Avgas

From Wikipedia, the free encyclopedia

  (Redirected from Aviation gasoline)
Jump to: navigation, search
An American Aviation AA-1 Yankee being refuelled with 100LL avgas.

Avgas is a high-octane aviation fuel used to power many aircraft and racing cars. Avgas is a portmanteau for aviation gasoline, as distinguished from mogas (motor gasoline), which is the everyday gasoline used in cars. Some light aircraft also use automobile fuel instead of avgas.

Avgas is used in aircraft that have piston or Wankel engines. Gas turbines can operate on avgas, but typically do not. Turbine and diesel engines are designed to use kerosene-based jet fuel.

Contents

[edit] Avgas properties and varieties

The main petroleum component used in blending avgas is alkylate, which is essentially a mixture of various isooctanes, and some refineries also use some reformate. Avgas has a density of 6.02 lb/US gallon at 15 °C, or 0.72 kg/l, and this density is commonly used for weight and balance computation. Density increases to 6.40 lb/US gallon at -40 °C, and decreases by about 0.5% per 5 °C increase in temperature.[1] Avgas has an emission coefficient (or factor) of 18.355 pounds CO2 per US gallon,[2][3] or about 3.05 units of weight CO2 produced per unit weight of fuel used. Avgas has a lower and more uniform vapor pressure than automotive gasoline, which keeps it in the liquid state at high-altitude, preventing vapor lock. The particular mixtures in use today are the same as when they were first developed in the 1950s and 1960s, and therefore the high-octane ratings are achieved by the addition of tetra-ethyl lead (TEL), a highly toxic substance that was phased out for car use in most countries in the late 20th century.

Avgas is currently available in several grades with differing maximum lead concentrations. Since TEL is a rather expensive additive, a minimum amount of it is typically added to the fuel to bring it up to the required octane rating so actual concentrations are often lower than the maximum.

Jet fuel is not avgas. It is similar to kerosene and is used in turbine engines. Confusion can be caused by the terms Avtur and AvJet being used for Jet Fuel. In Europe, environmental and cost considerations have led to increasing numbers of aircraft being fitted with highly fuel-efficient diesel engines; these too run on jet fuel. Civilian aircraft use Jet-A, Jet-A1 or in severely cold climates Jet-B. There are other classification systems for military turbine and diesel fuel. See Jet fuel.

[edit] Consumption

The annual U.S. usage of avgas was 236 million gallons (893 million liters) in 2006.[4]

[edit] Grades

Taking a fuel sample from an American Aviation AA-1 Yankee under-wing drain using a GATS Jar fuel sampler. The blue dye indicates that this fuel is 100LL.

Gasoline used for aviation fuel is generally identified by two numbers associated with its Motor Octane Number(MON). The first number indicates the octane rating of the fuel tested to "aviation lean" standards, which is similar to the an anti-knock index or "pump rating" given to automotive gasoline in the U.S. The second number indicates the octane rating of the fuel tested to the "aviation rich" standard, which tries to simulate a supercharged condition with a rich mixture, elevated temperatures, and a high manifold pressure. Fuel dyes aid ground crew and pilots in identifying the proper fuel grade:[5]

[edit] 100LL

Dyed blue, 100LL, spoken as "100 low lead", contains tetra-ethyl lead (TEL), a lead based anti-knock compound, but less than the "highly-leaded" 100/130 avgas it effectively replaced. Most piston aircraft engines require 100LL and a suitable replacement fuel has not yet been developed for these engines. While there are similar engines that burn non-leaded fuels, aircraft are often purchased with engines that use 100LL because many airports only have 100LL. 100LL contains a maximum of 2 grams of lead per US gallon, or maximum 0.56 grams/litre and is the most commonly available and used aviation gasoline.

[edit] 82UL

82UL is the specification for an unleaded fuel similar to automobile gasoline but without additives. It could potentially be used in aircraft that have a Supplemental Type Certificate for the use of automobile gasoline with an aviation lean octane rating (MON) of 82 or less or an antiknock index of 87 or less. It could not be used in engines that require 100LL. The FAA highly recommends installing placards stating the use of 82UL is or is not approved on those airplanes that specify unleaded autogas (mogas) as an approved fuel.[6] As of 2008, 82UL is not being produced and no refiner has announced plans to put it into production.[7].

[edit] 80/87

Dyed red, avgas 80/87 had the lowest lead content prior to its phase out in the late 20th century, with a maximum of 0.5 grams lead per U.S. gallon, and was only used in low compression ratio engines.

[edit] 100/130

Dyed green, avgas 100/130 had a higher octane grade aviation gasoline, containing a maximum of 4 grams of lead per US gallon, maximum 1.12 grams/litre. 100LL "low lead" has replaced avgas 100/130 in most places, but Avgas 100/130 is still sold in Australia and New Zealand as one of the two manufacturers in Australia is unable to make Avgas 100LL.[citation needed]

[edit] 91/96 & 115/145

In the past other grades were also available, particularly for military use, such as avgas 115/145 (dyed purple) and 91/96.

[edit] Automotive gasoline

Automotive gasoline (known as Mogas or Autogas among aviators) that does not contain oxygenates may be used in aircraft that have a Supplemental Type Certificate for automotive gasoline, and in experimental aircraft. Most of these applicable aircraft have low-compression engines which were originally certified to run on 80/87 avgas and require only "regular" 87 anti-knock index automotive gasoline. Examples of this include the popular Cessna 172 or Piper Cherokee with the 150 hp (110 kW) variant of the Lycoming O-320. Some aircraft engines were originally certified using a 91/96 avgas and have STC's available to run "premium" 91 anti-knock index automotive gasoline. Examples of this include some Cherokee's with the 160 hp (120 kW) Lycoming O-320 or 180 hp (130 kW) O-360 or the Cessna 152 with the O-235. However, for most aircraft, automotive gasoline is not considered to be a viable replacement for avgas, primarily because automotive gasoline is not subject to the stringent quality-control standards necessary for an aviation fuel.[8][9]

The requirement for a non-oxygenated fuel is a major problem with these STCs. In the name of reducing emissions, most autogas contains additives designed to boost the oxygen available to the fuel, such as alcohol. The FAA does not allow alcohol-containing gasoline to be used in aircraft.

[edit] Avgas compared to other fuels

Many general aviation aircraft engines were designed to run on 80/87 octane,[citation needed] roughly the standard for North American automobiles today. Direct conversions to run on automotive fuel are fairly common and applied via the supplemental type certificate (STC) process. However, the alloys used in aviation engine construction are rather outdated, and engine wear in the valves is a potential problem on automotive gasoline conversions. Fortunately, significant history of mogas-converted engines has shown that very few engine problems are actually caused by automotive gasoline. A larger problem stems from the wider range of allowable vapor pressures found in automotive gasoline; this can pose some risk to aviation users if fuel system design considerations are not taken into account. Automotive gasoline can vaporize in fuel lines causing a vapor lock (a bubble in the line), starving the engine of fuel. This does not constitute an insurmountable obstacle, but merely requires examination of the fuel system, ensuring adequate shielding from high temperatures and maintaining sufficient pressure in the fuel lines. This is the main reason why both the specific engine model as well as the aircraft in which it is installed must be supplementally certified for the conversion. A good example of this is the Piper Cherokee with high-compression 160 hp (120 kW) or 180 hp (130 kW) engines. Only later versions of the airframe with different engine cowling and exhaust arrangements are applicable for the automotive fuel STC, and even then require fuel system modifications.

Vapor lock typically occurs in fuel systems where a mechanically-driven fuel pump mounted on the engine draws fuel from a tank mounted lower than the pump. The reduced pressure in the line can cause the more volatile components in automotive gasoline to flash into vapor, forming bubbles in the fuel line and interrupting fuel flow. If an electric boost pump is mounted in the fuel tank to push fuel toward the engine, as is common practice in fuel-injected automobiles, the fuel pressure in the lines is maintained above ambient pressure, preventing bubble formation. Likewise, if the fuel tank is mounted above the engine and fuel flows primarily due to gravity, as in a Cessna high-wing airplane, vapor lock cannot occur, using either aviation or automotive fuels.

In addition to vapor locking potential, automotive gasoline does not have the same quality tracking as aviation gasoline. To help solve this problem, the specification for an aviation fuel known as 82UL has recently been developed. This fuel would be essentially automotive gasoline that has additional quality tracking and restrictions on permissible additives. This fuel is not currently in production and no refiners have committed to producing it.[7]

The main consumers of avgas at present (mid-2000s) are in North America, Australia, Brazil, and Africa (mainly South Africa). Care must be taken by small airplane pilots to select airports with avgas on flight planning. For example, U.S. and Japanese recreational pilots ship and depot avgas before flying into Siberia. Shrinking availability of avgas drives usage of small airplane engines that can use jet fuel.

In Europe, avgas prices are so high that there have been a number of efforts to convert the industry to diesel instead, which is common, inexpensive and has a number of advantages for aviation use. However, avgas remains the most common fuel in Europe as well.

[edit] Environmental regulation

The tetra-ethyl lead found in leaded avgas and its combustion products are potent neurotoxins that have been shown in scientific research to interfere with brain development in children. The United States Environmental Protection Agency (EPA) has noted that exposure to even very low levels of lead contamination has been conclusively linked to loss of IQ in children's brain function tests, thus providing a high degree of motivation to eliminate lead and its compounds from the environment.[10][11]

“ While lead concentrations in the air have declined, scientific studies have demonstrated that children's neurological development is harmed by much lower levels of lead exposure than previously understood. Low level lead exposure has been clearly linked to loss of IQ in performance testing. Even an average IQ loss of 1-2 points in children has a meaningful impact for the nation as a whole, as it would result in an increase in children classified as mentally challenged, as well as a proportional decrease in the number of children considered "gifted."[11] ”

On 16 November 2007, the environmental group Friends of the Earth formally petitioned the EPA, asking them to regulate leaded avgas. The EPA responded with a notice of petition for rulemaking.[7]

The notice of petition stated:

“ Friends of the Earth has filed a petition with EPA, requesting that EPA find pursuant to section 231 of the Clean Air Act that lead emissions from general aviation aircraft cause or contribute to air pollution that may reasonably be anticipated to endanger public health or welfare and that EPA propose emissions standards for lead from general aviation aircraft. Alternatively, Friends of the Earth requests that EPA commence a study and investigation of the health and environmental impacts of lead emissions from general aviation aircraft, if EPA believes that insufficient information exists to make such a finding. The petition submitted by Friends of the Earth explains their view that lead emissions from general aviation aircraft endanger the public health and welfare, creating a duty for the EPA to propose emission standards.[12] ”

The public comment period on this petition closed on 17 March 2008.[12]

Under a federal court order to set a new standard by 15 October 2008, the EPA cut the acceptable limits for atmospheric lead to 0.15 microgram/m3 from the previous standard of 1.5 microgram/m3. This was the first change to the standard since 1978 and represents an order of magnitude reduction over previous levels. The new standard requires the 16,000 remaining US sources of lead, which includes lead smelting, airplane fuels, military installations, mining and metal smelting, iron and steel manufacturing, industrial boilers and process heaters, hazardous waste incineration and production of batteries, to reduce their emissions by October 2011.[10][11][13]

The EPA's own studies have shown that to prevent a measurable decrease in IQ for children deemed most vulnerable, the standard needs to be set much lower, to 0.02 microgram/m3.[11]

The EPA has previously named avgas as one of the most "significant sources of lead", but it was not clear how this current change in standards will affect aircraft burning 100LL fuel.[10][11]

At an EPA public consultation held in June 2008 on the new standards, Andy Cebula, the Aircraft Owners and Pilots Association's Executive Vice President of Government Affairs stated that general aviation plays a valuable role in the US economy and any changes in lead standards that would change the current composition of avgas would have a "direct impact on the safety of flight and the very future of light aircraft in this country."[14]

In December 2008 AOPA filed formal comments to the new EPA regulations. AOPA indicated that piston-powered aircraft produce "one-tenth of 1 percent" of national lead emissions and that they are 0.55% of all transportation emissions. AOPA has asked the EPA to account for the cost and the safety issues involved with removing lead from avgas. They cited that the aviation sector employs more than 1.3 million people in the USA and has an economic "direct and indirect effect that "exceeds $150 billion annually." AOPA interprets the new regulations as not affecting general aviation as they are currently written.[15]

[edit] Phase-out of leaded aviation gasolines

The 100LL phase-out has been called "one of modern GA's most pressing problems",[16] because 70% of 100LL aviation fuel is used by the 30% of the aircraft in the general aviation fleet that cannot use any of the existing alternatives. [17] [18]

In February 2008, Teledyne Continental's new president, Rhett Ross, announced that the company is very concerned about future availability of 100LL avgas, and as a result, they will develop a diesel engine in the 300 horsepower (220 kW) range for certification in 2009 or 2010. This engine will be followed by lower power engines, as well.[19] In a February 2008 interview, Ross indicated that Continental Motors believes that the aviation industry will be "forced out" of using 100LL avgas in the near future, leaving automotive fuel and jet fuel as the only alternatives.[20]

In November 2008 National Air Transportation Association President Jim Coyne indicated that the environmental impact of aviation is expected to be a big issue over the next few years and will result in the phasing out 100LL, due to its lead content.[21]

[edit] Swift fuel

John and Mary-Louise Rusek founded Swift Enterprises in 2001 to develop renewable fuels and hydrogen fuel cells.[22] By 2006, they had submitted a sample of "Swift 142" to Oracle Airmotive Research & Development of Delphi, Indiana, which found that the fuel gave a 10% longer runtime than an equal volume of 100LL fuel in the 100 hp (75 kW) engine of a Bakeng Deuce aircraft.[23] The following year, Swift Enterprises filed US and international patent applications for non-alcoholic Renewable Engine Fuels of a variety of octane ratings, to be blended from "one or more low carbon number esters, one or more pentosan-derivable furans, one or more aromatic hydrocarbon, one or more C4-C10 straight chain alkanes derivable from polysaccharides, and one or more bio-oils... [and, optionally,] triethanolamine", which could be derived from biomass fermentation.[24] Swift Enterprises initiated "Carroll County Swift Development Inc.",[25] to plan a 2,500-square-foot (230 m2) pilot plant at the Delphi Municipal Airport in Indiana,[26], and submitted fuel to the FAA for testing.[27][28][29][30]

In 2008, an article by technology writer and aviation enthusiest Robert X Cringely, stating that the fuel was renewable, cleaner-burning, and potentially cheaper than avgas or even mogas, attracted popular attention to the fuel.[31] The company claims the fuel can be manufactured for USD$2 per gallon, although Swift Enterprises' cost per gallon for laboratory batches was USD$60.[27][32] The Swift Enterprises website claims their product has 15% more volumetric energy for a 15-25% increase in range over 100LL. The FAA found SwiftFuel 702 to have a motor octane number of 104.4, 96.3% of the energy per pound and 113% of the energy per gallon as 100LL, and meets most of the ASTM D 910 standard for leaded aviation fuel. Following tests in two Lycoming engines, the FAA concluded it performs better than 100LL in detonation testing and will provide a fuel savings of 8% per gallon, though it weighs 1 pound per gallon more than 100LL. GC–FID testing showed the fuel to be made primarily of two components -- one about 85% by weight and the other about 14% by weight.[33] [34] Soon afterwards, AVweb reported that Teledyne Continental Motors had begun the process of certifying several of its engines to use the new fuel.[35]

Swift fuel has been criticized by aviation analysts on a number of grounds, including that the forecast price is likely unattainable, that the USD$2 per gallon is a refinery price and not a retail price and that biomass yields are critical to the project and are unproven. As a replacement for 100LL avgas Paul Bertorelli of Aviation Consumer termed it "one that's still a long shot", but conceded "...if Swift Fuel's real manufacturing cost is $3 a gallon and that translates to $5 or a little more at retail, they've got a player. GA in the U.S. can and has adapted to $5 avgas. If Swift can deliver, this project could have legs".[36]

[edit] 94UL

In March 2009 Teledyne Continental Motors announced that it has been testing 94UL fuel. This fuel is essentially 100LL with the tetraethyl lead omitted during the production process. The company has indicated that this may be the best solution to the lead problems inherent with 100LL. The 94UL has been shown to meet the avgas specifications, including for vapor pressure, but has not been completely tested for detonation qualities in all Continental engines or under all conditions. Flight testing has been conducted on an IO-550-B powered Beechcraft Bonanza and also ground testing on Continental O-200, 240, O-470 and O-520 engines.[37]

[edit] See also

[edit] References

  1. ^ MacDonald, Sandy A. F.; Isabel L. Peppler (2004) [1941]. "Chapter 10. Airmanship". From The Ground Up (Millennium ed.). Ottawa, Ontario, Canada: Aviation Publishers Co. Limited. pp. 265, 261. ISBN 0-9680390-5-7. 
  2. ^ US Energy Information Administration (2007). "Voluntary Reporting of Greenhouse Gases Program - Fuel and Energy Source Codes and Emission Coefficients". US Energy Information Administration website. http://www.eia.doe.gov/oiaf/1605/factors.html. Retrieved on 2007-12-03. 
  3. ^ US Energy Information Administration (2005), "Appendix F. Fuel and Energy Source Codes and Emission Coefficients", Form EIA-1605EZ Short Form for Voluntary Reporting of Greenhouse Gases, Washington, DC, p. 22, ftp://ftp.eia.doe.gov/pub/oiaf/1605/cdrom/pdf/FormEIA-1605EZ_2005.pdf, retrieved on 2007-12-03 .
  4. ^ US Energy Information Administration. "U.S. Prime Supplier Sales Volumes of Petroleum Products". http://tonto.eia.doe.gov/dnav/pet/pet_cons_prim_dcu_nus_a.htm. 
  5. ^ Shell Aviation (2008-03-24). AVGAS Grades and Specifications
  6. ^ Federal Aviation Administration (2000-04-05). "Revised Special Airworthiness Information Bulletin (SAIB) Number CE-00-19R1". http://www.faa.gov/aircraft/safety/alerts/saib/media/CE-00-19R1.htm. Retrieved on 2006-10-28. "The FAA highly recommends installing placards stating the use of 82UL is or is not approved on those airplanes that specify unleaded autogas as an approved fuel." 
  7. ^ a b c Pew, Glenn (November 2007). "Avgas: Group Asks EPA To Get The Lead Out". http://www.avweb.com/avwebflash/news/GroupAsksEPAToGetTheLeadOutOfAvgas_196596-1.html. Retrieved on 2008-02-18. 
  8. ^ Berry, Mike (undated). "Avgas vs Autogas". http://www.eaa.org/autofuel/autogas/articles/1Autogas%20vs%20Avgas.pdf. Retrieved on 2008-12-31. 
  9. ^ Berry, Mike (undated). "Autogas Part 2". http://www.eaa.org/autofuel/autogas/articles/1Autogas%20vs%20Avgas%20Part%202.pdf. Retrieved on 2008-12-31. 
  10. ^ a b c Pew, Glenn (October 2008). "EPA Sets New Standard For Lead In Air". http://www.avweb.com/avwebflash/news/epa_100ll_lead_standard_aviation_fuel_199020-1.html. Retrieved on 2008-10-20. 
  11. ^ a b c d e Balbus, John (October 2008). "New EPA Lead Standard Significantly Improved to Protect Kids' Health". http://www.marketwatch.com/news/story/new-epa-lead-standard-significantly/story.aspx?guid={EC3D72C5-9037-4ECB-BC93-4B2EFF038E37}&dist=hppr. Retrieved on 2008-10-20. 
  12. ^ a b Environmental Protection Agency (November 2007). "Federal Register: 16 November 2007 (Volume 72, Number 221)". http://a257.g.akamaitech.net/7/257/2422/01jan20071800/edocket.access.gpo.gov/2007/E7-22456.htm. Retrieved on 2008-02-24. 
  13. ^ Canadian Broadcasting Corporation (October 2008). "U.S. tightens health standard for airborne lead". http://www.cbc.ca/health/story/2008/10/16/lead-air.html. Retrieved on 2008-10-17. 
  14. ^ Hirschman, Dave (October 2008). "EPA sets new air quality standard". http://www.aopa.org/advocacy/articles/2008/081017epa.html. Retrieved on 2008-10-20. 
  15. ^ Pew, Glenn (December 2008). "Leaded Fuel, Emissions, The EPA And AOPA". http://www.avweb.com/avwebflash/news/lead_fuel_emissions_air_epa_aopa_aviation_199344-1.html. Retrieved on 2008-12-08. 
  16. ^ editorial (2008-08). "Avgas Revolution?". Aeromarkt (235). http://www.aeromarkt.net/index.php?lng=1&cll=archive&ID=619. Retrieved on 2008-08-28. 
  17. ^ Taylor Graham (2008-08-28). "Swift developing synthetic fuel to replace 100LL". Airport Business News (Airport Business). http://www.airportbusiness.com/web/online/Top-News-Headlines/Swift-developing-synthetic-fuel-to-replace-100LL/1$20599. Retrieved on 2008-08-28. 
  18. ^ By AOPA ePublishing staff (2006-03-19). "AOPA working on future avgas". AOPA onlin. Aircraft Owners and Pilots Association. http://www.aopa.org/aircraft/articles/2008/080319avgas.html. Retrieved on 2008-08-28. 
  19. ^ AvWeb Staff (February 2008). "Teledyne Continental Plans Certified Diesel Within Two Years". http://www.avweb.com/eletter/archives/avflash/1054-full.html. Retrieved on 2008-02-18. 
  20. ^ Bertorelli (February 2008). "Make Room in the Aerodiesel Market, Thielert — TCM Tells Aviation Consumer About Some Big Engine Plans". http://www.avweb.com/podcast/podcast/197170-1.html?kw=RelatedStory. Retrieved on 2008-02-18. 
  21. ^ Niles, Russ (November 2008). "Aviation Off D.C. Radar". http://www.avweb.com/news/aopa/AOPAExpo2008_USGovernment_AviationOffWashingtonDCRadar_199142-1.html. Retrieved on 2008-11-07. 
  22. ^ "Business Profile: Swift Enterprises". http://www.purdueresearchpark.com/pdf/Swift%20Enterprises.web.pdf. 
  23. ^ Jennifer Archibald (2006-06-21). "Petroleum Free: New agriculture-based fuel revealed at Delphi Airport". Carroll County Comet (Flora, Indiana, USA). http://www.carrollcountycomet.com/news/2006/0621/front_page/002.html. Retrieved on 2008-08-28. 
  24. ^ . The patent lists Mary-Louise Rusek and Jon Ziulkowski as inventors.US patent application 2008168706, , "Renewable Engine Fuel", published 2008-07-17 , assigned to SWIFT ENTERPRISES, LTD.  WO patent application 2008013922A1, , "Renewable Engine Fuel", published 2008-01-31 , assigned to SWIFT ENTPR LTD [US] 
  25. ^ Lowe, Debbie (2007-11-07). "Permit required for tree activity in Delphi". Carroll County Comet (Flora, Indiana, USA). http://www.carrollcountycomet.com/news/2007/1107/local_news/033.html. Retrieved on 2008-09-18. 
  26. ^ Eric Weddle (2008-06-13). "Delphi could be showcase for renewable aviation fuel". Journal&Courrier (Federated Publisher Inc.). http://www.jconline.com/apps/pbcs.dll/article?AID=/20080613/NEWS0501/806130330. Retrieved on 2008-06-18. 
  27. ^ a b [|Sara Sargent] (2008-08-26). "Swift Enterprises hopes to take off with renewable aviation gas". Medill Reports (Chicago: Northwestern University Medill School of Journalism). http://news.medill.northwestern.edu/chicago/news.aspx?id=97989. Retrieved on 2008-08-28. 
  28. ^ "New Aviation Fuel Develloped in Indiana". Inside Indiana Business. 2008-06-05. http://www.insideindianabusiness.com/newsitem.asp?ID=29204. Retrieved on 2008-06-18. 
  29. ^ Lowe, Debbie (2008-07-30). "Demonstration fuel facility project accelerated". Carroll County Comet (Flora, Indiana, USA). http://www.carrollcountycomet.com/news/2008/0730/local_news/054.html. Retrieved on 2008-08-28. 
  30. ^ Lowe, Debbie (2008-07-09). "Annual EDC request approved by Delphi". Carroll County Comet (Flora, Indiana, USA). http://www.carrollcountycomet.com/news/2008/0709/front_page/006.html. Retrieved on 2008-09-18. 
  31. ^ Robert X Cringely (2008-06-06). "It's the Platform, Stupid". PBS. http://www.pbs.org/cringely/pulpit/2008/pulpit_20080606_005036.html. 
  32. ^ Bertorelli, Paul (March 2009). "FAA Evaluates 100LL Alternative". http://www.avweb.com/avwebbiz/news/FAAEvaluates100LLAlternative_199892-1.html. Retrieved on 2009-03-05. 
  33. ^ Bertorelli, Paul (2009-03-04). "FAA Evaluates 100LL Alternative". AvWeb 7 (9). http://www.avweb.com/eletter/archives/bizav/1325-full.html#199892. 
  34. ^ David Atwood (2009-01). "DOT/FAA/AR-08/53 Full-Scale Engine Detonation and Power Performance Evaluation of Swift Enterprises 702 Fuel" (PDF). FAA Office of Aviation Research and Development. http://www.tc.faa.gov/its/worldpac/techrpt/ar0853.pdf. 
  35. ^ Russ Niles (23 April 2009). "Continental-Powered Bonanza On Swift Fuel". AVweb. http://www.avweb.com/news/snf/ContinentalBonanzaFliesOnSwiftFuel_200216-1.html.  reporting on Press Release Teledyne Continental Motors, Inc (31 March 2009). Continental Motors Completes First Flight on Unleaded AvGas. Press release. http://tcmlink.com/pressReleases/UnleadedFuelFlight_Final.pdf. "With the first flights complete, TCM will begin the certification process of several engine models to meet the needs for existing and future aircraft" 
  36. ^ Bertorelli, Paul (March 2009). "Swift Fuel: Is It for Real?". http://www.avweb.com/blogs/insider/AvWebInsider_SwifFuelRealities_199927-1.html. Retrieved on 2009-03-05. 
  37. ^ Bertorelli, Paul (March 2009). "Continental: Maybe 94 Unleaded Fuel Will Fly". http://www.avweb.com/avwebbiz/news/Continental_94_UL_Replacement_100LL_200048-1.html. Retrieved on 2009-04-13. 

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Avgas"
Personal tools