### 64417 Federal Register / Vol. 78, No. 209 / Tuesday, October 29, 2013 / Proposed Rules

The Proposed Special Conditions

Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for Airbus Model A350–900 series airplanes in lieu of § 25.503:

1. The main landing gear and supporting structure must be designed for the loads induced by pivoting during ground maneuvers.

(a) The following rational pivoting maneuvers must be considered:

(i) Towing at the nose gear at the critical towing angle with no brakes applied, including cases with torque links disconnected; and separately,

(ii) Application of symmetrical or unsymmetrical forward thrust to aid pivoting, with or without braking by pilot action on the pedals.

(b) The airplane is assumed to be in static equilibrium, with the loads being applied at the ground contact points.

(c) The limit vertical load factor must be 1.0, and:

(i) For wheels with brakes applied, the coefficient of friction must be 0.8,

(ii) For wheels with brakes not applied, the ground tire reactions must be based on reliable tire data.

Issued in Renton, Washington, on September 12, 2013. Jeffrey E. Duven, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2013–25398 Filed 10–28–13; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2013–0393; Directorate Identifier 2012–CE–025–AD]** 

**RIN 2120–AA64**

**Airworthiness Directives; Twin Commander Aircraft LLC Airplanes;**  **Initial Regulatory Flexibility Analysis**

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Availability of an initial regulatory flexibility analysis.

**SUMMARY :**  This document announces the availability of and request for comments on the initial regulatory flexibility analysis for the previously published Airworthiness Directive (AD) 2013–09– 05 that applies to certain Twin Commander Aircraft LLC Models 690, 690A, and 690B airplanes. AD 2013–09– 05 requires inspection for cracking of the outer fuselage attachments, the lower wing main spar, the vertical channels, the upper picture window channels, aft cabin pressure web, external wing to fuselage fillets, and fasteners; repair or replacement of damaged parts as necessary; and modification of the structure with reinforced parts.

**DATES :**  Comments must be received on or before December 13, 2013.

**ADDRESSES :**  You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, 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 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

**FOR FURTHER INFORMATION CONTACT :**  Kathleen Arrigotti, Aerospace Engineer, FAA, Seattle Aircraft Certification Office (ACO), Airframe Branch, ANM– 120S, 1601 Lind Avenue SW., Renton, WA 98057; telephone: (425) 917–6426; fax: (425) 917–6590; email: kathleen.arrigotti@faa.gov.

**SUPPLEMENTARY INFORMATION :** 

Discussion

We issued AD 2013–09–05; Amendment 39–17446, which was published in the Federal Register on May 14, 2013 (78 FR 28125) (‘‘AD 2013– 09–05’’), to amend 14 CFR part 39 to add an AD that would apply to the specified products. AD 2013–09–05 requires inspection for cracking of the outer fuselage attachments, the lower wing main spar, the vertical channels, the upper picture window channels, aft cabin pressure web, external wing to fuselage fillets, and fasteners; repair or replacement of damaged parts as necessary; and modification of the structure with reinforced parts.

Reason for This Action

The Regulatory Flexibility Act of 1980 (Pub. L. 96–354) (RFA) establishes ‘‘as a principle of regulatory issuance that agencies shall endeavor, consistent with the objectives of the rule and of applicable statutes, to fit regulatory and informational requirements to the scale of the businesses, organizations, and governmental jurisdictions subject to regulation.’’ To achieve this principle, agencies are required to solicit and consider flexible regulatory proposals and to explain the rationale for their actions to assure that such proposals are given serious consideration. The RFA covers a wide-range of small entities,including small businesses, not-forprofit organizations, and small governmental jurisdictions.

Agencies must perform a review to determine whether a proposed or final rule will have a significant economic impact on a substantial number of small entities. In accordance with Section 608 of the Regulatory Flexibility Act, an agency head may waive or delay completion of some or all of the requirements of Section 603 by providing a written finding that the final rule is being promulgated in response to an emergency that makes compliance or timely compliance with the provisions of Section 603 impracticable. The agency issued AD 2013–09–05 in response to an immediate safety of flight condition that made compliance with the provisions of Section 603 impracticable. After issuing AD 2013– 09–05, the agency reviewed the AD actions and determined that the final rule did have a significant economic impact on a substantial number of small entities. The following presents the initial regulatory flexibility analysis prepared by the agency as described in the RFA. 1. Reason for Agency Action

We issued AD 2013–09–05 for certain Twin Commander Aircraft LLC Models 690, 690A, and 690B airplanes. The AD requires inspection for cracking of the outer fuselage attachments, the lower wing main spar, the vertical channels, the upper picture window channels, aft cabin pressure web, external wing to fuselage fillets, and fasteners; repair or replacement of damaged parts as necessary; and modification of the structure with reinforced parts. The AD was prompted by cracks found in the upper picture window frame channels, left- and right-hand wing main spar frame support channels, and aft pressure bulkhead web. This condition, if not corrected, could result in structural failure of the airplane. We issued the AD to correct the unsafe condition on these products. 2. Legal Basis and Objectives of the Final Rule

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


### 64418 Federal Register / Vol. 78, No. 209 / Tuesday, October 29, 2013 / Proposed Rules

detail the scope of the Agency’s authority.

We issued the AD 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 the AD. 3. Recordkeeping and Other Compliance Requirements of the Final Rule Compliance

Compliance with AD 2013–09–05 must occur within the times specified, unless already done.
Inspection

Inspect the airplane structural components, at the compliance times specified in paragraphs (g)(1)(i) through (g)(1)(iv) of the AD following Part I of Twin Commander Aircraft LLC Service Bulletin 241, September 26, 2012:

• For airplanes with 10,000 or more hours time-in-service (TIS), inspect within the next 30 days after May 29, 2013 (the effective date of the AD).

• For airplanes with 7,500 through 9,999 hours TIS, inspect within the next 60 days after May 29, 2013 (the effective date of the AD).

• For airplanes with 5,000 through 7,499 hours TIS, inspect within the next 6 months after May 29, 2013 (the effective date of the AD).

• For airplanes with less than 5,000 hours TIS, inspect when the airplane accumulates a total of 5,000 hours TIS or within the next 12 months after May 29, 2013 (the effective date of the AD), whichever occurs later.
Repair

If any damage, cracks, and/or cracks that exceed the allowable limits specified in the service bulletin are found during the inspection required in paragraph (g)(1) of the AD, before further flight, repair or replace parts as necessary following Twin Commander Aircraft LLC Service Bulletin 241, dated, September 26, 2012. If Twin Commander Aircraft LLC Service Bulletin 241, dated, September 26, 2012, does not give procedures for repair of the damaged area, before further flight, you must contact Twin Commander Aircraft LLC to obtain repair instructions approved by the Seattle ACO specifically for compliance with this AD and incorporate those instructions. You can find contact information for Twin Commander Aircraft LLC in paragraph (l)(2) of the AD. Modification and Reassembly

• Before further flight after completing the actions in paragraphs (g) and (h) of the AD, modify and reassemble the airplane using the modification and reassembly procedures in Part II of Twin Commander Aircraft LLC Service Bulletin 241, dated, September 26, 2012.

• Although Twin Commander Aircraft LLC Service Bulletin 241, dated September 26, 2012, states that at least one person on the modification team must have completed the Twin Commander Aircraft LLC approved training, the FAA does not require that a mechanic complete this specialized training to do the modification work required in the AD. Regulations 14 CFR 65.81(a) and 14 CFR 65.81(b) provide criteria about qualifications of those performing maintenance; in this case, the requirements of the AD. 4. Federal Rules That May Duplicate, Overlap, or Conflict With the Final Rule

There are no rules that duplicate, overlap, or conflict with AD 2013–09–
05. 5. Description and Estimation of the Number of Small Entities Affected by the Final Rule

Under the RFA, the FAA must determine whether a final rule significantly affects a substantial number of small entities. This determination is typically based on small entity size and revenue thresholds that vary depending on the affected industry. To determine the number of small entities affected by the airworthiness directive, we searched the FAA Aircraft Registry database. The database provides ownership information for 175 of the airplanes affected by AD 2013–09–05, and average airplane values for these airplanes are available in the Aircraft Bluebook Price Digest

.

The FAA aircraft registry categorizes owners of affected airplanes as individuals, co-owners, corporations, and governments. A review of the corporations shows that an overwhelming majority are privately held. In most cases, the information about these corporations cannot be determined because financial and employment data for privately held entities is sparse. Nevertheless, the FAA believes the number of small business entities affected by the AD is substantial.

The serial numbers for the 175 affected airplanes that we have information on was used to look up average retail values in the Aircraft Bluebook Price Digest . The ‘‘Digest’’ provides average retail values by model, year, and serial number. It is only a guide since the actual condition and upgrades to individual airplanes are not known. The value range for the 175 affected airplanes is between $225,000 and $555,000 per airplane. The range is primarily due to age (i.e., the older an airplane the lower its retail value versus a newer model of the same airplane). The total retail value of the affected airplanes is equal to the sum of the retail value for each individual airplane. This summation equals $78.9 million (or an average of about $451,000 per airplane).

The economic impact on small entities due to the AD is significant. This determination is based on the percentage of the cost of compliance per airplane ($58,090) to the average retail value per airplane ($451,000), which is estimated to be 12.9 percent.

Based on the discussion above, complying with the AD is determined to be significant economic impact on a substantial number of small entities.

6. Alternatives Considered

The FAA considered possible alternative actions and determined the actions taken were necessary to address the unsafe condition. The FAA did not extend the compliance time because we needed to act immediately to address the immediate safety problem. The inspection and modification both involve a complex disassembly that comprises most of the labor cost associated with the AD. Performing the modification while the airplane is already disassembled for inspection saves owners the labor cost of disassembling twice. If discrepancies are not found in the inspection, no repair expense, beyond the mandated modification expense, will occur. International Trade Impact Assessment

The Trade Agreements Act of 1979 (Pub. L. 96–39), as amended by the Uruguay Round Agreements Act (Pub. L. 103–465), prohibits Federal agencies from establishing standards or engaging in related activities that create unnecessary obstacles to the foreign commerce of the United States. Pursuant to these Acts, the establishment of standards is not considered an unnecessary obstacle to the foreign commerce of the United States, so long as the standard has a


### 64419 Federal Register / Vol. 78, No. 209 / Tuesday, October 29, 2013 / Proposed Rules

legitimate domestic objective, such as the protection of safety, and does not operate in a manner that excludes imports that meet this objective. The statute also requires consideration of international standards and, where appropriate, that they be the basis for U.S. standards. The FAA assessed the potential effect of the AD and determined that because it addresses an immediate safety issue the AD is not considered an unnecessary obstacle to the foreign commerce of the United States.

Unfunded Mandates Assessment

Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104–4) requires each Federal agency to prepare a written statement assessing the effects of any Federal mandate in a proposed or final agency rule that may result in an expenditure of $100 million or more (in 1995 dollars) in any one year by State, local, and tribal governments, in the aggregate, or by the private sector; such a mandate is deemed to be a ‘‘significant regulatory action.’’ The FAA currently uses an inflation-adjusted value of $143.1 million in lieu of $100 million. The AD does not contain such a mandate; therefore, the requirements of Title II of the Act do not apply.

Comments Invited

We invite you to send any written relevant data, views, or arguments about this IRFA. Send your comments to an address listed under the **ADDRESSES** section. Include ‘‘Docket No. FAA– 2013–0393; Directorate Identifier 2012– CE–025–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the IRFA as related to the AD action. The most helpful comments will reference a specific portion of the IRFA or related rulemaking document, explain the reason for any recommended change, and include supporting data.

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 the AD.

Issued in Kansas City, Missouri, on October 22, 2013. Earl Lawrence, Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2013–25526 Filed 10–28–13; 8:45 am]

**BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION** 

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2013–0740; Directorate Identifier 2013–NE–24–AD]** 

**RIN 2120–AA64**

**Airworthiness Directives; Pratt & Whitney Turbofan Engines** 

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Notice of proposed rulemaking (NPRM).

**SUMMARY :**  We propose to adopt a new airworthiness directive (AD) for all Pratt & Whitney (PW) PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043, PW2146, PW2240, PW2337, PW2643, and F117–PW–100 turbofan engines. This proposed AD wasprompted by a rupture of the diffuserto-high-pressure turbine (HPT) case flange. This proposed AD would require a one-time eddy current inspection (ECI) of affected engines with certain diffuser and HPT cases installed. This AD alsoproposes to require a fluorescentpenetrant inspection (FPI) of the diffuser case rear flange and HPT case front flange. We are proposing this AD to prevent failure of the diffuser-to-HPT case flange, which could lead to uncontained engine failure and damage to the airplane.

**DATES :**  We must receive comments on this proposed AD by December 30,
2013.

**ADDRESSES :**  You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, 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: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; phone: 860–565–8770; fax: 860–565–4503. You may view this 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. 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: 800–647–5527) is in the

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

**FOR FURTHER INFORMATION CONTACT :**  Robert Morlath, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7154; fax: 781–238– 7199; email: robert.c.morlath@faa.gov

. **SUPPLEMENTARY INFORMATION :** 
Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the **ADDRESSES** section. Include ‘‘Docket No. FAA– 2013–0740; Directorate Identifier 2013– NE–24–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 because of those
comments.

We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

We received a report of an engine event in October 2011 that resulted in a rupture of the engine diffuser-to-HPT case flange. The rupture caused the engine cowl doors to break open, which resulted in damage to the underside of the airplane’s wing. Subsequent investigation revealed that the root cause of this rupture was a crack that originated in HPT case M-flange boltholes (the forward flange of the HPT case that mates with the rear outer flange of the diffuser case). This condition, if not corrected, could result in failure of the diffuser-to-HPT case flange, which may cause an uncontained engine failure and damage to the airplane.