## 2057 Federal Register / Vol. 75, No. 9 / Thursday, January 14, 2010 / Rules and Regulations

(1) For airplanes equipped with booster control unit P/N 23400–3B, 23400–7, 23400– 3, or 23400–5, within 12 months after the effective date of this AD, perform a one-time inspection of the elevator booster control unit in accordance with Part 1 of the Accomplishment Instructions of Fokker Service Bulletin SBF100–27–088, dated June 4, 2007.

(2) At the time specified in Table 1 of this AD, and depending on the result of the inspection required by paragraph (f)(1) of this AD, replace the elevator booster control unit with a modified unit having P/N 23400–3B or P/N 23400–7, in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin SBF100–27–088, dated June 4, 2007. The replacement part must be modified in accordance with Goodrich Service Bulletin 23400–27–27, Revision 1, dated September 14, 2007.



### T ABLE 

### 1—R EPLACEMENT 

### P ARAMETERS

Dimension A Replace within

A < 0.12 millimeters

(mm). Not applicable.

0.12 mm ≤ A < 0.5

mm. 3,000 flight cycles.

0.5 mm ≤ A < 1.0 mm 2,000 flight cycles. 1.0 mm ≤ A < 1.5 mm 1,000 flight cycles. 1.5 mm ≤ A < 2.0 mm 500 flight cycles. 2.0 mm ≤ A < 2.5 mm 125 flight cycles. A ≥ 2.5 mm ............... Before further flight.

(3) Within 60 months after the effective date of this AD, replace all remaining unmodified elevator booster control units having P/N 23400–3B or P/N 23400–7 with modified units, in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin SBF100–27–088, dated June 4, 2007. The replacement part must be modified in accordance with Goodrich Service Bulletin 23400–27–27, Revision 1, dated September 14, 2007.

(4) Within 60 months after the effective date of this AD, replace all remaining elevator booster control units having P/N 23400–3 or P/N 23400–5 with modified units having P/N 23400–3B or P/N 23400–7, in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin SBF100–27–088, dated June 4, 2007. The replacement part must be modified in accordance with Goodrich Service Bulletin 23400–27–27, Revision 1, dated September 14, 2007.

(5) As of 12 months after the effective date of this AD, no person may install a Goodrich P/N 23400–3B, P/N 23400–7, P/N 23400–3 or P/N 23400–5 elevator booster control unit on any airplane, unless the conditions of paragraph (f)(5)(i) or (f)(5)(ii), as applicable,
are met.

(i) The unit has been inspected in accordance with paragraph (f)(1) of this AD, and the applicable action(s) required by paragraph (f)(2) is accomplished at the time specified in that paragraph.

(ii) The unit having P/N 23400–3B or P/N 23400–7 has been modified in accordance with Goodrich Service Bulletin 23400–27–27, Revision 1, dated September 14, 2007. (6) As of 60 months after the effective date of this AD, no person may install a Goodrich P/N 23400–3 or P/N 23400–5 elevator booster control unit on any airplane.

FAA AD Differences

Note 1: This AD differs from the MCAI and/or service information as follows: No differences.

Other FAA AD Provisions

(g) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM–116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Tom Rodriguez, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–1137; fax (425) 227–1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards 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.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. ), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120–0056.

Related Information

(h) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2009– 0032, dated February 17, 2009; Fokker Service Bulletin SBF100–27–088, dated June 4, 2007; and Goodrich Service Bulletin 23400–27–27, Revision 1, dated September 14, 2007; for related information.
Material Incorporated by Reference

(i) You must use Fokker Service Bulletin SBF100–27–088, dated June 4, 2007; and Goodrich Service Bulletin 23400–27–27, Revision 1, dated September 14, 2007; as applicable; 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 this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For Fokker service information identified in this AD, contact Fokker Services B.V., Technical Services Dept., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands; telephone +31 (0)252–627–350; fax +31 (0)252 627 211; e-mail technicalservices.fokkerservices@stork.com; Internet http://www.myfokkerfleet.com.

(3) For Goodrich service information identified in this AD, contact Goodrich Corporation, Landing Gear, 1400 South Service Road, West Oakville L6L 5Y7, Ontario, Canada; telephone 905–825–1568; e-mail jean.breed@goodrich.com; Internet http://www.goodrich.com/TechPubs.

(4) You may review copies of the 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 or 425–227–1152.

(5) 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 NARA, 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 December 28, 2009. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2010–102 Filed 1–13–10; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2009–1251; Directorate Identifier 2009–NM–133–AD; Amendment**  **39–16174; AD 2010–02–03]**

**RIN 2120–AA64**



### Airworthiness Directives; Airbus Model **A340–200 and A340–300 Series Airplanes** 

**AGENCY** 

### : Federal Aviation Administration (FAA), Department of Transportation (DOT).

**ACTION** 

### : Final rule; request for
comments.

**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:

* * * * *

Engineering analysis using the new calculated loads has shown that the structural integrity of the forward engine mount cannot be guaranteed after either thrust link has accumulated 15500 Flight Cycles (FC).


### * * * * *


## 2058 Federal Register / Vol. 75, No. 9 / Thursday, January 14, 2010 / Rules and Regulations

A loss of structural integrity of the forward engine mounts could lead to the loss of the load path for the forward engine mount and damage to other engine mount structures, which could result in failure of the forward engine mount, possible separation of the engine from the airplane, damage to the wing, or loss of control of the airplane. This AD requires actions that are intended to address the unsafe condition described in the MCAI.

**DATES** 

### : This AD becomes effective January 29, 2010.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of January 29, 2010.

We must receive comments on this AD by March 1, 2010.

**ADDRESSES** 

### : You may send comments 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: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC, 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 Operations office 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 street address for the Docket Operations office (telephone (800) 647–5527) is in the **ADDRESSES** 

### section. Comments will be available in the AD docket shortly after receipt.

**FOR FURTHER INFORMATION CONTACT** 

### : Vladimir Ulyanov, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–1138; fax (425)
227–1149.

**SUPPLEMENTARY INFORMATION** 

### :

Discussion

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2009–0115, dated May 29, 2009 (referred to after this as ‘‘ the MCAI ’’ ), to correct an unsafe condition for the specified products. The MCAI states:

A recent review of the A340–200/300 fleet has shown that the current utilization rate of the aeroplanes is different from the assumptions used at the time of A340 initial certification. New calculations have been performed taking into account an updated mission profile to determine the impact to the loads on the forward engine mount.

Engineering analysis using the new calculated loads has shown that the structural integrity of the forward engine mount cannot be guaranteed after either thrust link has accumulated 15500 Flight Cycles (FC).

Consequently, this AD introduces a Limit Of Validity (LOV) of 15500 FC for CFM 56– 5C forward engine mount thrust links Part Number (P/N) 340–7005–3 and P/N 340–
7005–4.

In addition, this AD requires establishing the deadline for replacement of forward engine mount thrust link assemblies, to trace the life of these assemblies and to replace them no later than the calculated deadline. 

### A loss of structural integrity of the forward engine mounts could lead to the loss of the load path for the forward engine mount and damage to other engine mount structures, which could result in failure of the forward engine mount, possible separation of the engine from the airplane, damage to the wing, or loss of control of the airplane. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Airbus has issued Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI. FAA’s Determination and Requirements of This AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all pertinent information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

There are no products of this type currently registered in the United States. However, this rule is necessary to ensure that the described unsafe condition is addressed if any of these products are placed on the U.S. Register in the future. Differences Between the 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 FAA policies. Any such differences are highlighted in a NOTE within the AD.

FAA’s Determination of the Effective Date

Since there are currently no domestic operators of this product, notice and opportunity for public comment before issuing this AD are unnecessary.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the **ADDRESSES** 

### section. Include ‘‘ Docket No. FAA–2009–1251; Directorate Identifier 2009–NM–133– AD ’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this 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 AD. 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


## 2059 Federal Register / Vol. 75, No. 9 / Thursday, January 14, 2010 / Rules and 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 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 this AD:

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); and

3. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment

■ 

### Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

**PART 39—AIRWORTHINESS DIRECTIVES** 

■ 

### 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

**§ 39.13 [Amended]**

■ 

### 2. The FAA amends § 39.13 by adding the following new AD:

2010–02–03 Airbus: Amendment 39–16174. Docket No. FAA–2009–1251; Directorate Identifier 2009–NM–133–AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective January 29, 2010.

Affected ADs

(b) None.
Applicability

(c) This AD applies to Airbus Model A340– 211, –212, –213, –311, –312, and –313 airplanes, all manufacturer serial numbers; certificated in any category.
Subject

(d) Air Transport Association (ATA) of America Code 71: Powerplant.

Reason

(e) The mandatory continued airworthiness information (MCAI) states:

A recent review of the A340–200/300 fleet has shown that the current utilization rate of the aeroplanes is different from the assumptions used at the time of A340 initial certification. New calculations have been performed taking into account an updated mission profile to determine the impact to the loads on the forward engine mount.

Engineering analysis using the new calculated loads has shown that the structural integrity of the forward engine mount cannot be guaranteed after either thrust link has accumulated 15500 Flight Cycles (FC).

Consequently, this AD introduces a Limit of Validity (LOV) of 15 500 FC for CFM 56– 5C forward engine mount thrust links Part Number (P/N) 340–7005–3 and P/N 340–
7005–4.

In addition, this AD requires establishing the deadline for replacement of forward engine mount thrust link assemblies, to trace the life of these assemblies and to replace them no later than the calculated deadline. A loss of structural integrity of the forward engine mounts could lead to the loss of the load path for the forward engine mount and damage to other engine mount structures, which could result in failure of the forward engine mount, possible separation of the engine from the airplane, damage to the wing, or loss of control of 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.

Actions

(g) Unless already done, do the following actions.

(1) At the applicable time in paragraph (g)(1)(i) or (g)(1)(ii) of this AD: Calculate the flight cycles, as applicable, and replace all CFM 56–5C forward engine mount thrust links P/N 340–7005–3 or P/N 340–7005–4, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009.

Note 1: P/N 340–7005–3 and P/N 340– 7005–4 are the part numbers for only the link. P/N 340–7005–503 and P/N 340–7005– 504 are the part numbers for the assembly (comprising the bearing and the link).

(i) For airplanes with thrust links for which the history of the part is available: Replace in accordance with Airbus Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009, prior to the accumulation of 15,500 total flight cycles on the part, or within 90 days from the effective date of the AD, whichever occurs later.

(ii) For airplanes with thrust links for which the part history is partial or unknown: Within 30 days after the effective date of this AD, calculate the replacement date in accordance with the calculation method provided in Airbus Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009, and replace the part no later than the calculated replacement date.

(2) Repeat the replacement required by paragraph (g)(1) of this AD at intervals not to exceed 15,500 flight cycles on the part in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009.

FAA AD Differences

Note 2: This AD differs from the MCAI and/or service information as follows: No differences.

Other FAA AD Provisions

(h) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM–116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Vladimir Ulyanov, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–1138; fax (425) 227–1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards 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.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. ), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120–0056.

Related Information

(i) Refer to Mandatory Continuing Airworthiness Information (MCAI) European Aviation Safety Agency (EASA) Airworthiness Directive 2009–0115, dated May 29, 2009; and Airbus Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009; for related information.
Material Incorporated by Reference

(j) You must use Airbus Mandatory Service Bulletin A340–71–4006, Revision 01, dated May 14, 2009, 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


## 2060 Federal Register / Vol. 75, No. 9 / Thursday, January 14, 2010 / Rules and Regulations

this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Airbus SAS—Airworthiness Office—EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 45 80; e-mail airworthiness.A330–A340@airbus.com; Internet http://www.airbus.com

.

(3) You may review copies of the 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 or 425–227–1152.

(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 NARA, 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 December 30, 2009. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2010–211 Filed 1–13–10; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2009–0610; Directorate Identifier 2009–NM–021–AD; Amendment**  **39–16171; AD 2010–01–12]**

**RIN 2120–AA64**



### Airworthiness Directives; Empresa **Brasileira de Aeronautica S.A. (EMBRAER) Model ERJ 170 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:

The result of re-assessment of rotor burst analysis has shown the possibility of loss of electrical power supply to the following aircraft systems: Air Data System (ADS), Ailerons, Multifunctional spoilers and rudder, which result in loss of the aircraft pitch and yaw control.


### * * * * * We are issuing this AD to require actions to correct the unsafe condition on these products.

**DATES** 

### : This AD becomes effective February 18, 2010.The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of February 18, 2010.

**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** 

### : Kenny Kaulia, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–2848; 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 July 15, 2009 (74 FR 34276). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

The result of re-assessment of rotor burst analysis has shown the possibility of loss of electrical power supply to the following aircraft systems: Air Data System (ADS), Ailerons, Multifunctional spoilers and rudder, which result in loss of the aircraft pitch and yaw control.


### * * * * * Required actions include modifying the electrical wiring in the overhead panel of the cockpit, modifying the air data smart probe 3B power supply bus, and modifying the Aeronautical Radio Incorporated (ARINC) 429 data bus, as applicable. 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 considered the comments received. Request To Withdraw NPRM

Embraer requests that we withdraw the NPRM. Embraer states that based on service experience, the probability of a rotor burst combined with the probability of a disk trajectory that hits the specific wiring bundle is extremely rare. Embraer disagrees that the modifications addressed by the service bulletins should be mandatory. Embraer also states that issuance of a Special Airworthiness Information Bulletin would be an alternative measure to be taken in this case, since it would address the concerns in the NPRM and still be in conformity with the 14 CFR part 39 requirements.

We disagree with the request to withdraw the NPRM. We have consulted with the Age ˆ ncia Nacional de Aviac

 ̧ a  ̃ o Civil (ANAC) regarding the manufacturer’s comment and determined that, regardless of the very low probability that a catastrophic event could occur due to a rotor burst, the requirements of 14 CFR part 25 do not permit the use of probability as a risk reduction parameter. Furthermore, the design must minimize the effects of rotor burst by any means practicable. This AD is necessary to address the identified unsafe condition. Therefore, the AD is not changed in this regard. Explanation of Changes Made to This AD

We have revised this AD to identify the correct legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models.

Conclusion

We reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We determined that this change will not increase the economic burden on any operator or increase the scope of the AD.

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 77 products of U.S. registry. We alsoestimate that it will take about 62 workhours per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour.