Source: https://www.federalregister.gov/articles/2013/01/09/2013-00238/requirements-for-chemical-oxygen-generators-installed-on-transport-category-airplanes
Timestamp: 2015-04-22 03:48:27
Document Index: 396707068

Matched Legal Cases: ['§ 25', '§ 25', 'art 25', '§ 25', 'art 121', 'art 129', '§ 25', '§ 25', 'art 25', '§ 121', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 21', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25', '§ 25']

Federal Register | Requirements for Chemical Oxygen Generators Installed on Transport Category Airplanes
Dates: Send comments on or before March 11, 2013.
-1772 (8 pages)
Document Number: 2013-00238
Shorter URL: https://federalregister.gov/a/2013-00238 Related Topics
A. New Requirements for Chemical Oxygen Generator Installations (§ 25.795)
E. Miscellaneous Amendments (§ 25.1450)
See the “Additional Information” section for information on how to comment on this proposal and how the FAA will handle comments received. The “Additional Information” section also contains related information about the docket, privacy, the handling of proprietary or confidential business information. In addition, there is information on obtaining copies of related rulemaking documents. Authority for This Rulemaking Back to Top
SaO 2—Blood Oxygen Saturation Level
I. Overview of the Proposed Rule Back to Top
In January 2002, the FAA adopted the first regulations that address security vulnerabilities in airplanes. The FAA later incorporated all of the ICAO standards into regulations by Amendment 25-127 to Title 14, Code of Federal Regulations (14 CFR) part 25. That amendment complemented other rulemaking initiatives that address security measures for flightdeck doors and added a new § 25.795, Security considerations. ICAO does not have recommended practices related to COGs. Nevertheless, the FAA has determined that COGs present an unacceptable vulnerability and has exercised its authority to take remedial action to correct this vulnerability in airplane design.
The FAA became aware of a security vulnerability with certain types of oxygen systems installed inside the lavatories of most transport category airplanes operating under 14 CFR part 121, as well as certain airplanes operating under part 129. As a result, in April 2011, the FAA issued AD 2011-04-09, mandating that these oxygen systems be rendered inoperative until the vulnerability could be eliminated.
However, by rendering the oxygen systems inoperative to comply with the AD, the airplanes do not comply with the requirements of §§ 25.1447, 121.329, and 121.333. The AD contained a provisional allowance to permit noncompliance in the lavatories from those specific requirements.
To further address that situation, the FAA also issued SFAR 111
to allow continued operation, delivery, and modification of affected airplanes, despite their non-compliance with the above-noted regulations. The AD and the SFAR (while still in effect) are interim measures to minimize the disruption to air commerce while the development of permanent solutions, including this proposed rule, are underway.
The minimum performance requirements for oxygen supply and oxygen mask presentation are contained in §§ 25.1443 and 25.1447. The supplemental oxygen systems are necessary safety equipment in the event of loss of cabin pressure. Each occupant is required to have a supplemental oxygen supply immediately available if cabin pressure drops to a certain level. The regulations specifically require lavatories to be equipped with two oxygen masks connected to oxygen supply terminals and, for airplanes flying above 30,000 feet, automatic presentation of the masks to the occupants. Two masks are required inside a lavatory to address the situation where one person may be assisting another, such as an adult assisting a small child. The quantity of oxygen available to each occupant is based on the route flown and how quickly the airplane can descend to an altitude that does not require supplemental oxygen.
Lavatory oxygen systems are generally similar to the systems provided for passenger and flight attendant use in the cabin. The intent of the supplemental oxygen requirements in 14 CFR part 25 is reinforced in the operational requirements of §§ 121.329 and 121.333, although neither section specifically references lavatories.
The regulations do not specify the use of COGs as an oxygen supply. However, COGs are common because they tend to provide a sufficient oxygen supply while retaining the optimum size, weight, and maintainability for most operations. Because COGs produce oxygen through a chemical reaction that generates heat, there are requirements in § 25.1450 to ensure that adjacent materials and systems are protected from damage and persons are protected from injury. Surface temperatures can reach temperatures up to 500 degrees Fahrenheit, so the COG often has a protective shroud installed.
In issuing AD 2011-04-09 and SFAR 111, the FAA carefully considered the safety ramifications of removing supplemental oxygen from the lavatories of a significant portion of the commercial fleet. The FAA conducted a risk analysis to assess the safety implications of temporarily
not having supplemental oxygen available inside lavatories. To support the risk assessment, earlier studies involving passengers' use of supplemental oxygen were reviewed.
Several years ago in an unrelated initiative, the FAA tasked the ARAC to make recommendations for safety standards when airplanes operate in high altitudes. As part of its efforts, the ARAC did a comprehensive assessment of the frequency and nature of the need for supplemental oxygen systems in service.
The ARAC identified 2,800 instances over a 40-year period and categorized them by cause, severity, and consequence. The majority of these instances were caused by malfunctions of the cabin pressurization system. However, in none of those 2,800 instances was there a loss of life due to lack of oxygen. The ARAC used these data to make recommendations to the FAA for future rulemaking not related to this action.
The ARAC found the frequency of the types of severe occurrences necessitating the use of supplemental oxygen was around 10 −8/flight-hour for causes other than a malfunction of the pressurization system. These malfunctions tend to be slower losses of pressure, or are identified at lower altitudes, and therefore, they are not as critical for this situation. For the purposes of the assessment leading to SFAR 111, the FAA assumed the probability of an occupied lavatory is 50%. The probability of an event when supplemental oxygen is physiologically required is around 5×10 −9/flight-hour. Since SFAR 111 was issued, there has been one decompression event due to a mechanical failure involving oxygen mask deployment and emergency descent. In that instance, no occupants were in a lavatory and no persons suffered any injury.
(3) Establish what type of safety assessment approach should be used (e.g., in accordance with SAE International Document ARP5577
or § 25.1309), and define the content and procedures of the safety assessment;
Incorporation of an active system to provide tamper-evidence would significantly increase complexity, cost, and time in implementing new designs into the existing U.S. fleet compared to other approaches for addressing the security concerns with COGs. This is because such a system must demonstrate a suitable level of reliability and not be susceptible to tampering. It would also require intervention on the part of the crew, which would result in new crew procedures and training. In addition, most of the modification work must be done on the airplane, which can lead to unscheduled time out of service. All of these factors contribute to the complexity of the design, the time it takes to install and certificate the design, and the costs associated with incorporating the design.
Irrespective of the method chosen to provide supplemental oxygen, there may be means to indirectly mitigate the space constraints by changing the way in which the supplemental oxygen dosage is measured. Historically, oxygen systems have provided a constant tracheal partial pressure of oxygen in accordance with § 25.1443. In order to maintain the requisite partial pressure, the system supplies oxygen at a given rate for a time period as determined by the routes being flown.
Recent developments in system technology have made a more direct approach feasible for meeting the physiological oxygen requirement. This approach measures the oxygen saturation level in the blood, known as SaO 2, instead of tracheal partial pressure. Because SaO 2 is more directly indicative of whether adequate oxygen is being supplied, this approach has merit. Further, for a system that can maintain adequate SaO 2, the total quantity of oxygen may be reduced, making the storage vessel smaller than one based on tracheal partial pressure. Using a smaller storage vessel makes such installations more practical by utilizing the existing locations. While there is no regulatory change proposed to incorporate SaO 2, the FAA will consider this approach as a basis for a finding of an equivalent level of safety to the oxygen quantity requirements of § 25.1443, Minimum mass flow of supplemental oxygen.
As previously discussed, the FAA began incorporating security measures into the airplane design in 2002. This proposal is keeping with that effort and reflects additional knowledge the FAA has acquired since then. The FAA recently superseded AD 2011-04-09 with AD 2012-11-09, Various Transport Category Airplanes (77 FR 38000, June 26, 2012) to include terminating action for installations meeting requirements of this proposal. To enable affected operators and modifiers to obtain approval of COG installations in advance of finalizing this proposed rulemaking, the FAA has also issued Policy Statement PS-ANM-25-04 regarding COGs using these proposed standards (based on the LOARC recommendations) as guidance for methods of compliance.
The policy statement enables operators to satisfy the requirements in AD 2012-11-09 while at the same time restoring a supplemental oxygen supply to lavatories.
The current requirements for COGs relate primarily to protecting the airplane and passengers from the heat produced by the generators. These standards are in § 25.1450 and will continue to apply. The requirements of § 25.1450 address safety requirements for COGs when correctly installed and operating, as well as predictable failures. These existing requirements do not consider the deliberate misuse of a COG, or the potential effects of that misuse.
As previously discussed, § 25.795 addresses the incorporation of security measures into an airplane design, following similar standards adopted by ICAO. Currently, § 25.795 does not address COGs, as they were not considered at the time that regulation was adopted. Nevertheless, since the issues of concern stem from security considerations, the FAA has determined that the most logical location for these new COG standards is in § 25.795, Security considerations.
Again, the FAA is proposing standards based on recommendations from the LOARC. This proposal would amend § 25.795 by requiring that each COG or its installation must be designed to be secure by meeting at least one of the following four conditions: (1) Provide effective resistance to tampering; (2) provide an effective combination of resistance to tampering and active tamper-evident features; (3) installing in a location or manner where any attempt to access the COG would be immediately obvious; and (4) by a combination of these approaches, provided the Administrator finds it to be a secure installation. These conditions are discussed in further detail below.
A COG that is inaccessible would be considered a tamper-resistant COG for the purposes of § 25.795(d). This could be accomplished by locating the COG in an inaccessible area, or installing it in a more conventional location in such a way that access to it is not possible. The ARC considered whether to characterize such an installation as “tamper proof” rather than “tamper resistant.” However, a literal interpretation of “tamper proof” was considered to be too stringent, since there would always be some conceivable, albeit unreasonable, method to overcome tamper-proof features. Nonetheless, where tamper resistance is the sole method of providing security, it is intended that the features be very robust.
If the installation cannot rely solely on a tamper-resistance approach, it is acceptable to incorporate a combined tamper-resistance and active tamper-evidence approach, as previously stated. Using this combined approach would also necessitate changes to crew procedures and concurrent training to provide the same level of security. In this case, it is intervention that ultimately prevents misuse of the generator, so crew involvement is essential. The use of a tamper-evidence approach alone is unacceptable, since this relies entirely on intervention and does not improve the security of the COG itself. Neither the LOARC nor the FAA considers a tamper-evidence approach alone to adequately provide the needed security.
All affected airplanes need to be modified either in accordance with the standards in this proposed rule, or via a prior approval as discussed in Policy Statement PS-ANM-25-04 before the expiration date of SFAR 111. For new design approvals on airplanes subject to AD 2012-11-09, or applications for type design changes after the effective date of the final rule, the FAA will use the requirements of the newly adopted § 25.795(d) as the approval basis. For example, if a design is approved per Policy Statement PS-ANM-25-04, and an applicant applies to amend the design after the effective date of the final rule, the amended design must comply with the requirements of § 25.795(d). For transport airplanes that are not subject to proposed AD 2012-NM-004-AD (e.g., all-cargo airplanes), §§ 21.17 and 21.101, as applicable, will be used to determine whether the requirements of § 25.795(d) must be met.
Section 25.1450, which contains the general standards for COGs, would be revised to refer to the new § 25.795(d), in addition to the existing standards for COGs.
Changes to Federal regulations must undergo several economic analyses. First, Executive Orders 12866 and 13563 direct that each Federal agency shall propose or adopt a regulation only upon a reasoned determination that the benefits of the intended regulation justify its costs. Second, the Regulatory Flexibility Act of 1980 (96) requires agencies to analyze the economic impact of regulatory changes on small entities. Third, the Trade Agreements Act (96) prohibits agencies from setting standards that create unnecessary obstacles to the foreign commerce of the United States (U.S.). In developing U.S. standards, this Trade Act requires agencies to consider international standards and, where appropriate, that they be the basis of U.S. standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires agencies to prepare a written assessment of the costs, benefits, and other effects of proposed or final rules that include a Federal mandate likely to result in the expenditure by state, local, or tribal governments, in the aggregate, or by the private sector, of $100 million or more annually (adjusted for inflation with base year of 1995). This portion of the preamble summarizes the FAA's analysis of the economic impacts of this proposed rule.
In conducting these analyses, FAA has determined that this proposed rule: (1) Would have benefits that justify its costs; (2) would not be an economically “significant regulatory action” as defined in section 3(f) of Executive Order 12866; (3) would not be “significant” as defined in DOT's Regulatory Policies and Procedures; (4) would not have a significant economic impact on a substantial number of small entities; (5) would not create unnecessary obstacles to the foreign commerce of the U.S.; and (6) would not impose an unfunded mandate on state, local, or tribal governments, or on the private sector by exceeding the threshold identified above.
The Trade Agreements Act of 1979 (96), as amended by the Uruguay Round Agreements Act (103), prohibits Federal agencies from establishing standards or engaging in related activities that create unnecessary obstacles to the foreign commerce of the United States (U.S.). Pursuant to these Acts, the establishment of standards is not considered an unnecessary obstacle to the foreign commerce of the U.S., so long as the standards have a legitimate domestic objective, such as protection of safety, and does not operate in a manner that excludes imports that meet this objective. The statute also requires consideration of international standards and, where appropriate, that they be the basis for U.S. standards. The FAA has assessed the potential effect of this proposed rule and determined that it would improve safety and, therefore, is not an unnecessary obstacle to international trade.
Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires each Federal agency to prepare a written statement assessing the effects of any Federal mandate in a proposed or final agency rule that may result in an expenditure of $100 million or more (adjusted annually for inflation with the base year 1995) in any one year by state, local, and tribal governments, in the aggregate, or by the private sector; such a mandate is deemed to be a “significant regulatory action.” The FAA currently uses an inflation-adjusted value of $143.1 million in lieu of $100 million. This proposed rule does not contain such a mandate; therefore, the requirements of Title II do not apply.
2.Amend § 25.795 by redesignating paragraphs (d) and (e) as (e) and (f) respectively, and by adding a new paragraph (d) to read as follows: § 25.795 Security considerations.
3.Amend § 25.1450 by adding a new paragraph (b)(3) to read as follows: § 25.1450 Chemical oxygen generators.
(3) Except as provided in SFAR 109, each chemical oxygen generator installation must meet the requirements of § 25.795(d).