Rule2024-15853
Special Conditions: Airbus Model A321neo Extra-Long Range (XLR) Airplane; Cabin Evacuation-Protection From Fuel Tank Explosion Due to External Fuel-Fed Ground Fire
Primary source
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Published
July 18, 2024
Effective
July 18, 2024
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
These special conditions are issued for the Airbus Model A321neo XLR airplane. This airplane will have a novel or unusual design feature when compared to the technology envisaged by the airworthiness standards for transport category airplanes. This design feature is an integral rear center tank (RCT). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for fire-safety performance of fuel-tank skin or structure in a post-crash external fuel-fed ground fire. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.
Full Text
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<title>Federal Register, Volume 89 Issue 138 (Thursday, July 18, 2024)</title>
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[Federal Register Volume 89, Number 138 (Thursday, July 18, 2024)]
[Rules and Regulations]
[Pages 58253-58257]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-15853]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2023-2412; Special Conditions No. 25-868-SC]
Special Conditions: Airbus Model A321neo Extra-Long Range (XLR)
Airplane; Cabin Evacuation--Protection From Fuel Tank Explosion Due to
External Fuel-Fed Ground Fire
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the Airbus Model
A321neo XLR airplane. This airplane will have a novel or unusual design
feature when compared to the technology envisaged by the airworthiness
standards for transport category airplanes. This design feature is an
integral rear center tank (RCT). The applicable airworthiness
regulations do not contain adequate or appropriate safety standards for
fire-safety performance of fuel-tank skin or structure in a post-crash
external fuel-fed ground fire. These special conditions contain the
additional safety standards that the Administrator considers necessary
to establish a level of safety equivalent to that established by the
existing airworthiness standards.
DATES: Effective July 18, 2024.
FOR FURTHER INFORMATION CONTACT: Douglas Bryant, Engine and Propulsion
Section, AIR-625, Technical Policy Branch, Policy and Standards
Division, Aircraft Certification Service, Federal Aviation
Administration, 2200 South 216th Street, Des Moines, Washington 98198;
telephone and fax 206-231-3166; email <a href="/cdn-cgi/l/email-protection#d2b6bda7b5beb3a1fcbcfcb0a0abb3bca692b4b3b3fcb5bda4"><span class="__cf_email__" data-cfemail="f0949f85979c9183de9ede928289919e84b0969191de979f86">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
On September 16, 2019, Airbus applied for an amendment to Type
Certificate No. A28NM to include the new Model A321neo XLR series
airplane. The Airbus Model A321neo XLR series airplane, which is a
derivative of the Model A321neo Airbus Cabin Flex (ACF) currently
approved under Type Certificate No. A28NM, is a twin-engine transport
category aircraft that seats up to 244 passengers and has a maximum
takeoff weight of 222,667 lbs.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.101, Airbus must show that the Model A321neo XLR series
airplane meets the applicable provisions of the regulations listed in
Type Certificate No. A28NM, or the applicable regulations in effect on
the date of application for the change, except for earlier amendments
as agreed upon by the FAA.
If the Administrator finds that the applicable airworthiness
regulations (e.g., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Airbus Model A321neo XLR series
airplane because of a novel or unusual design feature, special
conditions are prescribed under the provisions of Sec. 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, or should any other model already included on
the same type certificate be modified to incorporate the same novel or
unusual design feature, these special conditions would also apply to
the other model under Sec. 21.101.
In addition to the applicable airworthiness regulations and special
conditions, the Airbus Model A321neo XLR series airplane must comply
with the fuel venting and exhaust emission requirements of 14 CFR part
34 and the noise certification requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The Airbus Model A321neo XLR series airplane will incorporate the
following novel or unusual design feature:
An integral RCT.
Discussion
The Airbus Model A321neo XLR series airplane incorporates an
integral RCT. This tank is a ``center'' fuel tank, that would, if
approved, be located in the airplane fuselage rather than in its wings.
The tank is a ``rear'' tank, that would be located aft of the center
wing fuel tank and behind the wheel bay; it would be in an area of the
lower section of the fuselage, partially replacing the aft cargo
compartment of the airplane from which this model is derived. The top
of the tank would be directly below the floor of the passenger cabin.
The fuel tank would be ``integral'' to the airplane, in that its walls
would be part of the airplane structure. The exterior skin of the
airplane fuselage would constitute part of the walls of the fuel tank,
and these areas are usually separate boundaries (not integral) on other
fuselage fuel tanks. An integral fuel tank may be referred to as a
conformal fuselage structural fuel tank since boundaries of the fuel
tank ``conform'' with the airplane exterior. The integral RCT is
installed in a location that may be exposed to the direct effects of
post-crash ground, or pool, fuel-fed fires. An external fuel-fed ground
fire or external fuel-fed pool fire is also referred to as `external
ground fire'.
The airworthiness standards applicable to the Model A321neo XLR do
not contain specific standards for post-crash fire-safety performance
of fuel-tank skin or structure. In addition, the integral RCT on the
A321neo XLR was not envisaged by the FAA when promulgating requirements
related to occupant protection when fuel tanks are exposed to external
fuel-fed fires. The FAA considered fuel tank designs in widespread use
on transport airplanes, including main fuel tanks and auxiliary fuel
tanks when promulgating requirements related to occupant protection.
Auxiliary fuel tanks are normally located in the center wing and within
cargo holds, and in such cases are sometimes referred to as an
auxiliary center tank (ACT).
Airplane manufacturers commonly incorporate a center wing fuel tank
as an auxiliary fuel tank to make fuel available for increasing the
flight range of the airplane. Continued expansion of range performance
requirements has resulted in airplane designs using other
[[Page 58254]]
areas of the airplane to carry fuel, such as incorporating fuel tanks
in the empennage and fuselage. The Airbus model A321neo XLR airplane
includes a center wing fuel tank, an integral RCT and the option for
additional ACTs within the fuselage. Unlike an integral RCT, a center
wing fuel tank and optional ACTs are not expected by the FAA or
manufacturers to be exposed to the direct effects of post-crash ground
fire because the fuel tank walls are not exterior airplane skin on the
center fuel tank or ACT designs.
Due to its unusual configuration, the A321neo XLR's integral RCT
will also not incorporate the insulation that usually lines the
fuselage skin of a modern transport category airplane. Therefore, the
FAA has issued, after notice and comment, a set of special conditions
that address that novel or unusual aspect of the A321neo XLR's integral
RCT with regard to certain of the FAA's regulatory requirements for
thermal/acoustic insulation installations, specifically 14 CFR
25.856(b). Those special conditions, No. 25-825-SC, require that the
lower half of the fuselage spanning the longitudinal location of the
RCT resist penetration from an external fuel-fed fire, to ensure that
the design provides the same level of passenger protection from such
fires as do the FAA's existing regulations for such insulation. The
special conditions herein address a different flammability aspect of
the A321neo XLR's integral RCT.
Pertinent to the fuel tank structure, post-crash-fire occupant
survivability is dependent on the time available for occupant
evacuation prior to fuel-tank breach or structural failure. Structural
failure can be a result of degradation in load-carrying capability
caused by a fuel-fed ground fire. Structural failure can also be a
result of over-pressurization caused by ignition of fuel vapors inside
the fuel tank.
Past experience indicates that occupant survivability following a
post-crash fire is greatly influenced by the size and intensity of any
fire that occurs. The ability of main fuel tanks, when they have
aluminum wing surfaces wetted by fuel on their interior surface, to
withstand post-crash-fire conditions, has been demonstrated by tests
conducted at the FAA William J. Hughes Technical Center. Results of
these tests have verified adequate dissipation of heat across wetted
aluminum fuel-tank surfaces so that localized hot spots do not occur,
thus minimizing the threat of explosion. This inherent capability of
aluminum to dissipate heat also allows the aircraft's lower surface,
which is also the fuel tank boundary, to retain its load-carrying
characteristics during a fuel-fed ground fire, and significantly delays
structural collapse or burn-through for a time interval that usually
exceeds evacuation times. In addition, as an aluminum fuel tank with
significant quantities of fuel inside is heated, fuel vapor accumulates
in the ullage space, exceeding the upper flammability limit relatively
quickly and thus reducing the threat of a fuel-tank explosion prior to
fuel-tank burn-through.
The center wing tank and optional ACTs are surrounded by fuselage
structure and would not be directly exposed to a post-crash ground
fire. This inherent separation is also expected to significantly delay
structural collapse or burn-through and reduce the threat of explosion
for a time interval that usually exceeds evacuation times. Service
history of conventional aluminum airplanes has shown that fuel-tank
explosions caused by ground fires have been rare on airplanes
configured with flame arrestors in the fuel-tank vent lines. The Model
A321neo XLR integral RCT may or may not have equivalent capability of
past designs approved with existing regulations, due to the RCT design
and location being integral with the fuselage.
There are several part 25 requirements that address fire-safety
performance of the fuel tanks and fuselage in the Model A321neo XLR
certification basis. However, these requirements do not directly or
adequately address standards for post-crash fire-safety performance of
fuel-tank skin or structure. These standards address failure conditions
or minimize the hazard to the occupants in the event ignition of
flammable fluids or vapors occurs. For example, Sec. 25.863 requires
applicants to minimize the probability of ignition and resultant
hazards if ignition occurs for flammable fluid systems on the airplane.
Another example is Sec. 25.981(a) which requires applicants to
demonstrate no ignition source may be present at each point in the fuel
tank or fuel tank system where catastrophic failure could occur due to
ignition of fuel or vapors. Specifically, Sec. 25.981(a)(1) requires
``determining the highest temperature allowing a safe margin below the
lowest expected autoignition temperature of the fuel in the fuel
tanks.'' Then Sec. 25.981(a)(2) requires ``demonstrating that no
temperature at each place inside each fuel tank where fuel ignition is
possible will exceed the temperature determined under paragraph (a)(1)
of this section. This must be verified under all probable operating,
failure, and malfunction conditions of each component whose operation,
failure, or malfunction could increase the temperature inside the
tank.'' In addition, Sec. 25.981(a)(3) requires ``except for ignition
sources due to lightning addressed by Sec. 25.954, demonstrating that
an ignition source could not result from each single failure, from each
single failure in combination with each latent failure condition not
shown to be extremely remote, and from all combinations of failures not
shown to be extremely improbable, taking into account the effects of
manufacturing variability, aging, wear, corrosion, and likely damage.''
These airworthiness requirements address ignition sources and are part
of the FAA's regulatory framework for preventing fires and explosions;
however, taken together, they do not adequately address the potential
for a post-crash external ground fire to affect the safety of airplane
occupants.
The FAA therefore determined that the airworthiness standards
applicable to the Model A321neo XLR airplane do not contain adequate
standards for post-crash fire-safety performance of fuel-tank skin or
structure. The FAA therefore proposed that special conditions are
needed for the Model A321neo XLR airplane, because the integral RCT
design, including location in the lower fuselage, is considered an
unusual or novel design feature that could expose the RCT to an
external ground fire. Factors influencing occupant survival time when a
fuel tank is exposed to a ground-fed fire are the structural integrity
of the tank; burn-through resistance; flammability of the tank; and the
presence of auto-ignition threats during exposure to a fire. As
previously discussed, the FAA issued Special Conditions No. 25-825-SC
to address the novel or unusual aspect of the A321neo XLR's integral
RCT with regard to requirements for thermal/acoustic insulation
installations. The FAA considers the occupant survival time related to
the burn-through resistance of the integral RCT to be adequately
accounted for in those special conditions.
These special conditions address standards for post-crash fire-
safety performance of fuel-tank skin or structure by proposing a
requirement to prevent the ignition of fuel vapor during an external
fuel-fed ground fire. These special conditions include accounting for
the potential for hot surface ignition created by the external fuel-fed
fire. As described in FAA Advisory Circular 25.981-1D, ``Fuel Tank
Ignition Source Prevention Guidelines,'' hot surfaces that can exceed
the autoignition temperature of the flammable vapor under consideration
are considered to be ignition sources. The FAA intends
[[Page 58255]]
this requirement to adequately protect the airplane occupants from the
consequences of an integral RCT exposed to an external fuel-fed ground,
or pool fire.
The intention of the requirement for the design to prevent ignition
is for the applicant to show that ignition sources do not occur, such
as from a hot surface, due to the external heat applied to the integral
RCT from an external fuel-fed ground fire. Where previously discussed,
Sec. 25.981(a) requires applicants to demonstrate that no ignition
source may be present but does not specifically address ignition due to
an external fuel-fed ground fire.
To provide the same level of safety as provided by the relevant
regulations in this model's certification basis, Airbus must
demonstrate that the Model A321neo XLR series airplane has sufficient
post-crash fire-safety performance of fuel-tank skin or structure to
enable occupants to safely evacuate in the event that the integral RCT
is exposed to an external fuel-fed ground fire.
The FAA assessed post-crash-survival time during the adoption of
Sec. 25.856 and revisions to appendix F to part 25 at Amendment 25-111
for fuselage burn-through protection. Studies conducted by and on
behalf of the FAA indicated that following a survivable accident,
prevention of fuselage burn-through for approximately 5 minutes can
significantly enhance survivability.
The FAA would consider Airbus showing the design prevents ignition
of fuel tank vapors in the integral RCT during at least 5 minutes of
exposure to an external fuel-fed ground fire as a sufficient time
duration for the purposes of these special conditions. The time
duration of 5 minutes is consistent with the studies mentioned above
showing prevention of fuselage burn-through for approximately 5 minutes
enhances occupant survivability. The requirements of the special
conditions and the time duration are consistent with the European Union
Aviation Safety Agency Special Conditions No. SC-D25.863-01, Cabin
Evacuation--Protection from Fuel Tank Explosion due to External Fuel
Fed Ground Fire applicable to integral RCTs.
Airbus may consider a flammability reduction system or ignition
mitigation means that complies with Sec. 25.981 when showing
compliance with these special conditions, provided the system's
performance is demonstrated to meet the special conditions. As
discussed previously, showing compliance with only Sec. 25.981(b) is
insufficient to show post-crash fire-safety performance of fuel-tank
skin or structure. Airbus must also meet these special conditions.
The special conditions contain the additional safety standards that
the Administrator considers necessary to establish a level of safety
equivalent to that established by the existing airworthiness standards.
Discussion of Comments
The FAA issued Notice of Proposed Special Conditions No. 25-23-06-
SC for the Airbus Model A321neo XLR airplane, which was published in
the Federal Register on May 7, 2024 (89 FR 38004). The FAA received
several comments from an individual regarding the proposed special
conditions.
The commenter requested the FAA consider how passengers will be
made aware of what the commenter described as the ``unique''
configuration of a fuel tank directly under passenger seats in what is
traditionally a location for baggage and cargo. The commenter suggested
that the FAA make passengers aware of their proximity to the airplane
fuel.
In the Notice of Proposed Special Conditions No. 25-23-06-SC, which
was published in the Federal Register, the FAA informed the public of
the proposed configuration. As stated in that Notice, while the subject
integral RCT is a novel or unusual design feature, the configuration is
not unique. Many transport airplanes incorporate fuel tank
configurations that result in fuel in close proximity to some
passengers. These special conditions address standards for post-crash
fire-safety performance of fuel-tank skin or structure. No changes were
made to these special conditions as a result of this comment.
The commenter requested the FAA clarify how it addressed the
crashworthiness requirements of a fuel tank integral to the fuselage
applied by the FAA to the Model A321neo XLR series airplane. The
commenter recognized the request is beyond the proposed special
conditions.
The FAA disagrees that additional clarification of crashworthiness
requirements for the RCT is necessary for these special conditions. The
FAA discussed the type certification basis of the Model A321neo XLR
series airplane in the Notice of Proposed Special Conditions No. 25-23-
06-SC. The crashworthiness requirements applicable to the Model A321neo
XLR series airplane are addressed by the type certification basis, and
as acknowledged by the commenter, are outside the scope of these
special conditions. Therefore, no changes were made to these special
conditions as a result of this comment.
The commenter requested the FAA explain what considerations the FAA
is making relative to an otherwise survivable accident when the RCT is
ruptured and there is an external fuel-fed ground fire already present.
The FAA infers that the commenter requests the FAA further clarify
the requirements the FAA applied to the Model A321neo XLR series
airplane related to a ruptured RCT in addition to an external fuel-fed
ground fire. The FAA considers the commenter's request to be beyond the
scope of these special conditions, which addresses standards
specifically for the post-crash fire safety performance of fuel-tank
skin or structure by establishing a requirement to prevent the ignition
of fuel vapor during an external fuel-fed ground fire.
The FAA stated in Notice of Proposed Special Conditions No. 25-23-
06-SC, and restated in the discussion above, that several part 25
requirements applicable to the Model A321neo XLR series airplane
address fire-safety performance of the fuel tanks and fuselage in the
Model A321neo XLR certification basis. These standards address failure
conditions or minimize the hazard to the occupants in the event
ignition of flammable fluids or vapors occurs. The potential for a
ruptured RCT is thus already addressed in the Model A321neo XLR
certification basis. Therefore, no changes were made to these special
conditions as a result of this comment.
The commenter stated that ``the applicant should show not that the
design prevents but that it eliminates the possibility that ignition
will occur.'' The FAA interprets this statement as a request that the
FAA require the applicant to fully eliminate any possibility of fuel
ignition in the RCT, rather than to minimize the probability of
ignition to an acceptable level through ignition-preventative design
measures. The FAA does not agree that it is practical to eliminate the
possibility that ignition will occur from a design in the case of a
fuel tank exposed to a post-crash fuel-fed ground fire. Service
experience has shown that existing designs would not meet this standard
since aircraft fuel tanks exposed to an external fuel-fed ground fire
would eventually experience conditions that would support fuel tank
ignition (for example, refer to the fuel tank explosions discussed in
the China Airlines Boeing 737 accident report \1\). These special
conditions are necessary
[[Page 58256]]
to establish a level of safety equivalent to that established by the
existing airworthiness standards. The commenter's proposal would set a
requirement beyond existing airworthiness standards and place an
unnecessary burden on applicants. Therefore, no changes were made to
these special conditions as a result of this comment.
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\1\ Japan Transport Safety Board, Aircraft Accident
Investigation Report, AA2009-7, China Airlines B18616, August 28,
2009. <a href="http://www.mlit.go.jp/jtsb/eng-air_report/B18616.pdf">www.mlit.go.jp/jtsb/eng-air_report/B18616.pdf</a>.
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The commenter requested the applicant show compliance by testing
the capability of the design. The FAA acknowledges that some testing
may be necessary to show compliance with these special conditions but
does not agree that only testing must be used. To obtain a type
certificate the applicant must follow the requirements of Sec.
21.33(b)(1). No specific aspect of the proposed integral RCT, nor
requirement of these special conditions, necessitates or requires that
the applicant must demonstrate by test to show compliance. These
special conditions do not include specific means of compliance since
more than one means of compliance may be acceptable. No changes were
made to these special conditions as a result of this comment.
The commenter requested the FAA define the flame size and intensity
the applicant must use for representing an external fuel-fed ground
fire when showing compliance with these special conditions. Such
definition is unnecessary. A post-crash external fuel-fed ground fire
depends on many factors, including the specific airplane design and
fuel types approved for use. Well-established industry standard fire
test methods currently exist for powerplant installation fire
protection, as well as cabin safety fire protection, that include
standardized fire test conditions that are intended to represent a
large pool fire. Applicants may consider these standards and any other
available fire testing method, if shown to be applicable to these
special conditions, when developing test methods for these special
conditions. The FAA does not consider it is necessary to identify any
specific test conditions as requirements for these special conditions.
Therefore, no changes were made to these special conditions as a result
of this comment.
The commenter requested the FAA clarify what it means by sufficient
time to evacuate to include occupants to move safely away from the
aircraft due to the potential impact from a fuel tank explosion to the
surrounding area. The commenter stated the 90-second evacuation test
time would be insufficient and the 5-minute time referenced in the
Notice of Proposed Special Conditions No. 25-23-06-SC may be acceptable
if justified by the applicant. The commenter also stated the applicant
should include an assessment of other aircraft accidents and time to
move survivors clear of the aircraft in the justification.
The FAA does not agree to specify a requirement in these special
conditions for additional time for airplane occupants to move away from
the airplane once safely evacuated. These special conditions are
necessary to establish a level of safety equivalent to that established
by the existing airworthiness standards. The considerations of moving
occupants away from the airplane as proposed by the commenter apply
generally to all airplane designs and are not specifically associated
with or affected by the novel or unusual design feature of the RCT.
Since these special conditions are intended to establish the same level
of safety as the relevant regulations in this model's certification
basis, by providing sufficient time for a safe evacuation of all
occupants after the initiation of an external fuel-fed ground fire, it
is unnecessary to include an additional assessment to account for
moving occupants away from the airplane. Therefore, no changes were
made to these special conditions as a result of this comment.
The commenter requested that the FAA clarify how it considered
maintainability of the design features needed to ensure the original
design intent for each airplane as it ages. The FAA infers the
commenter requests the FAA to include requirements for the airplane
manufacturer to require airplane operators to maintain the critical
features of the type design associated with these special conditions
for the life of the airplane.
The FAA agrees that critical features that need to be identified by
the applicant and maintained in service should be appropriately
managed; however, the FAA does not agree these special conditions
should include a dedicated requirement to address this need. The FAA
considers that the Model A321neo XLR certification basis already
includes airworthiness standards that account for ensuring critical
design features are maintained in service. Specifically, Sec. Sec.
25.901(c) and 25.1309(b) include requirements for system safety
analysis of propulsion and airplane systems. FAA Advisory Circular 25-
19A, Certification Maintenance Requirements, provides guidance on the
selection, documentation, and control of Certification Maintenance
Requirements (CMR). A CMR is a required scheduled maintenance task
established during the design certification of the airplane systems as
an operating limitation of the type certificate. The FAA considers it
unnecessary to include additional requirements in these special
conditions to maintain the type design of critical features since the
Model A321new XLR certification basis includes airworthiness
requirements that address this issue. Therefore, no changes were made
to these special conditions as a result of this comment.
In conclusion, no changes were made to the special conditions as a
result of these comments, and the special conditions are adopted as
proposed.
Applicability
As discussed above, these special conditions are applicable to the
Airbus Model A321neo XLR series airplane for which they are issued.
Should the type certificate for that model be amended later to include
any other model that incorporates the same novel or unusual design
feature, or should any other model already included on the same type
certificate be modified to incorporate the same novel or unusual design
feature, these special conditions would apply to the other model as
well.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register. However, as the certification date for the Airbus
Model A321neo XLR series airplane is imminent, the FAA finds that good
cause exists to make these special conditions effective upon
publication.
Conclusion
This action affects only a certain novel or unusual design feature
on one model series of airplane. It is not a rule of general
applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
Authority Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Airbus Model A321neo XLR series
airplanes.
Cabin Evacuation--Protection From Fuel Tank Explosion Due to External
Fuel-Fed Ground Fire.
The applicant must show the design prevents ignition of fuel tank
vapors (due to hot surface) from occurring in
[[Page 58257]]
the integral rear center tank during the time required for evacuation.
The applicant's showing must also demonstrate that the design provides
sufficient time for a safe evacuation of all occupants after the
initiation of an external fuel-fed ground fire.
Issued in Kansas City, Missouri, on July 12, 2024.
Patrick R. Mullen,
Manager, Technical Policy Branch, Policy and Standards Division,
Aircraft Certification Service.
[FR Doc. 2024-15853 Filed 7-17-24; 8:45 am]
BILLING CODE 4910-13-P
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