Another mishap involving jet-A contaminated by diesel exhaust fluid (DEF) occurred on August 14 when a Fair Wind Air Charter-operated Dassault Falcon 900EX was forced to make an emergency return to Miami Opa-Locka Airport after suffering failure of two of its three engines. DEF, a urea-based solution that lowers nitrogen oxide pollutants in diesel exhaust, is not approved for use in jet fuel. When the two are accidentally mixed, crystals form, causing potentially catastrophic clogs throughout aircraft fuel systems.
According to Alexander Beringer, COO of Fair Wind, the problem manifested itself soon after takeoff, as the aircraft indicated a clog in its number-two engine fuel filter, followed quickly by the same indication in the number-three powerplant. The crew decided to return to base and then declared an emergency when the number-two engine failed. At 8,000 feet on approach, the number-three engine became unresponsive to throttle input, yet the crew landed safely on just the number-one engine, which also reported a filter clog. "We got lucky," he said, noting the entire incident occurred in less than 12 minutes from start to finish.
While the damage is still being tallied, Beringer noted that all three engines will have to be removed and undergo hot-section inspections; the APU will have to be removed, inspected and repaired; fuel pumps, filters, and control units will require replacement, and all the aircraft’s fuel tanks will have to be opened up and thoroughly cleaned. Estimates call for at least a month of downtime and more than $1 million in cost.
Beringer said the FBO, which he declined to identify, has claimed full responsibility for the incident. "Their safety controls were good. It fell apart on one issue and that could have happened anywhere.” He said his company performed an on-site investigation and it is believed that a refueler-mounted Prist tank, which was removed for repair, was accidentally filled with DEF in a leak test before it was reinstalled.
The FAA is investigating the situation and is expected to issue a Special Airworthiness Information Bulletin similar to the one it issued last December, after an incident at a Nebraska airport.
Last November, seven turbine-powered aircraft at Omaha’s Eppley Air Field were serviced with jet fuel that had accidentally been treated with DEF instead of fuel system icing inhibitor, while a further six aircraft were serviced using equipment that had been exposed to DEF.
Beringer believes that this mistake can happen again unless all airport service vehicles are exempted from any DEF-usage requirements. “That gets the fluid off airport properties and fixes it for good,” he told AIN. "The industry needs to petition, as a group with one voice, federal and state regulators to come up with a permanent fix to this risk."