What kind of fuel do airlines currently use?
Modern jet aircraft flown by passenger and cargo airlines use a petroleum-based fuel generally referred to as “Jet A” or “Jet A-1.”
Can airlines use fuel other than Jet A or Jet A-1?
Not today, but possibly in the future. In the United States, all aircraft and engines must be approved (technically, “certificated”) for use by the Federal Aviation Administration (FAA). To ensure safety, commercial jet fuel must meet precise technical and operational specifications; jet engines are designed to work with jet fuel having these specific characteristics. FAA approval is specific to the fuel that is used and the particular aircraft and/or engine type. Any deviation from FAA approval certificate requires extensive FAA reevaluation and approval. In light of this regulatory arrangement and the fact that the specification for Jet A and Jet A-1 fuel is identified in the FAA approval certificate, no other type of fuel can be utilized at this time in the United States.
How long will it be before planes can fly with alternative fuel?
Continental Airlines conducted a successful Boeing 737 test flight using Jet A, algae oil and jatropha on January 7, 2009. JetBlue is in the planning stages of its own test, using an Airbus 320. While there may be more flight tests to come, our industry partners and researchers tell us that they have a tremendous amount of data from the succession of flights over the past year, so data-oriented lab work and emphasis on demonstrating that alternative fuels meet the jet fuel specifications are likely to be a greater focus in the coming months.
Why are U.S. airlines exploring alternative fuels?
Airlines are pursuing alternative fuels to enhance energy supply security and as a potential additional means of reducing emissions typically associated with fossil fuels, including greenhouse gas (GHG) emissions. It is hoped that alternative fuels will assist in both regards, as well as in combating future price volatility in crude oil and heating oil markets. It also presents an opportunity for airlines to reinvent their energy supply chain while introducing competition to the petroleum sector over time.
Toward these ends, ATA is a founding and principal member of the Commercial Aviation Alternative Fuels Initiative (CAAFI), a consortium of airlines, government, manufacturers, fuel suppliers, universities, airports and other stakeholders who hold the various keys to research, development and responsible implementation of alternative aviation fuels. On April 22, 2008, ATA issued a Web-based call for alternative fuels entitled "Commercial Aviation Alternative Fuels: The ATA Commitment," which spells out for would-be fuel providers our rigorous safety, environmental, supply reliability and economic feasibility requirements.
Which alternative fuels do airlines think are most promising?
From a strictly technical standpoint, it appears that coal-to-liquid (CTL) jet fuel produced by the Fischer-Tropsch process is most promising in the near term. This type of alternative aviation fuel is presently used in some parts of the world, and extensive operational and environmental impact studies are underway to determine its potential for use in the United States, possibly with a biomass blend and other steps to make it more environmentally friendly.
While experience and advanced research in CTL fuels look promising, ATA supports the development of any viable alternative to traditional petroleum-based jet fuel that can meet the rigorous requirements set forth in the ATA alternative fuels principles. For instance, ATA applauds efforts to use various forms of biomass, natural gas or combinations of biomass and other material as a source of fuel, as long as the biomass does not compete with food supplies.
Even if alternative fuels do not prove feasible for near-term use in commercial aircraft, ATA supports their development for other uses. Recent studies show that jet fuels made with a CTL product mixed with biomass may result in major reductions in GHG emissions below levels seen in petroleum-based jet fuel.
What are the infrastructure/logistical hurdles to using alternative fuels?
Significant infrastructure hurdles exist. Because the production of alternative fuels will likely require new facilities located away from the existing distribution network, new handling and distribution capacity will be necessary if it is to be commercialized. For instance, additional road and rail networks may need to be constructed to deliver raw materials required for production, and new pipelines would have to be developed that could transport the finished product. The vast majority of jet fuel consumed in the United States is distributed by pipeline. New storage facilities at airports also might have to be developed. Having said that, ATA member airlines have called for alternative jet fuels that can be commingled with existing fuels (referred to as “drop-in fuels”), which could greatly reduce the need for duplicative infrastructure.
Does FAA certify jet fuel?
No - FAA certifies aircraft and engines. An element of this certification is a listing of the operational requirements and limitations for the specific equipment that is being certified, which includes identification of the type of jet fuel approved for use in that equipment. Therefore, FAA specifies what type of fuel is to be used but does not certify the jet fuel itself. Separately, airline fueling manuals, with which airlines must comply by law, are based on the jet fuel recognized by FAA. Before FAA identifies the fuel appropriate for specific equipment, and before airlines can include the fuel requirements in fueling manuals, the fuel already has been determined to meet the specifications necessary to be safely used in the relevant equipment.
In the case of jet fuel, the applicable standard (also referred to as a “specification”) is controlled by ASTM International, an organization devoted to the development and management of standards for a wide range of industrial products and processes. It is this specification that is included in FAA product approvals and required air carrier manuals. Specifically, aviation turbine fuel must meet specifications including, but not limited to, ASTM D1655 and others referenced and required by FAA. The following performance characteristics of alternative jet fuel, in addition to conformance with ASTM D1655 in its entirety, must be equivalent to those of conventional jet fuel at every stage of distribution, delivery, storage and utilization in the aircraft and its engines, including the auxiliary power units: lubricity, seal swell, dielectric constant, density, bulk modulus, water solubility, viscosity, thermal conductivity, specific heat, autoignition temperature, hot surface ignition, temperature, toxicity, storage stability.
Periodically, through established ASTM procedures, the specification is updated and revised by a specialized committee of experts. Proposed changes to the specification are carefully considered, and a formal balloting process is conducted to secure consensus before any revision is accepted. Fuels produced from alternative sources must complete this rigorous vetting process to establish that they meet the specification requirements to be safely used as jet fuel.
What are the key challenges associated with implementing biofuels in aviation?
Will they be certified? How expensive will they be to produce in mass quantity? Can they be injected into multiproduct pipelines for efficient transportation to airports? How much better will they be than today's jet fuel in environmental terms, including local air quality impacts? Will airlines have to sacrifice energy content?
How readily available are the biofuels that the airline industry would need?
Through CAAFI, the industry is striving to have biofuels certified for commercial aviation use between 2010 and 2013. Over time, they undoubtedly will be more available but, as of now, challenges include weakness in the capital markets, as well as technological hurdles to economically viable mass production.
How long will it take for biofuels to be used widely in commercial aviation?
Based on the CAAFI goals for successive revision to the jet fuel specifications for 2010-2013, ATA believes that biofuels will become commercially available in sufficient quantities for blending with traditional jet fuels as early as 2013. Given that it will take some time to scale up commercial production, ATA would expect only a small percentage of biojet fuel to be used by aviation in the early years, increasing over time.
What is the cost advantage to airlines offered by biofuels versus traditional fuels?
There may not be a cost advantage; that remains to be seen. Obviously, the economics of biofuels will evolve depending on the construct of any future regulatory schemes.
What are the climate-impact implications of biofuels?
Carbon emissions measured from aircraft engines likely will not be significantly different when biofuels are used than when traditional jet fuel is used. That is because jet engines rely on having a certain amount carbon-based energy. The significant carbon benefits of biofuels are realized earlier in the fuel production chain than with traditional fuels. Specifically, bio-feedstocks pull carbon out of the air as they are grown, so when they are burned they result in significantly less net carbon (and possibly even no net carbon) than traditional, petroleum-based fuels. Thus, the environmental benefits of alternative fuels are measured over the entire life cycle of the fuels.
What is the ATA position on climate change and aviation?
Although commercial aviation contributes only about 2-3 percent of man-made GHGs, ATA member airlines are committed to continuing to reduce their GHGs. Since airlines have achieved tremendous fuel efficiency improvements already, the potential for revolutionary improvements is limited. Thus, ATA actively supports the development of game-changing advancements, such as cleaner alternative fuels. Even more beneficial would be the implementation of a modernized air traffic management (ATM) system in the United States. The operational efficiencies from a modern, satellite-based ATM system would result in significant savings in GHGs. On the regulatory front, ATA supports the ongoing efforts of the International Civil Aviation Organization (ICAO), which is the United Nations body charged with establishing standards and recommended practices for international aviation, to further address aviation’s contribution to climate change.