2664 Federal Register / Vol. 77, No. 12 / Thursday, January 19, 2012 / Proposed Rules 

AD to prevent elongation of the pressure 

regulator neck, which could result in rupture 

of the oxygen cylinder, and in the case of 

cabin depressurization, oxygen would not be 

available when required. 

(f) Compliance 

You are responsible for having the actions 

required by this AD performed within the 

compliance times specified, unless the 

actions have already been done. 

(g) Actions 

Within 1,800 flight hours or 6 months after 

the effective date of this AD, whichever 

occurs first: Inspect the serial number of each 

oxygen pressure regulator, part number (P/N) 

806370–06, to determine if the serial number 

of the regulator is listed in ‘‘Table 2, 

Regulators’’ of paragraph 1.A.(1) of 

Bombardier Service Bulletin 670BA–35–011, 

dated July 5, 2011. If the serial number of the 

oxygen pressure regulator, P/N 806370–06, is 

listed in ‘‘Table 2, Regulators’’ of paragraph 

1.A.(1) of Bombardier Service Bulletin 

670BA–35–011, dated July 5, 2011, before 

further flight: Replace the affected oxygen 

cylinder and regulator assembly (CRA), in 

accordance with the Accomplishment 

Instructions of Bombardier Service Bulletin 

670BA–35–011, dated July 5, 2011. 

(h) Parts Installation 

As of the effective date of this AD, no 

person may install an oxygen pressure 

regulator, P/N 806370–06, having a serial 

number listed in ‘‘Table 2, Regulators’’ of 

paragraph 1.A.(1) of Bombardier Service 

Bulletin 670BA–35–011, dated July 5, 2011, 

on any airplane unless the serial number of 

the CRA and pressure regulator have a suffix 

‘‘A’’ beside the serial number. 

(i) Other FAA AD Provisions 

The following provisions also apply to this 

AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, New York Aircraft 

Certification Office (ACO), ANE–170, 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 ACO, send it to ATTN: 

Program Manager, Continuing Operational 

Safety, FAA, New York ACO, 1600 Stewart 

Avenue Suite 410, Westbury, New York 

11590; telephone (516) 228–7300; fax (516) 

794–5531. 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. The AMOC 

approval letter must specifically reference 

this AD. 

(2) Airworthy Product: For any requirement 

in this AD to obtain corrective actions from 

a manufacturer or other source, use these 

actions if they are FAA-approved. Corrective 

actions are considered FAA-approved if they 

are approved by the State of Design Authority 

(or their delegated agent). You are required 

to assure the product is airworthy before it 

is returned to service. 

(j) Related Information 

Refer to MCAI Canadian Airworthiness 

Directive CF–2011–28, dated July 28, 2011; 

and Bombardier Service Bulletin 670BA–35– 

011, dated July 5, 2011; for related 

information. 

Issued in Renton, Washington, on January 

6, 2012. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2012–857 Filed 1–18–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–1415; Directorate 

Identifier 2011–NM–145–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 all The 

Boeing Company Model 717–200 

airplanes. This proposed AD was 

prompted by reports of cracks found on 

the center section ribs of the horizontal 

stabilizers. This proposed AD would 

require repetitive inspections for 

cracking of the aft face of the left and 

right rib hinge bearing lugs of the center 

section of the horizontal stabilizer; and 

crack measurement, repairs, and 

installation of a new center section rib 

if necessary. We are proposing this AD 

to detect and correct cracks in the left 

and right bearing lugs of the rib hinge 

spreading at the same time, which could 

result in failure of both hinge bearing 

lugs. Failure of the hinge bearing lugs 

could result in the inability of the 

horizontal stabilizer to sustain flight 

loads and therefore reduce the 

controllability of the airplane. 

DATES: We must receive comments on 

this proposed AD by March 5, 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 Boeing 

Commercial Airplanes, Attention: Data 

& Services Management, 3855 

Lakewood Boulevard, MC D800–0019, 

Long Beach, California 90846–0001; 

phone: (206) 544–5000, extension 2; fax: 

(206) 766–5683; email: 

dse.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. 

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: 

George Garrido, Aerospace Engineer, 

Airframe Branch, ANM–120L, FAA, Los 

Angeles Aircraft Certification Office 

(ACO), 3960 Paramount Boulevard, 

Lakewood, California 90712–4137; 

phone: (562) 627–5357; fax: (562) 627– 

5210; email: George.Garrido@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– 

2011–1415; Directorate Identifier 2011– 

NM–145–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 


EMCDONALD on DSK29S0YB1PROD with PROPOSALS
Federal Register / Vol. 77, No. 12 / Thursday, January 19, 2012 / Proposed Rules 2665 

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 cracks 

found on the left, right, or, in several 

instances, both of the center section ribs 

of the horizontal stabilizer on Model 

MD–80 and MD–90 series airplanes. 

Two cracks were reported on Model 

MD–80 series airplanes having 

accumulated between 23,700 and 41,963 

total flight hours and between 23,300 

and 35,294 total flight cycles. Nine 

cracks were reported on Model MD–90 

series airplanes having accumulated 

between 9,051 and 26,053 total flight 

hours and between 8,939 and 25,260 

total flight cycles. These cracks were 

found on the aft face of the hinge 

bearing lugs of the horizontal stabilizer. 

Undetected cracks in the left and right 

bearing lugs of the rib hinge, if not 

corrected, could spread at the same 

time, which could result in failure of 

both hinge bearing lugs, the inability of 

the horizontal stabilizer to sustain flight 

loads, and consequent reduced 

controllability of the airplane. 

The design of the horizontal rib on 

Model 717–200 airplanes is the same rib 

design used on Model MD–80 and MD– 

90 series airplanes, and is susceptible to 

the same failure mode. Therefore, Model 

717–200 airplanes may also be subject 

to the identified unsafe condition. 

Related Rulemaking 

We have issued similar rulemaking in 

AD 2011–01–11, Amendment 39–16565 

(76 FR 430, January 5, 2011), for The 

Boeing Company Model MD–90 

airplanes, that requires repetitive high 

frequency eddy current (HFEC) 

inspections for cracking on the hinge 

bearing lugs of the left and right sides 

of the center section ribs of the 

horizontal stabilizer, and related 

investigative and corrective actions if 

necessary. 

We have also issued NPRM 2011– 

NM–027–AD (76 FR 53346, August 26, 

2011), for The Boeing Company Model 

DC–9–81 (MD–81), DC–9–82 (MD–82), 

DC–9–83 (MD–83), DC–9–87 (MD–87), 

and MD–88 airplanes. That NPRM 

proposes to require repetitive HFEC 

inspections for cracking of the left and 

right rib hinge bearing lugs of the aft 

face of the center section of the 

horizontal stabilizer; measuring crack 

length and blending out cracks; and 

replacing the horizontal stabilizer center 

section rib, if necessary. 

Relevant Service Information 

We reviewed Boeing Alert Service 

Bulletin 717–55A0011, dated May 17, 

2011. This service information describes 

procedures for repetitive eddy current 

high frequency (ETHF) inspections for 

cracks on the aft face on the left and 

right rib hinge bearing lugs of the center 

section of the horizontal stabilizer; and 

crack measurement, repairs, post-repair 

repetitive inspections, and installation 

of a new center section rib if necessary. 

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 the Proposed AD 

and the Service Information.’’ 

Differences Between the Proposed AD 

and the Service Information 

Operators should note that, although 

the Accomplishment Instructions of 

Boeing Alert Service Bulletin 717– 

55A0011, dated May 17, 2011, describe 

procedures for submitting inspection 

results, this proposed AD would not 

require those actions. 

Costs of Compliance 

We estimate that this proposed AD 

affects 129 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 

ETHF Inspection 6 work-hours × $85 per hour 

= $510 per inspection cycle.

$0 $510 per inspection cycle ...... $65,790 per inspection cycle. 

We have received no definitive data 

that would enable us to provide cost 

estimates for the on-condition labor 

costs specified in this proposed AD. The 

estimated parts cost for a replacement 

rib is $16,387. 

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 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. 


EMCDONALD on DSK29S0YB1PROD with PROPOSALS
2666 Federal Register / Vol. 77, No. 12 / Thursday, January 19, 2012 / Proposed Rules 

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– 

2011–1415; Directorate Identifier 2011– 

NM–145–AD. 

(a) Comments Due Date 

We must receive comments by March 5, 

2012. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all The Boeing 

Company Model 717–200 airplanes, 

certificated in any category. 

(d) Subject 

Joint Aircraft System Component (JASC)/ 

Air Transport Association (ATA) of America 

Code 5510, Horizontal Stabilizer Structure. 

(e) Unsafe Condition 

This AD was prompted by reports of cracks 

found on the center section ribs of the 

horizontal stabilizers. We are issuing this AD 

to detect and correct cracks in the left and 

right bearing lugs of the rib hinge spreading 

at the same time, which could result in 

failure of both hinge bearing lugs. Failure of 

the hinge bearing lugs could result in the 

inability of the horizontal stabilizer to sustain 

flight loads and therefore reduce the 

controllability of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Repetitive Eddy Current High Frequency 

(ETHF) Inspections 

Before the accumulation of 35,000 total 

flight cycles, or within 8,275 flight cycles 

after the effective date of this AD, whichever 

occurs later: Do an ETHF inspection for 

cracks of the aft face on the left and right rib 

hinge bearing lugs of the center section of the 

horizontal stabilizer, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 717–55A0011, dated May 

17, 2011. If no crack is found, repeat the 

inspection thereafter at intervals not to 

exceed 10,500 flight cycles. 

(h) Crack Measurement 

If any crack is found during any inspection 

required by paragraph (g) of this AD: Before 

further flight, measure the length of the 

crack, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 717–55A0011, dated May 

17, 2011. 

(i) Blend Out Repair, ETHF Inspections, and 

Corrective Action for Certain Crack Lengths 

For any crack that meets ‘‘Condition 2A’’ 

of Table 1 of 1.E., ‘‘Compliance,’’ of Boeing 

Alert Service Bulletin 717–55A0011, dated 

May 17, 2011: Do the actions in paragraphs 

(i)(1) and (i)(2) of this AD. 

(1) Before further flight, do a blend out 

repair, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 717–55A0011, dated May 

17, 2011. 

(2) Within 14,200 flight cycles after 

accomplishing the blend out repair required 

by paragraph (i)(1) of this AD: Do an ETHF 

inspection of the blend out repair area for 

cracking, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 717–55A0011, dated May 

17, 2011. If no cracking is found, repeat the 

inspection thereafter at intervals not to 

exceed 5,400 flight cycles. 

(i) If any crack is found during the ETHF 

inspection required by paragraph (i)(2) of this 

AD: Before further flight, remove the cracked 

center section rib of the horizontal stabilizer 

and install a new center section rib, in 

accordance with the Accomplishment 

Instructions of Boeing Alert Service Bulletin 

717–55A0011, dated May 17, 2011. 

(ii) Within 35,000 flight cycles after the 

installation of the new center section rib, do 

the actions in paragraph (g) of this AD. 

(j) Corrective Action for Certain Crack 

Lengths 

For any crack that meets ‘‘Condition 2D’’ 

of Table 1 of 1.E., ‘‘Compliance,’’ of Boeing 

Alert Service Bulletin 717–55A0011, dated 

May 17, 2011: Before further flight, remove 

the cracked center section rib of the 

horizontal stabilizer and install a new center 

section rib, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 717–55A0011, dated May 

17, 2011. Within 35,000 flight cycles after the 

installation of the new rib, do the actions in 

paragraph (g) of this AD. 

(k) No Reporting Requirement 

Although Boeing Alert Service Bulletin 

717–55A0011, dated May 17, 2011, specifies 

to submit certain information to the 

manufacturer, this AD does not include that 

requirement. 

(l) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager Los Angeles 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. 

(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, Los Angeles 

ACO, to make those findings. For a repair 

method to be approved, the repair must meet 

the certification basis of the airplane, and the 

approval must specifically refer to this AD. 

(m) Related Information 

(1) For more information about this AD, 

contact George Garrido, Aerospace Engineer, 

Airframe Branch, ANM–120L, FAA, Los 

Angeles Aircraft Certification Office (ACO), 

3960 Paramount Boulevard, Lakewood, 

California 90712–4137; phone: (562) 627– 

5357; fax: (562) 627–5210; email: 

George.Garrido@faa.gov. 

(2) For service information identified in 

this AD, Boeing Commercial Airplanes, 

Attention: Data & Services Management, 3855 

Lakewood Boulevard, MC D800–0019, Long 

Beach, California 90846–0001; phone: (206) 

544–5000, extension 2; fax: (206) 766–5683; 

email: dse.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 January 

6, 2012. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2012–858 Filed 1–18–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–1417; Directorate 

Identifier 2011–NM–159–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 777 

airplanes. This proposed AD was 

prompted by reports that escape slides/ 

rafts did not deploy due to galvanic 

corrosion of the door-mounted slide/raft 

packboard release mechanisms. This 

proposed AD would require doing a 

general visual inspection of the housing 


EMCDONALD on DSK29S0YB1PROD with PROPOSALS