A series of recent events involving the mixing of an incorrect additive into jet fuel dispensed at a Florida airport has triggered safety warnings to both turbine operators and fuel handlers.
Diesel exhaust fluid (DEF) is a colourless fluid derived from urea that is added to diesel fuel but is not approved for use in aircraft because of its propensity to form crystals that can clog filters and other components within aircraft fuel systems. It can be mistaken for a common icing inhibitor that is also added to Jet-A, hence the caution advised.
Jet fuel, aviation turbine fuel (ATF), or avtur, is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colourless to straw-coloured in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance.
Two incidences of DEF contamination took place in November 2017, in Omaha, Nebraska, and in August 2018, in Opa Locka, Florida. The most recent contamination event occurred on May 9 at the Punta Gorda, Florida, airport, when DEF was mistakenly added to fuel in a fuel truck. Two Citation 550s operated by charter company Air Trek were serviced with the contaminated fuel. One, enroute from Naples to Niagara Falls, New York, suffered an engine flameout, followed by a second engine failure, and diverted successfully to Savannah, Georgia. The second, enroute to Chicago, had a single engine failure and landed safely in Louisville, Kentucky.
The dramatic events highlight the seriousness of the issue. AOPA’s Air Safety Institute has issued a bulletin to accompany the FAA’s Safety Alert For Operators 18015 advising fuelers to put procedures into place to mitigate the likelihood of introducing DEF into aircraft fuel. Because the presence of DEF in fuel is impossible to detect during a preflight inspection, the situation must be addressed prior to fueling.