Fuel mismanagement continues to be a causal factor in general aviation accidents. It’s not the biggest issue – “loss of control” is – but it’s not being outdone by too many other factors that sometimes finish as smoking craters in the ground.
Mismanaging of fuel doesn’t necessarily only happen in the air. Furthermore, fuel issues that strike in the air can have their cause in mistakes that started on the ground. Fuelling mistakes happen. A recap of the process will help you avoid the pitfalls that can sneak into your fuelling protocol.
Has it happened to you that, after a long and tiring flight, you’ve pulled up to the pumps and forgot to ground your airplane? Trained line personnel will know to do this. However, if you’re at a self-serve pump and are accustomed to having the pumping done for you, forgetting to ground the airplane risks turning you and your aircraft into an epic gasoline fireball.
Static electricity builds up in your aircraft simply by its action of flying through the air. That build up of charge has nowhere to go owing to the fact that your aircraft’s tires insulate the charge against passing to the ground. That charge, ungrounded, risks creating a spark that could ignite fuel vapour during the refuelling process. Fireworks are impressive; but not when you and your airplane are the source of the display. Every pump has a ground wire. Over commit yourself to attaching that wire to a metal component of your airplane before you do anything else after egressing from your aircraft at the pumps.
Ready to pour the fuel? Make sure that the hose nozzle makes metal-to-metal contact with the tank’s filler neck before you start pumping. This is especially important when the temperature outside is very cold given that chilly temperatures are more favourable to static electricity build-up. And be aware that certain clothing materials have an affinity for static. If you can avoid it, don’t wear nylon or synthetics when filling your tanks.
Obviously, be sure that the proper type of fuel is being pumped into your aircraft. Accident investigations are aplenty in which it was discovered that the wrong fuel went into an aircraft’s tanks. (More than a few accidents have happened when a lineman has mistakenly dispensed Jet-A into a tank that should have been taking avgas.) Different grades of avgas have their own distinctive colour. When they are mixed, they become colourless. It so happens that Jet-A is colourless too. Be sure, then, you know what’s in your tanks, especially if you weren’t there to watch when someone else pumped it into your tanks.
Water is colourless too, and it can easily make its way into your tanks. Water vapour suspended in the air inside an empty, or partially empty, tank will condense and contaminate the fuel. It’s for this reason that refilling of the tanks after a flight is a highly recommended practice. A full tank leaves no room for moisture-filled air.
Every pilot should know that water must be removed if present in the fuel. Yet accidents still happen because of it. Since all aviation fuels absorb moisture from the air, the tank must be checked before flight. Fortunately, water is heavier than fuel so it settles to the tank’s lowest point. When drained into a sampler cup for inspection, the water should thus come out first and leave your sample looking cloudy or hazy, if not very evidently sedimented from the coloured fuel itself.
Other contaminants can slip into your fuel. Guard against sand or dust being blown into tanks while refuelling. Also, unclean refuelling equipment can introduce impurities into your tank. Rust particles can find their way there too, especially if using poorly maintained filtering devices or older fuel storage tanks. Microbes like to grow in fuels, especially diesel and unleaded fuels. They can multiply to the point of causing corrosion, and clogging filters and screens.
Be alert when refuelling your aircraft. Take the time to do things methodically, and don’t skimp on your fuel verification procedures. Doing things right at the pumps will keep you from becoming a data point for when fouled up refuelling leads to things going wrong in the air.