Following the first flight of an Aero Vodochody L-29 jet trainer on 100% biodiesel fuel, planning is under way for a US transcontinental flight in November as a precursor to an eventual round-the-world biofuel trip.
The first 100% biofuel flight of the Greenflight International-owned L-29 took place on 3 October from Nevada's Reno-Stead airport. The milestone came on the third day of testing, in which the fuel was changed from a 25% blend of biodiesel with Jet A to 50:50 biodiesel/kerosene and eventually to only biodiesel.
Greenflight, founded in 2006 by Douglas Rodante to demonstrate available biofuel technology for aviation, is supplied fuel by the Sparks, Nevada based-Biodiesel Solutions. The biodiesel supplied for testing was made from recycled vegetable-derived cooking oil.
The next step is to make a 10-leg flight across the USA using the L-29 to highlight the capability of biodiesels and make a television documentary. "Greenflight exists to show what is possible with existing [biofuel] technology. There are lots of classes of aircraft that could use this tomorrow: a Boeing 767 could use a 20% blend of Jet A and biodiesel," says the L-29's chief pilot, Carol Sugars.
All the L-29 flights were conducted at about 17,000ft (5,180m) where temperatures above Nevada can reach -4e_SDgrC (24.8°F). The biodiesel used has a gel point of -10e_SDgrC, but commercial aircraft need a fuel able to operate down to -40e_SDgrC. Greenflight is not involved in developing any biodiesel that would have the same cold-flow characteristics as Jet , but the company's work is also supported by Maxwell Shauk, chairman of Baylor University's Institute for Air Science in Waco, Texas, which conducts renewable aviation fuel research.
NASA and other aeronautical research organisations had expressed an interest in what Greenflight is doing, she says, adding that a potential carbon-neutral source of biofuel is desert-based, farm-grown algae.