Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
HQ-18-30 R2
February 4, 2020
This is information only. Recommendations
aren’t mandatory.
Introduction
This revised Special Airworthiness Information Bulletin (SAIB)
advises airplane operators, fixed base operators (FBOs), FAA repair
stations, Flight Standards District Offices (FSDOs), and foreign civil
aviation authorities of defective dye lots that jet fuel suppliers
should be aware of when conducting key fuel property tests required for
compliance with FAA-approved jet fuel operating limitations. These
operating limitations require the measurement of aromatic hydrocarbon
concentration in accordance with methods specified by the type
certificate (TC) holder. The FAA has not received any reports of jet
fuel being delivered to aircraft with improperly measured or missing
properties, but owners and operators of turbine engine-powered aircraft
should advise jet fuel suppliers that they cannot use fuel that has not
had this property measured in accordance with the specified ASTM
methods.
At this time, the airworthiness concern is not considered an unsafe
condition that would warrant airworthiness directive (AD) action under
Title 14 of the Code of Federal Aviation Regulations (14 CFR) part 39.
This revision identifies dye lot numbers that should not be used for
the measurement of aromatic concentration and identifies two new test
methods that will soon be available.
Background
The FAA relies on ASTM International to develop aviation fuel
specifications and test methods that TC holders may designate as
operating limitations for their approved products. The TC holders may
also use these ASTM specifications and test methods to develop their
own documents, such as company specifications, service bulletins and
instructions, or other documents, they designate as jet fuel operating
limitations. These aviation fuel operating limitations may be listed in
the product’s type certificate data sheet (TCDS), installation manual,
service instructions, or as limitations associated with a supplemental
type certificate (STC).
Aircraft and jet engine TC holders almost exclusively designate ASTM
Standard Specification D1655, “Standard Specification for Aviation
Turbine Fuels,” or company documents based on this specification, as a
jet fuel operating limitation. ASTM D1655, and the associated company
documents, specifies a maximum allowable concentration of aromatics of
25 volume percent measured by the ASTM Standard Test Method D13191,
“Standard Test Method for Hydrocarbon Types in Liquid Petroleum
Products by Fluorescent Indicator Adsorption.” However, production lot
numbers 3000000975 through 3000000980 of a dye necessary to conduct the
ASTM D1319 test were improperly formulated and will not provide an
accurate measurement of the aromatic concentration. ASTM D1655 also
references test method ASTM D63792, “Standard Test Method for
Determination of Aromatic Hydrocarbon Types in Aviation Fuels and
Petroleum Distillates—
High Performance Liquid Chromatography Method with Refractive Index
Detection,” which specifies a maximum allowable concentration of
aromatics of 26.5 volume percent, but this method is rarely used, is
not widely available, and is expensive to run.
Two additional test methods for measurement of the aromatics
concentration in jet fuel are expected to be added to ASTM D1655 by
mid-2020. These test methods are ASTM D8267, “Standard Test Method for
Determination of Total Aromatic, Monoaromatic and Diaromatic Content of
Aviation Turbine Fuels Using Gas Chromatography with Vacuum Ultraviolet
Absorption Spectroscopy Detection (GC-VUV)”, and ASTM D8305, “Standard
Test Method for Determination of the Aromatic Content and Polynuclear
Aromatic Content of Aviation Turbine Fuels by Supercritical Fluid
Chromatography,” Upon incorporation into ASTM D1655, jet fuel suppliers
may use these test methods to measure the aromatic concentration of jet
fuel.
Aromatic hydrocarbons are limited in jet fuel because they emit more
radiant energy during combustion than paraffinic hydrocarbons. At high
concentrations, this can have an adverse effect on turbine engine
combustor durability. They also produce more smoke and harmful
particulate emissions than paraffinic hydrocarbons and are limited due
to environmental concerns.
Jet fuel that has not been tested for aromatics concentration in
accordance with ASTM D1319, alternative test method ASTM D6379, test
methods ASTM D8267 or D8305 (after incorporation into ASTM D1655), or
that has been tested with ASTM D1319 with a dye from lot numbers
3000000975 through 3000000980, no longer meets the aviation fuel
operating limitations of airplanes certificated to operate on Jet A or
Jet A-1 fuel, and therefore, cannot be used on those airplanes.
The FAA has received reports that refiners and other fuel handlers are
finding it difficult to locate testing facilities that can conduct the
ASTM D1319 test due to the dye shortage. However, we anticipate that
the existing quality control procedures in the jet fuel supply chain
will prevent untested fuel from being supplied to aircraft. Operators
should continue to operate within their existing aviation fuel handling
procedures unless advised by their fuel supplier that the fuel does not
meet the specification requirements.
Recommendations
The FAA recommends that owners and operators of turbine engine-powered
aircraft advise fuel suppliers that operators may only use jet fuel
that has been tested for aromatics concentration in accordance with one
of the following methods:
ASTM D1319 with a dye other than lot numbers 3000000975 through 3000000980, or
ASTM D6379, or
ASTM D8267 or D8305, but only after incorporation into ASTM D1655
For Further Information Contact
Mark Rumizen, Senior Technical Specialist, FAA, 1200 District Avenue,
Burlington, MA 01803; mobile: (781) 402-4609; fax: (781) 238-7199;
email: mark.rumizen@faa.gov.