Avgas• Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft.• Generally of a higher quality than fuels used in less critical applications such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures, amongst other properties.
Avgas• Avgas (aviation gasoline) is an aviation fuel used to power piston-engine aircraft.• It can be distinguished from mogas (motor gasoline), which is the everyday petroleum spirit used in cars.• Avgas is formulated for stability, safety, and predictable performance under a wide range of environments.• Avgas is typically used in aircraft that use reciprocating or wankel engines.• Dyes for the fuel are required in some countries.
Avgas• Aviation fuels consist of blends of over a thousand chemicals: – primarily Hydrocarbons (paraffins, olefins, naphth enes, and aromatics) as well as additives such as antioxidants and metal deactivators, and impurities. – Principal components include n-octane, isooctane. – Like other fuels, blends of Aviation fuel used in piston engine aircraft are often described by their Octane rating.
100LL• The most commonly used aviation fuel is dyed blue for easy visual identification.• 100LL, spoken as "100 low lead", contains a small amount of tetra-ethyl lead (TEL), a lead compound that reduces gasolines tendency to spontaneously explode (detonation or "knock") under high loads, high temperatures and high pressures.• Sustained detonation causes catastrophic engine failure.
Avgas Table of Aviation Fuel Types Country Fuel Lead content Status Dye Phased out,Worldwide 80/87 Low lead difficult to red obtain Not producedWorldwide 82UL Unleaded purple since 2008 Most commonlyWorldwide 100LL Low lead used aviation blue fuel 4 grams of lead In process ofWorldwide 100/130 per US gallon being replaced green (1.1 g/l) by 100LL Discontinued (sometimesWorldwide 91/96 brown produced for races) DiscontinuedWorldwide 115/145 (mainly military purple use)
Don’t Lie About Your Fuel State• I’ve never overloaded my airplane• I have the traffic in sight• Yes, tower, I responded. You didnt hear me?• Youre not picking up my squawk code? Here, let me recycle the transponder• I have the check-list memorized• I broke out of the clouds right at minimums
Weight & Balance• Avgas has a density of 6.02 lb/U.S. gal at 15 °C, or 0.721 kg/l, and this density is commonly used for weight and balance computation.• Density increases to 6.40 lb/US gallon at -40 °C, and decreases by about 0.5% per 5 °C (9 °F) increase in temperature.• As you use fuel, your CG will move.
What’s Going In?• Be present when Fuel is pumped. – Quantity – Quality – Correctness – Damage to A/C
CasesOn March 2, 2008, a turbo-normalized CirrusSR22 was destroyed when it crashed shortlyafter takeoff in Rio de Janeiro, Brazil, killing allfour people aboard. Shortly after the aircraftdeparted from Runway 20, the airplanes enginelost power, and the aircraft hit a building andexploded. Further investigation revealed thatthe aircraft had been refueled with Jet A insteadof 100LL.
Effects of Contamination• Zero Octane• Instant destructive detonation• You will loose the engine
Question Using a fuel grade higher than specified cancause cylinder head and engine temperatures to exceed normal operating limits. False
Question You arrive at your aircraft for a flight and realize you need fuel. The fuel should be drained andchecked immediately following the filling/adding of fuel to the fuel tanks. False
Fuel Tips• Infrequently used fuel tanks should have their sumps drained before filling• Agitation action of fuel entering the tank may suspend or entrain liquid water or other contaminants.• After fueling, wait at least 15 minutes per foot of depth of the tank before sumping
AC-20-125• How much fuel says the FAA? – 10 ounces or more!!• Cross feed and multiple tanks should be checked separately.
3 Useless Things in AviationThe runway behind youThe sky above youThe Fuel in the truck