A Boeing 737 left Houston bound for Chicago last Monday, and it seemed like a typical flight if not for the unusual item aboard: algae. The United flight was powered by a blend of algae-derived biofuels and traditional jet fuels.
Two day later, Alaska Airlines sent two planes from Seattle using a cooking oil cocktail. One headed to Washington, D.C.; the other hopped to Portland, Ore., in a display of the renewable jet fuel's versatility.
Both airlines are planning to continue the move to cut their emissions of greenhouse gases. Alaska Airlines scheduled 75 commercial flights powered by biofuels during the next few weeks. United has promised to negotiate the purchase of 20 million gallons of the stuff per year.
Part of the impetus might be consumers' interest in the environment. But really, who shops for flights according to which airlines emit the least carbon per passenger? (For the record, among the best would be JetBlue, Continental, which is merging with United, and US Airways, according to research group Brighter Planet.)
As you might suspect, cutting costs seems to be the biggest motivator. Though the price of biofuels is high now -- Alaska Airlines paid a per-gallon price that would make most motorists park the car: $17 -- airlines are betting it will drop as more is produced. According to Alaska Air Group CEO Bill Ayer, biofuels "can insulate airlines from the volatile price swings of conventional fuel to help make air travel more economical."
Let's hope so, because more affordable tickets fuel fliers, no matter what's fueling the flight.
Send your questions or tips to travel editor Kerri Westenberg at email@example.com, and follow her on twitter @kerriwestenberg.