This page contains answers to common questions handled by our support staff, along with some tips
and tricks that we have found useful and presented here as questions.
Note: In these answers we will follow a few shorthand conventions for describing user-interface
procedures. Key combinations will be presented like this: Ctrl+Alt+Delete, which means that you
should press and hold down the Control key, the Alt key, and the Delete key at the same time.
Menu selections will be presented like this: File->Open, which means that you should open the File
menu, and then make the Open selection.
- How do I ensure clean fuel ?
- What is Avgas
- What is Jet Fuel?
- What additives are used?
Clean fuel is something our customers take for granted, but we can't guarantee
the clean, on-spec fuel we deliver gets into your aircraft.
There are three key checkpoints that require attention.
1. The Tank. As steel tanks age rust can build up on the interior walls
when the tank is low on fuel. condensation is also an issue when the fuel tank
is low. Inspect the interior of your tank with an explosion proof
Flashlight. you should wear an approved benzene mask and eye
protection. if you see rust you may decide to use the tank for non
aviation products. Water can usually be drained from the bottom tank
bung on overhead tanks, or with a small pump on ground level tanks. it
is recommended to hire an approved contractor to clean your tank and dispose
of the residue. Call us for a contractor reference or for a Quote on a
new tank install.
2. Filtration. An aviation <1 micron filtration unit should be
placed on the outlet of any aviation tank. They should be replaced if flow
decreases or after 3 years. call us for a great selection of filters, perfect
for your application.
3. Hose & Nozzle. often given little consideration, Hose
condition can seriously affect your aircraft fuel system. if your hose
is cracking or flaking on the outside, it's potentially happening on the
inside. Replace any fuel hose with visible cracks or flaws on
inspection. Nozzles are your last checkpoint, and therefore most
important. Proper Aviation nozzles have a 100 mesh screen in the nozzle
tube that can easily inspected. these screens can catch moisture, contamination
and even cracking hose rubber. not having a
nozzle screen is taking a chance that unwanted particles are entering your
fuel system. It is also important to protect the nozzle from external
contamination. when not in use it should be in a clean dry
location.
Aviation Gasoline (AVGAS)
Avgas is
gasoline fuel for reciprocating piston engined aircraft. As with all gasolines,
Avgas is very volatile and is extremely flammable at normal operating
temperatures. Procedures and equipment for safe handling of this product must
therefore be of the highest order.
Avgas grades
are defined primarily by their octane rating. Two ratings are applied to
aviation gasolines (the lean mixture rating and the rich mixture rating) which
results in a multiple numbering system, e.g. Avgas 100/130 (in this case the
lean mixture performance rating is 100 and the rich mixture rating is 130).
In the past,
there were many different grades of aviation gasoline in general use, e.g.
80/87, 91/96, 100/130, 108/135 and 115/145. However, with decreasing demand
these have been rationalised down to one principle grade, Avgas 100/130. To
avoid confusion and to minimise errors in handling aviation gasoline, it is
common practice to designate the grade by just the lean mixture performance,
i.e Avgas 100/130 becomes Avgas 100.
More recently,
an additional grade was introduced to allow one fuel to be used in engines
originally designed for grades with lower lead contents: this grade is called
Avgas 100LL, the LL standing for 'low lead'. Only 100LL is sold in Canada.
Aviation
gasoline is produced to the latest version of the Canadian Standard
CAN/CGSB-3.25 Aviation Gasoline.
In specifying
requirements for aircraft piston-engine fuel the principle objective is to
ensure that the fuel has satisfactory combustion qualities. The most important
property is the anti-knock rating, but others such as the distillation range
and volatility are also important because of their influence on mixture
distribution and cold starting. Other specification items are included to
ensure that the fuel has a good storage life, will not corrode engine or fuel
system components and can be satisfactorily supplied to the engine under all
operating conditions.
All equipment
and facilities handling Avgas are colour coded and display prominently the API
markings denoting the actual grade carried. Currently the two major grades in
use internationally are Avgas 100LL and Avgas 100. To ease identification the
fuels are dyed, i.e. Avgas 100LL is coloured blue, while Avgas 100 is coloured
green.
Avgas fueling
nozzles for overwing dispensing are painted red. To help prevent the
possibility of jet fuel being supplied to a piston engined aircraft. Nozzles
for jet fuel (painted black) are normally a different shape and larger
diameter than the aperture on most aircraft Avgas tanks.
Shell does not
supply or recommend motor gasoline for use in light aircraft.
Aviation Turbine Fuel (Jet Fuel)
In specifying
requirements for jet fuels, the main objective is to ensure that fuel systems
will function satisfactorily over a wide range of temperatures and pressures.
These environmental factors can be very severe owing to the conditions under
which modern jet aircraft operate. In addition to these requirements, engine
developments and the continual effort to lengthen the period between engine
overhauls has led to the introduction of a number of new sophisticated
specification requirements, far removed from those for aviation gasoline.
Among these are the need for high thermal stability, low luminosity and compatibility
with certain fuel system materials.
Aviation kerosene
is the most common fuel in commercial use. The standard civil grade
of Shell aviation turbine fuel, Jet A-1, is manufactured to meet the
requirements of the latest version of the Canadian Standard CAN/CGSB-3.23. It
also meets Aviation Fuel Quality Requirements for Jointly Operated Systems (AFQRJOS)
"Check List". The Check List was drawn up by the major international
oil supply companies to ensure uniform quality standards for civil jet fuels
world-wide (excluding USA) and comprises the most restrictive requirements of
the major fuel specifications. Compliance with Check List requirements thus
guarantees meeting the requirements of the individual specifications.
There are only
limited civil requirements for the other standard civil grade of Shell
aviation turbine fuel, Jet B, which consequently is not covered by the AFQRJOS
Check List. It is manufactured to meet the latest version of the Canadian
Standard CAN/CGSB3.22. It also meets DERD2486, ASTM D1655 (Jet B) and IATA
Guidance Material for wide cut fuel.
Civil Jet Fuels
Aviation
turbine fuels are used for powering jet and turbo-prop engined aircraft.
Outside former communist areas, there are currently two main grades of turbine
fuel in use in civil commercial aviation: Jet A-1 and Jet A, both are kerosene
type fuels. There is another grade of jet fuel, Jet B which is a wide cut kerosene
(a blend of gasoline and kerosene) but it is rarely used except in
cold climates, such as northern Canada.
Jet
A-1
Jet A-1 is a kerosene
grade of fuel suitable for most turbine engined aircraft. It is
produced to a stringent internationally agreed standard, has a flash point
above 38ºC (100ºF) and a freeze point maximum of -47ºC. Jet A-1 is the
usual fuel for turbines in Canada. Jet A-1 meets the latest version
requirements of Canadian Standard CAN/CGSB-3.23 Aviation Turbine Fuel, Kerosene
Type, Jet A-1 Grade. It also meets British specification DEF STAN
91-91, ASTM specification D1655 and IATA Guidance Material (Kerosene Type),
NATO Code F-35.
Jet
A
Jet A is a
similar kerosene type of fuel, produced to the latest version of the Canadian
Standard CAN/CGSB-3.23 Jet A Grade, and normally only available in the USA. It
has the same flash point as Jet A-1 but a higher freeze point maximum (-40ºC).
It also meets the requirements of ASTM D1655 (Jet A) specification. Jet A is
used in summer at some airports in Canada and is usually imported from the
USA.
Jet
B
Jet B is a
distillate covering the naphtha and kerosene fractions. It can be used as an
alternative to Jet A-1 but because it is more difficult to handle (higher
flammability), there is only significant demand in very cold climates where
its better cold weather performance is important. In Canada it is supplied
against the latest version of the Canadian Specification CAN/CGSB 3.23. Jet B
is used by the military and in general aviation (very limited use).
Military Jet Fuels
Shell jet fuels
for military use are basically the same as the civil grades but generally
include special additives, and a special high flash kerosene is also
available.
F-40
(or JP-4)
JP-4 is the
military equivalent of Jet B with the addition of corrosion inhibitor and
de-icing additives; it meets the requirements of the latest version of the
Canadian Standard CAN/CGSB-3.22 for Aviation Turbine Fuel, Wide Cut Type, F-40
Grade. JP-4 also meets the requirements of the British Specification DEF STAN
91-88 AVTAG/FSII (formerly DERD 2454), where FSII stands for Fuel Systems
Icing Inhibitor. Nato Code F-40.
F-44
(or JP-5)
JP-5 is a high
flash point kerosene meeting the latest requirements of the Canadian
Specification 3-GP-24C and US Military Specification MIL-PRF-5624S Grade JP-5.
JP-5 also meets the requirements of the British Specification DEF STAN 91-86
AVCAT/FSII (formerly DERD 2452). Nato Code F-44.
F-34
(or JP-8)
JP-8 is the
military equivalent of Jet A-1 with the addition of corrosion inhibitor and
anti-icing additives; it meets the latest requirements of the Canadian
Specification CAN/CGSB-3.23, F-34 Grade, and the US Military Specification
MIL-T-83133D. JP-8 also meets the requirements of the British Specification
DEF STAN 91-87 AVTUR/FSII (formerly DERD 2453). Nato Code F-34.
Aviation Fuel Additives
Aviation fuel
additives are compounds added to the fuel in very small quantities, usually
measurable only in parts per million, to provide special or improved
qualities. The quantity to be added and approval for its use in various grades
of fuel is strictly controlled by the appropriate specifications.
A few additives
in common use:
