### 1339 Federal Register / Vol. 79, No. 5 / Wednesday, January 8, 2014 / Proposed Rules

characteristics for what are considered survivable crash conditions. The proposed special conditions are necessary to ensure a level of safety equivalent to that provided by 14 CFR part 25.

Discussion

Factors in crash survivability are retention of items of mass, maintenance of occupant emergency egress paths, maintenance of acceptable acceleration and loads experienced by the occupants, and maintenance of a survivable volume. To provide the same level of safety as exists with conventional airplane construction, Airbus should show that the Model A350–900 series airplanes have sufficient crashworthiness capabilities under foreseeable survivable impact events. To show this, Airbus should evaluate the impact response characteristics of the Model A350–900 series airplane to ensure that its crashworthiness characteristics are not significantly different from those of a similarly sized airplane built from traditionally used metallic materials.

In their evaluation of the Model A350–900 series airplane response to an impact event, Airbus should demonstrate that the structural behavior is similar to that expected from a metallic airframe of similar size to the Model A350–900, or incorporate mitigating design features that provide a similar level of safety.

Airbus should demonstrate either through analysis using validated analytical tools or by direct test evidence that the crash dynamics of the A350 fuselage structure provides a level of occupant protection consistent with previously certificated large transport category airplanes.
Applicability

As discussed above, these proposed special conditions apply to Airbus Model A350–900 series airplanes. Should Airbus apply later for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the proposed special conditions would apply to that model as well.

Conclusion

This action affects only certain novel or unusual design features on the Airbus Model A350–900 series airplanes. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 25

Aircraft, Aviation safety, Reporting and recordkeeping requirements.

The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704. 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.

The Airbus Model A350–900 series airplanes must provide an equivalent level of occupant safety and survivability to that provided by previously certificated wide-body transports of similar size under foreseeable survivable impact events for the following four criteria. In order to demonstrate an equivalent level of occupant safety and survivability, the applicant must demonstrate that Model A350–900 series airplanes meet the following criteria for a range of airplane vertical descent velocities up to 30 ft/

sec.

1. Retention of items of mass. The occupants, i.e., passengers, flight attendants, and flightcrew, must be protected during the impact event from release of seats, overhead bins, and other items of mass due to the impact loads and resultant structural deformation of the supporting airframe and floor structures. The applicant must show that loads due to the impact event and resultant structural deformation of the supporting airframe and floor structure at the interface of the airplane structure to seats, overhead bins, and other items of mass are comparable tothose of previously certificated widebody transports of similar size for the range of descent velocities stated above. The attachments of these items need not be designed for static emergency landing loads in excess of those defined in § 25.561 if impact response characteristics of the Airbus Model A350–900 series airplanes yield load factors at the attach points that are comparable to those for a previously certificated wide-body transport category airplane.

2. Maintenance of acceptable acceleration and loads experienced by the occupants. The applicant must show that the impact response characteristics of the Airbus Model A350–900 series airplane, specifically the vertical acceleration levels experienced at the seat/floor interface and loads experienced by the occupants during the impact events, are consistent with those found in § 25.562(b) or with levels expected for a previously certificated wide-body transport category airplane for the conditions stated above.

3. Maintenance of a survivable volume. For the conditions stated above, the applicant must show that all areas of the airplane occupied for takeoff and landing provide a survivable volume comparable to that of previously certificated wide-body transports of similar size during and after the impact event. This means that structural deformation will not result in infringement of the occupants’ normal living space so that passenger survivability will not be significantly affected.

4. Maintenance of occupant emergency egress paths. The evacuation of occupants must be comparable to thatfrom a previously certificated widebody transport of similar size. To show this, the applicant must show that the suitability of the egress paths, as determined following the vertical impact events, is comparable to the suitability of the egress paths of a comparable, certificated wide-body transport, as determined following the same vertical impact events.

Issued in Renton, Washington, on October
22, 2013. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2014–00104 Filed 1–7–14; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 25**

**[Docket No. FAA–2013–0911; Notice No. 25–13–22–SC]** 

**Special Conditions: Airbus, Model A350–900 Series Airplane; Lateral Trim**  **Function Through Differential Flap Setting** 

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

**ACTION :**  Notice of proposed special conditions.

**SUMMARY :**  This action proposes special conditions for the Airbus Model A350– 900 series airplanes. These airplanes will have a novel or unusual design feature associated with a lateral trim function that deploys flaps asymmetrically for airplane lateral trim control. This function replaces the traditional method of providing airplane lateral trim over a small range through flap and aileron mechanical rigging. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety


### 1340 Federal Register / Vol. 79, No. 5 / Wednesday, January 8, 2014 / Proposed Rules

equivalent to that established by the existing airworthiness standards.

**DATES :**  Send your comments on or before February 24, 2014.

**ADDRESSES :**  Send comments identified by docket number FAA–2013–0911 using any of the following methods:

• Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending your comments electronically.

• Mail: Send comments to Docket Operations, M–30, U.S. Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room W12–140, West Building Ground Floor, Washington, DC

20590–0001.

• Hand Delivery or Courier: Take comments to Docket Operations in Room W12–140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except federal holidays.

• Fax: Fax comments to Docket Operations at 202–493–2251.

Privacy: The FAA will post all comments it receives, without change,

to http://www.regulations.gov/

, including any personal information the commenter provides. Using the search function of the docket Web site, anyone can find and read the electronic form of all comments received into any FAA docket, including the name of the individual sending the comment (or signing the comment for an association, business, labor union, etc.). DOT’s complete Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477–19478), as well as at http://DocketsInfo. dot.gov/.

Docket: Background documents or comments received may be read at http://www.regulations.gov/ at any time. Follow the online instructions for accessing the docket or go to the Docket Operations in Room W12–140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except federal holidays.

**FOR FURTHER INFORMATION CONTACT :**  Robert C. Jones, FAA, Propulsion/ Mechanical Systems, ANM–112, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057–3356; telephone (425) 227–1234; facsimile (425) 227–1320.

**SUPPLEMENTARY INFORMATION :** 

Comments Invited

We invite interested people to take part in this rulemaking by sending written comments, data, or views. The most helpful comments reference a specific portion of the special conditions, explain the reason for any recommended change, and include supporting data.

We will consider all comments we receive on or before the closing date for comments. We may change these proposed special conditions based on the comments we receive.
Background

On August 25, 2008, Airbus applied for a type certificate for their new Model A350–900 series airplane. Later, Airbus requested and the FAA approved an extension to the application for FAA type certification to June 28, 2009. The Model A350–900 series has aconventional layout with twin wingmounted Rolls-Royce Trent XWB engines. It features a twin aisle 9-abreast economy class layout, and accommodates side-by-side placement of LD–3 containers in the cargo compartment. The basic Model A350– 900 series configuration will accommodate 315 passengers in a standard two-class arrangement. The design cruise speed is Mach 0.85 with a Maximum Take-Off Weight of 602,000 lbs. Airbus proposes the Model A350– 900 series to be certified for extended operations (ETOPS) beyond 180 minutes at entry into service for up to a 420- minute maximum diversion time.

On conventional airplanes, small lateral airplane asymmetries have typically been addressed through flap and aileron rigging (e.g., using shims). On Model A350–900 series airplanes, an order for asymmetric flap deployment will be computed by the primary flight control system as a function of the aileron position. The current airworthiness standards do not contain adequate safety standards for asymmetric use of the flaps as proposed for Airbus Model A350–900 series airplanes. Special conditions are needed to account for the aspects of a function used to command an intended flap asymmetry. The lateral trim function is intended to be performed once during climb and once during cruise to compensate for small airplane lateral asymmetries.

The lateral trim function is not a trim control system in the conventional sense as it has no pilot interface and is not governed by § 25.677. In fact some fly-by-wire airplanes have no pilot operated lateral trim at all. The lateral trim function is simply an additional fly-by-wire flight control function that nulls small roll asymmetries in certain flight phases with small asymmetric flap deployments. Although the function operates under normal conditions within the small range of the traditional rigging, there may be failure cases leading to a significant out of range asymmetric flap condition. An asymmetry threshold will protect the system against excessive flap asymmetry.
Type Certification Basis

Under Title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus must show that the Model A350–900 series meets the applicable provisions of 14 CFR part 25, as amended by Amendments 25–1 through 25–129.

If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the Model A350–900 series because of a novel or unusual design feature, special conditions are prescribed under § 21.16.

Special conditions are initially applicable to the model for which they are issued. Should the type certificate for that model be amended later to include any other model that incorporates the same novel or unusual design feature, the proposed special conditions would also apply to the other model under § 21.101.

In addition to the applicable airworthiness regulations and proposed special conditions, the Model A350–900 series must comply with the fuel vent and exhaust emission requirements of 14 CFR part 34 and the noise certification requirements of 14 CFR part 36 and the FAA must issue a finding of regulatory adequacy under § 611 of Public Law 92–574, the ‘‘Noise Control Act of 1972.’’

The FAA issues special conditions, as defined in 14 CFR 11.19, under § 11.38,and they become part of the typecertification basis under § 21.17(a)(2).
Novel or Unusual Design Features

The Airbus Model A350–900 series will incorporate the following novel or unusual design features: the asymmetric use of flaps to address lateral trim which is not adequately addressed by § 25.701.

Discussion

Title 14 Code of Federal Regulations (14 CFR) part 25 § 25.701(a) requires that unless the airplane has safe flight characteristics with the flaps or slats retracted on one side and extended on the other, flap and slat surfaces must be synchronized by either a mechanical interconnection or any equivalent means that has the same integrity. Synchronization is interpreted to mean that flap movement is symmetrical throughout the full range of flap motion. Because the lateral trim function


### 1341 Federal Register / Vol. 79, No. 5 / Wednesday, January 8, 2014 / Proposed Rules

intentionally creates asymmetric flap motions, the flap system installation of the Model A350–900 series does not meet the requirement of § 25.701(a) and (d).
Applicability

As discussed above, these proposed special conditions apply to Airbus Model A350–900 series airplanes. Should Airbus apply later for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the proposed special conditions would apply to that model as well.

Conclusion

This action affects only certain novel or unusual design features on the Airbus Model A350–900 series airplanes. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 25

Aircraft, Aviation safety, Reporting and recordkeeping requirements.

The authority citation for these special conditions is as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704. 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.

1. Lateral Trim Function through Differential Flap Setting.

Current airworthiness standards, specifically § 25.701, do not contain adequate safety standards for the proposed design. In lieu of the requirements of § 25.701(a) and (d) for the lateral trim function, the following special condition is proposed:

a. Airbus must demonstrate that an unsafe condition is not created by using the flaps asymmetrically,

b. The degree of acceptable asymmetry must be defined and justified for all flight phases with respect to:

• § 25.701(b) and (c), with the worst case asymmetric flap configurations, and

• providing equivalent protection against excess asymmetry in the same manner as § 25.701 provides to systems that are synchronized or use another equivalent means to prevent asymmetry.

c. This lateral trim function is a flight control system and therefore must show compliance to both general system requirements as well as general flight control requirements. Therefore, the function must be demonstrated not to embody, where practicable, significant latent failures. Issued in Renton, Washington, on October
22, 2013. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2014–00105 Filed 1–7–14; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 71**

**[Docket No. FAA–2013–0175; Airspace Docket No. 13–AGL–12]** 

**Proposed Amendment of Class D and Class E Airspace; Traverse City, MI** 

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

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

**SUMMARY :**  This action proposes to amend Class D and Class E airspace at Traverse City, MI. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Cherry Capital Airport. Geographic coordinates of the airport also would be adjusted. The FAA is taking this action to enhance the safety and management of Instrument Flight Rules (IFR) operations for SIAPs at the airport.

**DATES :**  Comments must be received on or before February 24, 2014.

**ADDRESSES :**  Send comments on this proposal to the U.S. Department of Transportation, Docket Operations, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12–140, Washington, DC 20590–0001. You must identify the docket number FAA–2013– 0175/Airspace Docket No. 13–AGL–12, at the beginning of your comments. You may also submit comments through the
Internet at http://www.regulations.gov. You may review the public docket containing the proposal, any comments received, and any final disposition in person in the Dockets Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone 1–800–647– 5527), is on the ground floor of the building at the above address.

**FOR FURTHER INFORMATION CONTACT :**  Scott Enander, Central Service Center, Operations Support Group, Federal Aviation Administration, Southwest Region, 2601 Meacham Blvd., Fort Worth, TX 76137; telephone: (817) 321–

7716.

**SUPPLEMENTARY INFORMATION :**  Comments Invited
Interested parties are invited to participate in this proposed rulemaking by submitting such written data, views, or arguments, as they may desire. Comments that provide the factual basis supporting the views and suggestions presented are particularly helpful in developing reasoned regulatory decisions on the proposal. Comments are specifically invited on the overall regulatory, aeronautical, economic, environmental, and energy-related aspects of the proposal. Communications should identify both docket numbers and be submitted in triplicate to the address listed above. Commenters wishing the FAA to acknowledge receipt of their comments on this notice must submit with those comments a self-addressed, stamped postcard on which the following statement is made: ‘‘Comments to Docket No. FAA–2013–0175/Airspace Docket No. 13–AGL–12.’’ The postcard will be date/time stamped and returned to the commenter.
Availability of NPRMs

An electronic copy of this document may be downloaded through the
Internet at http://www.regulations.gov. Recently published rulemaking documents can also be accessed through the FAA’s Web page at http:// www.faa.gov/airports

_ airtraffic/
air

_ traffic/publications/ airspace

_amendments/.

You may review the public docket containing the proposal, any comments received and any final disposition in person in the Dockets Office (see

**ADDRESSES** section for address and phone number) between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. An informal docket may also be examined during normal business hours at the office of the Central Service Center, 2601 Meacham Blvd., Fort Worth, TX 76137.

Persons interested in being placed on a mailing list for future NPRMs should contact the FAA’s Office of Rulemaking (202) 267–9677, to request a copy of Advisory Circular No. 11–2A, Notice of Proposed Rulemaking Distribution System, which describes the application procedure.
The Proposal

This action proposes to amend Title 14, Code of Federal Regulations (14 CFR), part 71 by amending Class D airspace, Class E airspace designated as a surface area, and Class E airspace extending upward from 700 feet above the surface to accommodate new standard instrument approach