Flight Abort Burden Reducing Clarification on End of Flight Safety Limits

Issuing agencies

Abstract

FAA proposes to amend its commercial space launch and reentry licensing regulations to streamline the licensing process and reduce regulatory burden for license applicants. Specifically, FAA proposes to clarify the conditions under which a vehicle operator is not required to abort a flight.

Full Text

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<title>Federal Register, Volume 91 Issue 215 (Monday, November 9, 2026)</title>
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[Federal Register Volume 91, Number 215 (Monday, November 9, 2026)]
[Proposed Rules]
[Pages 70817-70821]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22782]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 450

[Docket No.: FAA-2026-9943; Notice No. 26-21]
RIN 2120-AM37


Flight Abort Burden Reducing Clarification on End of Flight 
Safety Limits

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: FAA proposes to amend its commercial space launch and reentry 
licensing regulations to streamline the licensing process and reduce 
regulatory burden for license applicants. Specifically, FAA proposes to 
clarify the conditions under which a vehicle operator is not required 
to abort a flight.

[[Page 70818]]


DATES: Send comments on or before December 9, 2026.

ADDRESSES: Send comments identified by docket number FAA-2026-9943 
using any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">www.regulations.gov</a> and 
follow the online instructions for sending your comments 
electronically.
    <bullet> Mail: Send comments to Docket Operations; U.S. Department 
of Transportation (DOT), 1200 New Jersey Avenue SE, West Building, 5th 
Floor (W58-213), Washington, DC 20590-0001.
    <bullet> Hand Delivery or Courier: Take comments to Docket 
Operations in Room W58-213 of the West Building, 5th Floor at 1200 New 
Jersey Avenue SE, Washington, DC 20590 between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    <bullet> 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 inform its rulemaking process better. DOT posts 
these comments, without edit, including any personal information the 
commenter provides, to <a href="http://www.regulations.gov">www.regulations.gov</a>, as described in the system 
of records notice (DOT/ALL-14 FDMS), which can be reviewed at 
<a href="http://www.dot.gov/privacy">www.dot.gov/privacy</a>.
    Docket: Background documents or comments received may be read at 
<a href="http://www.regulations.gov">www.regulations.gov</a> at any time. Follow the online instructions for 
accessing the docket or go to the Docket Operations in Room W58-213 of 
the West Building 5th Floor at 1200 New Jersey Avenue SE, Washington, 
DC 20590 between 9 a.m. and 5 p.m., Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Lisa E. Cacciatore, Office of 
Commercial Space Transportation, Federal Aviation Administration, 1200 
New Jersey Avenue SE, Washington, DC 20590; telephone (202) 880-1489; 
email <a href="/cdn-cgi/l/email-protection#da96b3a9bbf49ff499bbb9b9b3bbaeb5a8bf9abcbbbbf4bdb5ac"><span class="__cf_email__" data-cfemail="521e3b21337c177c113331313b33263d2037123433337c353d24">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

I. Overview

    In accordance with Executive Order (E.O.) 14335 ``Enabling 
Competition in the Commercial Space Industry,'' FAA proposes to amend 
its commercial space launch and reentry regulations at 14 CFR part 450 
to further streamline the commercial licensing process. Currently, 14 
CFR 450.108(e) provides that a vehicle operator using flight abort as a 
hazard control strategy is not required to initiate flight abort to 
protect against high consequence events once certain conditions are 
met. The proposed rule would clarify that the exception in paragraph 
(e) applies only to a phase of flight in which the conditions are 
present.

II. Authority for This Rulemaking

    The Commercial Space Launch Act of 1984, as amended and codified at 
51 U.S.C. 50901-50924, authorizes the Secretary of Transportation to 
oversee, license, and regulate commercial launch and reentry 
activities, and the operation of launch and reentry sites within the 
United States (U.S.) or as carried out by U.S. citizens. Section 50905 
directs the Secretary to exercise this responsibility consistent with 
public health and safety, safety of property, and the national security 
and foreign policy interests of the United States. In addition, section 
50903 requires the Secretary to encourage, facilitate, and promote 
commercial space launches and reentries by the private sector. As 
codified in 49 CFR 1.83(b), the Secretary has delegated authority to 
the FAA Administrator to carry out these functions.

III. Background

    FAA has established commercial space regulations governing 
licensing of launch and reentry in 14 CFR chapter III. On December 10, 
2020, FAA issued a final rule consolidating all substantive launch and 
reentry licensing regulations into a new part 450 (85 FR 79566) that 
went into effect on March 10, 2021.
    On August 13, 2025, the President issued E.O. 14335, ``Enabling 
Competition in the Commercial Space Industry,'' requiring the Secretary 
of Transportation to ``reevaluate, amend, or rescind'' the part 450 
regulations for the purpose of further streamlining the commercial 
licensing process. This proposed rule is being published in furtherance 
of this E.O.
    Section 450.101(c) provides that an operator may use flight abort 
as a hazard control strategy to protect against a high consequence 
event in uncontrolled areas. Flight abort accomplishes a controlled 
ending to vehicle flight, such as through explosive destruct. Section 
450.108 provides requirements for flight abort, including requirements 
for flight safety limits. Flight safety limits, in this context, define 
the criteria under which a vehicle operator must initiate flight abort.
    For some mission scenarios, at some point in flight, flight abort 
can no longer mitigate risk, and applicants may wish to turn off the 
flight abort system to prevent accidental initiation of the abort 
system. This possibility is addressed by Sec.  450.108(e), which states 
that a flight does not need to be aborted to protect against high 
consequence events beginning immediately after critical vehicle 
parameters are validated, if the vehicle is able to achieve a useful 
mission, and if, for the remainder of flight: (1) flight abort would 
not materially decrease the risk from a high consequence event; and (2) 
there are no key flight safety events.
    To meet the first condition that flight abort would not materially 
decrease the risk of a high consequence event for the remainder of 
flight, an operator should perform a comparison of the risk (i.e., 
expected casualties (E<INF>C</INF>)) with and without flight abort from 
failure modes that produce conditional expected casualties 
(CE<INF>C</INF>) greater than 0.01. If flight abort would not reduce 
E<INF>C</INF> associated with each failure mode materially, then this 
condition is met. To meet the second condition, an operator must 
demonstrate that the remainder of flight does not include any ``key 
flight safety event,'' which is defined in 14 CFR 401.7 to mean ``a 
flight activity that has an increased likelihood of causing a failure 
compared with other portions of flight.'' However, even if these 
conditions are satisfied for the remainder of flight, an operator is 
only permitted to switch off the flight abort system if, during flight, 
the operator is able to validate ``critical vehicle parameters,'' 
meaning parameters that demonstrate the vehicle is capable of 
completing safe flight through the upcoming phase of flight where 
population is exposed to hazardous debris effects from reasonably 
foreseeable failure modes.

IV. Discussion of the Proposal

    The proposed rule maintains the essential requirements and 
structure of Sec.  450.108(e), with two minor revisions. First, the 
proposed rule would change the title of Sec.  450.108(e) from ``End of 
flight abort'' to ``End of flight safety limits'' to match the 
intention of the paragraph more closely. Paragraph (e) does not require 
an operator to turn off flight abort capability or eliminate flight 
abort as a hazard control strategy, as unintentionally suggested by the 
current title, but rather describes conditions under which an operator 
is not required to set flight safety limits to protect against high 
consequence events in uncontrolled areas during some subsequent phases 
of flight.
    Second, the proposed rule would also scope paragraph (e) to apply 
only to a phase of flight rather than ``the remainder of flight,'' as 
the paragraph currently states. Current paragraph (e) was drafted with 
the understanding that most operators would only turn off the flight 
abort capability at the end of a

[[Page 70819]]

flight, such as the phase immediately before orbital insertion. 
However, FAA anticipates that operators may seek to turn off flight 
abort capability during one phase of flight and turn it back on during 
a subsequent phase. As such, this revision would provide additional 
flexibility to operators while preserving public safety by explicitly 
accommodating this practice. This proposal, therefore, would amend 
paragraph (e) to say that a flight does not need to be aborted for the 
remainder of a phase of flight if the specified conditions are present 
during that phase.

V. Regulatory Notices and Analyses

A. Regulatory Impact Analysis

    E.O. 12866 (``Regulatory Planning and Review'') and E.O. 13563 
(``Improving Regulation and Regulatory Review'') require agencies to 
regulate in the ``most cost-effective manner,'' to make a ``reasoned 
determination that the benefits of the intended regulation justify its 
costs,'' and to develop regulations that ``impose the least burden on 
society.'' The Office of Management and Budget has determined this 
proposed rule is not a significant regulatory action as defined in 
Section 3(f) of E.O. 12866.
    The proposed rule would change the title of Sec.  450.108(e) from 
``End of flight abort'' to ``End of flight safety limits'' to match the 
intention of the paragraph more closely. Paragraph (e) does not require 
an operator to turn off flight abort capability or eliminate flight 
abort as an option during any subsequent phase of flight, as suggested 
by the current title, but rather describes conditions under which an 
operator is not required to set flight safety limits to protect against 
high consequence events in uncontrolled areas during a specified phase 
of flight. In addition, the proposed rule would amend Sec.  450.108(e) 
so that the section only applies to a phase of flight rather than ``the 
remainder of flight,'' as the paragraph currently states. This proposed 
rule would not impose incremental costs. However, there may be minimal 
cost savings. FAA estimates that the change would save FAA time in 
providing guidance per licensee. The proposed rule would provide 
operators the additional flexibility to turn off flight abort 
capability during one phase of flight and turn it back on during a 
subsequent phase of flight. In addition, FAA estimates that the change 
would also save licensees time in seeking and receiving guidance. FAA 
requests public comments on these assumptions.

B. Regulatory Flexibility Act

    Under the Regulatory Flexibility Act (RFA) (5 U.S.C. 601-612), 
agencies must prepare and make available for public comment a 
regulatory flexibility analysis that describes the effect of the 
rulemaking on small entities (i.e., small businesses, small 
organizations, and small government jurisdictions). No regulatory 
flexibility analysis is required, however, if the head of an agency 
certifies that the proposed rule would not have a significant economic 
impact on a substantial number of small entities. FAA has concluded and 
hereby certifies that this proposed rule would not have a significant 
economic impact on a substantial number of small entities; therefore, 
an analysis is not included.

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, they be the basis for U.S. standards.
    FAA has assessed the potential effect of this proposed rule and 
determined that it would not create unnecessary obstacles to the 
foreign commerce of the United States.

D. Unfunded Mandates Assessment

    The Unfunded Mandates Reform Act of 1995 (2 U.S.C. 1531-1538) 
governs the issuance of Federal regulations that require unfunded 
mandates. An unfunded mandate is a regulation that requires a State, 
local, or Tribal government or the private sector to incur direct costs 
without the Federal Government having first provided the funds to pay 
those costs. FAA determined the proposed rule would not result in the 
expenditure of $193,000,000 or more ($100,000,000 adjusted for 
inflation using the most current Implicit Price Deflator for the Gross 
Domestic Product) by State, local, or Tribal governments, in the 
aggregate, or the private sector, in any one year.

E. Paperwork Reduction Act

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

F. International Compatibility

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to conform to 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. FAA has 
determined there are no ICAO Standards and Recommended Practices that 
correspond to these proposed regulations.

G. Environmental Analysis

    The Department has analyzed the environmental impacts of this 
notice of proposed rulemaking pursuant to the National Environmental 
Policy Act of 1969 (NEPA) (42 U.S.C. 4321, et seq.). FAA has determined 
this rule is categorically excluded pursuant to FAA Order 1050.1G. 
Categorical exclusions are categories of actions FAA has determined 
normally do not significantly affect the quality of the human 
environment and therefore do not require either an environmental 
assessment (EA) or environmental impact statement (EIS). In analyzing 
the applicability of a categorical exclusion, FAA must also consider 
whether extraordinary circumstances are present that would warrant the 
preparation of an EA or EIS. This proposed rulemaking, which would 
clarify the conditions under which a vehicle operator is not required 
to abort a flight, is categorically excluded pursuant to FAA Order 
1050.1G, Appendix B, Paragraph B-2.6(f), which categorically excludes 
issuance of regulatory documents. FAA does not anticipate any 
environmental impacts, and there are no extraordinary circumstances 
present in connection with this rulemaking.

VI. E.O. Determinations

A. E.O. 13132, Federalism

    FAA has analyzed this proposed rule under the principles and 
criteria of E.O. 13132, Federalism. FAA has determined this action 
would not have a substantial direct effect on the States, or the 
relationship between the Federal Government and the States, or on the

[[Page 70820]]

distribution of power and responsibilities among the various levels of 
government, and, therefore, would not have federalism implications.

B. E.O. 13175, Consultation and Coordination With Indian Tribal 
Governments

    Consistent with E.O. 13175, Consultation and Coordination with 
Indian Tribal Governments,\1\ and FAA Order 1210.20, American Indian 
and Alaska Native Tribal Consultation Policy and Procedures,\2\ FAA 
ensures Federally Recognized Tribes (Tribes) are given the opportunity 
to provide meaningful and timely input regarding proposed Federal 
actions that have the potential to affect uniquely or significantly 
their respective Tribes. At this point, FAA has not identified any 
unique or significant effects, environmental or otherwise, on Tribes 
resulting from this proposed rule.
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    \1\ 65 FR 67249 (November 6, 2000).
    \2\ FAA Order No. 1210.20 (January 28, 2004), available at: 
<a href="http://www.faa.gov/documentLibrary/media/1210.pdf">www.faa.gov/documentLibrary/media/1210.pdf</a>.
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C. E.O. 13211, Regulations That Significantly Affect Energy Supply, 
Distribution, or Use

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

D. E.O. 13609, Promoting International Regulatory Cooperation

    E.O. 13609, Promoting International Regulatory Cooperation, 
promotes international regulatory cooperation to (1) meet shared 
challenges involving health, safety, labor, security, environmental, 
and other issues and to reduce, eliminate, or (2) prevent unnecessary 
differences in regulatory requirements. FAA has analyzed this action 
under the policies and agency responsibilities of E.O. 13609 and has 
determined this action would have no effect on international regulatory 
cooperation.

E. E.O. 14192, Unleashing Prosperity Through Deregulation

    This proposed rule, if finalized as proposed, is expected to be an 
E.O. 14192 deregulatory action.

VII. Additional Information

A. Comments Invited

    FAA invites interested persons to participate in this rulemaking by 
submitting written comments, data, or views. FAA also invites comments 
relating to the economic, environmental, 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 submit only one time if comments are filed electronically, or 
commenters should send only one copy of written comments if comments 
are filed in writing.
    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 rule. Before acting on this proposal, FAA will 
consider all comments it receives on or before the closing date for 
comments. FAA will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
FAA may change this proposal in light of the comments it receives.

B. Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), 
CBI is exempt from public disclosure. If your comments responsive to 
this NPRM contain commercial or financial information that is 
customarily treated as private, that you actually treat as private, and 
is relevant or responsive to this NPRM, it is important you clearly 
designate the submitted comments as CBI. Please mark each page of your 
submission containing CBI as ``PROPIN.'' FAA will treat such marked 
submissions as confidential under the FOIA, and they will not be placed 
in the public docket of this NPRM. Submissions containing CBI should be 
sent to the person in the FOR FURTHER INFORMATION CONTACT section of 
this document. Any commentary FAA receives that is not specifically 
designated as CBI will be placed in the public docket for this 
rulemaking.

C. Electronic Access and Filing

    A copy of this NPRM, all comments received, any final rule, and all 
background material may be viewed online at <a href="http://www.regulations.gov">www.regulations.gov</a> using 
the docket number listed above. Electronic retrieval help and 
guidelines are available on the website. It is available 24 hours each 
day, 365 days each year. An electronic copy of this document may also 
be downloaded from the Office of the Federal Register's website at 
<a href="http://www.federalregister.gov">www.federalregister.gov</a> and the Government Publishing Office's website 
at <a href="http://www.govinfo.gov">www.govinfo.gov</a>. A copy may also be found at FAA's Regulations and 
Policies website at <a href="http://www.faa.gov/regulations_policies">www.faa.gov/regulations_policies</a>.
    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. 
Requesters must identify the docket or notice number of this 
rulemaking.
    All documents FAA considered in developing this proposed rule, 
including economic analyses and technical reports, may be accessed in 
the electronic docket for this rulemaking.

D. Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act of 1996 
(Pub. L. 104-121, 110 Stat. 857, Mar. 29, 1996) requires FAA to comply 
with small entity requests for information or advice about compliance 
with statutes and regulations within its jurisdiction. A small entity 
with questions regarding this document may contact its local FAA 
official or the person listed under the FOR FURTHER INFORMATION CONTACT 
heading at the beginning of the preamble. To find out more about SBREFA 
on the internet, visit <a href="http://www.faa.gov/regulations_policies/rulemaking/sbre_act/">www.faa.gov/regulations_policies/rulemaking/sbre_act/</a>.

List of Subjects in 14 CFR Part 450

    Aircraft, Aviation safety, Environmental protection, 
Investigations, Reporting and recordkeeping requirements, Space 
transportation and exploration.

The Proposed Amendments

    For the reasons discussed in the preamble, the Federal Aviation 
Administration proposes to amend chapter III of title 14, Code of 
Federal Regulations, as follows:

PART 450--LAUNCH AND REENTRY LICENSE REQUIREMENTS

0
1. The authority citation for part 450 is revised to read as follows:

    Authority: 51 U.S.C. Chapter 509.


[[Page 70821]]


0
2. Revise Sec.  450.108(e) to read as follows:


Sec.  450.108  Flight abort.

* * * * *
    (e) End of flight safety limits. A flight does not need to be 
aborted to protect against high consequence events in uncontrolled 
areas for the remainder of a phase of flight beginning immediately 
after critical vehicle parameters are validated, if the vehicle is able 
to achieve a useful mission and the following conditions are met for 
the remainder of the phase:
* * * * *

    Issued under authority provided by 49 U.S.C. 106(f) and 51 
U.S.C. chapter 509 in Washington, DC.
Anh Minh Ngoc Nguyen,
Deputy Associate Administrator, Office of Commercial Space 
Transportation.
[FR Doc. 2026-22782 Filed 11-6-26; 8:45 am]
BILLING CODE 4910-13-P


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