There is ongoing development of fuels, including aviation fuels, from biomass and hydrogen gas. In a few years it may be possible to use synthetic fuel produced from natural gas or biogas mixed with jet propulsion fuel. It will take longer before pure biofuel can be introduced in regular air traffic.

Most experts look to alternative fuels and technologies as promising complements to petroleum in the near term and likely substitutes in the long term. Currently, 98 percent of the U.S. transport sector runs on petroleum. The reasons for this dominance are simple. Transportation fuels derived from petroleum pack a lot of energy in a small volume and weight. The internal combustion engine (ICE) found in practically every vehicle is compact, powerful, and well suited to transportation applications. And until recently, petroleum has been a bargain, at least in the United States. If alternative energy sources are to compete effectively with petroleum, they must be price competitive, perform well with existing ICE technology, or be packaged with a new motor entirely, probably an electric one.

Recently, a small plane operating from a airport suffered an engine failure on takeoff and crashed. One of the hazmat responders dealing with the resulting fuel spill mentioned 'a strong smell of Jet A', leading to speculation that the airplane had its tanks filled with the wrong fuel. Would he have been able to distinguish Jet A from 100LL by smell?

Most experts look to alternative fuels and technologies as promising complements to petroleum in the near term and likely substitutes in the long term. Currently, 98 percent of the U.S. transport sector runs on petroleum. The reasons for this dominance are simple. Transportation fuels derived from petroleum pack a lot of energy in a small volume and weight. The internal combustion engine (ICE) found in practically every vehicle is compact, powerful, and well suited to transportation applications. And until recently, petroleum has been a bargain, at least in the United States. If alternative energy sources are to compete effectively with petroleum, they must be price competitive, perform well with existing ICE technology, or be packaged with a new motor entirely, probably an electric one.