UNITED STATES OF AMERICA 

DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRATION 

RENTON, WASHINGTON 98057-3356 

In the matter of the petition of 

Exemption No. 13582 

Gulfstream Aerospace Corporation Regulatory Docket No. FAA-2015-3311 

for an exemption from§ 25.1447(c)(l) of 

Title 14, Code of Federal Regulations 

GRANT OF EXEMPTION 

By letter dated July 30,2015, Mr. Robert Glasscock, Gulfstream Aerospace Corporation, P.O. 

Box 2206, M/S R-02, Savannah. GA 31402-2206, petitioned the Federal Aviation 

Administration (FAA) for an exemption from a requirement in§ 25.1447(c)(1), at Amendment 

25-116, of Title 14, Code of Federal Regulations (14 CFR). This exemption, if granted, would 

permit relief from the requirement that oxygen-dispensing units must be automatically presented 

to occupants before the cabin pressure altitude exceeds 15,000 feet on Gulfstream Model GVIIG500 airplanes and subsequent derivatives. 

The petitioner requests relief from the following regulation(s): 

Section 25.1447(c)(l) requires, in pertinent part, that there must be an oxygen-dispensing 

unit connected to oxygen-supply terminals immediately available to each occupant, 

wherever seated. If certification for operation above 30,000 feet is requested, the 

dispensing units providing the required oxygen flow must be automatically presented to 

the occupants before the cabin-pressure altitude exceeds 15,000 feet, and the crew must 

be provided with a manual means to make the dispensing units immediately available in 

the event of failure of the automatic system. 

The petitioner supports its request with the following information: 

This section quotes the relevant information from the petitioner's request, with minor edits for 

clarity. The complete petition is available at the Department of Transportation's Federal Docket 

Management System, on the Internet at http://regulations.gov, in Docket No. FAA-20 15-3311. 
Relief from section 14 CFR Part 25.1447(c)(l) Arndt. 25-116 

Oulfstream Aerospace Corporation (Oulfstream) of Savannah, Georgia has submitted 

application to the FAA ·s Atlanta Aircraft Certification Office for type certification of a 

new, twin-engine, transport category aircraft to be known as the Oulfstream model OVII0500. Oulfstream ODA project number TC-01-2010-0024 has been assigned to this 

effort. Oulfstream intends to certify the OVII-0500 and any subsequent derivative models 

to support landing field elevations (LFE) of up to 15.000 feet. 

14 CFR 25.1447(c)(l), Amendment 25-116 states in part that an oxygen-dispensing unit 

must be connected to oxygen-supply terminals immediately available to each occupant, 

wherever seated. If certification for operation above 30,000 feet is requested, the 

dispensing units providing the required oxygen flow must be automatically presented to 

the occupants before the cabin pressure altitude exceeds 15,000 feet, and the crew must 

be provided with a manual means to make the dispensing units immediately available in 

the event of failure of the automatic system. 

In accordance with the provisions of 14 CFR 11.81, Oulfstream requests an exemption to 

14 CFR 25.1447(c)(l). This will allow the OVII-0500 and any subsequent derivative 

models to operate in and out of airports with landing field elevations approaching 15,000 

feet and will prevent nuisance deployment of oxygen masks. Oulfstream is proposing 

alternative design requirements to provide an appropriate equivalent level of safety. This 

information provided herewith will outline this rationale. 

Supportive Information 

Nagqu Dagring Airport is a new airport under construction in northern Tibet. The airport 

is scheduled to be completed in 2015 and will have a landing field elevation (LFE) of 

14,554 ft above sea level (excluding barometric pressure variations). This airport will 

help improve the transportation conditions in the region. 

In order for the OVII-0500 and any subsequent derivative models to provide the 

additional capability for landing at airports [with elevations] up to 15,000 feet, the Cabin 

Pressure Control System (CPCS) and the passenger oxygen control panel will be 

configured to allow the cabin internal pressure altitude to reach as high as 15,300 feet 

during normal operations. 

Factors supporting the Petition 

14 CFR 25.1447(c)(l) was designed to provide passenger safety during flight conditions. 

Oulfstream proposes that passenger safety can be maintained during all flight conditions 

and can be further enhanced with simple and logical flight crew procedures to allow 

operation at high [elevation] airports. The changes proposed are designed to maintain an 

equivalent level of safety during flight while minimizing the possibility of nuisance 

passenger-oxygen-mask deployment during takeoff and descent at high [elevation] 

airports. 

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The GVII-G500 and any subsequent derivative models will be designed to provide 

operations into high LFE airports. The design will prevent nuisance deployment of the 

passenger oxygen masks when operating into and out of airports up to 15,000 feet LFE. 

14 CFR 25.1447(c)(l) states that oxygen dispensing units must be presented to the 

occupants before the cabin pressure exceeds 15,000 feet and that the crew must have a 

manual means of making dispensing units available in the event of a failure of the 

automatic system. An exemption is requested to allow a maximum oxygen altitude limit 

of more than 15,000 feet. 

The passenger oxygen control system design will account for field elevations up to 

14,000 ft, and will have a secondary setting for high field elevations. To provide this, the 

Passenger Oxygen Control Panel will have an airport elevation selection switch installed 

that has two positions: 

• "NORMAL'"- Automatic passenger oxygen mask activation at 14,750 ± 250 feet 

• ''HI AL T''- Automatic passenger oxygen mask activation at 15,750 ± 250 feet 

During operations into and out of an airport with a landing field elevation greater than 

14,000 ft, "Hl AL T"" must be selected in order to reset the automatic passenger oxygen 

mask activation to approximately 15.750 feet and prevent a nuisance deployment of the 

passenger oxygen masks. 

The switch will remain in the "HI AL T" position during ground operations. An indication 

light on the switch will be illuminated when it is in the "HI ALT" position so that the 

crew is reminded to reset the switch after departure from high [elevation] airports. The 

indication light will turn off when the switch is reset to "NORMAL." The manual mask 

deployment feature is available regardless of switch position. 

Gulfstream will include AFM operational procedures for LFE :S 14,000, and procedures 

for LFE > 14,000 feet. For operations at LFEs > 14,000 feet, the procedures will instruct 

the crew to depress the "HI AL T'' switch on the passenger oxygen control panel during 

descent and similarly after take-off when the cabin altitude has decreased below 14,000 

feet. 

The AFM high elevation procedures will require that after engine start, the cockpit crew 

will wear oxygen masks until the cabin altitude is less than 10,000 feet. If the airplane 

takes offunpressurized for any reason (crew error, CPCS failure etc.) when departing an 

airport with elevation above 14.500 feet, the oxygen masks will be automatically 

presented to the passengers at 15,750 ± 250 feet. The passengers who boarded the 

airplane from high altitude airports should already be acclimated to the elevation. 

The crew will be alerted to Low Cabin Pressure at cabin altitudes appropriate for high 

landing field elevation. The CPCS logic, (which is discussed in the AFM), specifies that 

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during descent/climb the Cabin Pressure Low Warning is reset according the LFE 

selected (see below): 

r-----------------.-------.-............... -............................. _ .. _ . ___ _ 

Landing Field Elevation (Entered in 

FMS) 

Cabin Pressure Low Warning Setpoint for 

Aircraft with 15,000 feet LFE Maximum t--- ·---+--

Less than or equal to 7,500 feet 8,000 feet -~-------+--~ ------- --------~ 

7,500 < LFE :s; 9,500 feet 10,000 feet f-----· 

9,500 < LFE ::i14,000 feet 14,500 feet ----- ·--·-------1------ --------------l 

...___ __ 14,000 ....;._ ________ feet to 15.000 feet .. ____ _ 15,500 feet 

A Blue CAS message "Cabin Alt Alert Exceeds 1 OK" will display anytime the Cabin 

Pressure Low Warning is set above 10,000 ft. 

For high field elevation, during ground operation and at the start of climb, the Cabin 

Pressure Low Warning can start as high as 16,000 ft (LFE + 1000 ft) and is reset towards 

8,000 ft as the cabin altitude decreases. During climb whenever the aircraft is above 

34,000 ft, the Cabin Pressure Low Warning is reset to 8,000 ft and remains at 8,000 feet 

in cruise regardless of the LFE. During descent the Cabin Pressure Low Warning is reset 

according to the LFE selected. 

The additional 15,500-ft set point allows a 500-foot margin above maximum LFE to 

account for the Cabin Pressure Controller Unit (CPCU) internal sensor tolerance plus 

additional margin to prevent nuisance warnings. 

The passenger oxygen control system for the OVII-0500, and any subsequent derivative 

models, will incorporate a digital cabin pressure altitude sensor. This design will increase 

the accuracy and reliability of the passenger oxygen system over previous mechanical 

aneroid control systems. The new design will utilize a 3-way knob (OFF, AUTO, and 

MANUAL selections). In the event of a fai I ure of the automatic system to deploy the 

passenger oxygen masks, indication will provide to the crew through CAS message alert. 

The flight crew will then have the ability to manually deploy the oxygen masks to the 

passengers. 

The OVII aircraft models will comply with 14 CFR 25 .1447(c)(l) under all other 

conditions since the "NORMAL" set point for passenger mask deployment is 14,750 ft. 

Oulfstream will include all detailed instructions for High Field Elevation operation in the 

Airplane Flight Manual (AFM). 

Effect of the Exemption on Safety 

The exemption requested will not adversely affect the level of safety provided for the 

OVII-0500 and any subsequent derivative models. 

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The safety features described above are to ensure the avoidance of nuisance oxygen-mask 

deployment while still allowing deployment in the event of a CPCS failure during 

operations into high LFE airports. The proposed CPCS will comply with 14 CFR 

25.841(a)(l) as there are no probable failure conditions in the pressurization system that 

would cause the cabin pressure to exceed 15,000 feet. The CPCS and passenger oxygen 

control panel meet or exceed the FAA probability of failure requirements in all areas. As 

stated earlier, in the event of an unannunciated CPCS failure, the oxygen masks will drop 

automatically at a cabin altitude of no more than 16,000 feet, same as the Oulfstream 

Model OVI. Manual passenger oxygen mask deployment is always available to the crew 

in the event of Low Cabin Pressure indication, and the cabin oxygen masks fail to 

automatically deploy. 

The design ofthe OVII-0500 pressurization and oxygen systems and the AFM 

procedures provide for a safe environment for the crew and passengers while allowing for 

operation into and out of landing field elevations of up to and including 15,000 ft. 

Issue of Public Interest 

Gulfstream Aerospace Corporation designs, develops, manufactures, markets and services 

the world's most technologically advanced business jet aircraft to an International market. 

Gulfstream's leadership position in the global business jet market is due to the efforts of 

its nearly ten thousand employees in the manufacturing plants, completion centers, and 

services centers access North America. The corporation utilizes numerous products, such 

as avionics and environmental control systems, from scores of suppliers located 

throughout the United States. 

Gulfstream competes for new business all over the world. This exemption will directly 

impact the high-altitude utility of the OVII-0500, and any subsequent derivative models, 

thereby having a direct effect on sales. High Landing field elevation operations are being 

requested by prospective aircraft operators who compare the OVII-0500 airplane, or 

derivatives, with products of European and other aircraft manufacturers located outside 

the United States. This operational capability will make Oulfstream aircraft more 

marketable to these prospective operators. This exemption as proposed above is in 

essence an alternative method of achieving an appropriate level of safety, while at the 

same time providing features attractive to prospective purchasers. 

The manufacture, completion, and support of Oulfstream aircraft would aid in the 

stabilization of the job market as well as the growth of the American economy, which is 

in the interest of the public. 

Waiver of Notice and Public Procedure 

Oulfstream Aerospace Corporation respectfully requests that action on this petition 

should not be delayed by publication and comment procedures. Oulfstream believes that 

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the nature of this exemption does not set a precedent and this exemption is effectively 

identical to those previously granted for which [there] were no public comments. 

Previously Granted Exemptions: 

• Exemption No. 9940, Gulfstream GVI 

• Exemption No. 6076, Boeing 757 

• Exemption No. 8668A, Boeing 73 7 

• Exemption No. 9801 , Boeing 787 

• Exemption No. 6994, Airbus A320 

Operation Outside the United States 

In accordance with 14 CFR 11.81 (h), Gulfstream requests consideration be given to 

extending this exemption for operation outside of the United States. Gulfstream aircraft 

are routinely registered and operated outside of the United States and projections are the 

same for the GVH-G500 and its derivatives. Gulfstream believes that limiting this 

exemption to use within the United States would put unfair restrictions on the 

marketability of this aircraft. Conclusion: 

Gulfstream believes that the above arguments favor an exemption from 14 CFR 

25.1447(c)(l) that would allow uncomplicated operations into landing fields up to 15,000 

feet elevation for the GVII-G500 and its derivatives. In addition, Gulfstream believes that 

an exemption is in the public interest and will not adversely affect passenger safety. 

Federal Register publication 

The FAA has determined that good cause exists for waiving the requirement for Federal Register 

publication for public comment because the request is identical in all material respects to 

previously granted exemptions; the exemption, if granted, would not set a precedent; and any 

delay in acting on this petition would be detrimental to the Gulfstream Aerospace Corporation. 

The FAA's analysis 

The FAA considers that granting an exemption to a part of§ 25 .144 7( c)( 1) is in the public 

interest for the reasons stated by the petitioner, and because the exemption is the same in all 

material respects to previously granted exemptions from the same part of§ 25.144 7( c)( I). 

The petitioner requests an exemption for Gulfstream Model GVU-G500 airplanes and seeks relief 

from the requirement in§ 25.1447(c)(l), which states that oxygen-dispensing units must be 

automatically presented to occupants before the cabin pressure altitude reaches 15,000 feet. A 

requirement for automatic presentation of oxygen masks for airplanes certificated to operate 

above 30,000 feet originated in§ 4b.651(d)(3)(i) ofthe Civil Aviation Regulations (CAR) and 

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was carried over as§ 25.1447(c)(l) when 14 CFR part 25 was codified. The CAR requirement 

did not specify the maximum cabin pressure altitude allowed prior to presentation. The 

requirement that the oxygen-dispensing units be automatically presented before the cabin 

pressure altitude reaches 15,000 feet was added at Amendment 25-41, effective September 1, 

1977. 

For operation of the Oulfstream Model OVII-0500 airplane into and out of an airport with a 

landing field elevation above 14,000 feet, the flightcrew must activate the "HI AL T' high 

airport-elevation selection switch located on the Passenger Oxygen Control Panel. This results in 

automatic deployment of the passenger oxygen masks when the cabin pressure altitude is 15,750 

feet, ± 250 feet. This feature is necessary to reduce the occurrence of inadvertent deployment of 

oxygen masks. 

The FAA's decision 

In consideration of the foregoing, I find that a grant of exemption is in the public interest. 

Therefore, pursuant to the authority contained in 49 U.S.C. §§ 40113 and 44701 delegated to me 

by the Administrator, I grant Oulfstream Aerospace Corporation an exemption from the 

requirement of 14 CFR 25.1447(c)(l) that the passenger oxygen equipment must be 

automatically presented before the cabin pressure altitude exceeds 15,000 feet. For Oulfstream 

Model OVII-0500 series airplanes and subsequent derivatives, this grant of exemption will 

permit passenger oxygen masks to be automatically presented before the cabin pressure altitude 

exceeds 16,000 feet when operating into and out of airports with altitudes above 14,000 feet. 

Issued in Renton, Washington, on 

~~ NOV 11 2015 

Michael Kaszycki 

Acting Manager. Transport Airplane Directorate 

Aircraft Certification Service 

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