AFS

- 13

- 56 4

- E Exemption No. 10827A

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. FAA

- 2011

- 0618

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

DENIAL OF PETITION FOR RECONSIDERATION

By letter dated September 23, 2013 , 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 Administ ration (FAA) on behalf of Delta for reconsideration of the FAA’s July 24, 2013 denial of Delta’s petition for exemption from § 121.333(e)(2) of Title 14, Code of Federal Regulations (14 CFR) . I f granted, that exemption would allow Delta aircraft, followin g 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 oxygen for emergency descent and for first aid; turbine engine powered airplanes with pressurized cabins, that :

(e) Pa ss enger cabin occupants. When the airplane is operating at flight altitudes above
10,000 feet, the following supply of oxygen shall be provided for the use of passenger cabin

occupants:

(2) When an airplane is operated at flight altitudes up to and includ ing 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 shall be available at the rate prescribed by this part for not less t ha n 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) and (3),

except that there shall be not less than a 10

- minute supply for the passenger cabin occupants.

The petitioner supports its request with the following information:2

Delta states that the FAA “i mproperly based its risk assessment on the difference of an effective oxygen altitud e difference of 4000 feet and a 30

- minute duration at 14

, 000 feet when it should have been based on an effective difference of 1750 feet and 18 minutes at 14,000 feet. ” Delta

claims that the rule only requires mass flow oxygen at 14,000 feet equivalent to breathing ambient air at 12,250 feet and, therefore, asserts that the FAA should have considered the difference between 12,250 feet and 14,000. Further, Delta suggests that the FAA should have considered the effects of decompression for a n 18

- minute period to account for a 12

- minute supply of supplemental oxygen.

Delta as serts that the FAA does not provide detail on what “serious problems for passengers with compromised cardiovascular and pulmonary function” could occur following a decompr ession event. Delta explains that the possibility of decompression injury falls int o two categories:

h ypoxic and b arot r aumatic. In regard to hypoxia, Delta cites the World Health Organization respiratory functional assessment classification and provides i nformation on the possible effects

of altitudes on each of the se classes. Delta indicates that individuals in certain respiratory classes

should travel with their own supplemental oxygen and that the oxygen flow required by § 25.1443(c)(1) would not produc e a sufficient amount of oxygen to sustain the appropriate

“ oxyhemoglobin saturation rate ” for these people

. Further, Delta states that barotraumatic injuries are the most common injuries due to decompression and that levelling off at 14,000 feet

for 30 mi nutes will reduce risk by allowing time for equalization of pressure within the body’s inner air chambers and the atmosphere.

Delta highlights the existence of other current U.S. Federal Aviation Regulations which allow passenger operations at the altit ude Delta seeks without the carriage of passenger supplemental

oxygen. Delta contend s that passengers carried under these operations are n o different physiologically than the passengers carried aboard part 121 operations. Further, Delta mentions Operations Specification (OpSpec) A525 that allowed 20 minutes at 14,000 feet without supplemental oxygen.

Delta asserts that , in the FAA’s initial denial, the “t he probability of a decompression event was overstated because the FAA applied data from Service Diffic ulty Reports (SDRs) and did not factor in the number of actual operations.” Further, Delta questions the FAA’s rationale in basing its analysis on all depressurization events regardless of severity. Delta states that, as of July 2013, looking back 66 month s, it recorded 89 events where some level of cabin pressurization was compromised. Delta contends that none of these events would be conside red explosive or rapid and that there were 19 events where the passenger oxygen system was activated.

Delta maint ains that the exemption would reduce c ontrolled f light into t errain ( CFIT ) risk that it identified as a hazard through its Safety Management System. Delta estimates the probability of

a n aircraft having a depressurization event requiring oxygen mask deploy ment in a terrain

restricted area as approximately one in 50 million flights.

Finally, Delta contends that relief from the regulation will reduce flight times that will result in decreased radiation exposure to passengers and flight crews. Delta suggests that the increase in flight time to avo id high terrain increases the risk of cancer due to radiation exposure.3

The Air Line Pilots Association International submitted comments in support of the petition for reconsideration, suggesting that the exemption w ould not endanger passenger safety but would

enable routes that would reduce CFIT risk.

The FAA's analysis is as follows:

The FAA has reviewed its rationale in Denial of Exemption No. 10827 issued to Delta on July 24, 2013 and its petition for reconsider ation. In that denial, the FAA found that Delta had

not identified how it would be in the public interest , and 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 b y § 121.333. T he FAA also determined that Delta’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, resulting in an unacceptab le transfer of risk to passengers. Upon reviewing the petition for reconsideration, the FAA still finds that a grant of exemption would not be in the public interest and would not provide a level of safety equivalent to that provided by the current regula tions.

Upon receiving a denial of exemption, § 11.101 states that a petitioner may ask the FAA to

reconsider its petition for exemption. The petition for reconsideration must show a significant

additional fact that was not presented in the original petiti on , that the FAA made an important factual error in the denial, or that the FAA did not correctly interpret a law, regulation, or preceden t. As discussed below, Delta asserts that, in denying its petition, the FAA incorrectly

assessed the risk to passenge rs.

Delta’s assumption that FAA did not consider supplemental oxygen already insta lled on aircraft

is incorrect

. FAA based its risk analysis on a clear understanding of Delta’s request, as described

in the initial denial:

The petitioner has stated the i nstalled drop

- down oxygen system will provide oxygen to 100 percent of the passengers for the first 12 minutes following the decompression event. The petitioner did not propose to provide supplemental oxygen to passengers for the remaining 18 minutes betwe en 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 those 18 minutes.

T he FAA maintains its determination that the exemption would not provide a level o f safety equivalent to that provided by the rule

. Delta’s initial petition relied heavily on increased safety

benefit related to CFIT . In its petition for reconsideration, Delta admits that increased safety benefit by way of reducing CFIT risk would be rea lized in “approximately one event in 50 million flights.” In this area, the FAA continues to find that the petitioner has already developed procedures to mitigate the risk of flying over critical terrain, including additional training, flight planning, and restrictions on the deferral of equipment. Delta states that special routing to avoid high

- terrain areas results in increased flight times compared to other carriers (part 125, part 135,

and EASA carriers )

. It is Delta’s belief that relief from the regula tion will enable it to fly shorter

routes. The FAA finds that these benefits, particularly the benefit of decreased flight time, do not outweigh the increased risk to passengers, particularly children, the elderly, and passengers with cardiopulmonary condi tions

.4

In its petition for reconsideration, Delta provided information on physiological effects imposed on the traveling public and risks of decompression injury , such as hypoxia or barotraumatic injury

. Delta is correct in its assertion that there is n o data substantiating the FAA's claim that passengers with compromised cardiovascular and respiratory function may be at increased risk when exposed to a 14,000 feet ambient environment

. However, a s evidenced by data in the clinical literature, s ome patien ts in this group desaturate even at ground level

. The index of

concern for com promised passengers at 14,000 feet is provided entirely thr ough the clinical judgement of the medical community based on training and experi ence. It is unlikely that an

Instituti onal Review Board would approve a study of this nature involving human subjects

. T herefore, the altitude

- related risk remains unquantified.

Delta also stated that passengers with reduced physical capacity (qualified as Class II) should provide their own supplemental oxygen. While Delta is correct that individuals in certain

conditions should travel with their own supplemental oxygen, the FAA recognizes that this is not always true in practice because many passengers may not realize their physical conditi on and

associated risk since they do not need supplemental oxygen at rest or at ground level

. In regard to barotrauma and gas embolism issues, the FAA contends that these issues are more related to the initial decompression event and are of secondary impor tance to the 14,000 feet hypoxia concern

. The FAA finds that p roviding passengers with less emergency supplemental oxygen than required by the regulation is less safe and would unacceptably transfer risk to passengers.

Delta cites sections of part s 135 a nd 91 that allow passenger

- carrying operations at the requested altitude without carriage of supplemental oxygen. While these sections may allow for passenger

carrying operations at Delta’s requested altitude under those operating rules , the regulation tha t Delta must demonstrate an equivalent level of safety for is § 121.333, not regulations under

parts 91 or 135. As required for a Petition for Reconsideration, Delta has not presented any significant additional fact that was not presented in the original petition to show that Delta’s request would provide a level of safety equivalent to that provided by the current regulation.

The FAA finds also that Delta has failed to demonstrate how an exemption is appropriate in its particular circumstances as compare d to other part 121 air carriers. The basis upon which Delta is asking for relief would be essentially the same for other part 121 carriers. The refore, an exemption is not the appropriate mechanism for accomplishing a change of general applicability

such as presented here

.

Additionally, the FAA finds that Delta has not provided any new information in regard to the

issuance of OpSpec A525. In the FAA’s July 2 4 , 2013

, Denial of Exemption letter , the FAA properly considered and explained the FAA’s rational e for issuing OpSpec A525 and explained the differences between the risks posed to military members and the risks posed to non

- military

passengers.

Delta state s that the FAA’s method of analysis based on the SDR is statistically flawed and questions the FAA’s rationale in including depressurization events of all levels of severity

. The FAA emphasizes that a statistical analysis was not performed

. Delta asserts that only 40 of the 66

SDR s identified by the FAA in its exemption denial involved an actual dec ompression event and that, of these 40 SDRs , 17 events involved oxygen mask deployment. Despite any weakness in the FAA’s initial analysis

, Delta admits in its petition for reconsideration that it “recorded 89 events where some level of cabin pressurizatio n was compromised” in the past 66 months

. T his5

demonstrates that cabin depressurization and mask deployment occur with enough frequency t o merit concern. Th ese events support the FAA’s analysis that the risk of decompression, rapid or gradual

, is not low, particularly if the number of incidents recorded by Delta is comparable to

other p art 121 carriers. Additionally, the FAA contends that slow decompression can be just as dangerous as rapid decompression. By its nature, rapid decompression commands attentio n

. On the other hand, s low decompression may go unnoticed and the resultant hypoxia may be unrecognized by the pilot. 1 T he FAA concludes that Delta has not provided any additional or

new information in this area that would warrant granting the petitioner’s request at this time.

Lastly, Delta contends that the reduced flight times enabled by the exemption will reduce radiation exposure and, therefore, risk of cancer for flight crews and passengers. The FAA recognizes that flight crews are occupationally exp osed to ionizing radiation and that the probability of radiation

- caused cancer is related to the total amount of radiation accumulated by

an individual. 2 The FAA points out that, in addition to reducing flight time, reducing flight altitude is also a way t o reduce exposure to ionizing radiation. 3 The FAA concludes that t he environmental concerns cited by Delta as justification for the requested relief are not directly concerned with passe nger safety during an emergency and are , therefore, tangential to the oxygen issue

. The FAA finds that Delta has provided insufficient data to substantiate a claim that any reduced risk with regard to radiation exposure offsets the increased risks assumed by passengers related to supplemental oxygen. As such, the FAA finds t hat Delta has not provided

sufficient information or evidence to show that a grant would be in the public interest or would provide a level of sa fety at least equal to that provided by the rule

.

The FAA’s Decision:

In consideration of the foregoing, I f ind that a grant of exemption would not be in the public interest. Therefore, pursuant to the authority contained in 49 U.S.C. §§ 106(f), 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, DC, on September 18, 2014.

.

/s/

Michael G. Whitaker Deputy Administrator

1 FAA Advisory Circular AC

- 61

- 107B (3/29/2013), Ch. 2, ¶ 2

- 7(e)(3).

2 FAA Advisory Circular AC

- 120

- 61A (7/6/2006), Ch. 8 , ¶ 1 Risk Associat ed with Exposure

. 3 FAA Civil Aerospace Medical Institute

, What Aircrews Should Know About Their Occupational Exposure to Ionizing Radiation

. Springfield: Nationa l Technical Information Service, 2003.