AFS

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- E Exemption No. 10827

UNITED STATES OF AMERICA

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION WASHINGTON, DC 20591

In the matter of the petition of

DELTA AIR LINES, INC. Regulatory Docket No. 2011

- 0618

for an exemption from § 121.333(e)(2) of Title 14, Code of Federal Regulations

DENIAL OF EXEMPTION

By letter dated June 6, 2011, Mr. Stephen M. Dickson, Senior Vice President Flight Operations, Delta Air Lines, Inc., (Delta), P.O. Box 20706, Atlanta, GA 30320 petitioned the Federal Aviation Administration (FAA) on behalf of Delta for an exemption from § 121.333(e)(2) of Title 14, Code of Federal Regulations (14 CFR). The proposed exemption, if granted, would allow Delta aircraft

, following a cabin depressurization event

, to initially descend to 14,000 feet and subsequently descend to 10,000 feet no later than 30 minutes after the initial depressurization event, without carrying the additional supplemental oxygen required by §121.333(e)(2).

The petitioner requests relief from the following regulation:

Section 121.333(e)(2), prescribes, in pertinent part, that s upplemental oxy gen for emergency descent and for first aid; turbine engine powered airplanes with pressurized cabins, states in pertinent part:

(e) Passenger cabin occupants. When the airplane is operating at flight altitudes above 10,000 feet, the following supply of o xygen shall be provided for the use of passenger cabin
occupants:

(2) When an airplane is operated at flight altitudes up to and including flight level 250 and cannot descend safely to a flight altitude of 14,000 feet within four minutes, or when an2

a irpl ane is operated at flight altitudes above flight level 250, oxygen shall be available at the rate prescribed by this part for not less than 10 percent of the passenger cabin occupants for the entire flight after cabin depressurization, at cabin pressure al titudes above 10,000 feet up to and including 14,000 feet and, as applicable, to allow compliance with §121.329(c)(2) and (3), except that th ere shall be not less than a 10

- minute supply for the passenger cabin
occupants.

The petitioner supports its reque st with the following information:

The petitioner states in its petition for exemption that t he last amendment to the passenger supplemental oxygen carrying requirements was in 1958. The amendment established a requirement to supply supplemental oxygen fo r 10 percent of the passengers for the entire time the aircraft cabin altitude is above 10,000 feet mean sea level (MSL) up to and including 14,000 feet MSL after a depressurization event. This part of the rule applied to aircraft certified to operate to 25,000 feet MSL that could not descend to 14,000 feet MSL within

4 minutes or any aircraft operating above 25,000 feet MSL. For the maximum size of aircraft operating at that time the rule would require the carriage of supplemental oxygen for approximatel y 15 passengers if the aircraft could not descend to 10,000 feet MSL after a depressurization event and the normal passenger oxygen system supply was not enough for the time above 10,000 feet MSL. This would generally require the carriage of 15 portable

o xygen bottles.

Manufacturers design most modern aircraft to descend from the maximum certified altitude to 14,000 feet MSL within 4 minutes with enough supplemental oxygen to reach 10,000 feet within the normal passenger oxygen system supply. Passenger o xygen systems are certified to a minimum of 12 minutes for aircraft operated by the petitioner. In many areas of its operation s the petitioner has specifically designed depressurization routes that allow the aircraft to descend to 10,000 feet MS L within t he 12

- minute passenger oxygen supply to comply with §121.333(e)(2). Once at or below 10,000 feet MSL oxygen is no longer required for compliance with §121.333(e)(2). Depending on the airplane location and surrounding terrain, these routes may require the aircraft to be operated below grid MORAs (Minimum Off Route Altitudes) on defined routes. In layman’s terms, this procedure often requires the pilots to navigate around areas of high terrain instead of flying above the terrain.

The petitioner operates t o over seventy countries within six continents. The petitioner states it consistently use s its Safety Management System (SMS) to identify hazards and reduce risks to its operation. Due to its global network, its flight crews could operate in many theater s spanning six continents in a given month. This makes the petitioner unique compared to the majority of other air carriers who do not need to prepare their flight crews for such a diverse operation. Using its internal risk assessments, SMS, and pilot tr aining programs the petitioner develops procedures and curricula to prepare its crews, which are described later in the petition. One of these procedures and challenges is operating over critical terrain. Ninety

- five percent of the routes operated by the petitioner allow an immediate descent to 10,000 feet MSL after a depressurization. However, approximately five percent of the operation is over3

critical terrain airspace where the grid MORAs are above 10,000 feet and immediate descent to 10,000 feet is no t possible without being established on a published airway or the engineered route designed by the petitioner. These areas are primarily in Western Canada, Central America, South America, the Middle East, the Himalayas and Greenland.

The petitioner states a depressurization event is a higher risk situation. The flight crew must don oxygen masks, deal with the situation that caused the depressurization, perform an emergency descent to a safe altitude and, if over critical terrain, transition to a critical t errain route in order to avoid the terrain while descending to 10,000 feet MSL within the time limitation of the passenger supplemental system. In certain parts of its network, such as South America, pilots face the likelihood of executing these critical terrain procedures at night or in the weather, greatly adding to the complexity of the maneuver and exacerbating the challenge of maintaining situational awareness.

In order to comply with §121.333(e)(2), the petitioner employs three methods:

1. Avoid th e critical terrain areas where descent to 10,000 MSL is not possible within the supply of the onboard oxygen system. This option creates less efficient routes.

2. Operate over the terrain where immediate descent to 10,000 feel MSL is not possible but prov ide the crews with specific critical terrain diversion routes that allow initial descent to 14,000 feet then further descent to 10,000 feet MSL within the time of standard oxygen supply (normally 12 minutes).

3. Certain fleets have been configured with ad ditional supplemental oxygen to allow additional time to remain at 14,000 feet MSL. All of the B

- 777 aircraft operated by Delta carry 32 bottles of supplemental oxygen. For certain B

- 767

- 300 aircraft, Delta has the capability to place a minimum of 24 suppl emental bottles in specially configured overhead bins. In this case the bottles take up overhead passenger carry

on storage capacity by at least six bins. The cost to carry the extra oxygen bottles in

direct fuel cost for the B

- 777 is $339,212.00 annually based on fuel price as of March 23, 2011. This is fuel that is burned in order to carry the extra weight. In addition to the increased cost and fuel burn, the carriage of the additional oxygen bottles increases Delta’s carbon footprint and is not environme ntally friendly.

Through its Safety Management System (SMS), the petitioner has previously identified operations over high terrain as an increased risk operation. Currently the petitioner has implemented several risk mitigation elements. These include:

• T heater Qualification for the pilots;

• Pilot qualification training and continuing qualification training with respect to critical terrain procedures;

• Engineered terrain avoidance routes;4

• Flight planning system identifying to the flight crews when a route re quires special depressurization routes; and

• Aircraft theater equipment restrictions requiring certain operational equipment above regulatory requirements, e.g., not always allowing Minimum Equipment List (MEL) relief for enhanced ground proximity warning s ystems depending on the planned route.

While these mitigations make operations in areas of high terrain acceptable, the petitioner states there is still the latent condition of controlled flight into terrain (CFIT) inherent anytime the aircraft is require d to operate below a grid MORA. Raising the initial descent to 14,000 feet MSL for 30 minutes removes the vast majority of CFIT risk associated with

critical terrain areas. In its request, the petitioner attached 8

, 000 foot MSL and 12,000 foot MSL maps for parts of South America, Middle East and Greenland

. They illustrate the reduction of the terrain risk by initially descending to 14,000 feet MSL versus the current requirement to descend to 10,000 feet MSL.

The petitioner further states the likelihood of a rapid decompression event is extremely low and the likelihood of a rapid decompression occurring over critical terrain is even lower. The petitioner states therefore granting relief from the requirements of §121.333(e)(2) would be inconsequential, based on event probability alone. The petitioner states the FAA has affirmed the low probability of a decompression event in its rulemaking to temporarily deactivate the supplemental oxygen system in aircraft lavatories.

The petitioner states the request for relief is not precedent setting in that the FAA has previously granted deviation from the requirements of §121.333(e)(2) utilizing 14 CFR §119.55. The petitioner was granted Operations Specifications A525, Oxygen Supply: Passenger Cabin Occupants. In this deviation the FAA granted relief from §121.333(e)(2) for up to 20 minutes for international supplemental operations associated with Iraqi Freedom.

The petitioner states it has identified a hazardous materials risk associated with carrying large quantities of oxygen. The petitioner states in the event several of the oxygen bottles were

turn ed on in a confined space with other flammable materials

, the area could ignite creating a severe fire and possible explosion.

The petitioner states they have configure d certain fleets with additional supplemental oxygen to allow additional time to remain at 14,000 feet MSL. All of Delta’s B

- 777 aircraft carry 32 supplemental oxygen bottles. In addition, Delta’s B

- 767

- 300 aircraft have the capability to place a minimum o f 24 supplemental oxygen bottles in specially configured overhead bins.

The petitioner states they are at an economic disadvantage to foreign operators because the foreign operators have less stringent oxygen requirements.

A summary of the petition was published in the Federal Register on June 29, 2011 (76 FR 38266). Five comments were received.5

Four comments from Delta Airlines, Inc. flight operations management were received in support of granting the exemption. One comment was received from the Delt a Air Line Pilots Association Central Air Safety Committee in support of the petition.

The FAA requested additional information about the demographics of Delta passengers from Delta, which was submitted to the Docket No. FAA

- 2011

- 0618

- 0008 (www.regulation s.gov) on September 9, 2011.

The FAA's analysis is as follows:

The FAA finds the issuance of an exemption to §121.333(e)(2) would be precedent

- setting. After a review of the petitioner’s request and supporting information, the FAA has determined

that the petitioner has not identified how its proposal would not adversely affect safety or how a grant of exemption would provide a level of safety at least equal to that provided by § 121.333.

The requirements of § 121.333 recognize a difference between non

- emergency flight between 10,000 and 14,000 feet as addressed in § 121.329, and flight at these altitudes following a decompression and subsequent rapid descent. In fact, at the time the FAA promulgated the requirements, subsequently incorporated into § 121 .333, it noted that turbine

- powered airplanes may require continued cruise at an altitude demanding sustaining oxygen to enable the airplane to reach a suitable landing field.

The petitioner has requested a grant of exemption to permit its pilots to des cend to 14,000 feet, and then subsequently descend to 10,000 no later than 30 minutes after the start of the decompression event. The additional time above 10,000 would permit the petitioner’s aircraft

to clear terrain and reduce the risk of controlled fl ight into terrain (CFIT) in certain critical terrain airspace.

The petitioner has stated the installed drop

- down oxygen system will provide oxygen to

100 percent of the passengers for the first 12 minutes following the decompression event. The petitione r did not propose to provide supplemental oxygen to passengers for the remaining 18 minutes between the cessation of the drop

- down oxygen and the descent to 10,000 feet. Section 121.333 would require oxygen for 10 percent of the cabin occupants during tho se 18 minutes. Ultimately, the petitioner’s proposal to keep an airplane at an altitude above 10,000 feet to remain clear of terrain and obstacles would expose passengers to higher cabin altitude without sustaining oxygen. The FAA believes this proposal unacceptably transfers risk to the

passengers.

In considering this petition, the FAA conferred with physicians from the Office of Aerospace Medicine and physiologists within its Civil Aerospace Medical Institute (CAMI) to determine any medical impli cations from the petitioner’s proposal. They concluded that exposure to altitudes between 10,000 and 14,000 feet for 30 minutes, without supplemental oxygen, can6

be tolerated by a healthy individual. However, such exposure may present a serious problem

f

or passengers with compromised cardiovascular and pulmonary function following a decompression ev e nt. Depending on the severity of the passenger’s condition, these individuals may tolerate exposure at 10,000 feet, but may have serious problems at 14,000

f

eet. Additionally an increasingly older flying population will predictably have more medical conditions that are affected by hypoxia at 14,000 feet. Following a decompression and rapid descent, the standard care for typical passenger injuries includes the provisions of continuous supplemental oxygen, making the carriage of supplemental oxygen necessary. Based on the information provided by the petitioner, CAMI determined a grant of exemption would result in a marginally increased aeromedical risk.

The petitioner states the FAA has previously granted a similar exemption when it issued operations specification (OpSpec) A525. The FAA issued OpSpec A525 to support essential operations for the national defense on behalf of the Department of Defense, in acco rdance with §119.55. Those operations carried military personnel physically fit for combat. As identified by the petition er, its passenger demographics d o not match those assumed in the issuance of OpSpec A525. Additionally, it contained limitations that prohibited its use in aeromedical evacuation operations, operations involving the carriage of non

- military passengers and any other passenger

- carrying operation conduct ed by the certificate holder. Furthermore, it allowed operation between 14,000 and 10, 000 feet for a maximum of

20 minutes, not 30 minutes as proposed in this petition. Neither the passenger demographics, nor the operational mission, are the same as the operations permitted by OpSpec A525.

The petitioner has stated that the likelihood of a rapid decompression event is extremely low and the likelihood of a rapid decompression occurring over critical terrain is even lower. The FAA reviewed data to determine the number of decompression events resulting in rapid (emergency) descents. Data collec ted from the Service Difficulty Report System showed 66 decompression events to include explosive, rapid, slow or gradual decompression events in part 121 operations over the previous five years or approximately one occurrence per month.

The FAA d oes not believe the likelihood of one occurrence per month represents low risk. Additionally, while the FAA did determine it was appropriate to deactivate the supplemental oxygen system in response to a security vulnerability, the FAA permitted this in th e lavatory only and for a limited duration. The FAA is currently working on rulemaking to restore supplemental oxygen to the lavatories.

The petitioner has already developed procedures to mitigate the risk of flying over critical

terrain to include addit ional training, flight planning, and restrictions on deferral of equipment. The petitioner has not proposed any mitigation to address the a bsence of supplemental oxygen and the FAA has determined the additional risk to passengers presented by the lack of s upplemental oxygen is not in the public interest.

The petitioner’s determination that a hazardous materials risk is associated with the carriage of large amounts of oxygen is unfounded. All aircraft in the petitioner’s fleet already carry

additional ox ygen supplies. The FAA has already addressed the risks associated with the7

carriage of oxygen. Oxygen bottles are manufactured in accordance with FAA

- approved

standards detailed in Technical Standard Orders and are installed and maintained in

accordance with FAA

- approved procedures.

The FAA has considered petitioner’s statement that foreign operators have less stringent supplemental oxygen rules and notes that the statement is correct as it relates to operators operating under EASA regulations, but not a s it relates to all foreign operators

. However, a difference in regulatory standards between States does not justify an exemption to a single U.S. operator. The r egulation cited by petitioner (14 CFR § 121.333(e)(2)) 1 requires supplemental oxygen for at least 10 percent of the passengers for the entire flight at altitudes between 10,000 feet and 14,000 feet following descent to those altitudes because of a depressurization event. Flight at or below 10,000 feet does not require supplemental oxygen.

Th e International Civil Aviation Organization (ICAO) Standards and Recommended Practices

found in Section 4.3.8.1(b) of Annex 6, is not limited to post

- depressurization events and

, states that 10 percent of the passengers should have supplemental oxygen aft er 30 minutes of flight between 10,000 feet and 13,000 feet. 2 Under this standard, level

- off at 14,000 feet requires supplemental oxygen for all passengers for any period at that altitude. This is more restrictive than the cited U.S. regulation.

For th ose operators operating under the European Aviation Safety Agency (EASA) regulations, t he applicable EASA rule, CAT.IDE.A.235 Supplemental oxygen

— pressurized airplanes, requires supplemental oxygen for at least 10 percent of the passengers for the

“remai nder of the flying time when the cabin pressure altitude exceeds 10,000 feet but does not exceed 14,000 feet, after the initial 30 minutes at these altitudes .” 3 This is less restrictive

1 Sec. 121.333 Supplemental oxygen for emergency descent and for first aid; turbine engine powered airplanes with pressur ized cabins. (e) Passenger cabin occupants. When the airplane is operating at flight altitudes above 10,000 feet, the following supply of oxygen must be provided for the use of passenger cabin occupants: (2) When an airplane is operated at flight altitudes up to and including flight level 250 and cannot descend safely to a flight altitude of 14,000 feet within four minutes, or when an airplane is operated at flight altitudes above flight level 250, oxygen must be available at the rate prescribed by this par t for not less than 10 percent of the passenger cabin occupants for the entire flight after cabin depressurization, at cabin pressure altitudes above 10,000 feet up to and including 14,000 feet and, as applicable, to allow compliance with §121.329(c) (2) a nd (3), except that there must be not less than a 10

- minute supply for the passenger cabin occupants.

2 ICAO Standards and Recommended Practices (SARP)Annex 6, 4.3.8.1(b) Gen. Reg. 7.9.1.13(a) Table 1

Annex Reference & SARP Identifier: 06

- 0000027600 Oxygen Supply A flight to be operated at flight altitudes at which the atmospheric pressure in personnel compartments will be less than 700 hPa shall not be commenced unless sufficient stored breathing oxygen is carried to supply: a) all crew members and 10 perc ent of the passengers for any period in excess of 30 minutes that the pressure in compartments occupied by them will be between 700 hPa and 620 hPa; and b) the crew and passengers for any period that the atmospheric pressure in compartments occupied by the m will be less than 620 hPa.

3 CAT.IDE.A.235 Supplemental oxygen

— pressurized airplanes (a) Pressurized airplanes operated at pressure altitudes above 10,000 ft. shall be equipped with supplemental oxygen equipment that is capable of storing and dispensin g the oxygen supplies in accordance with Table 1. Table 1 Oxygen minimum requirements for pressurized airplanes (data extracted by author) Supply for: 10 % of passengers8

than the cited U.S. regulation because it does allow 30 minutes of fli ght before supplemental oxygen must be provided to 10 percent of the passengers, whereas the U.S. regulation requires immediate availability of oxygen for 10 percent of the p assengers.

The FAA’s Decision:

In consideration of the foregoing, I find that a grant of exemption would not be in the public interest. Therefore, pursuant to the authority contained in 49 U.S.C. §§ 40113 and 44701, delegated to me by the Administrator, the petition of Delta Air Lines, Inc. for an exemption

from 14 CFR §121.333(e)(2 ) is hereby denied.

Issued in Washington, D.C., on July 24, 2013

/s/

John S. Duncan Deputy Director, Flight Standards

Service

Duration and cabin pressure altitude: The remainder of the flying time when the c abin pressure altitude exceeds 10,000 ft. but does not exceed 14,000 ft., after the initial 30 minutes at these altitudes.9

Project No.: AFS

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Project Officer: _______________

ARM

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ARM

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MR STEPHEN M DICKSON

SENIOR VICE PRESIDEN T FLIGHT OPERATIONS

DELTA AIR LINES INC

PO BOX 20706

ATLANTA GA 30320