Federal Register / Vol. 77, No. 143 / Wednesday, July 25, 2012 / Proposed Rules 43547 

(MLG) failed to extend using the alternate 

gear extension system. We are issuing this 

AD to detect and correct failure of the MLG 

to extend and lock, which could adversely 

affect the safe landing of the airplane. 

(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) Retained Actions for All Airplanes 

Within 2,000 flight hours after September 

19, 2011 (the effective date of AD 2011–17– 

04, Amendment 39–16768 (76 FR 50403, 

August 15, 2011): Incorporate Bombardier 

Modsum 4–113645, including performing a 

detailed visual inspection for damage or 

cracks of the bumper plate and base fitting 

and replacing any damaged or cracked part, 

in accordance with the Accomplishment 

Instructions of Bombardier Service Bulletin 

84–32–74, Revision A, dated May 17, 2010. 

Do all applicable replacements before further 

flight. 

Note 1 to paragraphs (g) and (h) of this 

AD: Bombardier Service Bulletin 84–32–74, 

Revision A, dated May 17, 2010, includes an 

operational check of the alternate extension 

system of the MLG. If the operational check 

fails, guidance on doing corrective actions 

can be found in the Bombardier Q400 Dash 

8 Aircraft Maintenance Manual. 

(h) Retained Actions for Airplanes Having 

Certain Bumper Plates 

For airplanes on which a bumper plate 

having part number 85424082–101 or 

85424082–103 is installed on which the 

rework specified in Bombardier Repair 

Drawing 8/4–54–553 has been done: Within 

1,000 flight hours after September 19, 2011 

(the effective date of AD 2011–17–04, 

Amendment 39–16768 (76 FR 50403, August 

15, 2011), reidentify the bumper plate, in 

accordance with paragraph 3.B., step (8) of 

the Accomplishment Instructions of 

Bombardier Service Bulletin 84–32–74, 

Revision A, dated May 17, 2010. 

(i) Retained Credit for Previous Actions 

This paragraph provides credit for the 

modification required by paragraph (h) of 

this AD by incorporation of Bombardier 

Modsum 4–113645 before September 19, 

2011 (the effective date of AD 2011–17–04, 

Amendment 39–16768 (76 FR 50403, August 

15, 2011), if the modification was performed 

using Bombardier Service Bulletin 84–32–74, 

dated December 23, 2009; and provided the 

modification is done within the compliance 

time specified in paragraph (h) of this AD. 

(j) New Requirements of This AD: 

Operational Check for Airplanes on Which 

the Action Required by Paragraph (h) Is 

Done 

Concurrently with doing the actions 

required by paragraph (h) of this AD, or 

within 30 days after the effective date of this 

AD, whichever occurs later: Perform an 

operational check of the alternate extension 

system of the MLG, in accordance with the 

Accomplishment Instructions of Bombardier 

Service Bulletin 84–32–74, Revision A, dated 

May 17, 2010. If the operational check fails, 

before further flight, repair in accordance 

with a method approved by either the 

Manager, New York Aircraft Certification 

Office (ACO), FAA; or the Transport Canada 

Civil Aviation (TCCA) (or its delegated 

agent). 

Note 2 to paragraph (j) of this AD: If the 

operational check fails, guidance on doing 

the repair can be found in the Bombardier 

Q400 Dash 8 Aircraft Maintenance Manual. 

(k) Credit for Previous Actions 

This paragraph provides credit for actions 

required by paragraph (g) of this AD, if those 

actions were performed before the effective 

date of this AD, provided the operational 

check specified in paragraph (j) of this AD is 

done within the compliance time specified in 

paragraph (g) of this AD, or within 30 days 

after the effective date of this AD, whichever 

occurs later, using Bombardier Service 

Bulletin 84–32–74, dated December 23, 2009. 

(l) Other FAA AD Provisions 

The following provisions also apply to this 

AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, New York 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 New York 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. 

(m) Related Information 

(1) Refer to MCAI Canadian Airworthiness 

Directive CF–2010–23, dated July 21, 2010; 

and Bombardier Service Bulletin 84–32–74, 

Revision A, dated May 17, 2010; for related 

information. 

(2) For service information identified in 

this proposed AD, contact Bombardier, Inc., 

Q–Series Technical Help Desk, 123 Garratt 

Boulevard, Toronto, Ontario M3K 1Y5, 

Canada; telephone 416–375–4000; fax 416– 

375–4539; email 

thd.qseries@aero.bombardier.com; Internet 

http://www.bombardier.com. You may 

review copies of the referenced service 

information at the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue SW., Renton, 

WA. For information on the availability of 

this material at the FAA, call 425–227–1221. 

Issued in Renton, Washington, on July 17, 

2012. 

Michael Kaszycki, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2012–18145 Filed 7–24–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0723; Directorate 

Identifier 2011–NM–137–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 737–600, 

–700, –700C, –800, and –900 series 

airplanes. This proposed AD was 

prompted by a report of cracks found in 

the skin at body station (STA) 540 just 

below stringer S–22L on a Model 737– 

700 series airplane. This proposed AD 

would require repetitive detailed and 

high frequency eddy current inspections 

for cracking of the skin around the eight 

fasteners common to the ends of the 

STA 540 bulkhead chords between 

stringers S–22 and S–23, left and right 

sides; and corrective actions and 

preventive modification if necessary. 

We are proposing this AD to detect and 

correct fatigue cracking in the skin, 

which can result in rapid 

decompression of the cabin. 

DATES: We must receive comments on 

this proposed AD by September 10, 

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 


TKELLEY on DSK3SPTVN1PROD with PROPOSALS
43548 Federal Register / Vol. 77, No. 143 / Wednesday, July 25, 2012 / Proposed Rules 

Commercial Airplanes, Attention: Data 

& Services Management, P.O. Box 3707, 

MC 2H–65, Seattle, WA 98124–2207; 

telephone 206–544–5000, extension 1; 

fax 206–766–5680; 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, WA. 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: 

Alan Pohl, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue SW., Renton, WA 

98057–3356; phone: 425–917–6450; fax: 

425–917–6590; email: 

alan.pohl@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– 

2012–0723; Directorate Identifier 2011– 

NM–137–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 

We received a report of cracks found 

in the skin at body station (STA) 540 

just below stringer S–22L on a Model 

737–700 series airplane. Subsequent 

investigation revealed that the design at 

the STA 540 bulkhead chords has 

insufficient load path where the chords 

meet between stringers S–22 and S–23 

on both the left and right sides of the 

airplane. This condition, if not 

corrected, could result in fatigue 

cracking in the skin, which can result in 

rapid decompression of the cabin. 

Relevant Service Information 

We reviewed Boeing Special 

Attention Service Bulletin 737–53– 

1294, dated March 31, 2011. The service 

information describes procedures for 

repetitive detailed and high frequency 

eddy current (HFEC) inspections for 

cracking of the skin around the eight 

fasteners common to the ends of the 

STA 540 bulkhead chords between 

stringers S–22 and S–23, and corrective 

actions and preventive modification if 

necessary. The preventive modification 

includes doing an open-hole HFEC 

inspection for cracking of the skin and 

STA 540 bulkhead chords, installing a 

new chord splice plate, and repair if 

necessary. The corrective actions 

include repairing cracking, and doing 

preventive modifications on any side on 

which cracking is not found. 

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 these same 

type designs. 

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 

Boeing Special Attention Service 

Bulletin 737–53–1294, dated March 31, 

2011, specifies to contact the 

manufacturer for instructions on how to 

repair certain conditions, but this 

proposed AD would require repairing 

those conditions in one of the following 

ways: 

• In accordance with a method that 

we approve; or 

• Using data that meet the 

certification basis of the airplane, and 

that have been approved by the Boeing 

Commercial Airplanes Organization 

Designation Authorization (ODA) whom 

we have authorized to make those 

findings. 

Clarification of Repetitive Inspections 

The Repeat Interval column of table 1 

of paragraph 1.E., ‘‘Compliance,’’ of 

Boeing Special Attention Service 

Bulletin 737–53–1294, dated March 31, 

2011, specifies repetitive detailed and 

HFEC inspections at intervals not to 

exceed 4,000 flight cycles, and the 

Accomplishment Instructions of Boeing 

Special Attention Service Bulletin 737– 

53–1294, dated March 31, 2011, specify 

repetitive detailed inspections only. We 

have determined that doing both 

repetitive detailed and HFEC 

inspections is necessary to address the 

unsafe condition of this AD. 

Clarification of Post-Repair Inspections 

Paragraph (j), and Note 1 to paragraph 

(j), of this proposed AD clarify that the 

post-repair inspections specified in 

Table 2 of paragraph 1.E., 

‘‘Compliance,’’ of Boeing Special 

Attention Service Bulletin 737–53– 

1294, dated March 31, 2011, are not 

required by this proposed AD. 

Costs of Compliance 

We estimate that this proposed AD 

affects 903 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 

Inspection (left and right sides) .. 3 work-hours × $85 per hour = 

$255 per inspection cycle.

$0 $255 per inspection cycle ......... $230,265 per inspection 

cycle. 

We estimate the following costs to do 

any necessary repairs and inspections 

that would be required based on the 

results of the proposed inspection. We 

have no way of determining the number 

of aircraft that might need these repairs: 


TKELLEY on DSK3SPTVN1PROD with PROPOSALS
Federal Register / Vol. 77, No. 143 / Wednesday, July 25, 2012 / Proposed Rules 43549 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Preventive modification (each side) .............................. 6 work-hours × $85 per hour = $510 ............................ $894 $1,404. 

Skin repair (each side) .................................................. 55 work-hours × $85 per hour = $4,675 ....................... Up to $5,635 Up to $10,310. 

According to the manufacturer, some 

of the costs of this proposed AD may be 

covered under warranty, thereby 

reducing the cost impact on affected 

individuals. We do not control warranty 

coverage for affected individuals. As a 

result, we have included all costs in our 

cost estimate. 

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. 

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– 

2012–0723; Directorate Identifier 2011– 

NM–137–AD. 

(a) Comments Due Date 

We must receive comments by September 

10, 2012. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to The Boeing Company 

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

series airplanes; certificated in any category; 

as identified in Boeing Special Attention 

Service Bulletin 737–53–1294, dated March 

31, 2011. 

(d) Subject 

Joint Aircraft System Component (JASC)/ 

Air Transport Association (ATA) of America 

Code 53, Fuselage. 

(e) Unsafe Condition 

This AD was prompted by a report of 

cracks found in the skin at body station 

(STA) 540 just below stringer S–22L. We are 

issuing this AD to detect and correct fatigue 

cracking in the skin, which can result in 

rapid decompression of the cabin. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Inspection and Corrective Action 

(1) Except as required by paragraphs (g)(2), 

(i)(2), (i)(3), and (i)(4) of this AD, at the 

applicable time specified in table 1 of 

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

Special Attention Service Bulletin 737–53– 

1294, dated March 31, 2011: Do detailed and 

high frequency eddy current (HFEC) 

inspections of the skin for cracking in the 

area around the eight fasteners securing the 

STA 540 bulkhead chords between stringers 

S–22 and S–23, and do all applicable 

corrective actions, in accordance with Parts 

1, 2, 3, 4, and 5 of the Accomplishment 

Instructions of Boeing Special Attention 

Service Bulletin 737–53–1294, dated March 

31, 2011, except as required by paragraph 

(i)(1) of this AD. If no cracking is found, 

repeat the detailed and HFEC inspections at 

the intervals specified in table 1 of paragraph 

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

Attention Service Bulletin 737–53–1294, 

dated March 31, 2011, except as required by 

paragraph (g)(2) of this AD, until the optional 

preventive modification specified in 

paragraph (h) of this AD is done. Do all 

applicable corrective actions before further 

flight. 

(2) For airplanes that have incorporated 

Boeing Business Jet Lower Cabin Altitude 

Supplemental Type Certificate (STC) 

ST01697SE (6,500 feet maximum cabin 

altitude in lieu of 8,000 feet), the flight-cycle 

related compliance times are different from 

those specified in Boeing Special Attention 

Service Bulletin 737–53–1294, dated March 

31, 2011. All initial compliance times 

specified in total flight cycles or flight cycles 

must be reduced to half of those specified in 

Boeing Special Attention Service Bulletin 

737–53–1294, dated March 31, 2011. All 

repetitive interval compliance times 

specified in flight cycles must be reduced to 

one-quarter of those specified in Boeing 

Special Attention Service Bulletin 737–53– 

1294, dated March 31, 2011. 

(h) Optional Preventive Modification 

Accomplishing the preventive 

modification, including an HFEC inspection 

for cracking of the skin and STA 540 

bulkhead chords, and all applicable repairs, 

in accordance with paragraph 3.B, Part 2 or 

Part 4 (left side), and Part 3 or Part 5 (right 

side), of the Accomplishment Instructions of 

Boeing Special Attention Service Bulletin 

737–53–1294, dated March 31, 2011, 

terminates the inspection requirements of 

paragraph (g) of this AD for the side on 

which the modification is done, except as 

required by paragraph (i)(1) of this AD. 

(i) Exceptions to Service Bulletin 

Specifications 

(1) If any cracking is found during any 

inspection required by this AD, and Boeing 

Special Attention Service Bulletin 737–53– 

1294, dated March 31, 2011, specifies to 

contact Boeing for appropriate action: Before 

further flight, repair using a method 

approved in accordance with the procedures 

specified in paragraph (k) of this AD. 


TKELLEY on DSK3SPTVN1PROD with PROPOSALS
43550 Federal Register / Vol. 77, No. 143 / Wednesday, July 25, 2012 / Proposed Rules 

(2) Where Boeing Special Attention Service 

Bulletin 737–53–1294, dated March 31, 2011, 

specifies to do the action after the original 

issue date of that service bulletin, this AD 

requires the compliance time after the 

effective date of this AD. 

(3) Where the Condition column of table 1 

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

Special Attention Service Bulletin 737–53– 

1294, dated March 31, 2011, specifies a 

condition as of the original issue date of that 

service bulletin, this AD specifies the 

condition as of the effective date of this AD. 

(4) Note 1 of paragraph 3.A. of the 

Accomplishment Instructions of Boeing 

Special Attention Service Bulletin 737–53– 

1294, dated March 31, 2011, is to be 

disregarded when accomplishing the actions 

required by this AD. 

(j) Post-Repair Inspections 

The post-repair inspections, specified in 

Table 2 of paragraph 1.E., ‘‘Compliance,’’ of 

Boeing Special Attention Service Bulletin 

737–53–1294, dated March 31, 2011, are not 

required by this AD. 

Note 1 to paragraph (j) of this AD: The 

damage tolerance inspections specified in 

Table 2 of paragraph 1.E., ‘‘Compliance,’’ of 

Boeing Special Attention Service Bulletin 

737–53–1294, dated March 31, 2011, may be 

used in support of compliance with Section 

121.1109(c)(2) or 129.109(c)(2) of the Federal 

Aviation Regulations (14 CFR 121.1109(c)(2) 

or 14 CFR 129.109(c)(2)). The corresponding 

actions specified in the Accomplishment 

Instructions of Boeing Special Attention 

Service Bulletin 737–53–1294, dated March 

31, 2011, are not required by this AD. 

(k) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, Seattle 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, it may be emailed 

to: 9-ANM-Seattle-ACO-AMOCRequests@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 (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. 

(l) Related Information 

(1) For more information about this AD, 

contact Alan Pohl, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, Seattle 

Aircraft Certification Office, 1601 Lind 

Avenue SW., Renton, WA 98057–3356; 

phone: 425–917–6450; fax: 425–917–6590; 

email: alan.pohl@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, WA 98124–2207; telephone 206– 

544–5000, extension 1; fax 206–766–5680; 

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, 

WA. For information on the availability of 

this material at the FAA, call 425–227–1221. 

Issued in Renton, Washington, on July 17, 

2012. 

Michael Kaszycki, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2012–18147 Filed 7–24–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2012–0520; Directorate 

Identifier 2002–NE–43–AD] 

RIN 2120–AA64 

Airworthiness Directives; Turbomeca 

S.A. Turboshaft Engines 

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 all Turbomeca S.A. Arriel 

1A, 1A1, 1A2, 1B, 1C, 1C1, 1C2, 1D, 

1D1, 1E, 1E2, 1K, 1K1, 1S, and 1S1 

turboshaft engines. The existing AD 

currently requires initial and repetitive 

visual inspections for erosion caused by 

dust ingestion and, if necessary, 

cleaning of the gas generator (module 

M03). Since we issued that AD, inservice experience has shown that dust 

inside the gas generator hollow shaft 

may be found when the axial 

compressor wheel has less erosion than 

initially assessed. This proposed AD 

would require determining the engine 

history, a one-time visual inspection of 

the axial compressor for erosion, initial 

and repetitive cleaning of the gas 

generator hollow shaft, and replacement 

of the rear bearing if the amount of dust 

collected during cleaning exceeds 8 

grams. This proposed AD also includes 

an optional terminating action. We are 

proposing this AD to prevent an 

unbalance of the gas generator rotating 

assembly, which may lead to gas 

generator rear bearing failure, and 

uncommanded engine shutdown. 

DATES: We must receive comments on 

this proposed AD by September 24, 

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 AD, contact Turbomeca S.A., 40220 

Tarnos, France; phone: 33 05 59 74 40 

00; fax: 33 05 59 74 45 15. 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: Rose 

Len, Aerospace Engineer, Engine 

Certification Office, FAA, Engine & 

Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; 

phone: 781–238–7772; fax: 781–238– 

7199; email: rose.len@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–2012–0520; Directorate Identifier 

2002–NE–43–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 


TKELLEY on DSK3SPTVN1PROD with PROPOSALS