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.
JET A-1
Jet A-1 is a kerosine 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, Kerosine Type, Jet A-1 Grade. It also meets British
specification DEF STAN 91-91, ASTM specification D1655 and IATA Guidance
Material (Kerosine Type), NATO Code F-35.
Shell Canada is an industry leader in Aviation products research and
development. Edward Fuels is proud to feature the following selection
of Aeroshell lubricants:
Edward Fuels is pleased to be the approved Shell Aviation distributor
for southern Ontario. We look forward to supplying the aviation community
and encourage your inquiries. 
