A group calling itself the Avgas Stakeholder Group has asked the Environmental Protection Agency to extend the comment period on its Advanced Notice of Proposed Rulemaking an additional 120 days. Originally scheduled for comments to close on June 28, the ANPRM addresses lead content in aviation fuels, and the implications of removing that lead are huge. AOPA president Craig Fuller calls it, "… one of the most complicated tasks our industry has ever faced." And Cirrus CEO Brent Wouters (who chairs an industry working group) points out that the issue is far from new, but that the EPA's Advanced Notice of Proposed Rulemaking has launched a regulatory decision-making process that could have major implications. At issue is how to get the lead out of 100 Low Lead aviation fuel. AOPA estimates that simply removing the lead (and reducing the octane rating) of current aviation fuel would have no affect on 70% of the GA aircraft in the fleet. But operators of the larger engines that need the higher octane to make their rated power fly proportionately higher numbers of hours, and tend to be aircraft used for charter, business flying and other missions that could be interpreted as more economically vital than those flown by operators of lower-power aircraft. In addition to AOPA, the Avgas Stakeholders Group includes: the American Petroleum Institute; the Experimental Aircraft Association, General Aviation Manufacturers Association, National Air Transportation Association, National Business Aviation Association and the National Petrochemical and Refiners Association.