There are likely to be no further alternative fuel trials this year after the imminent flight test by Japan Airlines.
The news comes as Continental Airlines completed the first US alternative fuels trial on 7 January with a twin-engined aircraft powered in part by a biofuel blend consisting of algae. While the US carrier says it successfully ran the aircraft through all phases of flight, it has no plans to conduct a second trial.
"We're now encouraging people to look at the data collected to see what's missing before [new trial] flights," says Billy Glover, who heads Boeing's environmental strategy, which partnered Continental in the trial.
He adds that fuel-certifying organisation ASTM International is not expected to request additional alternative fuel demonstrations, but could ask for endurance testing on specific engine components.
Continental pilots operated a Boeing 737-800 using a blend of 50% jet fuel and 50% biofuel derived from algae (2.5%) and jatropha plant (47.5%) oils to power the right CFM International CFM56-7B engine. The left engine flew on 100% jet fuel.
During the 2h trial in Houston, Continental recorded various flight parameters and ran acceleration and deceleration checks, two in-flight engine shutdowns and restarts - one windmilling start and one starter assisted - and a simulated landing and go-around. The aircraft also simulated an arrival at the high-altitude airport in Quito, Ecuador.
The biofuel-blend-powered engine burned 91kg (200lb) less fuel than the engine powered by Jet A for the same thrust setting. Exhaust gas temperature were also slightly lower. Both fuels emitted roughly the same amount of carbon dioxide in flight, with overall emissions savings realised during biofuel production.
While Glover says that other carriers have expressed an interest in running further trials, it will be JAL's 30 January 1h biofuel trial that will bring to an end the current suite of testing. JAL says a 50% blend of camelina, jatropha and algae, plus 50% Jet A fuel, will be tested during the 1h flight from Tokyo Haneda airport. Air New Zealand, meanwhile, reported a successful first test flight of a Rolls-Royce RB211-powered Boeing 747-400 using jatropha on 30 December.