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

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 ‘‘VSW.’’ 

• For § 25.1323(d), add ‘‘From 1.23 

VSR to Vmin . . .,’’ in lieu of, ‘‘1.23 VSR

to stall warning speed . . .,’’ and, ‘‘. . . 

speeds below Vmin . . .’’ 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 V2 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 (cb) and (gb): 

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

speeds: 

(c) In non-icing conditions V2, 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) V2MIN; 

(2) VR 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). 

(cb) In icing conditions with the 

‘‘takeoff ice’’ accretion defined in part 

25, appendix C, V2 may not be less 

than— 

(1) The V2 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 VSR; and 

(2) A speed that provides the 

maneuvering capability specified in 

§ 25.143(h). 

(gb) 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 V2 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 configuration 

corresponding to the normal all-enginesoperating procedure in which Vmin1g for 

this configuration does not exceed 

110% of the Vmin1g for the related allengines-operating landing configuration 

in icing, with a climb speed established 

with normal landing procedures, but not 

more than 1.4 VSR (VSR 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. 


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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 or 

unusual 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: 


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

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. The 

applicant 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, in 

accordance 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 


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