–5–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0228; Directorate 

Identifier 2012–NE–09–AD; Amendment 

39–17179; AD 2012–18–03] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Division Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for certain 

Pratt & Whitney Division PW4000–94′′ 

and PW4000–100′′ turbofan engines 

having a 1st stage high-pressure turbine 

(HPT) seal support, part number (P/N) 

55K601 (contained within assembly P/N 

55K602–01) or P/N 50K532 (contained 

within assembly P/N 50K530–01), 

installed. This AD was prompted by 58 

reports of cracked 1st stage HPT air seal 

rings, including 15 in-flight engine 

shutdowns. This AD requires removal 

and replacement of the 1st stage HPT 

seal support and inspection of the 1st 

stage HPT air seal ring. We are issuing 

this AD to prevent failure of the 1st 

stage HPT air seal ring, which could 

lead to an internal oil fire, uncontained 

engine failure, and damage to the 

airplane. 

DATES: This AD is effective October 11, 

2012. 

ADDRESSES: 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. You may view this 

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 AD, the regulatory 

evaluation, any comments received, and 

other information. The address for the 

Docket Office (phone: 800–647–5527) is 

Document Management Facility, 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: 

James Gray, Aerospace Engineer, Engine 

& Propeller Directorate, FAA, 12 New 

England Executive Park, Burlington, MA 

01803; phone: 781–238–7742; fax: 781– 

238–7199; email: james.e.gray@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 to include an AD that would 

apply to the specified products. That 

NPRM published in the Federal 

Register on April 20, 2012 (77 FR 

23637). That NPRM proposed to require 

removal and replacement of the 1st 

stage HPT seal support and inspection 

of the 1st stage HPT air seal ring. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. The 

following presents the comments 

received on the proposal and the FAA’s 

response to each comment. 

Support for the NPRM 

Commenter The Boeing Company 

supports the contents of the proposed 

AD (77 FR 23637, April 20, 2012) as 

written. 

Request To Add Credit for Prior 

Compliance 

FedEx Express (FedEx) requested that 

the AD include credit for previous 

compliance. 

We agree. We added ‘‘Comply with 

this AD the next time the HPT module 

is removed from the engine, unless 

already done’’ to paragraph (e) of the 

AD. 

Request To Change Compliance to Next 

Piece-Part Exposure 

FedEx requested that we clarify that 

the required removal and inspections 

occur when the part is completely 

disassembled and at the piece-part level. 

We do not agree. Removal of the 1st 

stage HPT seal support and inspection 

of the 1st stage HPT air seal ring are 

required when the HPT module is 

removed from the engine, which is not 

necessarily when the parts are at the 

piece-part level. Performing the actions 

the next time the HPT module is 

removed is required to maintain an 

acceptable level of safety for the fleet. 

We did not change the AD. 

Request To Add the P/N of the Affected 

1st Stage HPT Air Seal Ring 

Lufthansa Technik AG requested that 

we add the P/N of the 1st stage HPT air 

seal ring that requires inspection to 

paragraph (e)(2) of the proposed AD (77 

FR 23637, April 20, 2012). The 

commenter states that there are two air 

seals in this area of the engine and 

clarification would help avoid 

confusion over which one requires 

inspection. 

We agree. We revised paragraph (e)(2) 

of the AD to include 1st stage HPT air 

seal ring, P/N 50L664. 

Request To Change Compliance Time 

Martinair requested that paragraph (e) 

of the proposed AD (77 FR 23637, April 

20, 2012) be changed from ‘‘* * * the 

next time that the engine is separated at 

the M-flange and the HPT module is 

removed from the engine’’ to ‘‘* * * the 

next time the HPT module is removed 

from the engine.’’ The commenter states 

that the wording is confusing and may 

be interpreted that one is allowed to 

separate the engine at the M-flange, 

without intending to remove the HPT 

module from the engine, and therefore 

the support would not require 

replacement. 

We agree. Including reference to the 

M-flange is redundant and not required, 

since the M-flange must be separated for 

the HPT module to be removed from the 

engine. We changed paragraph (e) of the 

AD to ‘‘comply with this AD the next 

time that the HPT module is removed 

from the engine.’’ 

Request To Reference the Latest Service 

Information 

Pratt & Whitney (P&W) requested that 

the AD reference the latest versions of 

service bulletins (SBs) PW4ENG 72–721 

and PW4G–100–72–166 because they 

were revised since the proposed AD (77 

FR 23637, April 20, 2012) was 

published. 

We disagree. The service information 

is only included as related information 

and is not incorporated by reference. 

Therefore, it is not necessary to specify 

a revision level and date of the service 

information in the AD. The proposed 

AD did include the revision level and 

date, but we modified the AD to remove 

those details. 


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54792 Federal Register / Vol. 77, No. 173 / Thursday, September 6, 2012 / Rules and Regulations 

Request To Revise the P/Ns of the 1st 

Stage HPT Seal Support 

Martinair, United, and P&W requested 

that the P/Ns of the 1st stage HPT seal 

support be changed because the 1st 

stage HPT seal support P/N is not 

generally tracked by itself, although the 

assembly P/N is. One commenter 

recommended mandating full 

incorporation of P&W SBs PW4ENG 72– 

721 and PW4G–100–72–166, while 

another commenter recommended 

including the assembly P/Ns. 

We partially agree. We agree that the 

assembly P/Ns should be included for 

clarity because the 1st stage HPT seal 

support is not generally tracked by 

itself. The assembly includes the 

support and the mating brush seal. Even 

though they are sold as sets and 

generally tracked together, it is 

important to note that the unsafe 

condition has been identified on the 

HPT seal support and not the brush seal. 

We disagree that the SBs should be 

incorporated by reference because there 

are multiple acceptable methods of 

performing the actions required by the 

AD. We changed paragraph (e)(1) of the 

AD to ‘‘Remove the 1st stage HPT seal 

support, P/N 55K601 (contained within 

assembly P/N 55K602–01) or P/N 

50K532 (contained within assembly P/N 

50K530–01), from service and replace it 

with a serviceable 1st stage HPT seal 

support.’’ 

Request To Revise the Cost of 

Compliance 

United requested that we revise the 

costs of compliance because the latest 

parts cost is $48,695, not $45,723, as 

stated in the proposed AD (77 FR 23637, 

April 20, 2012). 

We agree. We included the latest parts 

costs in the Costs of Compliance 

paragraph of the AD. 

Conclusion 

We reviewed the relevant data, 

considered the comments received, and 

determined that air safety and the 

public interest require adopting the AD 

with the changes described previously. 

We also determined that, other than the 

updated parts cost, these changes will 

not increase the economic burden on 

any operator nor increase the scope of 

the AD. 

Costs of Compliance 

We estimate that this AD will affect 

446 P&W PW4000–94′′ and PW4000– 

100′′ turbofan engines installed on 

airplanes of U.S. registry. We also 

estimate that it will take about 3 workhours to perform the removal and 

replacement of the 1st stage HPT seal 

support, and the removal, inspection, 

and replacement if necessary of the 1st 

stage HPT air seal ring. The average 

labor rate is $85 per work-hour. 

Required parts will cost about $48,695 

per engine. Based on these figures, we 

estimate the total cost of the AD to U.S. 

operators to be $21,831,700. 

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. 

Regulatory Findings 

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) Is not a ‘‘significant rule’’ under 

DOT Regulatory Policies and Procedures 

(44 FR 11034, February 26, 1979), 

(3) Will not affect intrastate aviation 

in, 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. 

Adoption of 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 adding 

the following new airworthiness 

directive (AD): 

2012–18–03 Pratt & Whitney Division: 

Amendment 39–17179; Docket No. 

FAA–2012–0228; Directorate Identifier 

2012–NE–09–AD. 

(a) Effective Date 

This AD is effective October 11, 2012. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to the following Pratt & 

Whitney Division turbofan engines: 

(1) PW4000–94′′ engine models PW4050, 

PW4052, PW4056, PW4152, PW4156, 

PW4650, PW4060, PW4060A, PW4060C, 

PW4062, PW4062A, PW4156A, PW4158, 

PW4160, PW4460, and PW4462, including 

models with any dash-number suffix, with a 

1st stage high-pressure turbine (HPT) seal 

support, part number (P/N) 55K601 

(contained within assembly P/N 55K602–01) 

or P/N 50K532 (contained within assembly 

P/N 50K530–01), installed. 

(2) PW4000–100′′ engine models PW4164, 

PW4164C, PW4164C/B, PW4168, and 

PW4168A with a 1st stage HPT seal support, 

P/N 55K601 (contained within assembly P/N 

55K602–01) or P/N 50K532 (contained 

within assembly P/N 50K530–01), installed. 

(d) Unsafe Condition 

This AD was prompted by 58 reports of 

cracked 1st stage HPT air seal rings, 

including 15 in-flight engine shutdowns. We 

are issuing this AD to prevent failure of the 

1st stage HPT air seal ring, which could lead 

to an internal oil fire, uncontained engine 

failure, and damage to the airplane. 

(e) Compliance 

Comply with this AD the next time the 

HPT module is removed from the engine, 

unless already done. 

(1) Remove the 1st stage HPT seal support, 

P/N 55K601 (contained within assembly P/N 

55K602–01) or P/N 50K532 (contained 

within assembly P/N 50K530–01), from 

service and replace it with a serviceable 1st 

stage HPT seal support. 

(2) Remove the 1st stage HPT air seal ring, 

P/N 50L664, from the engine and fluorescentpenetrant-inspect, or eddy current-inspect, it 

for cracks. If found cracked, remove the 1st 

stage HPT air seal ring from service. 

(f) Definition 

For the purpose of this AD, a serviceable 

1st stage HPT seal support is one that has a 

P/N that is not listed in this AD. 


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Federal Register / Vol. 77, No. 173 / Thursday, September 6, 2012 / Rules and Regulations 54793 

(g) 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. 

(h) Related Information 

(1) For more information about this AD, 

contact James Gray, Aerospace Engineer, 

FAA, Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 

01803; phone: 781–238–7742; fax: 781–238– 

7199; email: james.e.gray@faa.gov. 

(2) Pratt & Whitney Service Bulletin (SB) 

No. PWENG 72–721 and SB No. PW4G–100– 

72–166, pertain to the subject of this AD. 

(3) For service information identified in 

this AD, contact Pratt & Whitney, 400 Main 

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

565–8770; fax: 860–565–4503. 

(i) Material Incorporated by Reference 

None. 

Issued in Burlington, Massachusetts, on 

August 16, 2012. 

Colleen M. D’Alessandro, 

Assistant Manager, Engine & Propeller 

Directorate, Aircraft Certification Service. 

[FR Doc. 2012–21821 Filed 9–5–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–1229; Directorate 

Identifier 2011–NM–132–AD; Amendment 

39–17181; AD 2012–18–05] 

RIN 2120–AA64 

Airworthiness Directives; the Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for certain 

The Boeing Company Model DC–9–10, 

DC–9–20, DC–9–30, DC–9–40, and DC– 

9–50 series airplanes; and Model DC–9– 

81 (MD–81), DC–9–82 (MD–82), DC–9– 

83 (MD–83), DC–9–87 (MD–87), MD–88, 

and MD–90–30 airplanes; equipped 

with center wing fuel tank and Boeing 

original equipment manufacturerinstalled auxiliary fuel tanks. This AD 

was prompted by fuel system reviews 

conducted by the manufacturer. This 

AD requires adding design features to 

detect electrical faults and to detect a 

pump running in an empty fuel tank. 

We are issuing this AD to reduce the 

potential of ignition sources inside fuel 

tanks, which, in combination with 

flammable fuel vapors, could result in 

fuel tank explosions and consequent 

loss of the airplane. 

DATES: This AD is effective October 11, 

2012. 

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 AD, the regulatory 

evaluation, any comments received, and 

other information. The address for the 

Docket Office (phone: 800–647–5527) is 

Document Management Facility, 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: Serj 

Harutunian, Aerospace Engineer, 

Propulsion Branch, ANM–140L, FAA, 

Los Angeles Aircraft Certification 

Office, 3960 Paramount Boulevard, 

Lakewood, California 90712–4137; 

phone: 562–627–5254; fax: 562–627– 

5210; email: serj.harutunian@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 to include an AD that would 

apply to the specified products. That 

NPRM published in the Federal 

Register on November 14, 2011 (76 FR 

70377). That NPRM proposed to require 

adding design features to detect 

electrical faults, to detect a pump 

running in an empty fuel tank, and to 

ensure that a fuel pump’s operation is 

not affected by certain conditions. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. The 

following presents the comments 

received on the proposal (76 FR 70377, 

November 14, 2011) and the FAA’s 

response to each comment. 

Request To Revise Applicability 

Boeing requested that we revise the 

applicability of the NPRM (76 FR 70377, 

November 14, 2011) to exclude 

airplanes from which auxiliary fuel 

tanks have been removed, and to add 

certain airplanes equipped with a center 

wing fuel tank. Boeing stated that the 

system safety assessments (SSAs) of 

Special Federal Aviation Regulation No. 

88 (‘‘SFAR 88,’’ Amendment 21–78 (66 

FR 23086, May 7, 2001) concluded that 

design changes were required on all 

auxiliary fuel tanks on Model DC–9, 

MD–80, and MD–90 airplanes, and on 

the center wing fuel tank on Model MD– 

80 and MD–90 airplanes. American 

Airlines (American) concurred with 

Boeing’s position on this issue. 

We agree to limit the applicability of 

this AD to affected airplanes equipped 

with center wing fuel tanks and Boeing 

OEM-installed auxiliary fuel tanks. We 

also agree that airplanes on which 

auxiliary fuel tanks have been removed 

are not subject to the requirements of 

this AD. We have revised paragraph (c) 

in this final rule accordingly. 

Requests To Remove Criteria for Mean 

Time Between Failures (MTBF) 

Boeing and TDG Aerospace requested 

that we provide justification for the 

removal of pump nuisance trip relative 

to the 100,000-hour MTBF reliability 

requirements to mitigate the ignition 

prevention unsafe condition. The 

commenters asserted that the 100,000- 

hour MTBF reliability requirement is 

not a contributing factor to the ignition 

source unsafe condition for design 

changes mandated by the NPRM (76 FR 

70377, November 14, 2011). American 

concurred with Boeing’s position on 

this issue. 

We agree with the request. The MTBF 

of the component will be addressed in 

the design change package provided for 

certification to satisfy the criteria for 

compliance with the requirements of 

this AD. We have accordingly removed 

paragraph (g)(3) in this final rule. 

Request To Redefine Certain Failure 

Conditions 

Boeing claimed that the NPRM (76 FR 

70377, November 14, 2011) was too 

broad in its descriptions of the unsafe 

failure modes. Boeing requested that we 

revise paragraph (g) of the NPRM to 

define the failure modes that would 

require corrective action as electrical 

faults that are ‘‘capable of burning 

through the pump housing’s explosionproof boundaries’’ (instead of those that 

‘‘can cause arcing and burn through the 

fuel pump housing,’’ as specified in the 

NPRM). Boeing asserted that this 

clarification would ensure that the 

corrective actions would target only the 

potential fuel tank ignition sources 

identified during the SSAs, by 

identifying only those fuel pump 

electrical faults and fuel pump dryrunning conditions capable of 

developing a fuel tank ignition source. 

American concurred with Boeing’s 

position on this issue. 

We disagree with the request. 

Narrowing the failure conditions to 

certain types of failures or certain 

explosion-proof pump boundaries 

would limit the application of a broader 


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