ASTM F3397/F3397M-21

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F3397/F3397M − 21
Standard Practice for
Aeroplane Turbine Fuel System Hot Weather Operations
ThisstandardisissuedunderthefixeddesignationF3397/F3397M;thenumberimmediatelyfollowingthedesignationindicatestheyear
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This standard practice provides requirements for per- 2.1 ASTM Standards:
forming hot weather testing as a means of compliance to D910 Specification for Leaded Aviation Gasolines
Subsection 7.7 of Specification F3063/F3063M for kerosene- D1655 Specification for Aviation Turbine Fuels
type turbine fuels such as Jet A and Jet A-1 (Specification F3063/F3063M Specification for Aircraft Fuel Storage and
D1655). The appendix provides supplemental information and Delivery
considerations for turbine fuel system hot weather operation. F3064/F3064M Specification for Aircraft Powerplant
The material was developed through open consensus of inter- Control, Operation, and Indication
national experts in general aviation. F3179/F3179M Specification for Performance of Aircraft
2.2 FAA Standards:
1.2 An applicant intending to propose this information as
AC 23-16A Powerplant Guide for Certification of Part 23
Means of Compliance for a design approval must seek guid-
Airplanes and Airships
ance from their respective oversight authority (for example,
CAR 3 Airplane Airwothiness – Normal, Utility, and Acro-
published guidance from applicable civil aviation authorities
batic Categories
(CAAs)) concerning the acceptable use and application
thereof. For information on which oversight authorities have
2.3 CRC Report:
accepted this standard (in whole or in part) as an acceptable
CRC AV-20-14 Determination of Heat of Vaporization and
Means of Compliance to their regulatory requirements herein-
Creating Enthalpy Diagrams for Several Common Jet
after (“the Rules”), refer to the ASTM Committee F44 web
Fuels
page (www.astm.org/COMMITTEE/F44.htm).
2.4 Fuel Standards:
1.3 The values stated in either SI units or inch-pound units GOST 10227 Russian Standards and Regulations: Jet Fuel
are to be regarded separately as standard. The values stated in Specification
each system are not necessarily exact equivalents; therefore, to MIL-DTL-5624 Detail Specification: Turbine Fuel,
ensure conformance with the standard, each system shall be
Aviation, Grades JP-4 and JP-5
used independently of the other, and values from the two
systems shall not be combined. 3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions:
safety concerns, if any, associated with its use. It is the
3.1.1 fuel volatility, n—thefuel’stendencytoevaporate(that
responsibility of the user of this standard to establish appro- is, change to a vapor from a fluid).
priate safety, health, and environmental practices and deter-
3.1.2 vapor pressure, n—pressure exerted by its vapor in
mine the applicability of regulatory limitations prior to use. A
equilibrium with the liquid at a specific temperature with the
specific warning is given in Section 6 on Test Setup.
absence of air over the fuel.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Development of International Standards, Guides and Recom-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
mendations issued by the World Trade Organization Technical
the ASTM website.
Barriers to Trade (TBT) Committee.
Available from Federal Aviation Administration (FAA), 800 Independence
Ave., SW, Washington, DC 20591, http://www.faa.gov.
Available from Coordinating Research Council (CRC), 5755 North Point
This practice is under the jurisdiction of ASTM Committee F44 on General Parkway, Suite 265, Alpharetta, GA 30022, https://www.crcao.org.
Aviation Aircraft and is the direct responsibility of Subcommittee F44.40 on Available from Russian Gost, LLC. P.O. Box 366, Alief, TX 77411, https://
Powerplant. www.russiangost.com.
Current edition approved Jan. 1, 2021. Published February 2021. DOI: 10.1520/ Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
F3397_F3397M-21. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3397/F3397M − 21
3.1.3 weathering, v—reduction of fuel volatility when given elevated temperatures is hazardous to ground and flight per-
sufficient time, agitation, temperature cycles, or pressure sonnel. Safety precautions should be taken.)
changes, or combinations thereof.
6.3 Aeroplane:
3.2 Definitions of Terms Specific to This Standard: 6.3.1 The aeroplane shall be in a configuration representa-
3.2.1 initial boiling point, n—for the purpose of this stan- tive of type design, particularly with respect to installations
dard practice, the temperature and pressure at which a fuel that affect fuel system performance. Instrumentation and other
begins vapor formation. modifications shall not interfere with the test results to be
considered representative of type design system performance.
3.2.2 vapor formation, v—for the purpose of this standard
6.3.2 Theweightandcenterofgravityoftheaeroplaneshall
practice, the transition of a liquid fuel to fuel vapor, which may
be within the limits prescribed by the aeroplane flight manual
result in vapor lock or cavitation within the fuel system.
(AFM).
6.3.3 Fuel loading shall be in accordance with the following
4. Significance and Use
requirements, unless otherwise coordinated with the CAA:
4.1 This specification provides designers of general aviation
6.3.3.1 The aeroplane shall be loaded with full fuel if the
aeroplanes a process for evaluating and testing a fuel system
fuel system is not subject to heat rejection described in 5.2 that
underhotweatherconditionstoensuresafetyduringflight.The
canheatfuelbeyondmaximumtemperaturesrequiredby6.2.2.
specificationisapplicabletokerosene-typeturbineenginefuels
and fuel systems for traditional general aviation aeroplanes. NOTE 1—A full fuel volume results in higher fuel temperatures during
the flight due to a larger volume retaining more heat. A fuel system with
no heat rejection and a full fuel load, for example, will retain more heat
5. Test Prerequisites
resulting in higher fuel temperatures during flight.
5.1 Determine the fuel grade requested for approval that is
6.3.3.2 The aeroplane shall be loaded with a “low” fuel
the most susceptible to vapor formation (that is, the most
quantity if the fuel system is subject to heat rejection described
volatile). This is indicated by the highest fuel vapor pressure.
in 5.2 that can heat fuel above the maximum ambient tempera-
In addition, volatility is supported by distillation data; a higher
tures required by 6.2.2.
percentage of fuel recovered at lower temperatures indicates a
higher volatility. NOTE 2—The critical test configuration for a fuel system with heat
rejection is with a reduced fuel volume, which will be more susceptible to
5.2 Determine any sources of heat rejection, within or
the effects of heat rejection, particularly if the heat rejection is capable of
adjacent to the fuel system, into the fuel and what portions of
warming the fuel beyond hot weather conditions. Note that “low” fuel
the fuel system are directly affected. quantity is not necessarily the “fuel low level” quantity satisfying
Specification F3064/F3064M, but a volume of fuel not more than what is
5.2.1 Each source of heat rejection shall be evaluated.
sufficient to safely execute the test.
5.2.2 The evaluation shall consider heat rejection from
6.3.3.3 If multiple tanks that directly feed an engine are
multiple sources in accordance with their duty cycles.
symmetric, then only testing one of the symmetric tanks is
6. Test Setup required.
6.3.3.4 If multiple tanks that directly feed an engine are not
6.1 Ambient Conditions—The flight test shall be conducted
symmetric, then the testing shall evaluate all such tanks.
with outside air temperatures at 29 °C [85 °F] or higher
measured at 1.2 m to 1.8 m [4 ft to 6 ft] above the runway 6.4 Data Recording and Instrumentation:
surface. 6.4.1 The following data shall be recorded, either manually
or automatically, throughout the test:
6.2 Fuel:
6.4.1.1 Fuel temperature in the fuel tank under test that
6.2.1 Do not allow the fuel to weather by exposing it to the
directly feeds the engine.
atmosphere for extended periods prior to the test.
6.4.1.2 Usable fuel quantity, including at takeoff.
6.2.2 The fuel shall be heated such that the fuel temperature
6.4.1.3 Fuel delivery to the engine, either fuel pressure or
at takeoff is at least the maximum temperature for which the
fuel flow.
cooling requirements of Specification F3064/F3064M have
6.4.1.4 Main pump operation, as applicable.
been shown or 43 °C [110 °F], whichever is greater. The fuel
6.4.1.5 Emergency pump operation, as applicable.
temperatureismeasuredwithinthefuelstoragesystemnearthe
6.4.1.6 Pressure altitude.
intake of the fuel distribution system.
6.4.1.7 Ambient air temperature.
6.2.2.1 The fuel shall be heated artificially when the fuel
6.4.1.8 Airspeed.
cannot be raised to the required temperature by parking the
6.4.1.9 Engine power or other representative parameter,
aeroplane in full sun.Artificial heating should be accomplished
engine inlet temperature, exhaust gas temperature, and fuel
within 90 min to prevent excessive weathering. Extended fuel
flow, as appropriate.
heating time may be required for aeroplanes with large fuel
storage systems. Fuel heating beyond 90 min should be
7. Test Procedure
coordinated with the CAA.
7.1 Prepare the test setup as established by Section 6.
6.2.2.2 Heating fuel beyond the initial boiling point shall be
avoided in order to prevent weathering prior to the test. 7.2 Begin the flight test as quickly as is practical once the
6.2.2.3 Do not agitate or excessively handle the fuel during fuel temperature within the fuel tank reaches the fuel tempera-
any heating process. (Warning—Heating and handling fuel at ture determined in 6.2.2.
F3397/F3397M − 21
NOTE 3—Emergency fuel pump operation might be required for the
7.3 Conduct the flight test as follows:
continued safety of the flight.
7.3.1 Throughout the test:
7.3.1.1 The fuel system shall be operated normally in
8. Post-Test
accordance with the AFM;
7.3.1.2 Maintain the speed and performance limits in accor-
8.1 Evaluate the test results data and determine if the
dance with the AFM and in accordance with the requirements
pass/fail criteria in 7.5 was met.
specified in Specification F3179/F3179M;
8.1.1 Consider additional testing to evaluate any test points
7.3.1.3 Do not operate the emergency fuel pumps if they are
that exhibited fuel flow, fuel pressure, or engine power
being considered for use as “backup” pumps, as this test may
fluctuations to determine if additional testing is required.
be used to establish the maximum pressure altitude for opera-
8.2 Determine any AFM procedures, such as fuel pump
tion with the emergency pumps off; and
usage, required for hot weather operation.
7.3.1.4 The pilot shall note any unusual or unexpected
engine or fuel system fluctuations at the point in the flight at
8.3 Determine any limitations, such as outside air
which they occur.
temperature, fuel temperature, or reduced service ceiling, or
7.3.2 Perform a takeoff using takeoff power.
combinations thereof, required for hot weather operation.
7.3.3 Climb to the maximum approved altitude using maxi-
8.4 Documentanyproceduresorlimitationsrequiredforhot
mum continuous power at the maximum vertical climb rate
weather operation in the AFM.
(Vy).
7.3.4 Establish maximum continuous cruise power and
9. Applicability of Results
maintain until engine speed, airspeed, and fuel flow stabilize.
7.3.5 Reduce power to a low to moderate cruise power
9.1 Successful test results for one grade of fuel may be
setting and maintain altitude for 5 min.
considered to envelope less volatile fuel grades requested for
approval.
7.4 Perform a normal descent and landing.
9.1.1 Any procedures or limitations for hot weather opera-
7.5 Pass/fail Criteria:
tion with the most volatile fuel shall be applied to all less
7.5.1 The fuel pressure or flow, as applicable, remains at or
volatilefuelgradesunlessadditionaltestinginaccordancewith
above the minimum prescribed by the engine manufacturer
9.1.1 is performed for those less volatile fuels. The test may be
throughout the test;
repeated as desired for fuel grades that are less volatile than a
7.5.2 The fuel temperature remains at or below the maxi-
tested fuel grade. This is typically done to minimize or remove
mum prescribed by the engine manufacturer throughout the
procedures or limitations resulting from testing of the more
test;
volatile fuel.
7.5.3 The fuel pressure or flow does not fluctuate exces-
9.1.2 Any differing procedures or limitations for specific
sively throughout the test; and
fuel grades shall be specified in the AFM.
7.5.4 No engine malfunctions occur due to fuel flow or
pressure interruption throughout the test.
10. Keywords
7.5.5 The operation of the emergency fuel pump, manually
or automatically, during the test due to excessive fuel pressure 10.1 cavitation; fuel system testing; heat rejection; hot fuel;
or fuel flow fluctuations is considered a test failure and will hot weather operation; hot weather testing; turbine fuel hot
require a retest. weather; turbine fuel testing; vapor formation; vapor lock
APPENDIXES
(Nonmandatory Information)
X1. REGULATORY DISCUSSION
X1.1 The initial regulatory requirement for fuel system hot baseline for fuel temperature prior to commencement of the
weather testing with fuel at 43 °C [110 °F] appeared in the
test. This limit is discussed within FAA AC 23-16A with the
Civil Airworthiness Regulation (CAR) 3 in 1949. The most
following explanation: “… autogas heated to 110°F in a vented
common fuels at the time were fuels similar to AvGas
vessel (i.e., an airplane fuel tank) will boil off approximately
(SpecificationD910)forreciprocatingenginesandwide-cutjet
18 percent of its mass in the form of non-recoverable vapors.
fuels similar to JP-4 (MIL-DTL-5624) for turbine engines.The
These lost constituents are primarily the highly volatile
initial boiling point of these fuels is in the temperature and
fractions, mainly pentane and butane, the fuel constituents that
pressure regime of hot weather conditions.
can cause vapor lock problems. In contrast, aviation gasoline
will boil off approximately 1 percent of its mass when heated
X1.2 In previous CAA regulations and guidance, a fuel
to 110°F.”
temperature of 43 °C [110 °F] has been established as a
...