The International Civil Aviation Organization (ICAO) is seeking input from MRO providers that service halon systems and components as part of a global effort to quantify halon emissions and remaining reserves.
Long recognized as an effective, economical fire-suppression agent, halon also contributes to ozone depletion. Halon's production was banned in 1994, but some applications--including aviation fire-suppression--were classified as essential, and allowed to continue, using existing, recycled or recovered chemicals.
The aviation industry has been examining alternatives for more that two decades, but halon 1301 is still used for most onboard fire-suppression systems in cargo holds, engine nacelles and auxiliary power units. ICAO, working with the United Nations Environment Program’s Halons Technical Options Committee (HTOC) and other industry stakeholders, developed the survey to help quantify how much halon is being recovered during system maintenance, and how much remains in reserve.
"Responses to the questionnaire will be analysed to determine the current and projected future quantities of halon installed in civil aviation fire protection systems, the associated uses and releases of halon from those systems and any potential courses of action to minimize unnecessary halon emissions," ICAO explained. The responses also will help "ensure the better management and preservation of existing halon reserves that civil aviation could take to reduce those uses and releases," it added.
In the U.S., transport-category aircraft onboard fire suppression systems must use halon or an "equivalent" substance, FAA regulations say. Absent regulatory guidance on what constitutes an acceptable alternative, industry has largely stuck with halon, hampering global efforts to eliminate the substance.
An FAA-industry rulemaking committee in 2014 recommended that aviation regulators, industry, and other government agencies work together to unite the various halon-replacement efforts with an emphasis on delivering results. Beyond environmental concerns, relying on a finite amount of a chemical for an integral part of an aircraft is financially risky.
“International regulators and aviation interest groups are already taking action on halon replacement and the industry has to remain proactive in transitioning away from these compounds," said Brett Levanto, vice president of communications for the Aeronautical Repair Station Association, which served on the rulemaking committee. "In the U.S., the ‘or equivalent’ language in the FAA’s rules on fire suppression opens the door, but its up to manufacturers, operators and maintainers to go through it."
ICAO's confidential, 10-question survey is available online at https://www.surveymonkey.com/r/NDJPGH3.