11418 Federal Register / Vol. 77, No. 38 / Monday, February 27, 2012 / Proposed Rules 

(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): 

The Boeing Company: Docket No. FAA– 

2012–0183; Directorate Identifier 2011– 

NM–131–AD. 

(a) Comments Due Date 

We must receive comments by April 12, 

2012. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to The Boeing Company 

Model 737–600, –700, –700C, –800, –900, 

and –900ER series airplanes, certificated in 

any category, as identified in Boeing Special 

Attention Service Bulletin 737–25–1641, 

Revision 1, dated August 8, 2011. 

(d) Subject 

Joint Aircraft System Component (JASC)/ 

Air Transport Association (ATA) of America 

Code 25: Equipment/Furnishings. 

(e) Unsafe Condition 

This AD was prompted by reports from the 

manufacturer that center overhead stowage 

(COS) boxes could fall from their supports 

under forward load levels less than the 9G 

forward load requirements as defined by 

Federal Aviation Regulations. We are issuing 

this AD to prevent detachment of COS boxes 

at forward load levels less than 9G during an 

emergency landing, which would cause 

injury to passengers and/or crew and could 

impede subsequent rapid evacuation. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Modification and Installation of Center 

Overhead Stowage Boxes 

Within 60 months after the effective date 

of this AD, modify the COS boxes in 

accordance with the Accomplishment 

Instructions of Boeing Special Attention 

Service Bulletin 737–25–1641, Revision 1, 

dated August 8, 2011. 

(h) Credit for Previous Actions 

This paragraph provides credit for the 

modification required by paragraph (g) of this 

AD, if the modification was performed before 

the effective date of this AD using Boeing 

Special Attention Service Bulletin 737–25– 

1641, dated May 13, 2011. 

(i) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, Seattle Aircraft 

Certification Office (ACO), 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 ACO, send it to the 

attention of the person identified in the 

Related Information section of this AD. 

Information may be emailed to: 9-ANMSeattle-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 

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 

Aircraft Certification Office to make those 

findings. 

(j) Related Information 

(1) For more information about this AD, 

contact Patrick Gillespie, Aerospace 

Engineer, Cabin Safety and Environmental 

Systems Branch, ANM–150S, FAA, Seattle 

ACO, 1601 Lind Avenue SW., Renton, WA 

98057–3356; phone: 425–917–6429; fax: 425– 

917–6590; email: patrick.gillespie@faa.gov. 

(2) For service information identified in 

this AD, contact Boeing Commercial 

Airplanes, Attention: Data & Services 

Management, P.O. Box 3707, MC 2H–65, 

Seattle, Washington 98124–2207; telephone 

206–544–5000, extension 1; fax 206–766– 

5680; email me.boecom@boeing.com; Internet 

https://www.myboeingfleet.com. You may 

review copies of the referenced service 

information at the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue SW., Renton, 

Washington. For information on the 

availability of this material at the FAA, call 

425–227–1221. 

Issued in Renton, Washington, on February 

14, 2012. 

Kalene C. Yanamura, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2012–4382 Filed 2–24–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0102; Directorate 

Identifier 2012–NM–004–AD] 

RIN 2120–AA64 

Airworthiness Directives; Various 

Transport Category Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to supersede an 

existing airworthiness directive (AD) 

that applies to certain transport category 

airplanes. The existing AD currently 

requires either activating all chemical 

oxygen generators in the lavatories until 

the generator oxygen supply is 

expended, or removing the oxygen 

generator(s); and, for each chemical 

oxygen generator, after the generator is 

expended (or removed), removing or 

restowing the oxygen masks and closing 

the mask dispenser door. Since we 

issued that AD, we have identified 

means to provide a supplemental 

oxygen system that does not have the 

unsafe condition. This proposed AD 

would require installing a supplemental 

oxygen system in affected lavatories, 

which would terminate the 

requirements of the existing AD. We are 

proposing this AD to eliminate a hazard 

that could jeopardize flight safety, and 

to ensure that all lavatories have a 

supplemental oxygen supply. 

DATES: We must receive comments on 

this proposed AD by April 12, 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. 

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 

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Federal Register / Vol. 77, No. 38 / Monday, February 27, 2012 / Proposed Rules 11419 

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: Jeff 

Gardlin, Aerospace Engineer, Airframe 

and Cabin Safety Branch, ANM–115, 

FAA, Transport Airplane Directorate, 

1601 Lind Avenue SW., Renton, 

Washington 98057–3356; phone: 425– 

227–2136; fax: 425–227–1149; email: 

jeff.gardlin@faa.gov. 

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–2012–0102; Directorate Identifier 

2012–NM–004–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 

On March 2, 2011, we issued AD 

2011–04–09, Amendment 39–16630 (76 

FR 12556, March 8, 2011), for certain 

transport category airplanes. That AD 

requires either activating all chemical 

oxygen generators (COGs) in the 

lavatories until the generator oxygen 

supply is expended, or removing the 

oxygen generator(s); and, for each 

chemical oxygen generator, after the 

generator is expended (or removed), 

removing or restowing the oxygen 

masks and closing the mask dispenser 

door. That AD resulted from reports that 

the current design of these oxygen 

generators presents a hazard that could 

jeopardize flight safety. We issued that 

AD to eliminate this hazard. 

Actions Since Existing AD Was Issued 

When we issued AD 2011–04–09, 

Amendment 39–16630 (76 FR 12556, 

March 8, 2011), we also issued Special 

Federal Aviation Regulation (SFAR) 111 

(76 FR 12550, March 8, 2011) to address 

the fact that, with inoperative COGs, 

affected airplanes would not be in 

compliance with certain airworthiness 

standards that require supplemental 

oxygen to be available in all lavatories. 

That SFAR permitted airplanes affected 

by AD 2011–04–09 to be delivered, 

modified, and returned to service even 

though they were not in compliance 

with the affected regulations. 

The FAA considered SFAR 111 (76 

FR 12550, March 8, 2011) and AD 2011– 

04–09, Amendment 39–16630 (76 FR 

12556, March 8, 2011), to be interim 

measures until they could be 

superseded by additional rulemaking 

activity. The FAA analyzed the risk of 

removing supplemental oxygen from 

lavatories for the time required to 

develop a system that addresses the risk 

identified by the underlying AD, and 

concluded that the risk was low. 

However, this assessment was based on 

a finite exposure time; we never 

intended to allow airplanes to fly 

indefinitely without a supplemental 

oxygen supply in the lavatories. The 

preamble to AD 2011–04–09 explained 

that that AD would be in effect until 

superseded by further rulemaking, and 

SFAR 111 discussed a 2- to 4-year 

period to restore oxygen to lavatories, 

once the identified vulnerability was 

adequately addressed by the new 

rulemaking. 

To address the vulnerability, the FAA 

chartered an Aviation Rulemaking 

Committee (ARC) to recommend new 

standards for COG installations that 

would eliminate the identified 

vulnerability, and permit acceptable 

installation of COGs in lavatories. The 

ARC completed its work, and we now 

have sufficient information to approve 

new COG installations. FAA Policy 

Statement PS–ANM–25–04, issued 

December 21, 2011 (http://rgl.faa.gov/ 

Regulatory_and_Guidance_Library/ 

rgPolicy.nsf/0/06EE1CEFE9804A

2F8625796E005C017F?OpenDocument

&Highlight=ps-anm-25-04), summarizes 

the ARC recommendations and provides 

guidance to applicants that want to 

begin restoring oxygen to lavatories in 

advance of rulemaking. This policy will 

be used in making approvals of COG 

installations that will be used to comply 

with this proposed AD. The FAA may 

also propose new airworthiness 

standards for the safe installations of 

COGs using the ARC recommendations. 

As stated in the preamble to AD 

2011–04–09, Amendment 39–16630 (76 

FR 12556, March 8, 2011), our original 

intention was to adopt new type 

certification and operational rules for 

installing lavatory oxygen systems. In 

reviewing the ARC’s recommendations, 

however, we recognized the need to 

terminate the requirements of that AD to 

adequately address the identified unsafe 

condition. This is consistent with our 

normal AD process in which we 

typically issue superseding ADs 

mandating modifications that terminate 

interim actions imposed by earlier 

superseded ADs. This proposed AD 

would serve as superseding action to 

AD 2011–04–09 and provide 

terminating action to the unsafe 

condition identified by that AD. The 

lack of oxygen in lavatories, as noted 

above, is noncompliant with 

airworthiness and operational 

standards. This proposal requires a 

terminating action that addresses the 

identified unsafe condition in a manner 

that maintains compliance with the 

existing standards. 

Design approval holders have not 

released service information at this 

time. However, we anticipate that 

relevant service information for the 

terminating action will be available in 

time for operators to comply with this 

proposed AD. Depending on the 

technical approach taken, we propose to 

use different approval processes as 

discussed below. 

Approval Process for Compliance With 

Proposed AD, Using Chemical Oxygen 

Generators 

Because of the issues addressed by 

AD 2011–04–09, Amendment 39–16630 

(76 FR 12556, March 8, 2011), COG 

installations will require new 

considerations in order to be found 

acceptable methods of compliance with 

this proposed AD. The approval for 

COG installations will therefore be in a 

manner approved by the FAA as 

discussed below. 

Approval Process for Compliance With 

Proposed AD, Using Other Systems 

Chemical oxygen generators are one 

type of system used to provide 

supplemental oxygen. While the 

majority of transport category airplanes 

use this system in lavatories, there are 

other systems as well. If another system 

type is used to meet this AD, the 

original unsafe condition is not a 

concern. In that case, the means of 

compliance is straightforward, and we 

have determined that the approval 

method could be more flexible than is 

usually the case for an AD. For example, 

delegated organizations cannot normally 

make compliance findings for ADs; 

service information associated with ADs 

must be adhered to exactly, or else an 

alternative method of compliance 

(AMOC) must be granted. For this 

proposed AD, if the type of system is 

other than a COG, then we have 

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11420 Federal Register / Vol. 77, No. 38 / Monday, February 27, 2012 / Proposed Rules 

determined that these restrictions could 

be relaxed. Therefore, paragraph (k)(2) 

of this proposed AD contains provisions 

to permit existing approval processes to 

be used, as long as the means of 

compliance is other than a COG. This 

provision takes precedence over current 

limitations in operators’ authority to use 

their organizational delegations when 

showing compliance with an AD. In 

addition, if an operator uses service 

information that is approved for such 

installations, deviations from the service 

information can be addressed using the 

operator’s normal procedures without 

requiring an AMOC. 

Oversight Office 

Paragraph (k) of this proposed AD 

refers to the FAA oversight office 

responsible for approval of 

modifications used to show compliance. 

This will typically be the aircraft 

certification office having geographic 

oversight of the applicant. In the case of 

service instructions from foreign design 

approval holders, this would be the 

Transport Standards Staff. We anticipate 

that modifications to meet this proposal 

will require either supplemental type 

certification or amended type certificate 

approval. 

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 retain the 

requirements of AD 2011–04–09, 

Amendment 39–16630 (76 FR 12556, 

March 8, 2011). This proposed AD 

would also require installing a 

supplemental oxygen system in affected 

lavatories, which would terminate the 

existing requirements. 

Costs of Compliance 

We estimate that this proposed AD 

affects 5,500 airplanes of U.S. registry. 

We estimate the following costs to 

comply with the actions specified in 

this proposed AD. 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per product Cost on U.S. operators 

Activate COG/expend oxygen supply [actions 

retained from AD 2011–04–09, Amendment 

39–16630 (76 FR 12556, March 8, 2011)].

Up to 2 work-hours × $85 

per hour = Up to $170.

$0 Up to $170 .................. Up to $935,000. 

Oxygen system installation (new proposed action).24 work-hours × $85 per 

hour = $2,040.

6,000 $8,040 ......................... $44,220,000. 

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 

We have 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 that the 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 

removing airworthiness directive (AD) 

2011–04–09, Amendment 39–16630 (76 

FR 12556, March 8, 2011), and adding 

the following new AD: 

Transport Category Airplanes: Docket No. 

FAA–2012–0102; Directorate Identifier 

2012–NM–004–AD. 

(a) Comments Due Date 

The FAA must receive comments on this 

AD action by April 12, 2012. 

(b) Affected ADs 

This AD supersedes AD 2011–04–09, 

Amendment 39–16630 (76 FR 12556, March 

8, 2011). 

(c) Applicability 

This AD applies to transport category 

airplanes, in passenger-carrying operations, 

as specified in paragraph (c)(1) or (c)(2) of 

this AD. 

(1) Airplanes that are in compliance with 

the requirements of AD 2011–04–09, 

Amendment 39–16630 (76 FR 12556, March 

8, 2011). 

(2) Airplanes equipped with any chemical 

oxygen generator installed in any lavatory 

and are: 

(i) Operating under 14 CFR part 121; or 

(ii) U.S.-registered and operating under 14 

CFR part 129, with a maximum passenger 

capacity of 20 or greater. 

(d) Subject 

Joint Aircraft System Component (JASC)/ 

Air Transport Association (ATA) of America 

Code 35, Oxygen. 

(e) Unsafe Condition 

This AD was prompted by the 

determination that the current design of 

chemical oxygen generators presents a hazard 

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Federal Register / Vol. 77, No. 38 / Monday, February 27, 2012 / Proposed Rules 11421 

that could jeopardize flight safety. We are 

issuing this AD to eliminate this hazard and 

ensure that all lavatories have a 

supplemental oxygen supply. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Restatement of Requirements of AD 2011– 

04–09, Amendment 39–16630 (76 FR 12556, 

March 8, 2011): Oxygen Generator 

Deactivation 

Within 21 days after March 14, 2011 (the 

effective date of AD 2011–04–09, 

Amendment 39–16630 (76 FR 12556, March 

8, 2011)), do the actions specified in 

paragraphs (g)(1) and (g)(2) of this AD. 

(1) Activate all chemical oxygen generators 

in the lavatories until the generator oxygen 

supply is expended. An operator may also 

remove the oxygen generator(s), in 

accordance with existing maintenance 

practice, in lieu of activating it. 

(2) For each chemical oxygen generator, 

after the generator is expended (or removed), 

remove or re-stow the oxygen masks and 

close the mask dispenser door. 

Note 1 to paragraph (g) of this AD: 

Chemical oxygen generators are considered a 

hazardous material and subject to specific 

requirements under Title 49 CFR for 

shipping. Oxygen generators must be 

expended prior to disposal but are 

considered a hazardous waste; therefore, 

disposal must be in accordance with all 

Federal, State, and local regulations. 

Expended oxygen generators are forbidden in 

air transportation as cargo. For more 

information, contact 1–800–HMR–4922. 

Note 2 to paragraph (g) of this AD: Design 

approval holders are not expected to release 

service instructions for the action specified 

in paragraph (g) of this AD. 

(h) Restatement of Requirements of AD 

2011–04–09, Amendment 39–16630 (76 FR 

12556, March 8, 2011): Compliance With 

Federal Aviation Regulations 

Notwithstanding the requirements of 

Sections 25.1447, 121.329, 121.333, and 

129.13 of the Federal Aviation Regulations 

(14 CFR 25.1447, 121.329, 121.333, and 

129.13), operators complying with this AD 

are authorized to operate affected airplanes 

until accomplishment of the actions specified 

in paragraph (k) of this AD. 

(i) Restatement of Requirements of AD 2011– 

04–09, Amendment 39–16630 (76 FR 12556, 

March 8, 2011): Parts Installation 

After March 14, 2011, and until 

accomplishment of the actions specified in 

paragraph (k) of this AD, no person may 

install a chemical oxygen generator in any 

lavatory on any affected airplane. 

(j) Restatement of Requirements of AD 2011– 

04–09, Amendment 39–16630 (76 FR 12556, 

March 8, 2011): Special Flight Permit 

Special flight permits, as described in 

Section 21.197 and Section 21.199 of the 

Federal Aviation Regulations (14 CFR 21.197 

and 21.199), are not allowed for the 

accomplishment of the actions specified in 

paragraph (g) of this AD. 

(k) New Requirements of This AD: Oxygen 

System Restoration 

Within 24 months after the effective date 

of this AD, install a supplemental oxygen 

system that meets the requirements of 

Sections 25.1447, 121.329, 121.333, and 

129.13 of the Federal Aviation Regulations 

(14 CFR 25.1447, 121.329, 121.333, and 

129.13) in each lavatory, as specified in 

paragraph (k)(1) or (k)(2) of this AD, as 

applicable. 

(1) If compliance with paragraph (k) of this 

AD is achieved using a chemical oxygen 

generator, the actions specified in paragraph 

(k) of this AD must be done in accordance 

with a method approved by the Manager of 

the responsible FAA oversight office having 

responsibility over the modification. For a 

method to be approved, it must meet the 

certification basis of the airplane, and the 

approval must specifically refer to this AD. 

(2) If compliance with paragraph (k) of this 

AD is achieved without a chemical oxygen 

generator, the specifications of paragraphs 

(k)(2)(i) and (k)(2)(ii) of this AD apply. 

(i) The modification must receive FAA 

approval in accordance with 14 CFR part 21 

as a major design change. Notwithstanding 

operations specification restrictions to the 

contrary, organizational approval holders 

may exercise their full authority in approving 

installations that meet the installation 

requirements of this AD. 

(ii) Deviation from approved service 

instructions and subsequent modifications 

may be handled by normal operator 

procedures without requiring approval of an 

alternative method of compliance. 

(l) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, Transport Standards 

Staff, ANM–110, 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 Transport Standards 

Staff, send it to the attention of the person 

identified in the Related Information section 

of this AD. 

(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. 

(m) Related Information 

For more information about this AD, 

contact Jeff Gardlin, Aerospace Engineer, 

Airframe and Cabin Safety Branch, ANM– 

115, FAA, Transport Airplane Directorate, 

1601 Lind Avenue SW., Renton, Washington 

98057–3356; phone: 425–227–2136; fax: 425– 

227–1149; email: jeff.gardlin@faa.gov. 

Issued in Renton, Washington, on January 

27, 2012. 

Ali Bahrami, 

Manager,Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2012–4031 Filed 2–24–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0071; Directorate 

Identifier 2012–NE–05–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Canada, Auxiliary Power Units 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for certain 

serial numbers of Pratt & Whitney 

Canada (P&WC) PW901A auxiliary 

power units (APUs) approved under 

Technical Standard Order TSO–C77A 

and installed on, but not limited to, 

Boeing 747–400 series airplanes. This 

proposed AD was prompted by several 

events of high-pressure turbine blade 

fracture leading to separation of the rear 

gas generator case and release of high 

energy debris. This proposed AD would 

require modifications of the rear gas 

generator case, exhaust duct support, 

and turbine exhaust duct flanges. We 

are proposing this AD to prevent 

separation of the rear gas generator case 

and release of high energy debris, which 

could result in injury and damage to the 

airplane. 

DATES: We must receive comments on 

this proposed AD by April 27, 2012. 

ADDRESSES: You may send comments by 

any of the following methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov and follow 

the instructions for sending your 

comments electronically. 

• Mail: Docket Management Facility, 

U.S. Department of Transportation, 1200 

New Jersey Avenue SE., West Building 

Ground Floor, Room W12–140, 

Washington, DC 20590–0001. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 

5 p.m., Monday through Friday, except 

Federal holidays. 

• Fax: 202–493–2251. 

For service information identified in 

this proposed AD, contact Pratt & 

Whitney Canada Corp., 1000 MarieVictorin, Longueuil, Quebec, Canada 

J4G 1A1; phone: 450–677–9411. 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. 

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