Exemption No. 10089

UNITED STATES OF AMERICA

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

RENTON, WASHINGTON 98057-3356

In the matter of the petition of

Cessna Aircraft Company

for an exemption from § 25.144 7(c)(1) of

Title 14, Code of Federal Regulations

Regulatory Docket No. FAA-201 0-0290

GRANT OF EXEMPTION

By letter L390-1 0-0656, dated March 1, 20 to, Ms. Donna DeBuhr on behalf of Mr. Carlos

Ayala, Type Certification Organization Designation Authorization Administrator, Cessna

Aircraft Company, One Cessna Boulevard, P.O. Box 7704, Wichita, Kansas, 67277-7704,

petitioned for an exemption from § 25.1447(c)(1) ofTitJe 14, Code of Federal Regulations

(14 CFR). The proposed exemption, if granted, would pernlit relief from the requuement that

oxygen dispensing units be automatically presented to occupants before the cabin pressure

altitude exceeds 15,000 feet on Cessna Model 680 airplanes.

The petitioner requests relief from the following regu lations:

Section 25.1447(c)(I) requires, in part, that an oxygen dispensing unit must he connected,

to oxygen supply terminals immediately available to each occupant, wherever seated. 11 certification for operation above 30,000 feet is requested, the dispensing units providing

the required oxygen flow must he automatically presented to the occupants before the I

cabin pressure altitude exceeds 15,000 feet, and the crew must be provided with a manual

means of making the dispensing units inunediately available in the eveot of failure ofthb

automatic system.

The petitioner supports its request with the following:

The following material is quoted from Cessna's petition.

"A new airport is under construction in Nagqu, China in the northwest portion of the

Qinghai-Tibet Plateau. This airport is scheduled to be-completed in 2010 and has a
landing field elevation (LFE) of 14,639 feet above sea level. The customer has requested

the aircraft be capable of operations at this and other airports with field elevation above

14,000 feet (with anticipated barometric pressure variations) up to 15,000 feet. In order

for the Model 680 Sovereign to provide the additional capability for landing at airports up

to 15,000 feet pressure altitude, the Cabin Pressure Control System (CPCS) and

Passenger Oxygen Control System (POCS) will be modi_fledto allow the cabin internal

pressure altitude to reach as high as 15,150 +/- 150 feet during "> 14K" operations.

Manual control of the oxygen system is not affected and can be activated at any time the

crew deems necessary.

Public Interest Statement:

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

nearly eight lhousand employees in manufacturing plants, completion centers, and service

centers across the United States. This further includes the many vendors located across

the United States that provide the numerous aircraft pieces such as avionics, oxygen

components, as well as the modified CPCS components that would be used for the

aircraft to operate at this high elevation. Cessna competes for new business all over the

world. Although the current economy has slowed Cessna is striving hard to gain

international markets for its business jets. This increased market directly affects the

viability of Cessna and would aid in the stabilization of the job market as well as the

growth of the American economy, which is directly in the interest of the public.

Supporting Information:

The oxygen mask presentation at 15,750 +/- 250 feet is only selected when a "> 14K"

switch is activated by the pilot. An indication light indicating that the aircraft is in

"> 14K" mode is also provided. This feature assists in limiting use of this mode to

conditions when the airplane will operate from airfie-Idswith an elevation greater than

14,000 feet. The activation point for the cabin altitude warning is also shifted with the

same switch to avoid nuisance alerts when operating to and from airports at an altitude

greater than 14,000 feet.

Appropriate procedures will be provided in the Airplane Flight Manual to address proper

operation of the "> 14K" switch function. These features will have the flight crew select

this function when descending to land at an airfield elevation greater than 14,000 feet and

to reselect the "> 14K" switch back to the «Normal" mode when climbing after takeoff

fTOman airport with a field elevation greater than 14,000 feet. The procedure will

mimmize the time the aircraft is in the elevated altitude to that required to safely land

and/or takeoff from airports with a field elevation greater than 14,000 feet."

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Feder-al Register publication

A summary of the petition was not published in the Federal Register. The FAA determined that

good cause existed for waiving the publication requirement because this exemption would not set

a precedent.

The FAA's analysis

The FAA considers that granting the petition is in the public interest for the reasons stated by the

petitioner and because this exemption is effectively identical to previously granted exemptions to

§ 25.1447(c)(I).

The petitioner requests an exemption for Cessna Model 680 airplanes and seeks relief from the

requirement of § 25.1447(c)(I), which states that oxygen dispensing units must be automaticaHy

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

automatic presentation of masks for airplanes certificated to operate above 30,000 feet originat6d

in § 4b.651 (d)(3)(i) of the Civil Aviation Regulations (CAR) and was carried over as I

§ 25.1447(c)(I) when part 25 was caddied. The CAR requirement did not specify the maximum

cabin altitude pressure 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 Cessna Model 680 airplane into and out of an airport with a landing field

above 14,000 feet, the flightcrew must select the "> 14K" position on the airport elevation

selection switch. This results in automatic deployment oftbe passenger oxygen masks when the

cabin pressure altitude is 15,750 ±250 feet. This feature is necessary to reduce the occurrence of

inadvertent deployment of oxygen masks.

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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. §§ 401 (3 and 44701, delegated to me

by the Administrator, Cessna Aircraft Company is granted an exemption, for Cessna Model 680

airplanes, from the requirement of § 25.1447(c)( 1) to automatically present oxygen dispensing

units to occupants before the cabin pressure altitude exceeds 15,000 feet. Instead, this grant of

exemption will permit oxygen dispensing units to be automatically presented at cabin pressure

altitudes of 15,750 ±250 feet when operating into and out of airports at altitudes above

14,000 feet.

Issued in Renton, Washington, on JUN 30 2010

/~a Todd Dixon

Acting Manager, Transport Airplane Directorate

Aircraft Certification Service

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