Exemption No. 10136 

UNITED STATES OF AMERICA 

DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRATION 

WASHINGTON, DC 20591 

 

In the matter of the petition of 

 

FEDEX EXPRESS Regulatory Docket No. FAA-2009-1217

 

for an exemption from § 121.333(c)(3) 

of Title 14, Code of 

Federal Regulations 

 

DENIAL OF EXEMPTION 

 By letter dated December 17, 2009, Captain James Bowman, Director of Operations, 

FedEx Express, 3131 Democrat Road, Building C, Suite C112, Memphis, TN 38118 

petitioned the Federal Aviation Administration (FAA) on behalf of FedEx Express for an 

exemption from § 121.333(c)(3) of Title 14, Code of Federal Regulations (14 CFR). The 

proposed exemption, if granted, would allow one pilot to leave their station at the controls of 

the airplane when operating at flight altitudes above flight level (FL) 250, while the remaining 

pilot at the controls could remove their oxygen mask from the stowage unit and have it in his 

or her lap until the other pilot has returned to his or her duty station. 

The petitioner requests relief from the following regulation:

Section 121.333(c)(3) prescribes, in pertinent part, that notwithstanding paragraph 

(c)(2) of this section, if for any reason at any time it is necessary for one pilot to leave 

his station at the controls of the airplane when operating at flight altitudes above flight 

level 250, the remaining pilot at the controls shall put on and use his oxygen mask until 

the other pilot has returned to his duty station. 

The petitioner supports its request with the following information:

The petitioner asserts that this petition for exemption is reasonable and urgently needed 

due to the World Health Organization (WHO) raising the worldwide pandemic alert level 

for influenza A (H1N1) to Phase 6. Additionally the U.S. Centers for Disease Control 

and Prevention (CDC) has announced that a pandemic has been declared for the H1N1 

AFS-10-128-E 
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flu within the United States. The petitioner believes that the potential exists for flight 

crewmembers to contract H1N1. 

The petitioner notes that on December 10, 2009, the CDC updated its “Outbreak” notice 

for Hand, Foot, and Mouth Disease (HFMD) to include Hong Kong, Taiwan, Singapore 

and mainland China. Most notable are the 50,000 plus cases of HFMD confirmed in 

China to include Guangdong Province. FedEx Express currently operates from all the 

noted countries to include its principle Asian Hub at Guangzhou Airport located in 

Guangdong Province. 

The petitioner believes that the current oxygen mask use procedures place FedEx 

Express pilots at increased risk for contracting transmissible disease such as H1N1, 

measles, polio, and forms of tuberculosis in areas as varied as the United Kingdom to 

Southeast Asia, which are all in its areas of operation. 

The petitioner notes that the current method of disinfecting oxygen masks is to use 

Celeste Industries Sanicom disinfectant wipes to clean the masks. However, the 

petitioner adds that the effectiveness of this method is limited due to the need to subject 

the mask to a wet solution for an adequate period of time. The petitioner believes that 

the problem of disinfecting the mask is compounded by the fact that the active ingredient 

in Sanicom disinfectant wipes, benzalkonium chloride has been shown to be a factor in 

creating super bacteria that are becoming more resistant to antibiotics. 

The petitioner states that both Boeing and Airbus have collected data since the 1950s 

over millions of flight hours regarding rapid depressurizations above flight level FL 250. 

Since that time, there have been only a handful of incidents, none of which has had an 

adverse outcome due to pilot physiology. The petitioner states that the probability of 

rapid depressurization is miniscule yet the risk to pilot health from sharing contaminated 

oxygen masks is significant. 

The petitioner proposes to have pilots remove the oxygen mask from its stowage 

container whenever one pilot leaves his or her duty station on the flight deck. The 

remaining pilot at the controls would then have his or her oxygen mask out, tested and in 

his or her lap at the ready, further reducing the time required to don the oxygen mask. 

The petitioner points out that FAA Advisory Circular (AC) 61-107A dated January 02, 

2003, (Operations of Aircraft at Altitudes Above 25,000 feet MSL and/or Mach 

Numbers (MMO) Greater Than .75) states in Table 1-1 that expected time of useful 

consciousness (TUC) at a cabin altitude of 40,000 feet is between 7-10 seconds. The 

petitioner asserts that, using standard pressurization tables for all of FedExExpress’s 

transport category aircraft, it is reasonable to expect a cabin decompression rate of 

approximately 7,000 feet at FL400. Using a cabin altitude of 7,000 feet per second, the 

flight deck altitude would take 4 seconds to reach 35,000 feet. The petitioner added this 
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time to the TUC and determines that a pilot would have between 11-14 seconds to don 

the oxygen mask. 

The petitioner believes that the FAA needs to harmonize its regulations on oxygen mask 

use with the rest of the world. The petitioner cites Canadian Aviation Regulations and 

European Aviation Regulations that have no requirement to don an oxygen mask when a 

single pilot is at the controls below FL420. 

The petitioner contends that non-U.S. pilots flying in United States airspace are not 

required to don oxygen mask above FL250 when only one pilot is at the controls. 

The petitioner indicates that a grant of exemption would result in a safer and more 

healthful working environment for its pilots. It would minimize the potential for the 

spread of serious, life-threatening illnesses among its flight crewmembers and ground 

personnel, while helping to protect airline scheduling integrity. The petitioner believes 

that there would be no compromise to safety with this exemption, and in fact, that safety 

would be improved. 

The petitioner includes a copy of the following as attachments to the petition. 

1. “Oxygen Mask Use in Aviation,” Air Line Pilots Association (October 2009). 

2. Nancy C. Burton, PhD, MPH, Letter of Health Hazard Evaluation, National 

Institute for Occupational Safety and Health, (July 10, 2009). 

3. “Transmission of Influenza A in Human Beings,” Infection Prevention and 

Control Unit, University Health Network, Toronto, Ontario, Canada (February 19, 

2007). 

4. “Significance of Fomites in the Spread of Respiratory and Enteric Viral Disease,” 

Applied and Environmental Microbiology (March 2007). 

5. Respiratory Protection Against Bioaerosols: Literature Review and Research 

Needs,” American Journal of Infection Control (2004). 

6. Operations of Aircraft at Altitudes Above 25,000 Feet MSL and/or Mach Numbers 

(MMO) Greater Than .75. 

 A summary of the petition was published in the Federal Register on March 4, 2010 

(75 FR 10016). Three comments were received; one opposing a grant of exemption and two 

in support of a grant of exemption. The Air Line Pilots Association, International (ALPA) 

supports a grant of exemption. As justification for the exemption, ALPA cited the 

documentation that was submitted in the FedEx Express petition, the inability to clean oxygen 

masks adequately on the flight deck, and aircraft reliability. 
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The FAA's analysis is as follows: 

The FAA has fully considered the petitioner’s supporting information as well as the 

comments submitted in response to the announcement in the Federal Register supporting and 

opposing the petition on behalf of FedEx Express. The FAA has determined that the 

circumstances the petitioner presents do not justify a grant of exemption. The FAA finds that 

the petitioner has not shown how a grant of exemption would be in the public interest or how 

it would provide a level of safety equivalent to that provided under the current regulation. 

The FAA notes that the transport category aircraft the petitioner operates are type-certified for 

operation by two fully trained and qualified pilots. The FAA also notes that normal, 

abnormal, and emergency procedures and checklists require both pilots to participate in 

operating the aircraft. The FAA notes that during part 121 operations, one pilot is allowed to 

leave the seat for brief intervals for physiological breaks. The FAA requires that if the 

aircraft is above FL250, the pilot remaining on the flight deck must wear an oxygen mask. 

This requirement ensures the remaining pilot is never without oxygen. The FAA notes that in 

an emergency, the remaining pilot would have to immediately initiate and accomplish 

multiple tasks that would otherwise be accomplished by two pilots working in coordination 

with each other. Therefore, the FAA finds that if an emergency were to occur, it is critical 

that the remaining pilot have his or her oxygen in use. The FAA finds that the petitioner’s 

proposal to have the oxygen mask in the pilot’s lap and ready for use would not provide a 

level of safety equivalent to that provided under the regulation. 

The applicable regulation, § 121.333, requires that pilots flying aircraft with a payload 

capacity of more than 7,500 pounds have oxygen immediately available between FL 250 and 

FL 410 feet. This is defined as being able to maneuver the quick-don mask into position 

within 5 seconds. Furthermore, if one pilot leaves the flight deck while the aircraft is 

operating above 25,000 ft, the remaining pilot must wear his or her oxygen mask. This mask 

must be a pressure demand type mask that will deliver 98.4% oxygen with the first breath 

after a decompression. FedEx Express is requesting an exemption from § 121.333 because of 

disease transmission concerns. Its argument that safety of flight is not an issue has two main 

points: 

1. Time of useful consciousness (TUC) at FL410 averages 16-17 seconds. 

2. Five seconds is sufficient time for the pilot remaining in the cockpit to don an oxygen 

mask following a decompression, which is well within the average 16-17 seconds of 

TUC. 

 

Regarding petitioner’s assertion that 5 seconds is sufficient time to don a mask, the FAA is in 

the process of rewriting AC-61-107 because of misconceptions among pilots regarding TUCs 

following a decompression. Although pilots may not become completely unconscious until 
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the end of the periods given in the table, their judgment and motor skills may become 

impaired almost immediately. 

Because of the possibility of immediate impairment, the exemption the petitioner proposes 

poses an unacceptable risk to the safety of flight because crewmembers may not be aware of a 

gradual decompression. In such situations, crewmembers may fail to recognize the effects of 

hypoxia, and a single pilot not wearing an oxygen mask may not be able to don the mask 

before he or she is affected by hypoxia. See NTSB accident report number CHI96IA157, 

May 26, 1996 (incident involving American Trans Air, flight 406); see also William F. 

O’Conner, Ph.D. and George E. Pendergrass, Effects of Decompression on Operator 

Performance, DOT/FAAAM 66-10 at 6 (concluding that “the various analyses indicate 

impairment of the operator’s rate of performance for 2 to 4 minutes following rapid 

decompression with some suggestion that the severity of effects increases with increase in 

decompression altitude;” further, “[t]he operator’s total time lost from his primary task, at the 

point of decompression where donning is required, has a mean value of some 16 seconds, 

while the 95th percentile falls at about 25 seconds”); G. Bennett, Reactions and Performance 

of Pilots Following Decompression, Aerospace Medicine 32 at 134-136 (finding that only 

36% of pilots were able to don their masks within 10 seconds following a decompression to 

30,000 feet; and further finding that all subjects reported hypoxia symptoms; finally, 

concluding that full protection at 40,000 feet could not be guaranteed unless pilots were 

wearing their masks and breathing oxygen at the time of decompression). 

The petitioner asserts that given the advances in technology, a rapid decompression event 

would be very rare, and even in the case of a such an event, the mask could be easily donned 

by the crewmembers. However, the FAA notes that relative to the potential duration of a 

decompression, the Transport Aircraft Directorate (TAD) has developed mathematical 

decompression models for aircraft certification. According to the TAD, an engine rotor burst 

event could cause a very rapid decompression, even in a large volume aircraft. Such an event 

is rare; however, the TAD can not classify the event as “extremely improbable.” In the case 

of such an event, however, a crewmember must be able to respond quickly, and to ensure 

such response, it is necessary for the crewmember to comply with § 121.331. 

Furthermore, the FAA notes that the FedEx Express pilot group is not at any greater risk of 

contracting H1N1 than the general population. Rather, the petitioner believes that the FAA 

needs to harmonize its regulations on oxygen masks use with the rest of the world. This 

argument indicates that this request for relief is not unique to FedEx Express and is more 

appropriate for a petition for rulemaking. 

Finally, the FAA finds that the operational safety risk of a rapid decompression to the flying 

public by a single pilot not wearing the oxygen mask outweighs the risk of a single pilot 

catching a life-threatening communicable disease. Therefore, a grant of exemption is not in 

the public interest. 
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The FAA’s Decision: 

 In consideration of the foregoing, I find that a grant of exemption would not be in the 

public interest. Therefore, under the authority contained in 49 U.S.C. §§ 40113 and 44701, 

delegated to me by the Administrator, the petition of FedEx Express for an exemption from 

14 CFR § 121.333(c)(3) is denied. 

Issued in Washington, DC, on October 22, 2010 

/s/ 

Raymond Towles 

Acting Director, Flight Standards 

 Service