Solutions sought for jet-fuel contamination incidents

The bizjet, a charter operator’s Dassault Falcon 900EX, made a forced return to Florida’s Miami-Opa Locka Executive Airport after the crew received multiple clogged fuel filter warnings on departure, followed by failure of the trijet's No. 2 engine, according to a letter from the air charter company, alerting AOPA and others. A second engine failed during the return to the airport and the crew successfully completed an emergency landing with the remaining, No. 1 engine. The event’s duration from initial alert to landing was about 10 minutes, it said.

The Aug. 14 incident raised new concerns following occurrences in November 2017 in which several airplanes received jet fuel to which DEF had inadvertently been added instead of fuel system icing inhibitor, often referred to by the brand name Prist, at Eppley Air Field Airport in Omaha, Nebraska. The addition of contaminated fuel, and the servicing of other aircraft with refueling equipment that had been exposed to the substance, prompted the FAA to issue a Special Airworthiness Information Bulletin on Dec. 26, 2017, urging operators of certain aircraft to familiarize themselves with maintenance and inspection methods; report related service difficulties; and avoid using fuel suspected of being contaminated. In response to the Omaha incidents, the National Air Transportation Association (NATA) released a DEF Contamination Prevention training course through its Safety 1st Supplemental Safety Training program—available free of charge to anyone in the industry.

According to the SAIB, “DEF is a urea-based chemical that is not approved for use in jet fuel. When mixed with jet fuel, DEF will react with certain jet fuel chemical components to form crystalline deposits in the fuel system. These deposits will flow through the aircraft fuel system and may accumulate on filters, fuel metering components, other fuel system components, or engine fuel nozzles. The deposits may also settle in the fuel tanks or other areas of the aircraft fuel system where they may potentially become dislodged over time and accumulate downstream in the fuel system as described above.” The SAIB identified aircraft that “have experienced clogged fuel filters and fuel nozzle deposits that led to service difficulties and unplanned diversions.”

Aviation groups responded quickly and jointly to the recurrence.

“After this new incident, we feel a broader, collaborative approach is needed to help ensure another event doesn’t occur,” said David Oord, AOPA senior director of regulatory affairs. “Additionally, it is important for operators to be aware of the issue, and if a fuel filter light comes on, land as soon as practical and look for the possibility of DEF contamination. We are working with the FAA, NATA, National Business Aviation Association, and other stakeholders to provide additional education, awareness, and other measures to help prevent another DEF-contamination occurrence.”