Sustainable flight

Continental Airlines has used a sustainable biofuel to power a commercial aircraft for the first time ever in North America.

The demonstration flight - which was conducted in partnership with Boeing, GE Aviation/CFM International, and Honeywell’s UOP - marks the first sustainable biofuel demonstration flight by a commercial carrier using a twin-engined aircraft, a Boeing 737-800 powered by CFM International CFM56-7B engines.

The biofuel blend included components derived from algae and jatropha plants.

The algae oil was provided by Sapphire Energy, and the jatropha oil by Terasol Energy.

Continental’s Boeing 737-800 departed from and returned to Houston’s Bush Intercontinental Airport, operating under a specially issued ‘Experimental’  aircraft type certificate, and carried no passengers.

During the flight, which lasted approximately two hours, Continental test pilots engaged the aircraft in a number of flight manoeuvres, such as mid-flight engine shutdown and re-start, and power accelerations and decelerations.

The biofuel blend, which consists of 50 per cent biologically derived fuel and 50 per cent traditional jet fuel, was used to power one of the aircraft’s engines, while the other operated on traditional jet fuel, allowing Continental to compare performance between the biofuel blend and traditional fuel.

The biofuel is a ‘drop-in’ fuel, and no modifications to the aircraft or engine were necessary for the flight to operate.

The biofuel meets and exceeds specifications necessary for jet fuel, including a flash point and a freezing point appropriate for use in aircraft.

‘We still have a lot of work to do in terms of testing various biofuels, but we are very pleased with, and encouraged by, the results we have achieved to date,’ said Eric Bachelet, president and chief executive officer of CFM International.

‘What we have found is that the fuel comes closer to simulating the characteristics of traditional jet fuel in terms of engine performance and operability, such as fuel consumption, engine start and other parameters.

‘We have also found that engines running this mix emit less smoke even than those fuelled by traditional jet fuel.’

Late last year, an Air New Zealand Boeing 747-400 jetliner hit the headlines when it too made a ‘sustainable flight’ powered by biofuels.

During the flight, one of the aeroplane’s four Rolls-Royce RB211 engines was powered in part using biofuels derived from jatropha, which was converted to bio jet fuel also using fuel processing technology from UOP.