The National Air Transportation Association (NATA) and the National Business Aviation Association (NBAA), in conjunction with an industry-led working group, have released recommendations for aircraft operators, FBOs, fuel suppliers and other stakeholders to mitigate the possibility of diesel exhaust fluid (DEF) contamination in jet fuel.

DEF is a colourless liquid, injected directly into the catalytic convertor in diesel engine light- and heavy-duty vehicles in order to meet the US Environmental Protection Agency's (EPA) emission control standards. When mistakenly added to aircraft jet fuel, DEF crystalises and clogs fuel systems, leading to engine failure.

In three instances over the past three years at locations in the United States, including Nebraska and Florida, DEF has been mistaken for fuel system icing inhibitors (FSII), a clear liquid that is added to aircraft jet fuel.

“Currently, there is no available field test that can detect the injection of DEF into aviation fuel,” the working group said in a recent report. “FBO staff and aircraft operators cannot visually or chemically (using current field methods) detect that a contamination event has occurred. This situation places the full burden of risk mitigation upon initial contamination prevention.”

NATA COO Timothy Obitts adds: “Safety is central to our mission at NATA. We are committed to working with our members and other industry stakeholders to eliminate the hazard of diesel exhaust fluid contamination of aircraft fuel. NATA encourages all of our members, including aircraft operators, FBOs and fuel suppliers, to read this report and implement the recommendations as soon as practicable.”

His words are echoed by NBAA CEO Ed Bolen, who comments: “We call on all business aviation stakeholders to familiarise themselves with risk of diesel exhaust fluid contamination of aircraft fuel, and to partner in our industry’s efforts to prevent another DEF contamination event by immediately adopting the report’s short-term mitigation recommendations and incorporating future mitigations and technologies as they are identified.”

The working group is comprised of representatives from AOPA, AvFuel, CommScope, Dassault Falcon Jet, Fair Wind Air Charter, FAA, FBO Partners, Epic Fuels, GAMA, Gammon Technical Products, Gulfstream, Murray Equipment Inc., Midwest Aviation, NATA, NBAA, Phillips 66, Sheltair, Signature Flight Support, TAC Air, Total Control Systems, Truckee Tahoe Airport, Union Pacific and World Fuel Services.