## 64798 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Rules and Regulations

Credit for Actions Done in Accordance With Previous Service Information

(6) Actions done before the effective date of this AD in accordance with Sicma Aero Seat Service Bulletin 90–25–013, Issue 3, dated December 19, 2001, including Annex 1, Issue 1, dated June 26, 2001, are acceptable for compliance with the corresponding actions of this AD.

FAA AD Differences

Note 2: This AD differs from the MCAI and/or service information as follows: The MCAI specifies doing repetitive inspections for cracking of links having over 12,000 flight hours since new until the replacement of the link is done. This AD does not include those repetitive inspections because we have reduced the compliance time for replacing those links. This AD requires replacing the link before 12,000 flight hours since new or within 900 flight hours or 5 months of the effective date of this AD, whichever occurs later.

Other FAA AD Provisions

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

(1) Alternative Methods of Compliance (AMOCs): The Manager, Boston Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the ACO, send it to ATTN: Jeffrey Lee, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, Massachusetts 01803; telephone (781) 238–7161; fax (781) 238–7170. 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.

Related Information

(h) Refer to MCAI French Airworthiness Directive 2001–613(AB), dated December 12, 2001; and Sicma Aero Seat Service Bulletin 90–25–013, Issue 4, dated March 19, 2004, including Annex 1, Issue 2, dated March 19, 2004; for related information.
Material Incorporated by Reference

(i) You must use Sicma Aero Seat Service Bulletin 90–25–013, Issue 4, dated March 19, 2004, including Annex 1, Issue 2, dated March 19, 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 this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For service information identified in this AD, contact Sicma Aero Seat, 7 Rue Lucien Coupet, 36100 ISSOUDUN, France, telephone: +33 (0) 2 54 03 39 39; fax: +33 (0) 2 54 03 39 00; e-mail: customerservices.sas@ zodiacaerospace.com; Internet: http:// www.sicma.zodiacaerospace.com/en/.

(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.

Issued in Renton, Washington, on September 28, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2011–26083 Filed 10–18–11; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2011–0478; Directorate Identifier 2010–NM–138–AD; Amendment**  **39–16832; AD 2011–21–09]**

**RIN 2120–AA64**



### Airworthiness Directives; Airbus Model **A300 B4–103, B4–203, and B4–2C Airplanes** 

**AGENCY** 

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

**ACTION** 

### : Final rule.

**SUMMARY** 

### : We are superseding an existing airworthiness directive (AD) that applies to 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:

One operator reported a failure of the MLG [main landing gear] retraction actuator sliding rod. This incident occurred at a number of operating flight cycles lower than the limit value imposed by the MLG manufacturer.

This condition, if not detected and corrected, results in undampened extension of the MLG, leading to higher than usual loads on the MLG attachment. Higher loads affect the structural integrity of the MLG and could lead to MLG failure.


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

**DATES** 

### : This AD becomes effective November 23, 2011.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of November 23, 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** 

### : 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 June 8, 2011 (76 FR 33176), and proposed to supersede AD 2007– 25–15, Amendment 39–15297 (72 FR 69601, December 10, 2007). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI
states:

One operator reported a failure of the MLG [main landing gear] retraction actuator sliding rod. This incident occurred at a number of operating flight cycles lower than the limit value imposed by the MLG manufacturer.

This condition, if not detected and corrected, results in undampened extension of the MLG, leading to higher than usual loads on the MLG attachment. Higher loads affect the structural integrity of the MLG and could lead to MLG failure.

To address and correct this unsafe condition, EASA issued AD 2006–0075 (now at Revision 2) [which corresponds to FAA AD 2007–25–15 (72 FR 69601, December 10, 2007)] to require repetitive inspections of the retraction actuator sliding rod as installed on A300, A300–600 and A300–600ST aeroplanes and, depending on findings, repair or replacement of the affected parts.

Since this event, studies have been performed by Airbus, the consequences of which are that for A300 aeroplanes, a new inspection program (new threshold and interval) has been established.

For the reason described above, this new [EASA] AD retains the requirements of AD


## 64799 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Rules and Regulations

2006–0075R2, which is superseded and requires the accomplishment of the repetitive inspections and associated corrective actions at the new intervals. In addition, the Airbus A300 Aircraft Maintenance Manual (AMM) Chapter 12–22–32 (associated to Maintenance Planning Document (MPD) task 321112–0505–1) has been revised to introduce a greasing action at the level of the pick-up jack fitting. Consequently, this AD also requires the repetitive lubrication task.

For A300–600 and A300–600ST aeroplanes, the analyses have shown that, due to design differences, the loads induced on the MLG attachments are within acceptable margins. For that reason, this AD does not apply to those aeroplanes which were previously included in the applicability of EASA AD 2006–0075R2. 

### 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 Change Proposed Compliance Time

The Air Line Pilots Association, International (ALPA) stated it supports the intent and language of the subject NPRM (76 FR 33176, June 8, 2011), but requested the compliance time be changed in paragraph (g) of the NPRM to ‘‘not to exceed 1000 flight hours or 12 months, whichever occurs first, under any circumstances.’’

We disagree with this request because the unsafe condition is flight-cycle dependent, and the commenter did not provide any supporting data to justify a change in the compliance time. We have not changed the AD in this regard.

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 3 products of U.S. registry. We alsoestimate that it will take about 6 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 $1,530, or $510 per product.

In addition, we estimate that any necessary follow-on actions would take about 6 work-hours and require parts costing $0, for a cost of $510 per product. We have no way of determining the number of products that may need these actions. 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 (76 FR 33176, June 8, 2011), 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, 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 Amendment 39–15297 (72 FR 69601, December 10, 2007) and adding the following new AD:

2011–21–09 Airbus: Amendment 39–16832. Docket No. FAA–2011–0475; Directorate Identifier 2010–NM–138–AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective November 23, 2011.

Affected ADs

(b) This AD supersedes AD 2007–25–15, Amendment 39–15297 (72 FR 69601, December 10, 2007).
Applicability

(c) This AD applies to Airbus Model A300 B4–103, B4–203, and B4–2C airplanes; certificated in any category; equipped with main landing gear (MLG) retraction actuator having part number (P/N) C23129 fitted with sliding rod P/N C69029–2 or C69029–3.
Subject

(d) Air Transport Association (ATA) of America Code 32: Landing gear.

Reason

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

One operator reported a failure of the MLG [main landing gear] retraction actuator sliding rod. This incident occurred at a number of operating flight cycles lower than


## 64800 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Rules and Regulations

the limit value imposed by the MLG manufacturer.

This condition, if not detected and corrected, results in undampened extension of the MLG, leading to higher than usual loads on the MLG attachment. Higher loads affect the structural integrity of the MLG and could lead to MLG failure.


### * * * * *
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.
Revised Compliance Times for Inspection of MLG Retraction Actuator and Corrective Actions

(g) At the applicable time specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD: Remove the MLG retraction actuator having P/N C23129 and do a detailed and high frequency eddy current inspection for defectsthat exceed the criteria defined in MessierDowty Special Inspection Service Bulletin 470–32–806, dated October 27, 2005, of the retraction actuator sliding rods having P/N C69029–2 or C69029–3, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300–32–0450, Revision 02, dated July 28, 2009.

(1) For airplanes on which the retraction actuator sliding rod has accumulated 12,000 or fewer total flight cycles as of the effective date of this AD: Inspect at the later of the times specified in paragraphs (g)(1)(i) and (g)(1)(ii) of this AD.

(i) Before the accumulation of 12,000 total flight cycles on the retraction actuator sliding rod.

(ii) Within 2,000 flight cycles or 24 months after the effective date of this AD, whichever occurs first.

(2) For airplanes on which the retraction actuator sliding rod has accumulated more than 12,000 total flight cycles, and 22,000 or fewer total flight cycles, as of the effective date of this AD: Inspect at the earliest of the times specified in paragraphs (g)(2)(i), (g)(2)(ii), and (g)(2)(iii) of this AD.

(i) Before the accumulation of 23,000 total flight cycles on the retraction actuator sliding rod.

(ii) Within 2,000 flight cycles after the effective date of this AD.

(iii) Within 24 months after the effective date of this AD.

(3) For airplanes on which the retraction actuator sliding rod has accumulated more than 22,000 total flight cycles as of the effective date of this AD: Inspect within 1,000 flight cycles or 12 months after the effective date of this AD, whichever occurs first.

(h) Thereafter, repeat the inspections required by paragraph (g) of this AD at intervals not to exceed 12,000 flight cycles.

(i) If, during any inspection required by paragraph (g) or (h) of this AD, any defect is detected that exceeds the criteria defined in Messier-Dowty Special Inspection Service Bulletin 470–32–806, dated October 27, 2005, before further flight, replace the affected sliding rod with a serviceable unit in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300–32–0450, Revision 02, dated July 28, 2009.

(j) Before the accumulation of 32,000 flight cycles on any retraction actuator sliding rod, it must be replaced with a serviceable unit in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300–32–0450, Revision 02, dated July 28, 2009. Parts removed from an airplane as required by this paragraph must be returned to Messier-Dowty within 30 days after removing the part from the airplane.

(k) As of the effective date of this AD, any MLG retraction actuator sliding rod having P/ N C69029–2 or C69029–3 that has accumulated less than 32,000 total flight cycles, may be installed on any airplane, provided that the inspections required by paragraphs (g) and (h) of this AD are accomplished at the compliance times specified in paragraphs (g) and (h) of this AD and all applicable replacements required by paragraphs (i) and (j) of this AD are done.
Lubrication of the MLG Assembly

(l) Within 1,500 flight hours after the effective date of this AD: Clean and lubricate the MLG assembly, in accordance with Task 321112–0505–1 ‘‘Main Landing Gear Assy,’’ of Section 2–32, ‘‘Systems and Powerplant Program: Landing Gear,’’ of the Airbus A300 Maintenance Planning Document, Revision 30, dated April 1, 2010. Repeat the cleaning and lubrication thereafter at intervals not to exceed 1,500 flight hours.
Credit for Actions Accomplished in Accordance With Previous Service Information

(m) Inspections accomplished before the effective date of this AD, in accordance with Airbus Mandatory Service Bulletin A300–32– 0450, dated December 1, 2005; or Airbus Mandatory Service Bulletin A300–32–0450, Revision 01, dated May 10, 2006; are acceptable for compliance with the corresponding requirements of this AD.

FAA AD Differences

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

Other FAA AD Provisions

(n) 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. 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 International Branch, send it to ATTN: 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. Information may be e-mailed to: 9- ANM-116-AMOC-REQUESTS@faa.gov. 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. AMOCs approved previously in accordance with AD 2007–25–15, Amendment 39–15297 (72 FR 69601, December 10, 2007), are approved as AMOCs for the corresponding provisions of 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.

Related Information

(o) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2010– 0102, dated June 8, 2010; Airbus Mandatory Service Bulletin A300–32–0450, Revision 02, dated July 28, 2009; Messier-Dowty Special Inspection Service Bulletin 470–32–806, dated October 27, 2005; and Task 321112– 0505–1, ‘‘Main Landing Gear Assy,’’ of Section 2–32, ‘‘Systems and Powerplant Program: Landing Gear,’’ of the Airbus A300 Maintenance Planning Document, Revision 30, dated April 1, 2010; for related information.
Material Incorporated by Reference

(p) You must use Airbus Mandatory Service Bulletin A300–32–0450, Revision 02, excluding Appendix 1, dated July, 28, 2009; Messier-Dowty Special Inspection Service Bulletin 470–32–806, dated October 27, 2005; and Task 321112–0505–1, ‘‘Main Landing Gear Assy,’’ of Section 2–32, ‘‘Systems and Powerplant Program: Landing Gear,’’ of the Airbus A300 Maintenance Planning Document, Revision 30, dated April 1, 2010; to do the actions required by this AD, unless the AD specifies otherwise. (The revision level of the Airbus A300 Maintenance Planning Document is identified in only the title page and transmittal letter of this document.)

(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 Messier-Dowty service information identified in this AD, contact Messier Services Americas, Customer Support Center, 45360 Severn Way, Sterling, Virginia 20166– 8910; telephone 703–450–8233; fax 703–404– 1621; Internet https://techpubs.services/ messier-dowty.com.

(3) For Airbus service information identified in this AD, contact Airbus SAS– EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail account.airwortheas@airbus.com; Internet http:// www.airbus.com.

(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.


## 64801 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Rules and Regulations

(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 September 28, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2011–26082 Filed 10–18–11; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2011–0564; Directorate Identifier 2011–NM–021–AD; Amendment**  **39–16830; AD 2011–21–07]**

**RIN 2120–AA64**



### Airworthiness Directives; Bombardier, **Inc. Airplanes**

**AGENCY** 

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

**ACTION** 

### : Final rule.

**SUMMARY** 

### : We are adopting a new airworthiness directive (AD) for Bombardier, Inc. Model CL–600–2B19 (Regional Jet Series 100 & 440); Model CL–600–2C10 (Regional Jet Series 700, 701, & 702); Model CL–600–2D15 (Regional Jet Series 705); and Model CL–600–2D24 (Regional Jet Series 900) airplanes. This AD results from mandatory continuing airworthiness information (MCAI) issued by an airworthiness authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

There have been several in-service reports of airspeed mismatch between the pilot and co-pilot’s airspeed indicators. It was discovered that during or after heavy rain, the pitot-static tubing may become partially or completely blocked by water, which fails to enter the drain bottles. Investigation revealed that drain bottles used in the primary pitot-static system include check valves, which impede the entry of water into the drain bottle. This condition, if not corrected, may result in erroneous airspeed and altitude indications.


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

### : This AD becomes effective November 23, 2011.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of November 23, 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** 

### : Christopher Alfano, Aerospace Engineer, Airframe & Mechanical Systems Branch, ANE–171, New York Aircraft Certification Office (ACO), FAA, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone: (516) 228–7340; fax: (516) 794–5531.

**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 9, 2011 (76 FR 33658). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

There have been several in-service reports of airspeed mismatch between the pilot and co-pilot’s airspeed indicators. It was discovered that during or after heavy rain, the pitot-static tubing may become partially or completely blocked by water, which fails to enter the drain bottles. Investigation revealed that drain bottles used in the primary pitot-static system include check valves, which impede the entry of water into the drain bottle. This condition, if not corrected, may result in erroneous airspeed and altitude indications.

This [Transport Canada Civil Aviation (TCCA)] directive mandates replacement of the [certain] Water Accumulator Assemblies [with new water accumulator assemblies] to improve drainage of the pitot-static tubing. 

### 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 for Frequent Repetitive Inspections Instead of Replacements

Mesa Airlines requested we revise the NPRM (76 FR 33658, June 9, 2011) to change the maintenance program to reduce the repetitive inspection intervals for the water accumulator as an option to installing the enlarged drain tubes. Mesa stated that the main pitot-static drain assemblies on its fleet are inspected for moisture every 500 or 600 flight hours (depending on the model).

We disagree because the pitot static tubing/water accumulator has a design deficiency that may cause it to become partially or completely blocked by water. This pitot static tubing/water accumulator design must be replaced with a new pitot static water accumulator design to eliminate this unsafe condition. Inspecting the pitot static water accumulator more frequently will not meet the intent of this AD. Once we issue this AD, any operator may request approval of an alternative method of compliance (AMOC) under the provisions of paragraph (k)(1) of this AD. Sufficient data must be submitted to substantiate that repetitive inspections would provide an acceptable level of safety. We have not changed the AD in this regard.
Request To Change Applicability Serial Numbers To Match Service Bulletin

American Eagle Airlines requested that paragraph (c) of the NPRM (76 FR 33658, June 9, 2011) be changed from including all serial numbers of the specified airplanes to only those serial numbers called out in Bombardier Service Bulletin 601R–34–147, Revision B, dated March 8, 2011; and Bombardier Service Bulletin 670BA–34–030, Revision B, dated March 23, 2010. American Eagle stated as justification that the requirements of the NPRM were incorporated on airplanes going forward in production, and the illustrated parts catalog applicability has been updated for the affected part as well.

We disagree. Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, has determined that all serial numbers of the specified airplane models need to be called out in its AD in order to prevent unsafe parts from being installed in any airplane. We agree with TCCA that all serial numbers need to be included in this AD, and also have included in paragraph (h) of the AD a prohibition against installing certain unsafe water accumulator assemblies on the pitot and static lines of the air data computer on any airplane.

Conclusion

We reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD as proposed.