Not in Regulatory Process Airport Authorities State and Regional Air Resource Agencies Local Government and Communities Limits Safety (flight) is primary concern FAA can ignore or modify U.S. EPAs standards Trade off for performance vs. emissions Exemptions for small aircraft
SOURCEWHO REGULATES Aircraft- EPA sets emission standards - FAA certification and enforcement Ground support equipment (GSE) - State & Local Agencies Auxiliary Power Units (APU) & facilities-State Vehicles accessing Airport/facilities- State & Local Agencies Ground Water, Soils etc. - Federal, State, Local Agencies
Approximately 167,000 aircraft in the United States and 230,000 worldwide rely on 100LL AvGas for safe operation. AvGas is tailored to meet challenges of aviation from the surface all the way up to 35,000 feet anywhere in the world. AvGas Production 225 million gallons of AvGas were produced within the U.S. in 2010 reflecting $1.3 billion in revenue. AvGas represents 0.5 % of automotive gasoline produced world-wide Total Consumption of AvGas is less than 25% of automotive gasoline evaporation Production of aviation gasoline has declined on average approximately 6.5 million gallons per year since By Comparison about 175 Billion gallons of auto gas is sold annually in the US
100LL is also the only remaining transportation fuel in the United States that contains the additive tetraethyl lead (TEL). AvGas is a world-wide standardized product (ASTM D910) So why is there lead in AvGas? To find out we need to go back in time to the earliest days in aviation.
Aviation Gasoline evolved to its present state out of the need for maximized engine performance by producing the greatest possible power output per unit weight under all environmental conditions. Detonation and pre-ignition was limiting the power output of the engines of the day. After years of laboratory and practical testing of some 30,000 chemicals and compounds, in 1922 General Motors Corporation discovered that a lead compound called tetraethyl lead could significantly improve the anti-detonation characteristics of gasoline.
In 1922,Thomas Midgley, Jr. (1889–1944) a U.S. chemist, discovered tetraethyl lead as an antiknock agent for gasoline.
TEL is an organolead compound. Mixed with gasoline it increased octane ratings and thus engine compression and horsepower to be boosted significantly thereby increasing performance and fuel economy. The anti-knock qualities of TEL were many orders of magnitude greater than any other chemical or metal researched. Adding only small amounts of the TEL to gasoline would yield dramatic results. Tetraethyl lead (CH3CH2)4Pb
Thus Thomas Midgleys discovery was directly responsible for the evolution of ever larger, faster and more capable aircraft. This advance in engine power to weight ratio was directly attributable to advances in fuel technology and paved the way for modern aviation. In the 1950s, commercial aviation reached its pinnacle of aviation gasoline use and general aviation was rapidly growing in the United States. During this decade there were six grades of AvGas commonly produced ranging from a low of 73 octane up to the 115 octane fuel required for many military and commercial piston powered aircraft. The change in propulsion technology from piston to turbine engines marked the beginning of the long-standing decline in aviation gasoline production that continues to this day. The rapid decline in AvGas consumption made it economically infeasible to continue to produce multiple grades of aviation gasoline. A period of consolidation occurred in the 1970s and 1980s leading to the one grade of aviation gasoline available today; 100LL
14 Max. Lead Content Grade mL TEL/galg Pb/galStatus 80/ Minor Civil--Limited Availability 82UL-0.05New Engine Fuel--Limited Availability 91/ Obsolete New in 2001 for Military 100/ Minor Civil and Military 100LL Major Civil--Predominant Grade 108/ Obsolete 115/ Obsolete
With passage of the Clean Air Act Amendments in 1990, new regulations were promulgated by the EPA to eliminate lead from the gasoline powering non-road engines and vehicles. It was feared at that time that aviation gasoline might be considered a non-road fuel and thus be subject to the lead elimination deadline in 1995.
This sparked the beginning of a serious exploration to remove lead from AvGas while attempting to preserve the performance characteristics of the fuel and thus aviation safety. Over 15 years of research was undertaken by the aviation and petroleum industries to develop a drop-in direct replacement for 100LL without the use of lead. The FAA played a key role in that effort. 245 fuels were examined and tested. Forty-five of the most promising blends were examined in full-scale engine testing. However, none of the fuels could satisfy all the performance requirements of 100LL.
Currently, petitions and potential litigation from environmental organizations regarding lead-containing AVGAS have called for the US Environmental Protection Agency (EPA) to consider regulatory actions to eliminate or reduce lead emissions from aircraft. Similar regulatory actions are under consideration globally. In response to these pressures, the FAA formed the Unleaded Avgas Transition Aviation Rulemaking Committee (UAT ARC) in January The UAT ARC has submitted its final report to the FAA which recommends options and challenges of transitioning the piston engine-powered aircraft fleet to single-fuel unleaded 100 octane avgas. The FAA is now considering the recommendations.
But dont expect to see unleaded AvGas anytime soon. The UAT ARC believes that an integrated strategy for implementation of its recommendations provides for the greatest opportunity for a successful transition. This implementation will require an estimated $57.5M of public funds and $13.5M of industry in-kind support over 11 years. The UAT ARC recommended the creation of the Piston Aviation Fuels Initiative as the vehicle for implementation of this strategy.
SWIFT Fuel GAMI G100UL Hjelmco 100UL There is no unleaded AVGAS in development that 100% meets existing 100LL AvGas standard ASTM D910 but is without lead
ASTMTitleMotorPb Max. Commercial Aviation GasolineONg Pb/gal D910Specification for Aviation Gasolines D6227Specification for Grades UL82 and UL87 Unleaded Aviation Gasoline82 or Experimental Aviation Gasoline D7547Specification for Hydrocarbon-Based Unleaded Aviation Gasoline D7592Specification for Grade 94 Unleaded Aviation Gasoline Certification and Test Fuel D7719Specification for High-Octane Unleaded Aviation Test Fuel
Santa Monica Airport 1953
SCAQMD General Aviation Study and City Augmentation Study Fall 2010 SCAQMD Supplemental Study and City Augmentation Study US EPA Lead Study 2012 ACRP Lead Emissions Study
Lead distributes throughout the body in the blood and is accumulated in the bones. Lead can adversely affect the nervous system, kidney function, immune system, reproductive and developmental systems, and cardiovascular system. Infants and young children are especially sensitive to even low levels of lead, which may contribute to behavioral problems, learning deficits, and lowered IQ. Lead is persistent in the environment and accumulates in soils and sediments through deposition from air sources. See lead 27
Characterize air toxics levels in the communities around GA airports Compare data to other air toxics studies such as SCAQMDs Multiple Air Toxics Exposure Study (MATES-III) Determine potential impact of airport emissions on measured pollutant levels Provide baseline data for future studies
TSP Lead and Hexavalent Chromium PM10 Mass and Carbon PM2.5 Mass & Components Continuous Particle Count (ultrafine) Volatile Organic Compounds (3 x 8 hour periods) Carbonyls (acetaldehyde, etc.) Continuous Carbon Monoxide
Lead Monitoring& CO (Site 5, 6) Complete Sampling Array (Site 1, 2, 3, 4, 7) Phase I Phase II
Residence Site #2 East Tarmac Site #3 Santa Monica Airport Sampling Sites
4.5/ / / */77.0* 28.6/ Annual Basin Average 3.4/ /7.7 Downtown LA – Average NEW FEDERAL STANDARD (3 month ave.) = 150 ng/m 3 Old Federal (3 month ave.) & State (1 month ave.) Standard = 1500 ng/m 3 9.5/13.1
Lead levels in communities and near runways below NEW federal standards, but elevated at near runway sites
Gasoline used in motor vehicles Re-suspended dust Avgas Primary lead production (e.g., smelters) Industrial processes (e.g., battery production) Waste incinerators Indoor exposure from paint 38
39 Maximum 30-Day Average Lead Levels in the Los Angeles Area
No complete replacement for 100LL Providing unleaded fuel for aircraft that can use it means investing in infrastructure. Choice may come down to economics for aircraft that can use unleaded fuel. FAA involved and created Unleaded AVGAS Transition Aviation Rulemaking Committee (UAT ARC) Report with recommendations for continued investigation issued in February 2012 (http://www.faa.gov/about/initiatives/avgas/)http://www.faa.gov/about/initiatives/avgas/ 40