## 32263 Federal Register / Vol. 75, No. 109 / Tuesday, June 8, 2010 / Rules and Regulations

Effective Date

(a) This airworthiness directive (AD) becomes effective July 13, 2010.

Affected ADs

(b) None.
Applicability

(c) This AD applies to CFM International, S.A. models CFM56–3 and –3B turbofan engines with 25 degrees midspan shroud fan blades, part numbers (P/Ns) 9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, 1285M39P01, or fan blade pairs, P/Ns 335– 088–901–0, 335–088–902–0, 335–088–903–0, and 335–088–904–0 installed. These engines are installed on, but not limited to, Boeing 737 series airplanes.

(d) CFM International, S.A. has added to the basic engine model number on the engine nameplate to identify minor variations in engine configuration, installation components, or reduced ratings peculiar to aircraft installation requirements.

(e) Those engines marked on the engine data plate as CFM56–3–B1 are included in this AD as CFM56–3 turbofan engines.

(f) Those engines marked on the engine data plate as CFM56–3B–2 are included in this AD as CFM56–3B turbofan engines.

Unsafe Condition

(g) This AD results from a report of a failed fan blade with severe out-of-limit wear on the underside of the blade platform where it contacts the damper. We are issuing this AD to prevent failure of multiple fan blades, which could result in an uncontained failure of the engine and damage to the airplane.
Compliance

(h) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Inspection for Wear

(i) Within 900 cycles-in-service after the effective date of this AD, perform an on-wing or in-shop inspection of the fan blade and damper for wear. Use paragraphs 3.A.(1) through 3.A.(5) or paragraphs 3.B.(1) through 3.B.(5) respectively, of the Accomplishment Instructions of CFM International Service Bulletin (SB) No. CFM56–3/3B/3C S/B 72– 1067, dated February 15, 2007.

(j) If you find out-of-limit wear on at least one fan blade platform underside, perform the additional inspections and disposition the parts, as specified in paragraphs 3.A.(3) and 3.A.(5) or paragraphs 3.B.(3) and 3.B.(5) respectively, of the Accomplishment Instructions of CFM International SB No. CFM56–3/3B/3C S/B 72–1067, dated February 15, 2007.

(k) Thereafter, within intervals not to exceed 3,000 cycles-since-last inspection, perform an on-wing or in-shop inspection for wear. Use paragraphs 3.A.(1) through 3.A.(5) or paragraphs 3.B.(1) through 3.B.(5) respectively, of the Accomplishment Instructions of CFM International SB No. CFM56–3/3B/3C S/B 72–1067, dated February 15, 2007.

(l) If you find wear on at least one fan blade platform underside, perform additional inspections and disposition the parts, as specified in paragraphs 3.A.(3) and 3.A.(5) or paragraphs 3.B.(3) and 3.B.(5) respectively, of the Accomplishment Instructions of CFM International SB No. CFM56–3/3B/3C S/B 72–1067, dated February 15, 2007.

Installation Prohibition

(m) After the effective date of this AD, don’t install any 25 degrees midspan shroud fan blades, P/Ns 9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, 1285M39P01, or fan blade pairs, P/Ns 335–088–901–0, 335– 088–902–0, 335–088–903–0, and 335–088– 904–0, unless they have passed an inspection specified in paragraph 3. of the Accomplishment Instructions of CFM International SB No. CFM56–3/3B/3C S/B 72–1067, dated February 15, 2007.
Optional Terminating Action

(n) Replacing the 25 degrees midspan shroud fan blade set with a 37 degrees midspan shroud fan blade set terminates the repetitive inspection requirements specified in paragraph (k) of this AD.
Alternative Methods of Compliance

(o) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(p) Contact Antonio Cancelliere, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: antonio.cancelliere@faa.gov; telephone (781) 238–7751; fax (781) 238– 7199, for more information about this AD.

(q) European Aviation Safety Agency AD 2009–0036, dated February 20, 2009, also addresses the subject of this AD.
Material Incorporated by Reference

(r) You must use CFM International Service Bulletin No. CFM56–3/3B/3C S/B 72–1067, dated February 15, 2007, to perform the inspections and parts dispositions required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact CFM International, S. A., Technical Publication Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 552–2800; fax (513) 552– 2816, for a copy of this service information. You may review copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or 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/federalregister/cfr/ibr-locations.html.

Issued in Burlington, Massachusetts, on May 25, 2010. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.
[FR Doc. 2010–13432 Filed 6–7–10; 8:45 am]

**BILLING CODE 4910–13–P** 

### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2009–1223; Directorate Identifier 2009–NM–114–AD; Amendment**  **39–16327; AD 2010–12–06]**

**RIN 2120–AA64**



### Airworthiness Directives; Bombardier, **Inc. Model DHC–8–400 Series 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:

During final Acceptance Test Procedure (ATP), a small oil leak was discovered on the Spoiler Unload Valve and Rudder Shutoff Valve bodies. Investigation revealed that a number of valves were manufactured with an incorrect wall thickness. This thin wall condition caused cracking, subsequent external weeping and pressure loss from the subject valves.

This condition, if not corrected, will cause a loss of hydraulic fluid and subsequent loss of spoiler and/or rudder control.


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

**DATES** 

### : This AD becomes effective July 13, 2010.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of July 13, 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** 

### : Cesar Gomez, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE–171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228– 7318; fax (516) 794–5531.

**SUPPLEMENTARY INFORMATION** 

### :


## 32264 Federal Register / Vol. 75, No. 109 / Tuesday, June 8, 2010 / Rules and Regulations

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 December 30, 2009 (74 FR 69038). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

During final Acceptance Test Procedure (ATP), a small oil leak was discovered on the Spoiler Unload Valve and Rudder Shutoff Valve bodies. Investigation revealed that a number of valves were manufactured with an incorrect wall thickness. This thin wall condition caused cracking, subsequent external weeping and pressure loss from the subject valves.

This condition, if not corrected, will cause a loss of hydraulic fluid and subsequent loss of spoiler and/or rudder control.

Revision 1 of this directive mandates a new interval for the initial inspection, clarifies the time for replacement of the valve(s) specified in Paragraphs 1.2 and 2.2, and clarifies the labeling of the inspected valves in Paragraph 3 of this directive. 

### Required actions include doing detailedinspections of the left-hand and righthand spoiler unload and rudder shutoff valve for leaking and weeping, replacing discrepant left-hand and right-hand spoiler unload and rudder shutoff valves with new or serviceable valves, and eventually replacing all valves having a certain part number.

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 comment received. Request To Address Valves Inspected Previously

Horizon Air requests that we address valves that have been inspected previously by the manufacturer by revising paragraphs (g)(1) and (g)(2) of the NPRM to include the phrase

‘‘without suffix ‘A’ after the serial number. ’’ Horizon Air explains that the NPRM, as written, requires the inspection to be done on all valves, regardless if they have been modified or unmodified. Horizon Air suggests that with the recommended phrasing, the NPRM would continue to require inspection of valves with the identified unsafe condition, but would not require inspection of valves inspected previously.

We agree. Adding the phrase ‘‘without suffix ‘A’ after the serial number ’’ will eliminate unnecessary inspections for valves that have been inspected previously by the manufacturer. We have revised paragraphs (g)(1) and (g)(2) of this AD accordingly.

Conclusion

We reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We determined that these changes 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. Explanation of Change to Costs of Compliance

Since issuance of the NPRM, we have increased the labor rate used in theCosts of Compliance from $80 per workhour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate. Costs of Compliance

We estimate that this AD will affect 61 products of U.S. registry. We alsoestimate that it will take about 3 workhours 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 $15,555, or $255 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 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 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. 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 the NPRM, 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. 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,


## 32265 Federal Register / Vol. 75, No. 109 / Tuesday, June 8, 2010 / Rules and Regulations

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:
2010–12–06 Bombardier, Inc.: Amendment 39–16327. Docket No. FAA–2009–1223; Directorate Identifier 2009–NM–114–AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective July 13, 2010.

Affected ADs

(b) None.
Applicability

(c) This AD applies to Bombardier, Inc. Model DHC–8–400, DHC–8–401, and DHC– 8–402 series airplanes, certificated in any category, serial numbers 4105 through 4179 inclusive.
Subject

(d) Air Transport Association (ATA) of America Code 27: Flight controls.

Reason

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

During final Acceptance Test Procedure (ATP), a small oil leak was discovered on the Spoiler Unload Valve and Rudder Shutoff Valve bodies. Investigation revealed that a number of valves were manufactured with an incorrect wall thickness. This thin wall condition caused cracking, subsequent external weeping and pressure loss from the subject valves.

This condition, if not corrected, will cause a loss of hydraulic fluid and subsequent loss of spoiler and/or rudder control.

Revision 1 of this directive mandates a new interval for the initial inspection, clarifies the time for replacement of the valve(s) specified in Paragraphs 1.2 and 2.2, and clarifies the labeling of the inspected valves in Paragraph 3 of this directive. Required actions include doing detailed inspections of the left-hand and right-hand spoiler unload and rudder shutoff valve for leaking and weeping, replacing discrepant left-hand and right-hand spoiler unload and rudder shutoff valves with new or serviceable valves, and eventually replacing all valves having a certain part number.
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) Do the actions specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, as applicable. (1) For airplanes having serial numbers 4105 through 4172 inclusive: Within 750 flight hours after the effective date of this AD, do a detailed inspection of the left-hand and right-hand spoiler unload valves having part number (P/N) 396000–1005 without suffix

‘‘ A ’’ after the serial number, for leaking and weeping, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–27–37, dated February 5,2009. For airplanes with left-hand and righthand spoiler unload valves having P/N 396000–1005 with suffix ‘‘ A ’’ after the serial number, no further action is required by this paragraph.

(i) If any leaking or weeping is found, prior to further flight, replace the affected spoiler unload valve with a new or serviceable valve, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–27–37, dated February 5, 2009.

(ii) If no leaking and no weeping are found, replace the valves with new or serviceable valves within 6,000 flight hours after the initial inspection required by paragraph (g)(1) of this AD, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–27–37, dated February 5,
2009.

(2) For airplanes having serial numbers 4113 through 4179 inclusive: Within 750 flight hours after the effective date of this AD, do a detailed inspection of the left-hand and right-hand rudder shutoff valves having P/N 412700–1001 without suffix ‘‘ A ’’ after the serial number, for leaking and weeping, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–27–39, dated February 5, 2009. For airplanes with left-hand and right-hand rudder shutoff valves having P/N 412700– 1001 with suffix ‘‘ A ’’ after the serial number, no further action is required by this paragraph.

(i) If any leaking or weeping is found, prior to further flight, replace the affected rudder shutoff valve with a new or serviceable valve, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–27–39, dated February 5, 2009.

(ii) If no leaking and no weeping are found, replace the valves with new or serviceable valves within 6,000 flight hours after the initial inspection required by paragraph (g)(2) of this AD, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–27–39, dated February 5,
2009.

(3) As of the effective date of this AD, no person may install a spoiler unload valve assembly having P/N 396000–1005, having a serial number from 0289 through 0424 inclusive, or rudder shutoff valve having P/ N 412700–1001, having a serial number from 0239 through 0384 inclusive, on any airplane, unless the valve has been inspected by the manufacturer and labeled with a suffix

‘‘ A ’’ after the serial number.

FAA AD Differences

Note 1: 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, 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. Send information 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 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 MCAI Canadian Airworthiness Directive CF–2009–25R1, dated July 23, 2009; Bombardier Service Bulletin 84–27–37, dated February 5, 2009; and Bombardier Service Bulletin 84–27–39, dated February 5, 2009; for related information.
Material Incorporated by Reference

(j) You must use Bombardier Service Bulletin 84–27–37, dated February 5, 2009; or Bombardier Service Bulletin 84–27–39, dated February 5, 2009; 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 service information identified in this AD, contact Bombardier, Inc., 400 Co ˆ teVertu Road West, Dorval, Que  ́ bec H4S 1Y9, Canada; telephone 514–855–5000; fax 514– 855–7401; e-mail thd.qseries@aero.bombardier.com ; Internet http://www.bombardier.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.

(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.


## 32266 Federal Register / Vol. 75, No. 109 / Tuesday, June 8, 2010 / Rules and Regulations

Issued in Renton, Washington, on May 25,
2010. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2010–13425 Filed 6–7–10; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0171; Directorate Identifier 2009–NM–185–AD; Amendment**  **39–16329; AD 2010–12–08]**

**RIN 2120–AA64**



### Airworthiness Directives; Airbus Model **A300 Series Airplanes; Airbus Model A300 B4–600, B4–600R, and F4–600R**  **Series Airplanes, and Model C4–605R Variant F Airplanes (Collectively Called**  **A300–600 Series Airplanes); and Model A310 Series 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:

During a maintenance check performed by an A310 operator, the recommended modification of the lower attachment beam of rack 101VU by accomplishment of Airbus Service Bulletin (SB) A310–53–2076 was embodied on the aeroplane, leading the operator to find three cracks on the FR15A crossbeam above the NLG [nose landing gear] box at the splicing with rack 107VU fitting.

This condition, if not detected and corrected, could degrade the structural integrity of the crossbeam on NLG FR15A Web attachment fitting of rack 107VU. Rack 107VU contains major airworthiness system components whose functioning could be adversely affected by the loss of the attachment fitting.

As the A300 and A300–600 aeroplanes share this design feature, they are also affected.



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

**DATES** 

### : This AD becomes effective July 13, 2010.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of July 13, 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** 

### : Dan Rodina, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–2125; 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 February 25, 2010 (75 FR 8549). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

During a maintenance check performed by an A310 operator, the recommended modification of the lower attachment beam of rack 101VU by accomplishment of Airbus Service Bulletin (SB) A310–53–2076 was embodied on the aeroplane, leading the operator to find three cracks on the FR15A crossbeam above the NLG [nose landing gear] box at the splicing with rack 107VU fitting.

This condition, if not detected and corrected, could degrade the structural integrity of the crossbeam on NLG FR15A Web attachment fitting of rack 107VU. Rack 107VU contains major airworthiness system components whose functioning could be adversely affected by the loss of the attachment fitting.

As the A300 and A300–600 aeroplanes share this design feature, they are also affected.

For the reasons stated above, this AD requires repetitive inspections for cracks of the crossbeam on NLG FR15A Web face attachment fitting of rack 107VU and corrective action, depending on findings.



### The corrective actions include contacting Airbus for repair instructions, and doing the repair if any crack is found. 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 comment received. The commenter, FedEx Express, supports the NPRM. Explanation of Change Made to This AD

We have revised the subject header of this AD to identify the affected airplane models as published in the most recent type certificate data sheet.

Conclusion

We reviewed the available data, including the comment received, 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 206 products of U.S. registry. We alsoestimate that it will take about 2 workhours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $35,020, or $170 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 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.