Air New Zealand completed the test flight of its 50:50 blend of a jatropha-derived synthetic paraffinic kerosene and conventional Jet A1 fuel (named NZ-J50) in an Air New Zealand Boeing 747-400 on Tuesday. (Earlier post.) The two-hour test flight took off from Auckland airport on Tuesday morning, with the jatropha-derived biofuel blend powering one of the four Rolls-Royce RB211 engines.
The two-hour test flight profile included:
Take off. Full powered take off. Throttles will be advanced slowly, establish at three-quarter power and then to full power.
Climb. Climb to 25,000 feet. At an altitude of 20,000-25,000 feet, the main fuel pump for engine one was switched off. This tested the lubricosity of the fuel, ensuring that the friction of the fuel does not slow down its flow to the engine.
Cruise. Cruise at 35,000 feet. The auto-throttle was switched off and the crew manually set all engine controls, so that the Engine Pressure Ratios (EPRs) had identical readings.
Deceleration/acceleration. The crew controlled the fuel pressure to manage the rate of change of engine.
Descent. Engine one was shut down at 26,000 feet with a windmilling restart at 300 knots. Another engine shutdown took place again at 18,000 feet, this time with a starter-assisted relight at 220 knots.
Simulated approach and go around. When the aircraft was at 11,000 feet, the autopilot was programmed to land on a runway that “located” at 8,000 feet and undertook a missed approach. This was to test the performance of the fuel under maximum thrust.
Landing. The flight was completed with a normal landing, including the use of reverse thrust. The aircraft will then taxi back to the hardstand, stop all engines and restart engine one by itself.
|Test flight profile. Click to enlarge.|
The synthetic paraffinic kerosene was produced by UOP from jatropha oil feedstock.
The Sustainable Aviation Fuel Users Group, launched in September 2008, has chartered a peer- reviewed, independent life cycle and socio-economic sustainability research report of the NZ-J50 fuel, which is expected to be completed in September 2009.