High Elevation Airport Operations, 13565-13571 [2019-06765]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 84, Number 66 (Friday, April 5, 2019)]
[Proposed Rules]
[Pages 13565-13571]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-06765]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No.: FAA-2019-0218; Notice No. 19-3]
RIN 2120-AL15


High Elevation Airport Operations

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to amend certain airworthiness regulations 
applicable to cabin pressurization systems and oxygen dispensing 
equipment on transport category airplanes to accommodate airplane 
operations into or out of airports with elevations at or above 8,000 
feet above sea level. Currently, the FAA makes and documents equivalent 
level of safety findings when an airplane manufacturer or modifier 
proposes to certify airplane cabin pressurization systems used for 
operations into or out of airports with elevations at or above 8,000 
feet. In addition, the FAA grants exemptions from the automatic oxygen 
mask presentation requirements for operations into or out of airports 
with elevations at or above 14,000 feet. This proposed action is 
necessary to relieve the burden on industry and the FAA that results 
from project-specific equivalent level of safety (ELOS) requests and 
petitions for exemption to accommodate operations at high elevation 
airports for transport category airplanes.

DATES: Send comments on or before June 4, 2019.

ADDRESSES: Send comments identified by docket number FAA-2019-0218 
using any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov and follow the online instructions for sending your 
comments electronically.
     Mail: Send comments to Docket Operations, M-30; U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: In accordance with 5 U.S.C. 553(c), DOT solicits comments 
from the public to better inform its rulemaking process. DOT posts 
these comments, without edit, including any personal information the 
commenter provides, to https://www.regulations.gov, as described in the 
system of records notice (DOT/ALL-14 FDMS), which can be reviewed at 
https://www.dot.gov/privacy.
    Docket: Background documents or comments received may be read at 
https://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE, 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: For questions concerning this action, 
contact Robert Hettman, Propulsion & Mechanical Systems Section, AIR-
672, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service, Federal Aviation Administration, 2200 S 
216th Street, Des Moines, Washington 98198; telephone and facsimile 
206-231-3171; email [email protected].

SUPPLEMENTARY INFORMATION: 

[[Page 13566]]

Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in 
Title 49 of the United States Code. Subtitle I, Section 106 describes 
the authority of the FAA Administrator. Subtitle VII, Aviation 
Programs, describes in more detail the scope of the agency's authority.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
Requirements.'' Under that section, the FAA is charged with promoting 
safe flight of civil aircraft in air commerce by prescribing 
regulations and minimum standards for the design and performance of 
aircraft that the Administrator finds necessary for safety in air 
commerce. This regulation is within the scope of that authority. It 
prescribes new, relieving, safety standards for the design and 
operation of transport category airplanes.

I. Overview of Proposed Rule

    The FAA proposes to amend title 14, Code of Federal Regulations (14 
CFR) part 25. Specifically, the FAA proposes to amend Sec. Sec.  
25.841, ``Pressurized cabins,'' and 25.1447, ``Equipment standards for 
oxygen dispensing units,'' for airplanes equipped with cabin 
pressurization systems and oxygen dispensing equipment intended for 
operations into or out of airports with elevations at or above 8,000 
feet, also referred to as ``high elevation airports.''
    The proposed amendments to Sec.  25.841 would eliminate the burden 
on industry and the FAA that results from project-specific ELOS 
findings currently necessary for the FAA to approve such designs for 
cabin pressurization systems intended to be used for operations into or 
out of high elevation airports.
    Section 25.841(a) limits the cabin pressure altitude to not more 
than 8,000 feet at the maximum operating altitude of the airplane under 
normal operating conditions. Operating at the maximum operating 
altitude of the airplane is considered a normal operating condition. 
Section 25.841(a) was never intended to imply that the cabin pressure 
altitude could exceed 8,000 feet under normal operating conditions 
provided the airplane was below the maximum operating altitude. 
Accordingly, the FAA proposes to revise Sec.  25.841(a) to clarify the 
limit on cabin pressure altitude to not more than 8,000 feet under 
normal operating conditions. This revision is not necessary for the 
other changes being proposed for operations into and out of high 
elevation airport operations, but since it is related, FAA is making 
this clarification here.
    The cabin pressure altitude requirement in Sec.  25.841(a) does not 
allow certification of airplane designs that can safely accommodate 
operations into or out of high elevation airports. The FAA proposes 
adding Sec.  25.841(c) as an exception to Sec.  25.841(a) to 
accommodate operations into or out of high elevation airports. Proposed 
Sec.  25.841(c) would allow the cabin pressure in pressurized cabins 
and occupied compartments to be equal to or less than the airport 
elevation while the airplane operates at or below 25,000 feet, provided 
the cabin pressurization system is designed to minimize the time that 
passenger cabin occupants would be exposed to cabin pressures exceeding 
8,000 feet in flight.
    Section 25.841(b)(6) requires a warning indication at the pilot or 
flight engineer station to indicate when the safe or preset cabin 
pressure altitude limit is exceeded to alert the flightcrew to 
potential hypoxic conditions. Section 25.841(b)(6) also states that 
this warning requirement for cabin pressure altitude limits is met if 
it warns the flightcrew when the cabin pressure altitude exceeds 10,000 
feet. The FAA proposes adding new Sec.  25.841(d) as an exception to 
Sec.  25.841(b)(6) to allow an applicant to change the cabin altitude 
warning to 15,000 feet or 2,000 feet above the airport elevation, 
whichever is greater, when operating into or out of a high elevation 
airport.
    Further, Sec.  25.1447(c)(1) requires that airplanes being 
certified for operation above 30,000 feet must be equipped with oxygen 
dispensing units providing the required oxygen flow, and that such 
units must be automatically presented to the occupant before the cabin 
pressure exceeds 15,000 feet above sea level. Section 25.1447(c)(1) 
also states the crew must be provided with a manual means to make the 
dispensing units immediately available in the event of failure of the 
automatic system. This proposal would add Sec.  25.1447(c)(5) as an 
exception to Sec.  25.1447(c)(1) to allow approval of passenger cabin 
oxygen dispensing units that automatically deploy at 15,000 feet, or 
2,000 feet above the airport elevation, whichever is greater, during 
operations into or out of high elevation airports. This proposed action 
would relieve industry from having to petition, and the FAA from the 
burden of evaluating and granting applicant-specific exemptions from 
Sec.  25.1447(c)(1), currently necessary to increase the cabin pressure 
at which passenger cabin oxygen dispensing unties automatically deploy.

II. Background

A. Statement of the Problem

    Cabin pressurization systems of airplanes are typically designed to 
maintain the interior cabin pressure so that the maximum cabin pressure 
altitude does not exceed 8,000 feet and to ensure that the change in 
cabin pressure altitude is minimized during flight. While an airplane 
is on the ground, the interior cabin pressure must be equal to the 
outside ambient air pressure to allow for easy opening of the exit 
doors should there be a need for an emergency evacuation. When an 
airplane ascends, its cabin pressure altitude starts at the equivalent 
altitude of the airport and slowly changes as the airplane climbs until 
the cabin pressure altitude is stabilized at an altitude not exceeding 
8,000 feet, which is the current regulatory maximum cabin pressure 
altitude allowable. However, when an airplane takes off from an airport 
with an elevation greater than 8,000 feet, the cabin pressure altitude 
must begin at that higher equivalent altitude and slowly decrease until 
it is less than 8,000 feet. Similarly, when an airplane is configured 
to land at a high elevation airport, the interior cabin pressure 
altitude will start near 8,000 feet and slowly rise as the airplane 
descends into the airport, until the interior cabin pressure altitude 
is the same as the equivalent pressure altitude at the airport when the 
airplane lands. Since the maximum cabin pressure altitude of 8,000 feet 
is exceeded when operating into or out of high elevation airports, the 
airplane is out of compliance with 14 CFR 25.841.
    Globally, there are several airports at elevations that exceed 
14,000 feet. An example of a high elevation airport is Daocheng Yading 
Airport, in Tibet, at 14,472 feet.
    To accommodate high elevation airport operations, applicants for 
type certificates incorporate design features for the cabin 
pressurization system that are intended to minimize the time that the 
cabin pressure altitude is above 8,000 feet. If a cabin altitude 
warning is set at 10,000 feet, for example, the flightcrew may receive 
nuisance warnings during high elevation airport takeoff and landing 
operations, unless special design features are incorporated. 
Accordingly, airplane manufacturers typically design the cabin 
pressurization control system to raise the cabin pressure altitude at 
which the warning occurs during these high elevation airport 
operations.
    Currently, when an airplane manufacturer applies for certification 
of an airplane with a cabin pressurization

[[Page 13567]]

system intended to be used for operations into or out of high elevation 
airports, the cabin pressurization system does not meet the design 
standard in Sec.  25.841(a) and (b)(6) and the FAA must make an ELOS 
finding, if appropriate. An ELOS finding is made when the design does 
not comply with the applicable airworthiness provisions, but 
compensating factors provide an equivalent level of safety.\1\ For the 
design standard provided by Sec.  25.841(a) and (b)(6), compensating 
factors such as the flight crew's use of supplemental oxygen and 
minimizing the time that the cabin pressure altitude may be above 8,000 
feet, provide an equivalent level of safety during high elevation 
airport operations. The FAA documents an ELOS finding in an ELOS 
memorandum that communicates to the public the rationale for the FAA's 
determination of equivalency to the level of safety intended by the 
regulations. The ELOS memorandum also documents those aspects of the 
ELOS finding that must be maintained for continued airworthiness. 
Processing an ELOS request (i.e., evaluating the request, making the 
finding, and creating the ELOS memorandum) creates an extra 
administrative burden on the applicant as well as the FAA during the 
aircraft certification process.\2\ The FAA typically makes about four 
ELOS findings per year related to high elevation airport operations. 
For each ELOS finding related to high elevation airport operations, the 
FAA may spend 20 to 100 engineering hours, depending on how unique the 
proposed design features are, and whether or not the applicant has 
previously proposed airplane designs intended for such operations in 
the past. We estimate that applicants expend similar resources.
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    \1\ The authority for the agency to make an ELOS finding is 
provided in 14 CFR 21.21(b). Paragraph (b) of Sec.  21.21 specifies 
that the FAA must find an applicant for a type certificate meets the 
applicable airworthiness requirements of subchapter C of Chapter I 
of title 14 Code of Federal Regulations or that any airworthiness 
provisions not complied with are compensated for by factors that 
provide an equivalent level of safety.
    \2\ ELOS memorandums are available at https://rgl.faa.gov/.
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    Section 25.1447(c)(1) requires that, for airplanes certified for 
operations above 30,000 feet, oxygen dispensing equipment be 
automatically deployed before the cabin pressure altitude reaches 
15,000 feet. To prevent unnecessary deployments and avoid unnecessary 
maintenance costs associated with servicing the oxygen system on 
airplanes intended to operate at high elevation airports, applicants 
typically incorporate design features to raise the automatic 
presentation altitude for the oxygen masks during high elevation 
airport operations. Currently, applicants that incorporate these design 
features do so pursuant to an agency-issued exemption from Sec.  
25.1447(c)(1).\3\ A petition for exemption for airplanes certified for 
operation above 30,000 feet into high elevation airports creates a 
burden for applicants who develop the petition as well as the FAA in 
the agency's evaluation and analysis of the petition. The FAA typically 
grants one or two exemptions per year related to high elevation airport 
operations.\4\ For each exemption related to high elevation airport 
operations, the FAA may spend 20 to 100 engineering hours depending on 
how similar the specific exemption petition is in relation to those 
previously granted. In addition to expended resources, exemptions 
typically increase the time for certification because the FAA follows 
the procedures for public comment described in 14 CFR part 11 as 
appropriate. We expect that applicants expend similar resources.
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    \3\ The Administrator's exemption authority is provided by 49 
U.S.C. 44701(e) and implemented in accordance with 14 CFR part 11.
    \4\ Complete exemption dockets can be found at https://www.regulations.gov/. Exemption grants and denials are also 
available at https://aes.faa.gov/ and https://rgl.faa.gov/.
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III. Discussion of the Proposal

A. Cabin Pressurization Requirements for Normal Operating Conditions

    The intent of Sec.  25.841(a) is to maintain a safe pressure 
environment within the cabin during normal operations. Currently, Sec.  
25.841(a) limits the cabin pressure altitude to not more than 8,000 
feet at the maximum operating altitude of the airplane under normal 
operating conditions. Operating at the maximum operating altitude of 
the airplane is considered a normal operating condition. Section 
25.841(a) was never intended to imply that the cabin pressure altitude 
could exceed 8,000 feet under normal operating conditions provided the 
airplane was below the maximum operating altitude. The physiological 
effects associated with exposure to high cabin pressure altitudes, 
namely hypoxia, vary from one individual to the next as a function of 
altitude and time. Common effects associated with hypoxia include 
increased heart rate, decreased cognitive ability, nausea, and 
increased chance of cardiac arrest or stroke. These physiological 
effects are rare when the cabin pressure altitude does not exceed 8,000 
feet. For clarity, the FAA proposes to revise Sec.  25.841(a) to limit 
the cabin pressure altitude to not more than 8,000 feet under normal 
operating conditions even though this clarification is not necessary 
for the proposed changes for operations into and out of high elevation 
airport operations.
    During normal operations into or out of high elevation airports, 
however, it is possible that the cabin pressure altitude will exceed 
8,000 feet while the airplane is on the ground. When the airplane is on 
the ground with a higher pressure inside the passenger cabin compared 
to the outside air pressure, it could be difficult if not impossible to 
open the emergency exits depending on the design and magnitude of 
pressure differential. For example, landing at an airport that is at 
10,000 feet while the passenger cabin is at 8,000 feet. This would 
impede emergency evacuation and decrease safety. Although some 
emergency exit designs may allow a cabin attendant to unlatch and start 
opening a door with a slight pressure differential, the door could 
quickly swing open and pull the attendant outside as the emergency 
escape slide is inflating, which would also impede evacuation efforts 
and endanger the flight attendant.
    The FAA proposes adding Sec.  25.841(c) as an exception to Sec.  
25.841(a), to accommodate operations into or out of high elevation 
airports. Proposed Sec.  25.841(c) would allow the cabin pressure in 
pressurized cabins and occupied compartments to be equal to or less 
than the airport elevation while the airplane operates at or below 
25,000 feet, provided the cabin pressurization system is designed to 
minimize the time that passenger cabin occupants would be exposed to 
cabin pressures exceeding 8,000 feet in flight. The exception to Sec.  
25.841(a) would only apply when the airplane is at or below 25,000 feet 
because the risk of hypoxia following a decompression increases with 
altitude. In addition, this will maintain consistency with other oxygen 
availability requirements that are not affected by this proposal. This 
proposed change would allow certification of airplane designs that can 
safely accommodate operations into or out of high elevation airports by 
minimizing the time that the cabin pressure may be above 8,000 feet 
without unnecessarily exposing occupants to high cabin pressures in the 
unlikely event of a pressurization failure.

B. Requirements for Flightcrew Warning Indication Following Loss of 
Pressurization

    The intent of the design requirement in current Sec.  25.841(b)(6) 
is to provide the flightcrew with a warning when the safe or preset 
cabin pressure altitude

[[Page 13568]]

limit is exceeded. Consistent with the proposed addition of Sec.  
25.841(c) to accommodate operations into high elevation airports and to 
reduce the possibility of exposure to high cabin pressures above 25,000 
feet, if a failure condition (decompression) occurs, the FAA proposes 
adding Sec.  25.841(d) as an exception to Sec.  25.841(b)(6).
    Proposed Sec.  25.841(d) would allow an applicant to change the 
cabin altitude warning to 15,000 feet, or 2,000 feet above the airport 
elevation, whichever is greater, when operating into or out of airports 
exceeding 8,000 feet provided that--
    1. The airplane is at or below 25,000 feet;
    2. An alert is provided to clearly indicate to the flightcrew that 
the cabin high altitude warning has shifted above 10,000 feet;
    3. If the cabin altitude warning alert shifts above 10,000 feet 
automatically, an alert is provided to notify the flightcrew to take 
action should the automatic shift function fail; and
    4. Either an alerting system is installed to notify the flightcrew 
on flight deck duty when to don oxygen mask(s), in accordance with the 
applicable operating regulations; or a flight procedure acceptable to 
the FAA administrator is provided in the airplane flight manual 
requiring the pilot in command to don oxygen when the cabin warning has 
shifted above 10,000 feet and other flightcrew on flight deck duty to 
monitor cabin pressure and utilize supplemental oxygen, in accordance 
with the applicable operating regulations.
    In addition, the potential risk of hypoxia by the flightcrew 
members following a decompression during high elevation airport 
operations is also minimized because the cabin pressure warning 
altitude can only be raised above 10,000 feet while the airplane is at 
or below 25,000 feet above sea level. Further, there are operational 
requirements, such as those at 14 CFR 91.211, 121.333, and 135.157, 
that describe when supplemental oxygen must be used for passengers, 
cabin crew, and flightcrew members on flight deck duty. The use of 
supplemental oxygen for airplane occupants is a function of altitude, 
time exposure, and flightcrew members duties anticipated on the 
airplane. (Such requirements are intended to minimize the symptoms of 
hypoxia for airplane occupants, but are not being proposed for revision 
by this notice.) Therefore, airplane designs that meet the requirements 
proposed in this NPRM would maintain an appropriate level of safety 
that is consistent with previously issued ELOS determinations.
    Also, for commonality with other regulatory text, the FAA is 
proposing to clarify existing Sec.  25.841(b)(6), which currently 
requires an aural or visual signal to warn the flightcrew when the 
cabin pressure altitude exceeds 10,000 feet, to simply require an alert 
rather than a specific additional aural or visual signal. At Amendment 
25-131 (75 FR 67201, November 2, 2010), effective January 3, 2011, the 
FAA created Sec.  25.1322 to add flightcrew alerting requirements. An 
alert designed in accordance with Sec.  25.1322 would ensure an 
appropriate alerting is provided to the flightcrew without the need for 
a separate aural or visual alert standard in Sec.  25.841(b)(6), which 
allows for more options in developing an appropriate alert.

C. Requirements for Automatic Presentation of Oxygen Dispensing 
Equipment

    The FAA proposes an exception to the passenger oxygen mask 
presentation requirement in current Sec.  25.1447(c) to allow for 
presentation at higher altitudes when operating into high elevation 
airports. Section 25.1447(c) describes presentation requirements for 
passenger oxygen masks. In accordance with Sec.  25.1447(c)(1), for 
airplanes certified for operation above 30,000 feet, oxygen masks 
providing the required oxygen flow must be automatically presented 
before the cabin pressure altitude exceeds 15,000 feet. Typical designs 
include oxygen mask storage doors located above the seats with 
electrically actuated latches. As electricity is supplied to the 
latches, the doors open and oxygen masks are made available. 
Electricity to the latches is typically provided through a pressure 
switch, which is either open or closed, depending on ambient pressure 
within the passenger cabin. Common pressure switches have a tolerance 
of 500 feet, so it is possible for oxygen masks to be 
presented as low as 14,000 feet to ensure they are made available 
before the cabin pressure reaches 15,000 feet.
    There are several airports throughout the world with elevations 
above 14,000 feet such that oxygen masks could be deployed when an 
airplane lands at or takes off from them. The FAA has granted numerous 
exemptions from the automatic presentation requirements in Sec.  
25.1447(c)(1) to accommodate such operations.\5\ For each exemption 
petition, the FAA works with the applicant to ensure that an adequate 
level of safety is maintained for each system design. To eliminate the 
need for exemptions as more airports open in high elevation terrains or 
more airplanes are designed with the intent to operate into existing 
high elevation airports, the FAA proposes adding Sec.  25.1447(c)(5) as 
an exception to Sec.  25.1447(c)(1). Proposed Sec.  25.1447(c)(5) would 
allow oxygen mask presentation at altitudes of up to 2,000 feet above 
the airport elevation to prevent the unnecessary deployment of oxygen 
masks.
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    \5\ Some examples include exemption 9940 (Docket No. FAA-2009-
0601), exemption 10089 (Docket No. FAA-2010-0290), exemption 13582 
(Docket No. FAA-2015-3311) and exemption 17590 (Docket No. FAA-2017-
0800).
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    The FAA recognizes that a sudden loss of cabin pressure could 
expose passengers and cabin crew to higher cabin pressure altitudes 
before oxygen masks are presented if the automatic presentation 
altitude is raised. To mitigate this risk, the proposed changes include 
limitations on the exception in that the automatic presentation 
altitude for the masks can only be raised when operating into or out of 
high elevation airports, and only when the airplane is at or below 
25,000 feet.
    As previously discussed, the proposed changes will not negatively 
affect safety during high elevation airport operations because of the 
limited portion of the operation during which the proposed change will 
apply and the measures already in place to ensure safety during 
emergency conditions. Additionally, these proposed changes are 
consistent with previously granted exemptions and ELOS determinations.

IV. Regulatory Notices and Analyses

A. Regulatory Evaluation

    Changes to Federal regulations must undergo several economic 
analyses. First, Executive Order 12866 and Executive Order 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 (Pub. 
L. 96-354) requires agencies to analyze the economic impact of 
regulatory changes on small entities. Third, the Trade Agreements Act 
(Pub. L. 96-39) prohibits agencies from setting standards that create 
unnecessary obstacles to the foreign commerce of the United States. In 
developing U.S. standards, the 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, 
which include a Federal mandate likely to result in the expenditure by

[[Page 13569]]

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) has benefits that justify its costs; (2) is not an 
economically ``significant regulatory action'' as defined in section 
3(f) of Executive Order 12866; (3) would not have a significant 
economic impact on a substantial number of small entities; (4) would 
not create unnecessary obstacles to the foreign commerce of the United 
States; and (5) would not impose an unfunded mandate on state, local, 
or tribal governments, or on the private sector by exceeding the 
threshold identified previously. These analyses are summarized below.
    Currently, the FAA processes ELOS memorandums to document ELOS 
findings when an airplane manufacturer or modifier requests 
certification of airplane cabin pressurization systems used for 
operations into or out of airports with elevations at or above 8,000 
feet. The FAA also processes exemptions to the automatic oxygen mask 
presentation requirements for operations into or out of airports with 
elevations at or above 14,000 feet. The proposed rule would eliminate 
the need to continue performing the administrative tasks and analyses 
associated with the processing of an ELOS or exemption to accommodate 
operations at high elevation airports for transport category airplanes 
without compromising safety.
    This proposed rule would result in small quantifiable cost savings. 
As previously discussed, the FAA issues about four ELOS findings and up 
to two exemptions per year related to high elevation airports, 
involving 20 to 100 engineering hours for each ELOS or exemption 
project. The FAA estimates industry and the FAA may expend the same 
range of engineering hours for each ELOS and exemption project. Using 
an average aerospace engineer hourly wage of $65, the FAA estimates the 
total annual cost savings of this proposed rule would range from 
$15,600 to $78,000 for both industry and FAA.\6\
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    \6\ To simplify the analysis since the cost savings are small, 
the FAA uses an average aerospace engineer hourly wage adjusted for 
benefits of $65 for both industry and FAA based on 2017 Bureau of 
Labor Statistics data and FAA salary data. The range of cost savings 
are calculated as $7,800 = (4 ELOS + 2 exemptions) x ($65 hourly 
wage) x (20 engineering hours) and $39,000 = (4 ELOS + 2 exemptions) 
x ($65 hourly wage) x (100 engineering hours). These cost savings 
are doubled to reflect the total cost savings of the proposed rule 
since the FAA estimates the cost savings to industry and the FAA are 
the same.
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    As previously discussed, in addition to expended resources, 
exemptions typically increase the time for certification because the 
FAA follows procedures for public comment described in 14 CFR part 11 
as appropriate. This proposed rule may reduce this time resulting in 
cost savings.
    As a result, this rulemaking will reduce the cost of airplane 
certification without reducing the current level of safety. The 
expected outcome would be a minimal economic impact resulting in a 
small regulatory burden relief. The FAA requests comments with 
supporting justification about the FAA determination of minimal 
economic impact.
    Therefore, the FAA has determined that this proposed rule is not a 
``significant regulatory action'' as defined in section 3(f) of 
Executive Order 12866, and is not ``significant'' as defined in DOT's 
Regulatory Policies and Procedures.

B. Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA) 
establishes ``as a principle of regulatory issuance that agencies shall 
endeavor, consistent with the objectives of the rule and of applicable 
statutes, to fit regulatory and informational requirements to the scale 
of the businesses, organizations, and governmental jurisdictions 
subject to regulation.'' To achieve this principle, agencies are 
required to solicit and consider flexible regulatory proposals and to 
explain the rationale for their actions to assure that such proposals 
are given serious consideration. The RFA potentially covers a wide-
range of small entities, including small businesses, and not-for-profit 
organizations.
    Agencies must perform a review to determine whether a rule will 
have a significant economic impact on a substantial number of small 
entities. If the agency determines that it will, the agency must 
prepare a regulatory flexibility analysis as described in the RFA.
    However, if an agency determines that a rule is not expected to 
have a significant economic impact on a substantial number of small 
entities, section 605(b) of the RFA provides that the head of the 
agency may so certify and a regulatory flexibility analysis is not 
required. The certification must include a statement providing the 
factual basis for this determination, and the reasoning should be 
clear.
    The proposed rule would relieve the industry from requesting that 
the FAA make a determination that an ELOS exists for certification of 
airplane cabin pressurization systems used for operations into or out 
of airports with elevations at or above 8,000 feet above sea level. 
This proposed rule would also relieve industry from petitioning for 
exemptions to the automatic oxygen mask presentation requirements for 
operations into and out of airports with elevations at or above 14,000 
feet above sea level. The expected outcome would be a minimal economic 
impact with small burden relief and savings for any small entity 
affected by this rulemaking action.
    If an agency determines that a rulemaking will not result in a 
significant economic impact on a substantial number of small entities, 
the head of the agency may so certify under section 605(b) of the RFA. 
Therefore, as provided in section 605(b), the head of the FAA certifies 
that this proposed rulemaking would not result in a significant 
economic impact on a substantial number of small entities.

C. International Trade Impact Assessment

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the 
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal 
agencies from establishing standards or engaging in related activities 
that create unnecessary obstacles to the foreign commerce of the United 
States. Pursuant to these Acts, the establishment of standards is not 
considered an unnecessary obstacle to the foreign commerce of the 
United States, so long as the standard has a legitimate domestic 
objective, such as the 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 have only a domestic impact and therefore no effect on 
international trade.

D. Unfunded Mandates Assessment

    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 
(in 1995 dollars) in any one year by State,

[[Page 13570]]

local, and tribal governments, in the aggregate, or by the private 
sector. Such a mandate is deemed a ``significant regulatory action.'' 
The FAA currently uses an inflation-adjusted value of $155 million in 
lieu of $100 million. This proposed rule does not contain such a 
mandate; therefore, the requirements of Title II of the Act do not 
apply.

E. Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires 
that the FAA consider the impact of paperwork and other information 
collection burdens imposed on the public. The FAA has determined that 
there would be no new requirement for information collection associated 
with this proposed rule.

F. International Compatibility and Cooperation

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA's policy to conform to 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA has 
reviewed the corresponding ICAO Standards and Recommended Practices and 
has found no differences with these proposed regulations.
    EASA certification requirements related to oxygen dispensing units 
in CS25.1447(c)(1) are similar to those in Sec.  25.1447(c)(1). In 
Amendment 18 of Certification Specifications and Acceptable Means of 
Compliance for Large Aeroplanes, CS-25,\7\ the European Aviation Safety 
Agency (EASA) describes an acceptable means of compliance (AMC) in AMC 
25.1447(c)(1). Specifically, AMC 25.1447(c)(1) states: ``The design of 
the automatic presentation system should take into account that when 
the landing field altitude is less than 610 m (2000 feet) below the 
normal preset automatic presentation altitude, the automatic 
presentation altitude may be reset to landing field altitude plus 610 m 
(2000 feet).'' Thus, the FAA's proposed change to Sec.  25.1447 is 
consistent with guidance provided by EASA.
---------------------------------------------------------------------------

    \7\ Amendment 18 of European Aviation Safety Agency, 
``Certification Specifications and Acceptable Means of Compliance 
for Large Aeroplanes,'' CS-25, dated June 22, 2016, can be found at 
this web address: https://www.easa.europa.eu/document-library/certification-specifications/cs-25-amendment-18.
---------------------------------------------------------------------------

    EASA has not published advisory material to accommodate operations 
into or out of high elevation airports in consideration of the cabin 
pressure altitude and warning requirements in CS 25.841.

G. Environmental Analysis

    FAA Order 1050.1F identifies FAA actions that are categorically 
excluded from preparation of an environmental assessment or 
environmental impact statement under the National Environmental Policy 
Act in the absence of extraordinary circumstances. The FAA has 
determined this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 5-6.6 of FAA Order 1050.1F and 
involves no extraordinary circumstances.

V. Executive Order Determinations

A. Executive Order 13132, Federalism

    The FAA has analyzed this proposed rule under the principles and 
criteria of Executive Order 13132, ``Federalism.'' The agency has 
determined that this action would not have a substantial direct effect 
on the States, or on the relationship between the Federal Government 
and the States, or on the distribution of power and responsibilities 
among the various levels of government, and, therefore, would not have 
Federalism implications.

B. Executive Order 13211, Regulations That Significantly Affect Energy 
Supply, Distribution, or Use

    The FAA analyzed this proposed rule under Executive Order 13211, 
``Actions Concerning Regulations that Significantly Affect Energy 
Supply, Distribution, or Use'' (May 18, 2001). The agency has 
determined that it would not be a ``significant energy action'' under 
the executive order and would not be likely to have a significant 
adverse effect on the supply, distribution, or use of energy.

C. Executive Order 13609, International Cooperation

    Executive Order 13609, ``Promoting International Regulatory 
Cooperation,'' promotes international regulatory cooperation to meet 
shared challenges involving health, safety, labor, security, 
environmental, and other issues and to reduce, eliminate, or prevent 
unnecessary differences in regulatory requirements. The FAA has 
analyzed this action under the policies and agency responsibilities of 
Executive Order 13609, and has determined that this action would have 
no effect on international regulatory cooperation.

D. Executive Order 13771, Reducing Regulation and Controlling 
Regulatory Costs

    This proposed rule is expected to be an Executive Order 13771 
deregulatory action. Details on the regulatory relief provided by this 
proposed rule can be found in the Regulatory Evaluation section.

VI. Additional Information

A. Comments Invited

    The FAA invites interested persons to participate in this 
rulemaking by submitting written comments, data, or views. The agency 
also invites comments relating to the economic, environmental, energy, 
or federalism impacts that might result from adopting the proposals in 
this document. The most helpful comments reference a specific portion 
of the proposal, explain the reason for any recommended change, and 
include supporting data. To ensure the docket does not contain 
duplicate comments, commenters should send only one copy of written 
comments, or if comments are filed electronically, commenters should 
submit only one time.
    The FAA will file in the docket all comments it receives, as well 
as a report summarizing each substantive public contact with FAA 
personnel concerning this proposed rulemaking. Before acting on this 
proposal, the FAA will consider all comments it receives on or before 
the closing date for comments. The FAA will consider comments filed 
after the comment period has closed if it is possible to do so without 
incurring expense or delay. The agency may change this proposal in 
light of the comments it receives.
    Proprietary or Confidential Business Information: Commenters should 
not file proprietary or confidential business information in the 
docket. Such information must be sent or delivered directly to the 
person identified in the FOR FURTHER INFORMATION CONTACT section of 
this document, and marked as proprietary or confidential. If submitting 
information on a disk or CD ROM, mark the outside of the disk or CD 
ROM, and identify electronically within the disk or CD ROM the specific 
information that is proprietary or confidential.
    Under 14 CFR 11.35(b), if the FAA is aware of proprietary 
information filed with a comment, the agency does not place it in the 
docket. It is held in a separate file to which the public does not have 
access, and the FAA places a note in the docket that it has received 
it. If the FAA receives a request to examine or copy this information, 
it treats it as any other request under the Freedom of Information Act 
(5 U.S.C. 552). The FAA processes such a request under Department of 
Transportation procedures found in 49 CFR part 7.

[[Page 13571]]

B. Availability of Rulemaking Documents

    An electronic copy of rulemaking documents may be obtained from the 
internet by--
    1. Searching the Federal eRulemaking Portal (https://www.regulations.gov);
    2. Visiting the FAA's Regulations and Policies web page at https://www.faa.gov/regulations_policies or
    3. Accessing the Government Printing Office's web page at https://www.gpo.gov/fdsys/.
    Copies may also be obtained by sending a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW, Washington, DC 20591, or by calling 202-267-9677. Commenters 
must identify the docket or notice number of this rulemaking.
    All documents the FAA considered in developing this proposed rule, 
including economic analyses and technical reports, may be accessed from 
the internet through the Federal eRulemaking Portal referenced in item 
(1) above.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

The Proposed Amendment

    In consideration of the foregoing, the Federal Aviation 
Administration proposes to amend chapter I of title 14, Code of Federal 
Regulations as follows:

PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

0
1. The authority citation for part 25 continues to read as follows:

    Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702 and 
44704.

0
2. Amend Sec.  25.841 by revising paragraphs (a) introductory text and 
(b)(6) and adding paragraphs (c) and (d) to read as follows:


Sec.  25.841  Pressurized cabins.

    (a) Except as provided in paragraph (c) of this section, 
pressurized cabins and compartments to be occupied must be equipped to 
provide a cabin pressure altitude of not more than 8,000 feet under 
normal operating conditions.
* * * * *
    (b) * * *
    (6) Warning indication at the pilot or flight engineer station to 
indicate when the safe or preset pressure differential and cabin 
pressure altitude limits are exceeded. Appropriate warning markings on 
the cabin pressure differential indicator meet the warning requirement 
for pressure differential limits, and an alert meets the warning 
requirement for cabin pressure altitude limits, if it warns the 
flightcrew when the cabin pressure altitude exceeds 10,000 feet, except 
as provided in paragraph (d) of this section.
* * * * *
    (c) When operating into or out of airports with elevations at or 
above 8,000 feet, the cabin pressure in pressurized cabins and occupied 
compartments may be equal to or less than the airport elevation 
provided:
    (1) The airplane is being operated at or below 25,000 feet; and
    (2) The cabin pressurization system is designed to minimize the 
time in flight that passenger cabin occupants may be exposed to cabin 
pressure altitudes exceeding 8,000 feet.
    (d) When operating into or out of airports with elevations 
exceeding 8,000 feet and the airplane is at or below 25,000 feet, the 
cabin altitude warning alert may be provided at 15,000 feet, or 2,000 
feet above the elevation, whichever is greater, provided that:
    (1) An alert is provided to clearly indicate to the flightcrew that 
the cabin high altitude warning has shifted above 10,000 feet;
    (2) If the cabin altitude warning alert is shifted above 10,000 
feet automatically, an alert is provided to notify the flightcrew to 
take action should the automatic shift function fail; and
    (3) Either an alerting system is installed to notify the flightcrew 
members on flight deck duty when to don oxygen in accordance with the 
applicable operating regulations; or flight procedures acceptable to 
the FAA administrator are provided in the airplane flight manual that 
require the pilot flying to don oxygen when the high altitude cabin 
warning has shifted above 10,000 feet and require other flightcrew 
members on flight deck duty to monitor the cabin pressure to utilize 
oxygen in accordance with the applicable operating regulations.
0
3. Amend Sec.  25.1447 by revising paragraph (c)(1) and adding 
paragraph (c)(5) to read as follows:


Sec.  25.1447  Equipment standards for oxygen dispensing units.

* * * * *
    (c) * * *
    (1) There must be an oxygen dispensing unit connected to oxygen 
supply terminals immediately available to each occupant wherever 
seated, and at least two oxygen-dispensing units connected to oxygen 
terminals in each lavatory. The total number of dispensing units and 
outlets in the cabin must exceed the number of seats by at least 10 
percent. The extra units must be as uniformly distributed throughout 
the cabin as practicable. Except as provided in paragraph (c)(5) of 
this section, if certification for operation above 30,000 feet is 
requested, the dispensing units providing the required oxygen flow must 
be automatically presented to the occupants before the cabin pressure 
altitude exceeds 15,000 feet. The crewmembers must be provided with a 
manual means of making the dispensing units immediately available in 
the event of failure of the automatic system.
* * * * *
    (5) When operating into or out of airports with elevations at or 
above 8,000 feet, the dispensing units providing the required oxygen 
flow may be automatically presented to the occupants at 15,000 feet or 
within 2,000 feet of the airport elevation, whichever is higher, 
provided the airplane is being operated at altitudes at or below 25,000 
feet.

    Issued under authority provided by 49 U.S.C. 106(f) and 44701(a) 
in Washington, DC, on March 29, 2019.
Earl Lawrence,
Executive Director, Aircraft Certification Service.
[FR Doc. 2019-06765 Filed 4-4-19; 8:45 am]
 BILLING CODE 4910-13-P