## 24349 Federal Register / Vol. 77, No. 79 / Tuesday, April 24, 2012 / Rules and Regulations

(a) Effective Date

This airworthiness directive (AD) becomes effective May 29, 2012.
(b) Affected ADs

None. (c) Applicability

This AD applies to Bombardier, Inc. Model CL–600–2B16 (CL–604 Variant) airplanes, certificated in any category, serial numbers 5408 through 5665 inclusive, and 5701 through 5856 inclusive.
(d) Subject

Air Transport Association (ATA) of America Code 24: Electrical Power.
(e) Reason

This AD was prompted by reports of the air driven generator (ADG) failing to power essential buses during functional tests, due to the low threshold setting of the circuit protection on the ADG’s generator control unit (GCU) preventing the ADG from supplying power to the essential buses. We are issuing this AD to prevent loss of power from the ADG to the essential buses which, in the event of an emergency, could prevent continued safe flight.
(f) Compliance

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

Within 36 months after the effective date of this AD, remove the ADG GCU, Bombardier part number (P/N) 604–90800–7 (Hamilton Sundstrand P/N 761341A), and install a new or serviceable ADG GCU Bombardier P/N 604–90800–27 (Hamilton Sundstrand P/N 761341B), in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 605–24–003, dated April 25, 2011 (for airplane serial numbers 5701 through 5856); or Bombardier Service Bulletin 604–24–023, dated April 25, 2011 (for airplane serial numbers 5408 through 5665).

Note 1 to paragraph (g) of this AD: Bombardier Service Bulletins 605–24–003 and 604–24–023, both dated April 25, 2011, refer to Hamilton Sundstrand Service Bulletin ERPS10G–24–1, dated February 9, 2011, as an additional source of guidance for modifying and testing the ADG GCU withnew printed wiring assemblies, and reidentifying the GCU using a new part number.

(h) Parts Installation

As of the effective date of this AD, no person may install an ADG GCU, Bombardier P/N 604–90800–7 (Hamilton Sundstrand P/N 761341A), on any airplane.
(i) Other FAA AD Provisions

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. 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: Program Manager, Continuing Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 10, Westbury, New York 11590; telephone 516–228–7300; fax 516– 794–5531. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/ certificate holding district office. The AMOC approval letter must specifically reference this AD.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.
(j) Related Information

Refer to MCAI Canadian Airworthiness Directive CF–2011–25, dated July 25, 2011; Bombardier Service Bulletin 605–24–003, dated April 25, 2011; and Bombardier Service Bulletin 604–24–023, dated April 25, 2011; for related information.
(k) Material Incorporated by Reference

(1) You must use the following service information to do the actions required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference (IBR) of the following service information under 5 U.S.C. 552(a) and 1 CFR part 51:

(i) Bombardier Service Bulletin 605–24– 003, dated April 25, 2011.

(ii) Bombardier Service Bulletin 604–24– 023, dated April 25, 2011.

(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; email thd.crj@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 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 April 10,
2012. John P. Piccola, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2012–9395 Filed 4–23–12; 8:45 am]

**BILLING CODE 4910–13–P** 

### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2011–1258; Directorate Identifier 2011–NM–184–AD; Amendment**  **39–17033; AD 2012–08–16]**

**RIN 2120–AA64**



### Airworthiness Directives; Learjet Inc. **Airplanes**

**AGENCY** 

### : Federal Aviation Administration (FAA), DOT.

**ACTION** 

### : Final rule.

**SUMMARY** 

### : We are adopting a new airworthiness directive (AD) for certain Learjet Inc. Model 60 airplanes. This AD was prompted by two incidents of swapped fire extinguishing wires. This AD requires inspecting the electrical leads routed to the fire extinguishing containers for proper identification and missing labels, and to ensure the electrical leads are connected to the correct squibs; and corrective actions if necessary. We are issuing this AD to prevent the extinguishing agent of the fire extinguishing container from being delivered to the wrong engine in the event of an engine fire, and a consequent uncontrolled fire.

**DATES** 

### : This AD is effective May 29,
2012.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of May 29, 2012.

**ADDRESSES** 

### : For service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209–2942; telephone 316–946–2000; fax 316–946–2220; email ac.ict@aero.bombardier.com; Internet http://www.bombardier.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 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


## 24350 Federal Register / Vol. 77, No. 79 / Tuesday, April 24, 2012 / Rules and Regulations

Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590.

**FOR FURTHER INFORMATION CONTACT** 

### : James Galstad, Aerospace Engineer, Mechanical Systems and Propulsion Branch, ACE–116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; phone: 316–946–4135; fax: 316–946–4107; email: james.galstad@faa.gov.

**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 published in the Federal Register on November 30, 2011 (76 FR 74010). That NPRM proposed to require inspecting the electrical leads routed to the fire extinguishing containers for proper identification and missing labels, and to ensure the electrical leads are connected to the correct squibs; and corrective actions if necessary.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comment received on the proposal (76 FR 74010, November 30, 2011) and the FAA’s
response. Request To Revise Compliance Time

The single commenter, SpiritJets, LLC, stated that the wording of the compliance time in paragraph (g) of the NPRM (76 FR 74010, November 30, 2011) appears to be inaccurate because many of those airplanes do not have auxiliary power units (APU) installed. The compliance time in the NPRM is worded as follows: ‘‘Within 300 flight hours after the effective date of this AD, or at the next auxiliary power unit (APU) removal, whichever occurs first * * *’’

We infer that the commenter requests we remove the reference to the next APU removal from the compliance time. We find that clarification is necessary. Paragraph (g) of this AD applies to all airplanes identified in the applicability (i.e., paragraph (c) of this AD). Therefore, if an APU is not installed on an airplane that is identified in paragraph (c) of this AD, ‘‘within 300 flight hours after the effective date of this AD’’ is the appropriate compliance time for accomplishing the requirements of the AD on that airplane. For clarification purposes, we have revised paragraph (g) of this AD to add paragraphs (g)(1) and (g)(2), which more clearly specify the compliance times for airplanes with and without an APU.

Conclusion

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously and minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM (76 FR 74010, November 30, 2011) for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM (76 FR 74010, November 30, 2011).

We also determined that this change will not increase the economic burden on any operator or increase the scope of the AD. Costs of Compliance

We estimate that this AD affects 232 airplanes of U.S. registry.

We estimate the following costs to comply with this AD:



### E STIMATED 

### C OSTS

Action Labor cost Parts cost Cost per product Cost on U.S. operators

Inspection .................................................. 3 work-hours × $85 per hour = $255 ....... 0 $255 $59,160



### We estimate the following costs to do any necessary modification that would be required based on the results of the inspection. We have no way of determining the number of aircraft that might need this modification:



### O N 

### -C ONDITION 

### C OSTS

Action Labor cost Parts cost Cost per product

Corrective actions ..................................................... 1 work-hour × $85 per hour = $85 ........................... $8 $93



### According to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate.
Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency’s authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: ‘‘General requirements.’’ Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings

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),


## 24351 Federal Register / Vol. 77, No. 79 / Tuesday, April 24, 2012 / Rules and Regulations

(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 adding the following new airworthiness directive (AD):
2012–08–16 Learjet Inc.: Amendment 39– 17033; Docket No. FAA–2011–1258; Directorate Identifier 2011–NM–184–AD.
(a) Effective Date

This AD is effective May 29, 2012.
(b) Affected ADs

None. (c) Applicability

This AD applies to Learjet Inc. Model 60 airplanes, certificated in any category, serial numbers 60–002 through 60–366 inclusive.
(d) Subject

Joint Aircraft System Component (JASC)/ Air Transport Association (ATA) of America Code 2620, Extinguishing system.
(e) Unsafe Condition

This AD was prompted by two incidents of swapped fire extinguishing wires, which could cause the extinguishing agent of the fire extinguishing container to be delivered to the wrong engine in the event of an engine fire, and a consequent uncontrolled fire. We are issuing this AD to correct the unsafe condition on these products.
(f) Compliance

Comply with this AD within the compliance times specified, unless already done.
(g) Inspection and Corrective Actions

At the applicable time specified in paragraph (g)(1) or (g)(2) of this AD: Inspect the electrical leads routed to the fire extinguishing containers for proper identification and missing labels, and to ensure the electrical leads are connected to the correct squibs, as specified in Bombardier Service Bulletin 60–26–4, dated May 2, 2011. Do the inspection in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 60–26–4, dated May 2, 2011. If any misidentification is found, or if any label is missing, or if the electrical leads are not connected to the correct squibs, as specified in Bombardier Service Bulletin 60– 26–4, dated May 2, 2011: Before further flight, do all applicable corrective actions, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 60–26–4, dated May 2, 2011.

(1) For airplanes equipped with an APU: Within 300 flight hours after the effective date of this AD, or at the next auxiliary power unit (APU) removal, whichever occurs first.

(2) For airplanes not equipped with an APU: Within 300 flight hours after the effective date of this AD.
(h) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD.

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/ certificate holding district office.
(i) Related Information

For more information about this AD, contact James Galstad, Aerospace Engineer, Mechanical Systems and Propulsion Branch, ACE–116W, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; phone: 316–946–4135; fax: 316–946– 4107; email: james.galstad@faa.gov.
(j) Material Incorporated by Reference

(1) You must use the following service information to do the actions required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51 of the following service information:

(i) Bombardier Service Bulletin 60–26–4, dated May 2, 2011.

(2) For service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209–2942; telephone 316–946–2000; fax 316–946–2220; email ac.ict@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/ cfr/ibr-locations.html.

Issued in Renton, Washington, on April 13,
2012. John P. Piccola, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2012–9557 Filed 4–23–12; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2012–0036; Directorate Identifier 2011–NM–142–AD; Amendment**  **39–17028; AD 2012–08–11]**

**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 certain Bombardier, Inc. Model DHC–8–400 series airplanes. This AD was prompted by test reports that showed that failure of a retract port flexible hose of a main landing gear (MLG) retraction actuator could cause excessive hydraulic fluid leakage. This AD requires a detailed inspection for defects and damage of the retract port flexible hose on the left and right MLG retraction actuator and replacement of the flexible hose if needed. We are issuing this AD to detect and correct defects and damage of the retract port flexible hose which could lead to an undamped extension of the MLG and could result in MLG structural failure, leading to an unsafe asymmetric landing configuration.

**DATES** 

### : This AD becomes effective May 29, 2012.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of May 29, 2012.

**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 20590.

**FOR FURTHER INFORMATION CONTACT** 

### : Cesar Gomez, Aerospace Engineer, Airframe and Mechanical Systems Branch, ANE–171, FAA, New York