## 64847 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Proposed Rules

(6) Thereafter, within every 350 cyclessince-the-last-engine core vibration survey, perform the engine core vibration survey as required in paragraphs (k)(1) through (k)(5) of this AD.

(7) If the engine has experienced any vibration reported by maintenance or flight crew that is suspected to be caused by the engine core (N2), perform the engine core vibration survey as required in paragraphs (k)(1) through (k)(5) of this AD within 10 cycles after the report.
(l) Initial and Repetitive FPI of LPT Rotor Stage 3 Disks

(1) At the next shop visit after the effective date of this AD:

(i) Clean the LPT rotor stage 3 disk forwardspacer arm, including the use of a wetabrasive blast to eliminate residual or background fluorescence.

(ii) Perform an FPI of the LPT rotor stage 3 disk forward spacer arm for cracks and for a band of fluorescence. Include all areas of the disk forward spacer arm and the inner diameter surface forward cone body (forward spacer arm) of the LPT rotor stage 3 disk.

(iii) Remove the disk from service before further flight if a crack or a band of fluorescence is present.

(2) Thereafter, clean and perform an FPI of the LPT rotor stage 3 disk forward spacer arm, as specified in paragraphs (l)(1)(i) through (l)(1)(iii) of this AD, at each engineshop visit that occurs after 1,000 cyclessince-the last FPI of the LPT rotor stage 3 disk forward spacer arm.
(m) Removal of LPT Rotor Stage 3 Disks

Remove LPT rotor stage 3 disks listed in Table 1 from service as follows:

(1) For disks that have fewer than 3,200 flight cycles since new (CSN) on the effective date of this AD, remove the disk from service before exceeding 6,200 CSN.

(2) For disks that have 3,200 CSN or more on the effective date of this AD, do the following:

(i) If the engine has a shop visit before the disk exceeds 6,200 CSN, remove the disk from service before exceeding 6,200 CSN.

(ii) If the engine does not have a shop visit before the disk exceeds 6,200 CSN, remove the disk from service at the next shop visit after 6,200 CSN, not to exceed 3,000 cycles from the effective date of this AD.
(n) Installation Prohibition

(1) After the effective date of this AD, do not install or reinstall in any engine any LPT rotor stage 3 disk that exceeds the new life limit of 6,200 CSN.

(2) Remove from service any LPT rotor stage 3 disk that is installed or re-installed after the effective date of this AD, before the disk exceeds the new life limit of 6,200 CSN.
(o) Definitions

(1) For the purposes of this AD, an EGTabove redline is a confirmed overtemperature indication that is not a result of EGT system error.

(2) For the purposes of this AD, a shift in the smoothed EGT trending data is a shift in a rolling average of EGT readings that can be confirmed by a corresponding shift in the trending of fuel flow or fan speed/core speed (N1/N2) relationship. You can find further guidance about evaluating EGT trend data in GE Company Service Rep Tip 373 ’’Guidelines For Parameter Trend Monitoring.’’

(3) For the purposes of this AD, an engine shop visit is the induction of an engine into the shop after the effective date of this AD, where the separation of a major engine flange occurs; except the following maintenance actions, or any combination, are not considered engine shop visits:

(i) Introduction of an engine into a shop solely for removal of the compressor top or bottom case for airfoil maintenance or variable stator vane bushing replacement.

(ii) Introduction of an engine into a shop solely for removal or replacement of the stage 1 fan disk.

(iii) Introduction of an engine into a shop solely for replacement of the turbine rear frame.

(iv) Introduction of an engine into a shop solely for replacement of the accessory gearbox or transfer gearbox, or both.

(v) Introduction of an engine into a shop solely for replacement of the fan forward

case. (p) Previous Credit

(1) A borescope inspection performed before the effective date of this AD using AD 2010–06–15, Amendment 39–16240 (75 FR 12661, March 17, 2010) or AD 2010–12–10, Amendment 39–16331 (75 FR 32649, June 9, 2010) or AD 2011–02–07, Amendment 39– 16580 (76 FR 6323, February 4, 2011) within the last 75 cycles, satisfies the initial borescope inspection requirement in paragraph (f)(1) of this AD.

(2) A UI performed before the effective date of this AD using AD 2011–02–07, Amendment 39–16580 (76 FR 6323, February 4, 2011) or GE SB No. CF6–50–SB 72–1312, dated August 9, 2010 or GE SB No. CF6–50– SB 72–1312 Revision 1, dated October 18, 2010, satisfies the inspection requirement in paragraph (j) of this AD.

(3) An engine core vibration survey performed before the effective date of this AD using AD 2011–02–07, Amendment 39– 16580 (76 FR 6323, February 4, 2011) or GE SB No. CF6–50–SB 72–1313, dated August 9, 2010 or GE SB No. CF6–50–SB 72–1313 Revision 1, dated October 18, 2010, within the last 350 cycles, satisfies the initial survey requirement in paragraphs (k)(1) through (k)(5) of this AD.

(4) An FPI of the LPT rotor stage 3 disk forward spacer arm performed before the effective date of this AD using AD 2011–18– 01, Amendment 39–16783 (75 FR 3, 52213, August 22, 2011), within the last 1,000 flight cycles of the LPT rotor stage 3 disk, satisfies the initial inspection requirements in paragraphs (l)(1)(i) through (l)(1)(iii) of this AD. (q) Alternative Methods of Compliance (AMOCs)

(1) AMOCs previously approved for AD 2010–06–15, Amendment 39–16240 (75 FR 12661, March 17, 2010) are not approved for this AD. However, AMOCs previously approved for AD 2010–12–10, Amendment 39–16331 (75 FR 32649, June 9, 2010), AD 2011–02–07, Amendment 39–16580 (76 FR 6323, February 4, 2011), or AD 2011–18–01, Amendment 39–16783 (76 FR 52213, August 22, 2011) are approved for this AD.

(2) The Manager, Engine Certification Office, may approve alternative methods of compliance for this AD. Use the procedures found in 14 CFR 39.19 to make your request.

(r) Related Information

(1) For more information about this AD, contact Tomasz Rakowski, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7735; fax: 781–238– 7199; e-mail: tomasz.rakowski@faa.gov.

(2) For service information identified in this AD, contact General Electric Company, GE-Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 45215, phone: 513–552–3272; e-mail: geae.aoc@ge.com. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125.

Issued in Burlington, Massachusetts, on October 13, 2011. Peter A. White, Manager, Engine & Propeller Directorate, Aircraft Certification Service.

[FR Doc. 2011–27006 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–2011–1090; Directorate Identifier 2011–NM–138–AD]** 

**RIN 2120–AA64**



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

**AGENCY** 

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

**ACTION** 

### : Notice of proposed rulemaking (NPRM).

**SUMMARY**

### : We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed 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 case of the inability to open the airstair door while on ground was reported in service. The airstair door seal did not deflate, preventing the airstair door from opening. It was found that the existing airstair door pneumatic shut-off valve control logic prevents the airstair door seal from


## 64848 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Proposed Rules

deflating due to a single Input/Output Module failure under certain conditions. The inability to open the airstair door could impede evacuation in the event of an
emergency. 

### * * * * *

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

**DATES** 

### : We must receive comments on this proposed AD by December 5, 2011.

**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.

For service information identified in this proposed AD, contact Bombardier, Inc., Q–Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416–375– 4000; fax 416–375–4539; e-mail thd.qseries@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 Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed 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**

### : 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** 

### :
Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the

**ADDRESSES** 

### section. Include ‘‘Docket No. FAA–2011–1090; Directorate Identifier 2011–NM–138–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on 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 proposed AD.

Discussion

The Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF–2011–15, dated June 20, 2011 (referred to after this as ‘‘the MCAI’’), to correct an unsafe condition for the specified products. The MCAI states:

One case of the inability to open the airstair door while on ground was reported in service. The airstair door seal did not deflate, preventing the airstair door from opening. It was found that the existing airstair door pneumatic shut-off valve control logic prevents the airstair door seal from deflating due to a single Input/Output Module failure under certain conditions. The inability to open the airstair door could impede evacuation in the event of an
emergency.

This [Canadian] directive mandates the wiring changes [ModSum 4–126513, Seal System Shut Off Valve Control Logic Change] to prevent the above-mentioned failure conditions. 

### You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Bombardier, Inc. has issued Service Bulletin 84–52–69, Revision C, dated June 28, 2011. 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 Proposed 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 proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.

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 proposed 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 proposed AD. Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 81 products of U.S. registry. We also estimate that it would take about 12 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $85 per work-hour. Required parts would 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 the proposed AD on U.S. operators to be $82,620, or $1,020 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


## 64849 Federal Register / Vol. 76, No. 202 / Wednesday, October 19, 2011 / Proposed Rules

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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 proposed regulation:

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 proposed 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. The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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: Bombardier, Inc.: Docket No. FAA–2011– 1090; Directorate Identifier 2011–NM– 138–AD.

Comments Due Date

(a) We must receive comments by December 5, 2011.

Affected ADs

(b) None.
Applicability

(c) This AD applies to Bombardier, Inc. Model DHC–8–400, –401, and –402 airplanes, certificated in any category, serial numbers 4001 through 4361 inclusive. Subject (d) Air Transport Association (ATA) of America Code 52: Doors.

Reason

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

One case of the inability to open the airstair door while on ground was reported in service. The airstair door seal did not deflate, preventing the airstair door from opening. It was found that the existing airstair door pneumatic shut-off valve control logic prevents the airstair door seal from deflating due to a single Input/Output Module failure under certain conditions. The inability to open the airstair door could impede evacuation in the event of an
emergency. 

### * * * * *
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) Within 6,000 flight hours after the effective date of this AD: Incorporate ModSum 4–126513, Seal System Shut Off Valve Control Logic Change, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84–52–69, Revision C, dated June 28, 2011.
Credit for Actions Accomplished in Accordance With Previous Service Information

(h) Actions accomplished before the effective date of this AD according to Bombardier Service Bulletin 84–52–69, dated January 28, 2011; Revision A, dated April 26, 2011; or Revision B, dated May 9, 2011; are considered acceptable for compliance with the corresponding actions specified in paragraph (g) 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

(i) 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 410, 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.

Related Information

(j) Refer to MCAI Canadian Airworthiness Directive CF–2011–15, dated June 20, 2011; and Bombardier Service Bulletin 84–52–69, Revision C, dated June 28, 2011; for related information.

Issued in Renton, Washington, on October 6, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2011–27009 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–2011–1088; Directorate Identifier 2011–NM–099–AD]** 

**RIN 2120–AA64**



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

**AGENCY** 

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

**ACTION** 

### : Notice of proposed rulemaking (NPRM).

**SUMMARY**

### : We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed 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:

Several operators have reported difficulties in opening the airstair door. Investigation revealed that the airstair door gearbox drain paths were blocked by sealant, causing water to accumulate and freeze in the gearbox assembly. An airstair door that is unable to be opened could hinder evacuation in the event of an emergency.


### * * * * * The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

**DATES** 

### : We must receive comments on this proposed AD by December 5, 2011.

**ADDRESSES** 

### : You may send comments by any of the following methods: