### UNITED STATES OF AMERICA DEPARTMENT OF TRANSPORTATION FEDERAL AVIATION ADMINISTRATION RENTON, WASHINGTON 98057-3356

In the matter ofthe 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 ofFederal 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, ofTitle 14, Code ofFederal Regulations (14 CFR). This exemption, ifgranted, would permit relieffrom 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 relieffrom 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

. Ifcertification 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 offailure ofthe 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 ofTransportation's Federal Docket Management System, on the Internet at http://regulations.gov, in DocketNo

. FAA-20 15-3311.

### Relieffrom section 14 CFR Part 25.1447(c)(l) Arndt. 25-116 Oulfstream Aerospace Corporation (Oulfstream) ofSavannah, Georgia has submitted application to the FAA·s Atlanta Aircraft Certification Office for type certification ofa 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) ofup 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. Ifcertification 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 offailure ofthe 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 ofairports with landing field elevations approaching 15,000 feet and will prevent nuisance deployment ofoxygen masks. Oulfstream is proposing alternative design requirements to provide an appropriate equivalent level ofsafety. 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 l evel (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 ofsafety during flight while minimizing the possibility ofnuisance passenger-oxygen-mask deployment during takeoffand descent at high [elevation] airports.
2The GVII-G500 and any subsequent derivative models will be designed to provide operations into high LFE airports. The design will prevent nuisance deployment ofthe passenger oxygen masks when operating into and out ofairports 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 ofmaking dispensing units available in the event ofa failure ofthe automatic system

. An exemption is requested to allow a maximum oxygen altitude limit ofmore 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 ALT''- Automatic passenger oxygen mask activation at 15,750 ± 250 feet During operations into and out ofan airport with a landing field elevation greater than 14,000 ft, "Hl ALT"" must be selected in order to reset the automatic passenger oxygen mask activation to approximately 15.750 feet and prevent a nuisance deployment ofthe 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 offwhen the switch is reset to "NORMAL." The manual mask deployment feature is available regardless ofswitch 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 ALT'' switch on the passenger oxygen control panel during descent and similarly after take-offwhen 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. Ifthe 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

3during 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 Setpointfor Aircraftwith 15,000feet 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 ofclimb, 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 ofthe 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 ofthe 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 ofa fai I ure ofthe 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 ofthe Exemption on Safety The exemption requested will not adversely affect the level ofsafety provided for the OVII-0500 and any subsequent derivative models

.

4The safety features described above are to ensure the avoidance ofnuisance oxygen-mask deployment while still allowing deployment in the event ofa 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 offailure requirements in all areas. As stated earlier, in the event ofan unannunciated CPCS failure, the oxygen masks will drop automatically at a cabin altitude ofno 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 ofLow 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 oflanding field elevations ofup to and including 15,000 ft. 

### Issue ofPublic Interest Gulfstream Aerospace Corporation designs, develops, manufactures, markets and services the world's most technologically advanced businessjet aircraft to an International market. Gulfstream's leadership position in the global businessjet 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 ofsuppliers located throughout the United States. Gulfstream competes for new business all over the world. This exemption will directly impact the high-altitude utility ofthe 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 ofEuropean 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 ofachieving an appropriate level ofsafety, while at the same time providing features attractive to prospective purchasers. The manufacture, completion, and support ofOulfstream aircraft would aid in the stabilization ofthejob market as well as the growth ofthe American economy, which is in the interest ofthe public. 

### Waiver ofNotice 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



### 5the nature ofthis 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 737

• 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 ofthe United States. Gulfstream aircraft are routinely registered and operated outside ofthe 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 ofthis 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, ifgranted, 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

. 1447(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§ 25.1447(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 ofoxygen masks for airplanes certificated to operate above 30,000 feet originated in§ 4b.651(d)(3)(i) ofthe Civil Aviation Regulations (CAR) and
6was 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 ofthe Oulfstream Model OVII-0500 airplane into and out ofan 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 ofthe passenger oxygen masks when the cabin pressure altitude is 15,750 feet, ± 250 feet. This feature is necessary to reduce the occurrence ofinadvertent deployment of oxygen masks

. 

### The FAA's decision
In consideration ofthe foregoing, I find that a grant ofexemption 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 ofexemption will permit passenger oxygen masks to be automatically presented before the cabin pressure altitude exceeds 16,000 feet when operating into and out ofairports with altitudes above 14,000 feet.

Issued in Renton, Washington, on



# ~~ NOV 11 2015

Michael Kaszycki Acting Manager. Transport Airplane Directorate Aircraft Certification Service

7