Concerned about the number of incidents surrounding diesel exhaust fluid (DEF) contamination, NBAA welcomed the FAA’s proposed changes to an advisory circular to highlight these issues. However, NBAA believes the draft guidance could go further to emphasize the hazards of such contamination and the need for proper training at both Part 139 certificated and non-certificated airports.
The Environmental Protection Agency requires the use of DEF in ground vehicles but the additive’s close appearance to the fuel system icing inhibitor (FSII) additive has led to several incidents of inadvertent DEF contamination, including clogging of a turbine airplane's fuel system and subsequent loss of engine power. Groups including NBAA and NATA have joined the FAA in an education campaign to urge awareness of contamination possibility and have encouraged the agency to release guidance.
Released last month, the draft advisory circular, AC 150/5230-4C – Aircraft Fuel Storage, Handling, Training, and Dispensing on Airports, remained open for comment through August 24.
NBAA said it supported the additions to the proposed guidance focused on the hazard of DEF contamination of aviation fuel but encouraged that agency to “consider additional elements related to DEF contamination in order to more fully address this hazard and the severity of its risk.”
NBAA recommended that FAA mandate DEF training for ground personnel working at non-certificated airports, in addition to certificated airports. The association also sought strengthened language around the importance of proper DEF handling and the need to include such guidance in training programs.
“NBAA believes that training providers in this space are in a position to include FSII handling and storage as well as DEF contamination prevention in their course offerings if they have not already done so,” NBAA told the agency. “The updates to this advisory circular help in taking another step to ensure compliance with best practices to minimize the likelihood of aviation fuel contamination by DEF.”
The association’s comments follow up on earlier industry/FAA dialog and a subsequent panel discussion on addressing the issue, said Mark Larsen, NBAA senior manager of safety and flight operations, in an NBAA article on the issue. “We hope to see greater emphasis in the final AC on the critical importance of this issue to aviation safety and ensure detailed industry training programs are available to all who would benefit from them.”