This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents. Prices of

new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

61033 

Vol. 76, No. 191 

Monday, October 3, 2011 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–1118; Directorate 

Identifier 2007–NM–318–AD; Amendment 

39–16792; AD 2011–18–10] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Model 737–600, –700, –700C, 

–800, –900, and –900ER Series 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are superseding an 

existing airworthiness directive (AD) for 

the products listed above. The existing 

AD currently requires reviewing the 

airplane maintenance records to 

determine whether an engine has been 

removed from the airplane since the 

airplane was manufactured. For 

airplanes on which an engine has been 

removed, the existing AD also requires 

an inspection of the aft engine mount to 

determine if the center link assembly is 

correctly installed, and follow-on 

actions if necessary. This new AD 

expands the applicability to include 

airplanes on which the engine has not 

been previously removed, and Model 

737–900ER airplanes. This AD was 

prompted by reports indicating that 

operators found that the center link 

assembly for the aft engine mount was 

reversed on several airplanes that had 

not had an engine removed since 

delivery. We are issuing this AD to 

prevent increased structural loads on 

the aft engine mount, which could 

result in failure of the aft engine mount 

and consequent separation of the engine 

from the airplane. 

DATES: This AD is effective November 7, 

2011. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in the AD 

as of November 7, 2011. 

ADDRESSES: 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; e-mail 

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. 

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: 

Alan Pohl, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6450; fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a supplemental notice of 

proposed rulemaking (SNPRM) to 

amend 14 CFR part 39 to supersede 

airworthiness directive (AD) 2003–03– 

01, Amendment 39–13025 (68 FR 4367, 

January 29, 2003). That AD applies to 

the specified products. The SNPRM 

published in the Federal Register on 

January 11, 2011 (76 FR 1552). The 

original NPRM (73 FR 64568, October 

30, 2008) proposed to continue to 

require reviewing the airplane 

maintenance records to determine 

whether an engine has been removed 

from the airplane since the airplane was 

manufactured. For airplanes on which 

an engine has been removed, the 

original NPRM also requires an 

inspection of the aft engine mount to 

determine if the center link assembly is 

correctly installed, and follow-on 

actions if necessary. The original NPRM 

also proposed to require those same 

actions on airplanes on which the 

engine has not previously been 

removed. The SNPRM proposed to 

further expand the applicability to 

include Model 737–900ER airplanes. 

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. 

Supportive Comments 

Boeing and Continental Airlines 

concur with the SNPRM (76 FR 1552, 

January 11, 2011). 

Request for Information 

American Airlines stated that it has 

accomplished the actions required by 

AD 2003–03–01 (68 FR 4367, January 

29, 2003) and the SNPRM (76 FR 1552, 

January 11, 2011), and although it will 

no longer be affected by the 

requirements in the SNPRM, asked the 

following questions: 

• What action has the original 

equipment manufacturer, Boeing, taken 

to prevent incorrect aft mount assembly 

installations? 

• Can Boeing specifically identify the 

procedures and/or best practices 

incorporated into their production 

process to prevent a recurrence of this 

type of event? 

We acknowledge the commenter’s 

concerns and provide the following 

responses: 

• Boeing Alert Service Bulletin 737– 

71A1462, Revision 2, dated May 29, 

2003; and Revision 3, dated May 20, 

2004; specify marking of the hangar 

fitting (pylon structure) and center link 

(engine structure) assembly, which is 

the same as the marking incorporated 

previously in production. These marks 

‘‘L,’’ ‘‘AFT,’’ and ‘‘R,’’ applied to both 

the hangar fitting and center link 

assembly will only be in close proximity 

if the center link is installed correctly. 

• Boeing has advised us that it has 

revised the instructions in its 

component maintenance manuals 


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(assembly level) and aircraft 

maintenance manuals (installation 

level) to put special emphasis on the 

center link installation. Boeing also 

advised us that it implemented drawing 

changes affecting both production 

assembly and field installation of this 

part; these changes incorporated 

specific markings on both the center 

link assembly and the hanger fitting to 

which it is attached. Boeing noted that 

after 2003 the parts were marked with 

an ‘‘L’’ and ‘‘R’’ (left and right) to 

indicate the part orientation when 

assembled, and the hanger assembly 

was marked with ‘AFT’ at the center 

line. Boeing has also developed a shop 

aid for use at the facility where the parts 

are fabricated and assembled which 

helps the assembler confirm the correct 

orientation of the parts. We have made 

no change to the AD in this regard. 

Conclusion 

We reviewed the relevant data, 

considered the comments received, and 

determined that air safety and the 

public interest require adopting the AD 

as proposed. 

Costs of Compliance 

We estimate that this AD affects 854 

airplanes of U.S. registry. There are no 

new requirements in this AD; however, 

we have expanded the applicability of 

this AD. The current costs for this AD 

are recalculated for the convenience of 

affected operators, as follows: 

ESTIMATED COSTS

Action Work hours Parts Cost per 

airplane Fleet cost 

Maintenance records review (required by AD 2003–03–01, Amendment 39– 

13025 (68 FR 4367, January 29, 2003)) ..................................................... 1 $0 $85 $72,590 

Inspection for correct installation of center link assembly (new required action) .............................................................................................................. 1 0 85 72,590 

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 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. 

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 

removing airworthiness directive (AD) 

2003–03–01, Amendment 39–13025 (68 

FR 4367, January 29, 2003), and by 

adding the following new AD: 

2011–18–10 The Boeing Company: 

Amendment 39–16792; Docket No. 

FAA–2008–1118; Directorate Identifier 

2007–NM–318–AD. 

Effective Date 

(a) This AD is effective November 7, 2011. 

Affected ADs 

(b) This AD supersedes AD 2003–03–01, 

Amendment 39–13025 (68 FR 4367, January 

29, 2003). 

Applicability 

(c) This AD applies to all The Boeing 

Company Model 737–600, –700, –700C, 

–800, –900, and –900ER series airplanes, 

certificated in any category. 

Subject 

(d) Air Transport Association (ATA) of 

America Code 71: Powerplant. 

Unsafe Condition 

(e) This AD was prompted by reports 

indicating that operators found that the 

center link assembly for the aft engine mount 

was reversed on several airplanes that had 

not had an engine removed since delivery. 

We are issuing this AD to prevent increased 

structural loads on the aft engine mount, 

which could result in failure of the aft engine 

mount and consequent separation of the 

engine from the airplane. 

Compliance 

(f) You are responsible for having the 

actions required by this AD performed within 

the compliance times specified, unless the 

actions have already been done. 

Restatement of Requirements of AD 2003– 

03–01 (68 FR 4367, January 29, 2003): 

Review of Maintenance Records 

(g) For Model 737–600, –700, –700C, –800, 

and –900 series airplanes: Within 90 days 

after February 13, 2003 (the effective date of 

AD 2003–03–01 (68 FR 4367, January 29, 

2003)), review the airplane maintenance 

records to determine whether either engine 

has been removed since the airplane’s date of 

manufacture. If neither engine has been 

removed since the airplane’s date of 

manufacture, no further action is required by 

this paragraph. 

Inspection of Engines That Have Been 

Removed To Determine If Center Link 

Assembly Is Installed Correctly 

(h) For Model 737–600, –700, –700C, –800, 

and –900 series airplanes on which any 

installed engine has been removed from the 

airplane since the airplane’s date of 

manufacture: Within 90 days after February 

13, 2003, do a one-time general visual 

inspection to determine if the center link 


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Federal Register / Vol. 76, No. 191 / Monday, October 3, 2011 / Rules and Regulations 61035 

assembly of the aft engine mount is installed 

correctly, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–71A1462, Revision 1, 

dated November 7, 2002; or Revision 3, dated 

May 20, 2004. If the center link assembly is 

installed correctly, no further action is 

required by paragraph (h) or (i) of this AD for 

that engine. As of the effective date of this 

AD, use only Boeing Alert Service Bulletin 

737–71A1462, Revision 3, dated May 20, 

2004. 

Note 1: For the purposes of this AD, a 

general visual inspection is: ‘‘A visual 

examination of an interior or exterior area, 

installation, or assembly to detect obvious 

damage, failure, or irregularity. This level of 

inspection is made from within touching 

distance unless otherwise specified. A mirror 

may be necessary to ensure visual access to 

all surfaces in the inspection area. This level 

of inspection is made under normally 

available lighting conditions such as 

daylight, hanger lighting, flashlight, or 

droplight and may require removal or 

opening of access panels or doors. Stands, 

ladders, or platforms may be required to gain 

proximity to the area being checked.’’ 

Follow-On and Corrective Actions 

(i) For airplanes on which any center link 

assembly is found installed incorrectly 

during any inspection required by paragraph 

(h), (k), or (l) of this AD: Before further flight, 

do the actions specified in paragraphs (i)(1), 

(i)(2), and (i)(3) of this AD, in accordance 

with the Accomplishment Instructions of 

Boeing Alert Service Bulletin 737–71A1462, 

Revision 1, dated November 7, 2002; or 

Revision 3, dated May 20, 2004; except that 

it is not necessary to submit a report of 

findings to the airplane manufacturer. As of 

the effective date of this AD, use only Boeing 

Alert Service Bulletin 737–71A1462, 

Revision 3, dated May 20, 2004. 

(1) Remove the center link assembly and 

install it correctly. 

(2) Perform a detailed inspection of the 

engine mounting lugs and engine turbine rear 

frame for cracking, yielding, buckling, or 

wear damage. 

(3) Perform a detailed inspection of the 

hardware for the aft engine mount; including 

the center link assembly, right link assembly, 

aft mount hanger assembly, and link pins; for 

cracking, yielding, buckling, or wear damage. 

Note 2: For the purposes of this AD, a 

detailed inspection is: ‘‘An intensive 

examination of a specific item, installation, 

or assembly to detect damage, failure, or 

irregularity. Available lighting is normally 

supplemented with a direct source of good 

lighting at an intensity deemed appropriate. 

Inspection aids such as mirror, magnifying 

lenses, etc., may be necessary. Surface 

cleaning and elaborate procedures may be 

required.’’ 

Repair 

(j) If any cracking, yielding, buckling, or 

wear damage is found during the inspections 

required by paragraphs (i)(2) and (i)(3) of this 

AD: Before further flight, replace the 

discrepant part with a new or serviceable 

part, or repair in accordance with a method 

approved in accordance with the procedures 

specified in paragraph (o) of this AD. 

New Requirements of This AD 

Inspection of Engines That Have Not Been 

Removed To Determine If Center Link 

Assembly Is Installed Correctly 

(k) For airplanes identified in Boeing Alert 

Service Bulletin 737–71A1462, Revision 3, 

dated May 20, 2004, on which any installed 

engine has not been removed from the 

airplane since the airplane’s date of 

manufacture: Within 90 days after the 

effective date of this AD, do a detailed 

inspection to determine if the center link 

assembly of the aft engine mount is installed 

correctly, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–71A1462, Revision 3, 

dated May 20, 2004. If the center link is 

installed correctly, no further action is 

required by this paragraph for that engine. 

Follow-On and Corrective Actions 

(l) For airplanes on which any center link 

assembly is found installed incorrectly 

during the inspection required by paragraph 

(k) of this AD: Before further flight, do the 

follow-on and corrective actions required by 

paragraph (i) of this AD. 

Credit for Actions Done Using Previous 

Service Information 

(m) Inspections and corrective actions 

done before the effective date of this AD in 

accordance with a Boeing service bulletin 

listed in Table 1 of this AD are acceptable for 

compliance with the corresponding 

requirements of this AD. 

TABLE 1—PREVIOUS SERVICE BULLETINS

Boeing Alert Service Bulletin— Revision— Dated— 

737–71A1462 ......................................................................................................................................................... Original .... August 29, 2002. 

737–71A1462 ......................................................................................................................................................... 1 .............. November 7, 2002. 

737–71A1462 ......................................................................................................................................................... 2 .............. May 29, 2003. 

Parts Installation 

(n) As of the effective date of this AD, no 

person may install an engine on any airplane 

identified in paragraph (c) of this AD unless 

the actions required by paragraph (n)(1) or 

(n)(2) of this AD are accomplished. 

(1) The inspection is accomplished in 

accordance with the Accomplishment 

Instructions of Boeing Alert Service Bulletin 

737–71A1462, Revision 3, dated May 20, 

2004, and the center link assembly of the aft 

engine mount is found to be installed 

correctly. 

(2) The hanger fitting and center link 

assembly are marked and part marked in 

accordance with Part 2 of the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–71A1462, Revision 3, 

dated May 20, 2004. 

Note 3: For hanger fittings and center link 

assemblies marked and part marked in 

production, as specified in Part 2 of the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–71A1462, Revision 3, 

dated May 20, 2004, the actions specified in 

paragraph (n)(2) of this AD do not apply. 

Alternative Methods of Compliance 

(AMOCs) 

(o) The certification office specified in 

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

applicable, has the authority to approve 

AMOCs for paragraphs (i) and (j) of this AD, 

if requested using the procedures found in 14 

CFR 39.19. 

(1) For the structure identified in 

paragraph (i)(2) of this AD: The Manager, 

Engine Certification Office (ECO), FAA. Send 

information to ATTN: Antonio Cancelliere, 

Aerospace Engineer, ANE–141, FAA, ECO, 

12 New England Executive Park, Burlington, 

Massachusetts 01803–5299; telephone 781– 

238–7751; fax 781–238–7199. 

(2) For the structure identified in 

paragraph (i)(3) of this AD: The Manager, 

Seattle Aircraft Certification Office (ACO), 

FAA. Send information to ATTN: Alan Pohl, 

Aerospace Engineer, Airframe Branch, ANM– 

120S, FAA, Seattle ACO, 1601 Lind Avenue, 

SW., Renton, Washington 98057–3356; 

telephone (425) 917–6450; fax (425) 917– 

6590. Information may be e-mailed to: 9- 

ANM-Seattle-ACO-AMOC-Requests@faa.gov. 

(3) To request a different method of 

compliance or a different compliance time 

for this AD, follow the procedures in 14 CFR 

39.19. Before using any approved AMOC on 

any airplane to which the AMOC applies, 

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. 

(4) An AMOC that provides an acceptable 

level of safety may be used for any repair 

required by paragraph (i)(3) of this AD if it 

is approved by Boeing Commercial Airplanes 

Organization Designation Authorization 

(ODA) that has been authorized by the 

Manager, Seattle 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. 

Material Incorporated by Reference 

(p) You must use Boeing Alert Service 

Bulletin 737–71A1462, Revision 3, dated 


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61036 Federal Register / Vol. 76, No. 191 / Monday, October 3, 2011 / Rules and Regulations 

May 20, 2004, to do the actions required by 

this AD, unless the AD specifies otherwise. 

(1) The Director of the Federal Register 

approved the incorporation by reference of 

Boeing Alert Service Bulletin 737–71A1462, 

Revision 3, dated May 20, 2004, under 5 

U.S.C. 552(a) and 1 CFR part 51. 

(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; e-mail me.boecom@boeing.com; 

Internet https://www.myboeingfleet.com. 

(3) 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. 

(4) You may also review copies of the 

service information that is incorporated by 

reference at the National Archives and 

Records Administration (NARA). For 

information on the availability of this 

material at an NARA facility, call 202–741– 

6030, or go to http://www.archives.gov/ 

federal_register/code_of_federal_regulations/ 

ibr_locations.html. 

Issued in Renton, Washington on 

September 8, 2011. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

Peter A. White, 

Manager, Engine and Propeller Directorate, 

Engine and Propeller Directorate, Aircraft 

Certification Service. 

[FR Doc. 2011–24681 Filed 9–30–11; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–0646; Directorate 

Identifier 2010–NM–224–AD; Amendment 

39–16814; AD 2011–20–04] 

RIN 2120–AA64 

Airworthiness Directives; Gulfstream 

Aerospace LP Model Galaxy and 

Gulfstream 200 Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for the 

products listed above. This AD results 

from mandatory continuing 

airworthiness information (MCAI) 

originated by an aviation authority of 

another country to identify and correct 

an unsafe condition on an aviation 

product. The MCAI describes the unsafe 

condition as: 

Cracked nuts * * * were found on 

aircraft’s production line during routine post 

assembly inspection. Investigation revealed 

that the cracks resulted from hydrogen 

embrittlement combined with high hardness. 

Non-conformity with certified mechanical 

properties of this fastener can potentially 

lead to an unsafe condition. 

The unsafe condition is cracked nuts in 

multiple locations (including aileron 

fittings, rudder tab assembly and 

mounting structure for power drive 

units) could result in failure of affected 

locations and consequent reduced 

controllability or reduced structural 

capability of the airplane. We are 

issuing this AD to require actions to 

correct the unsafe condition on these 

products. 

DATES: This AD becomes effective 

November 7, 2011. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of November 7, 2011. 

ADDRESSES: You may examine the AD 

docket on the Internet at http:// 

www.regulations.gov or in person at the 

U.S. Department of Transportation, 

Docket Operations, M–30, West 

Building Ground Floor, Room W12–140, 

1200 New Jersey Avenue, SE., 

Washington, DC. 

FOR FURTHER INFORMATION CONTACT: 

Mike Borfitz, Aerospace Engineer, 

International Branch, ANM–116, 

Transport Airplane Directorate, FAA, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 227–2677; fax (425) 227–1149. 

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 was published in the Federal 

Register on June 29, 2011 (76 FR 38062). 

That NPRM proposed to correct an 

unsafe condition for the specified 

products. The MCAI states: 

Cracked nuts (P/N [part number] MS– 

21042L3) were found on aircraft’s production 

line during routine post assembly inspection. 

Investigation revealed that the cracks 

resulted from hydrogen embrittlement 

combined with high hardness. Nonconformity with certified mechanical 

properties of this fastener can potentially 

lead to an unsafe condition. 

The unsafe condition of cracked nuts 

in multiple locations (including aileron 

fittings, rudder tab assembly and 

mounting structure for power drive 

units) could result in failure of affected 

locations and consequent reduced 

controllability or reduced structural 

capability of the airplane. The required 

actions include replacing nuts having 

P/N MS21042L3, and in certain 

locations, a one time radiographic 

inspection for cracked nuts and 

replacing any cracked nuts. You may 

obtain further information by examining 

the MCAI in the AD docket. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. We 

received no comments on the NPRM (76 

FR 38062, June 29, 2011) or on the 

determination of the cost to the public. 

Conclusion 

We reviewed the available data and 

determined that air safety and the 

public interest require adopting the AD 

as proposed. 

Differences Between This AD and the 

MCAI or Service Information 

We have reviewed the MCAI and 

related service information and, in 

general, agree with their substance. But 

we might have found it necessary to use 

different words from those in the MCAI 

to ensure the AD is clear for U.S. 

operators and is enforceable. In making 

these changes, we do not intend to differ 

substantively from the information 

provided in the MCAI and related 

service information. 

We might also have required different 

actions in this AD from those in the 

MCAI in order to follow our FAA 

policies. Any such differences are 

highlighted in a NOTE within the AD. 

Costs of Compliance 

We estimate that this AD will affect 2 

products of U.S. registry. We also 

estimate that it will take about 227 

work-hours per product to comply with 

the basic requirements of this AD. The 

average labor rate is $85 per work-hour. 

Required parts will cost about $0 per 

product. Where the service information 

lists required parts costs that are 

covered under warranty, we have 

assumed that there will be no charge for 

these parts. As we do not control 

warranty coverage for affected parties, 

some parties may incur costs higher 

than estimated here. Based on these 

figures, we estimate the cost of this AD 

to the U.S. operators to be $38,590, or 

$19,295 per product. 

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 


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