AVGAS AND ITS FUTURE IN GENERAL AVIATION

Robert D. Trimborn

Airport Director

Santa Monica Airport

REGULATORY ENVIRONMENT

FAA

Manufacturers/Operators

EPA Emission

Standards

Emission Standards for Aircraft

EPA

• Sets Engine Emission Standards

• Criteria Pollutants

FAA

• Certify Engines• Enforces Compliance

Emission Standards for General Aviation

Regulatory IssuesNot 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. EPA’s

standards• Trade off for performance vs. emissions• Exemptions for small aircraft

Airport Emission SourcesSOURCE WHO 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

The Great AvGas Debate

AvGas Facts

• 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 1981.• By Comparison about 175 Billion gallons of auto gas is sold annually in the US

AvGas

• 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.

AvGas

• 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.

Thomas Midgley, Jr.

In 1922,Thomas Midgley, Jr. (1889–1944) a U.S. chemist, discovered tetraethyl lead as an antiknock agent for gasoline.

Tetraethyl Lead (CH3CH2)4Pb

• 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

Evolution of AvGas

• Thus Thomas Midgley’s 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 1950’s, 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 1970’s and 1980’s leading to the one grade of aviation gasoline available today; 100LL

History of U.S. Aviation Gasolines

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  Max. Lead Content  

GrademL

TEL/gal g Pb/gal Status

80/87 0.5 0.53 Minor Civil--Limited Availability

82UL - 0.05 New Engine Fuel--Limited Availability

91/98 2.0 2.11 Obsolete

91 2.0 2.11 New in 2001 for Military

100/130 4.0 4.22 Minor Civil and Military

100LL 2.0 2.11 Major Civil--Predominant Grade

108/135 3.0 3.17 Obsolete

115/145 4.6 4.86 Obsolete

1990 Clean Air Act Amendments

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.

1990 Clean Air Act Amendments

• 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.

FAA Unleaded Avgas Transition Aviation Rulemaking Committee

• 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 2011.

 • 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.

FAA Unleaded Avgas Transition Aviation Rulemaking Committee

• But don’t 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.

Unleaded AvGas Currently in Development Stage

• 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

Current Commercial and Experimental Avgas

ASTM Title Motor Pb Max.

Commercial Aviation Gasoline ON g Pb/gal

D910 Specification for Aviation Gasolines 80.7-99.6 0.53-4.22

D6227 Specification for Grades UL82 and UL87 Unleaded Aviation Gasoline 82 or 87 0.05

Experimental Aviation Gasoline    

D7547 Specification for Hydrocarbon-Based Unleaded Aviation Gasoline 91 0.05

D7592 Specification for Grade 94 Unleaded Aviation Gasoline Certification and Test Fuel 94 0.05

D7719 Specification for High-Octane Unleaded Aviation Test Fuel 102 0.05

ENVIRONMENTAL STUDIES AT

SANTA MONICA AIRPORT

Santa Monica Airport

1953

Landmark Studies

2006-7 SCAQMD General Aviation Study and City Augmentation Study

Fall 2010 SCAQMD Supplemental Study and City Augmentation Study

2009-10 US EPA Lead Study

2012 ACRP Lead Emissions Study

Health Concerns 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 http://www.epa.gov/iaq/pubs/hpguide.html#airborne lead

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SCAQMD General Aviation AirportsStudy Objectives

Characterize air toxics levels in the communities around GA airports

Compare data to other air toxics studies such as SCAQMD’s Multiple Air Toxics Exposure Study (MATES-III)

Determine potential impact of airport emissions on measured pollutant levels

Provide baseline data for future studies

Measurements

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

AQMD General Aviation Study

Santa Monica Airport Sampling Sites

Lead Monitoring& CO (Site 5, 6) Complete Sampling Array (Site 1, 2, 3, 4, 7)

Phase I

Phase II

ResidenceSite #2

East TarmacSite #3

Santa Monica Airport Sampling Sites

Measured TSP Lead (ng/m3)Phase I - Apr 06 - Jul 06, Phase II - Oct 06 - Feb 07

4.5/7.6

3.3/5.5

4.6/9.1

85.2*/77.0*28.6/22.2

8.6Annual Basin Average

3.4/5.8

3.7/7.7

Downtown LA – Average

NEW FEDERAL STANDARD (3 month ave.) = 150 ng/m3

Old Federal (3 month ave.) & State (1 month ave.)Standard = 1500 ng/m3

9.5/13.1

SCAQMD GA Airport Findings

Lead levels in communities and near runways below NEW federal standards, but elevated at near runway sites

SMO - EPA Lead Study

Modeled Local-Scale Gradient in Lead

Sources of Ambient Lead

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

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Temporal Trends in Airborne Lead

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Maximum 30-Day Average Lead Levels in the Los Angeles Area

Current Situation

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/)

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Questions?