### 52169 Federal Register / Vol. 79, No. 170 / Wednesday, September 3, 2014 / Rules and Regulations

7. Proof of Compliance

We propose the following requirement be added in lieu of § 25.21(b), [Reserved]:

(b) The flying qualities must be
evaluated at the most unfavorable center-of-gravity position.

8. Sections 25.145(a), 25.145(b)(6), and 25.1323(d)

We propose the following requirements:

• For § 25.145(a), add ‘‘Vmin ’’ in lieu
of ‘‘stall identification.’’

• For § 25.145(b)(6), and ‘‘Vmin ’’ in
lieu of ‘‘V SW. ’’

• For § 25.1323(d), add ‘‘From 1.23

V SR to Vmin . . .,’’ in lieu of, ‘‘1.23 V SR to stall warning speed . . .,’’ and, ‘‘. . . speeds below V min . . .’’ in lieu of, ‘‘. . . speeds below stall warning . . . .’’

Special Conditions Part II

Credit for Robust Envelope Protection in Icing Conditions

The following special conditions are in lieu of the specified paragraphs of §§ 25.103, 25.105, 25.107, 25.121, 25.123, 25.125, 25.143, and 25.207.

1. Define the stall speed as provided in these special conditions, Part I, in lieu of § 25.103.

2. We propose the following requirements in lieu of § 25.105(a)(2)(i):

In lieu of § 25.105(a)(2)(i) Takeoff: (i) The V 2 speed scheduled in nonicing conditions does not provide the maneuvering capability specified in § 25.143(h) for the takeoff configuration,

or 3. In lieu of § 25.107(c) and (g) we propose the following requirements, with additional sections (c b ) and (g b ):

In lieu of § 25.107(c) and (g) Takeoff speeds:

(c) In non-icing conditions V 2 , in terms of calibrated airspeed, must be selected by the applicant to provide at least the gradient of climb required by § 25.121(b) but may not be less than—

(1) V 2MIN ; (2) V R plus the speed increment attained (in accordance with § 25.111(c)(2)) before reaching a height of 35 feet above the takeoff surface; and

(3) A speed that provides the maneuvering capability specified in § 25.143(h).

(c b ) In icing conditions with the ‘‘takeoff ice’’ accretion defined in part 25, appendix C, V 2 may not be less
than—

(1) The V 2 speed determined in nonicing conditions; and

(2) A speed that provides the maneuvering capability specified in § 25.143(h).

(g) In non-icing conditions, VFTO , in terms of calibrated airspeed, must be selected by the applicant to provide at least the gradient of climb required by § 25.121(c), but may not be less than—

(1) 1.18 V SR ; and (2) A speed that provides the maneuvering capability specified in § 25.143(h).

(g b ) In icing conditions with the
‘‘final takeoff ice’’ accretion defined in part 25, appendix C, VFTO , may not be
less than—

(1) The VFTO speed determined in non-icing conditions.

(2) A speed that provides the maneuvering capability specified in § 25.143(h).

4. In lieu of §§ 25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A), and 25.121(d)(2)(ii), we propose the following requirements:

In lieu of § 25.121(b)(2)(ii)(A): (A) The V 2 speed scheduled in nonicing conditions does not provide the maneuvering capability specified in § 25.143(h) for the takeoff configuration;

or In lieu of § 25.121(c)(2)(ii)(A):

(A) The VFTO speed scheduled in nonicing conditions does not provide the maneuvering capability specified in § 25.143(h) for the en-route configuration; or

In lieu of § 25.121(d)(2)(ii): (d)(2) The requirements of subparagraph (d)(1) of this paragraph
must be met:

(ii) In icing conditions with the approach ice accretion defined in appendix C, in a configurationcorresponding to the normal all-enginesoperating procedure in which Vmin 1g for this configuration does not exceed 110% of the V min 1g for the related allengines-operating landing configuration in icing, with a climb speed established with normal landing procedures, but not
more than 1.4 V SR (V SR determined in non-icing conditions).

5. In lieu of § 25.123(b)(2)(i) we propose the following requirements:

In lieu of § 25.123(b)(2)(i): (i) The minimum en-route speed scheduled in non-icing conditions does not provide the maneuvering capability specified in § 25.143(h) for the en-route configuration, or

6. In lieu of § 25.125(b)(2)(ii)(B) and § 25.125(b)(2)(ii)(C), we propose the following requirement:

(B) A speed that provides the maneuvering capability specified in § 25.143(h) with the landing ice accretion defined in part 25, appendix

C. 7. In lieu of § 25.143(j)(2)(i), we propose the following requirement:

(i) The airplane is controllable in a pull-up maneuver up to 1.5 g load factor or lower if limited by angle of attack protection; and 8. In lieu of § 25.207, Stall warning, to read as the requirements defined in these special conditions Part I, Section

4.

Issued in Renton, Washington, on August

27, 2014. Jeffrey E. Duven, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2014–20893 Filed 9–2–14; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 25**

**[Docket No. FAA–2014–0419; Special Conditions No. 25–563–SC]** 

**Special Conditions: Gulfstream Aerospace Corporation, Model GVI;**  **Electro-Hydraulically Actuated Seats Equipped With a Backup Power Supply** 

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

**ACTION :**  Final special condition; request
for comments.

**SUMMARY :**  These special conditions are issued for Gulfstream Aerospace Corporation Model GVI airplane. This airplane, as modified by Gulfstream Aerospace Corporation, will have novel or unusual design features associated
with the installation of electrohydraulically operated seats with a backup power supply (BPS) and hydraulic reservoir, pump, and actuators, as well as massage and heating functions. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety
standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

**DATES :**  The effective date of these special conditions is September 3, 2014. We must receive your comments by October 20, 2014.

**ADDRESSES :**  Send comments identified by docket number FAA–2014–0419 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.


### 52170 Federal Register / Vol. 79, No. 170 / Wednesday, September 3, 2014 / Rules and Regulations

• 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 :**  Dan Jacquet, FAA, Airframe and Cabin Safety Branch, ANM–115, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057–3356; telephone 425–227–2676; facsimile

425–227–1320.

**SUPPLEMENTARY INFORMATION :**  The FAA has determined that notice of, and opportunity for prior public comment on, these special conditions is impracticable because these procedures would significantly delay issuance of the design approval and thus delivery of
the affected aircraft. The FAA therefore finds that good cause exists for making these special conditions effective upon publication in the Federal Register

. 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 by the closing date for comments. We may change these special conditions based on the comments we

receive.

Background

On June 14, 2014, Gulfstream Aerospace Corporation applied for an amendment to a Supplemental Type Certificate (STC) ST04252AT–D for the installation of electro-hydraulically operated seats with novel or unusual features in the Model GVI airplane. These features include a backup power supply used to return the backrest, seat pan, and leg rest to the taxi, takeoff, and landing (TT&L) position in the event of a power failure. In addition, each seat contains a hydraulic reservoir, pump, and actuators, as well as massage and heating functions. The Model GVI is a business jet airplane powered by two Rolls-Royce Deutschland Ltd. and Company KG turbofan engines and is certified for 19 passengers and a crew of

3.

Type Certification Basis

Under the provisions of Title 14, Code of Federal Regulation (14 CFR) 21.101, Gulfstream Aerospace Corporation must show that the Model GVI, as changed, continues to meet the applicable provisions of the regulations incorporated by reference in Type
Certificate No. T00015AT or the applicable regulations in effect on the date of application for the change. The regulations incorporated by reference in the type certificate are commonly referred to as the ‘‘original type certification basis.’’ The regulations incorporated by reference in Type
Certificate No. T00015AT are as follows:

• 14 CFR part 25, Airworthiness Standards: Transport Category Airplanes, effective February 1, 1965, including Amendments 25–1 through 25–120 and 25–122, 25–124, and 25–
132. Amendment 25–118 was not published and therefore has no applicability.

• 14 CFR part 36, Noise Standards: Aircraft Type and Airworthiness Certification, effective December 1, 1969, including Amendments 36–1 through 36–28.

• Compliance with Section 44715(e) of Title 49 U.S.C. (Noise Control Act of 1972).

• Optional Design Regulations: (a) The Model GVI has been shown to comply with the requirements for ditching: §§ 25.801, 25.563, 25.807(e), and 25.1585(a). When the operating rules require emergency ditching equipment, compliance with §§ 25.1411
and 25.1415 must be shown. Gulfstream Report GVI–GER–1709, ‘‘Design Requirements Document for Ditching Equipment,’’ provides an acceptable means for showing compliance with §§ 25.1411 and 25.1415.

(b) The Model GVI is approved for flight into known icing conditions and has demonstrated compliance to § 25.1419.

• Exemptions pertinent to these special conditions: Exemption No. 9761, §§ 25.562(a) and 25.785(b), Side Facing

Divan.

In addition, the certification basis includes certain special conditions, exemptions, and equivalent safety findings that are not relevant to these proposed special conditions.

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 Gulfstream Model GVI because of a novel or unusual design feature, special conditions are prescribed under the provisions of 14 CFR 21.16.

Special conditions are initially applicable to the model for which they are issued. Should the applicant apply for a STC to modify any other model included on the same type certificate to incorporate the same novel or unusual design feature, the special conditions would also apply to the other model.

In addition to the applicable airworthiness regulations and special conditions, the Gulfstream Model GVI 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.

The FAA issues special conditions, as defined in 14 CFR 11.19, in accordance with § 11.38, and they become part of the type-certification basis under 14

CFR 21.101.

Novel or Unusual Design Features

The Gulfstream Model GVI will incorporate the following novel orunusual design features: Hydraulicallyactuated components on airplane seats including hydraulic reservoir, pump, and actuators, as well as massage and heating functions and backup power systems.

Discussion

Hydraulically-actuated components and backup power systems on airplane seats are considered novel or unusual by the FAA. Therefore, we developed special conditions that contain the
additional standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing
airworthiness standards.

The FAA has considered the
installation of seats with these features to have four primary safety concerns:


### 52171 Federal Register / Vol. 79, No. 170 / Wednesday, September 3, 2014 / Rules and Regulations

1. Reliability of the backup power supply;

2. Safety hazards to the occupants from the hydraulically-actuated components of the seat;

3. Structural integrity of the hydraulic components; and

4. Flammability. Emergency exits must be accessible to the passengers and the effectiveness of evacuation must be maintained. Typical airplane seats can be manually positioned to the lateral (track) and directional (swivel) TT&L position by mechanical means, so they can be positioned in the event of a loss of cabin power. For this electro-hydraulically operated seat design, in lieu of a manual means to re-position the hydraulically operated seat features (backrest, seat pan, and leg rest deployment) for TT&L, a BPS is used to temporarily power the hydraulic system. The BPS is only
intended for use in the event of a loss of cabin power. If the seats are installed in the path of the emergency over wing exits, failure to return the seat to a TT&L position may have an adverse effect on
evacuation. Substantiation of 14 CFR 25.809(b) and 25.813(c)(2)(ii) must be
shown with the seats in their most adverse positions.

It must be shown that the hydraulically-actuated components of the seat pose no safety hazard to the occupants or airplane. This includes injuries caused by crushing of airplane occupants who are between the hydraulically-actuated components and any part of the passenger cabin when seat features (e.g., leg rest or backrest) are actuated. Additionally, the risk of loss of function of a control or proximity switch resulting in the pump motor being commanded to stay on, after the hydraulic actuator(s) have reached their maximum/minimum limit, must not cause the overloaded motor to overheat,
as it could catch fire.

The FAA has also considered the emergency landing dynamic conditions
for the installation of electrohydraulically actuated seats. The applicant must show that the hydraulic system (actuators, reservoir, lines, etc.) remains intact and free from leakage under the conditions specified in § 25.562. Testing of each seat’s hydraulic system per § 25.1435(c) may be conducted off of the airplane.

Flammability of hydraulic fluid used
in the seat movement mechanism must be considered. If the fluid is flammable,it could contribute to a post-crash or inflight fire. Any failure modes that would
result in release of the flammable hydraulic fluid during a post-crash or in-flight fire causing such fluid to materially increase an existing fire must be examined. Examples of this could be flex lines burning through and releasing the flammable hydraulic fluid, or the
fluid reservoir could be heated in a fire resulting in a boiling liquid expanding vapor explosion. The potential for spontaneous ignition of the fluid coming into contact with hot surfaces or other ignition sources should also be addressed. The applicant should examine any possible failure mode in which the flammable hydraulic fluid could be absorbed into materials, like the seat foam/fabric, carpeting, etc. Theapplicant must show that any fluidsoaked seat parts are still selfextinguishing. The applicant must also show that flammability of dry residue, which may be present from a slow leak/ fluid weepage, does not degrade the flammability characteristics of any materials it may come into contact with to a level below the requirements specified in § 25.853.

Applicability

As discussed above, these special conditions are applicable to STC ST04252AT–D, which modifies the Gulfstream Model GVI airplane. Should Gulfstream Aerospace Corporation apply at a later date to amend this STC to incorporate the same novel or unusual design feature, the special conditions would apply to that
amended STC as well.

Conclusion

This action affects only certain novel or unusual design features on one airplane model. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on the airplane.

Under standard practice, the effective date of final special conditions would be 30 days after the date of publication
in the Federal Register ; however, as the
certification date for the modification to the Gulfstream Model GVI airplane is imminent, the FAA finds that good cause exists to make these special conditions effective upon publication in
the Federal Register

. 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 Special Conditions

Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for Gulfstream Aerospace Corporation airplanes modified by Gulfstream Aerospace Corporation.

Electro-Hydraulically Actuated Seats Equipped With a Backup Power Supply

1. The probability of failure of the backup power supply to return seat components to the required taxi, takeoff, and landing position must be shown to be no greater than 10

¥ 5 per flight hour.

2. It must be shown that the hydraulically-actuated components of the seat pose no safety hazard to the occupants. Hazards to be considered per the latest revision of Advisory Circular 25.1309–1, at a minimum are:

a. Injuries caused by crushing of airplane occupants who are between the hydraulically actuated components and any part of the passenger cabin when the leg rest or backrest is actuated.

b. The risk of loss of function of a control or proximity switch resulting in the pump motor being commanded to stay on after the hydraulic actuator(s)
have reached their maximum/minimum limit, creating potential for overheat or
fire.

c. The potential for a significant
contribution to a fire in the event fluid
comes into contact with hot surfaces or other ignition sources, and the potential for release of toxic or flammable vapors/

gasses.

3. It must be shown that the hydraulic system (actuators, reservoir, lines, etc.) remains intact and free from leakage under the conditions specified in § 25.562. Testing of each seat’s hydraulic system per § 25.1435(c) may be conducted off of the airplane.

4. Section 25.863 requires consideration of any effects the fluid, including the fluid as a dry residue, could have on combustible or absorbing
materials. The characteristics of the
flammable fluid in these conditions must be tested to the requirements of § 25.853(a) and (c), or the materials must be shielded in a manner that prevents contact by the fluid. However, as an alternative to such testing or shielding, the applicant may provide, inaccordance with § 25.863(c), a quickacting means that alerts the crew that
the fluid has leaked.

Issued in Renton, Washington, on August

26, 2014. Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2014–20865 Filed 9–2–14; 8:45 am]

**BILLING CODE 4910–13–P**