The Air New Zealand biofuel test flight went very well, by all accounts. The Jatropha-derived fuel performed as well as the normal Jet-A1 fuel in the other three engines of the Boeing 747-400. There will now be some further on-the-ground tests to be completed in Auckland before the second-generation biofuel is taken for even more analysis and then the rigorous steps towards certification for use in normal flights. You can’t fault our industry for being cautious with these things!
We are currently preparing for the 2009 Aviation & Environment Summit, to be held here in Geneva on 31 March and 1 April. I will post more details about it in due course, but the Summit website is up and running so you can visit to see who is on the programme so far at this invitation-only event.
But back to the test flight and Air New Zealand has made some video available on its excellent biofuel test flight website. In their media release, they explained some of the tests that occurred during the flight this morning, during all of which the biofuel performed excellently:
Take off: A full power take off, with throttles advanced as per normal operating conditions, establishing three-quarter power and then to full power.
Climb: The aircraft climbs to 25,000 feet. At an altitude of 20,000 – 25,000 feet, the main fuel pump for engine one (the engine powered by the biofuel) will be switched off. This will test the lubricity of the fuel, ensuring the friction of the fuel does not slow down its flow to the engine.
Cruise: Once cruising at 35,000 feet the auto-throttle will be switched off and the crew will manually set all engine controls, so the Engine Pressure Ratios (EPRs) and other engine performance parameters across all four engines can be checked for identical readings.
Deceleration/acceleration: The crew will control the fuel flow to the engine and measure the rate of change of the engine under these changing operating conditions.
Descent: Engine one will be shut down at 26,000 feet with a windmilling restart at 300knots. An engine shutdown will take place again at 18,000 feet, this time with a starter-assisted relight at 220 knots.
Simulated approach and go around: When the aircraft is at 11,000 feet the autopilot will be programmed to land on a runway “located” at 8,000 feet and undertake a missed approach. This is to test the performance of the fuel under maximum thrust.
Landing: The flight will be completed with a normal landing, including the use of reverse thrust upon touchdown. The aircraft will then taxi back to the hardstand, stop all engines and restart engine #1 by itself.
For full details and more video and images, visit the Air New Zealand website. Also, a few media items of note, from journalists on the ground:
The pre-flight briefing has just taken place at Auckland Airport, with Captain Dave Morgan going through some of the key stages of the test flight. One interesting point he made was that the Boeing 747-400 being used for today's test has had to be taken off the New Zealand aircraft registry and re-classified an 'experimental' aircraft. This is because the fuel that is being used is not certified for use in a commerical aircraft yet - all things going well on today's flight and, subject to a lot more testing, it should be certified for use in a few years.
The flight today will last for around two hours, during which the pilots will take the aircraft up to around 35,000 feet - normal cruising altitude - and back down again, pausing along the way to undertake various engine test including stopping the engine completely and then re-starting it a number of times. The Boeing 747-400 was chosen for the flight because each of its four engines has the ability to get fuel from seperate tanks, meaning they can do a test using the Jatropha biofuel mix in just one engine - in this case it is the #1 engine.
Bhe full range of tests that will be carried out on today's flight is outlined on the Air New Zealand website. After taking off from runway 23 at Auckland Airport, the flight will cruise around the Hauraki Gulf area to the east of Auckland City, out of the way of other commerical air traffic. Google Maps view shows the approximate location of the flight test, with Auckland Airport highlighted by "A" marker.
It is around an hour and a half until the Air New Zealand 747-400 takes off from the main runway at Auckland Airport on a flight powered, in part, by the oil from the plant Jatropha. So what exactly is Jatropha? Well, Jatropha is actually a species of around 175 types of plants, shrubs and trees. The specific plant that Air New Zealand will be using today is the Jatropha Curcas, which grows to around three metres high. Its seeds contain an oil that is able to be refined into a biofuel. The oil yield is around 40% of the mass of the seed and even when the oil has been extracted, the remaining material can also be used as a fuel source when dried.
The thing that makes Jatropha Curcas stick out as a possible aviation biofuel is its ability to be supplied in a sustainable manner.
The seeds are mildly toxic (in fact, one of the colloquial names for Jatropha Curcus is 'black vomit nut'... charming), and they are not eaten by humans or animals, so are able to become a sustainable supply for biofuels without hitting food supplies - a problem with some edible biofuel sources such as corn and sugarcane.
The plant can grow in some fairly inhospitable conditions, ensuring that it does not need to compete with food crops for land or water. In fact, this could be a new type of cash crop for developing nations with non-arable land that is currently unused.
Jatropha oil is also a good candidate for use in aviation, as when it has been refined, it has almost exactly the same chemical properties as the Jet-A1 fuel that currently powers the commercial aviation industry. This means that it can be 'dropped-in' to the existing fuel supplies. The industry will then be able to use the existing infrastructure (pipelines, tankers, engines etc) and gradually increase the mix of biofuel as supplies become available.
Just about to tune in to the pre-flight briefing, I will post more about the flight itself once that is over. By the way, the briefing will be given by Air New Zealand's chief pilot Dave Morgan - someone I used to bump into occasionally when I worked at Auckland Airport and who is pictured below holding some of the fuel that will power this morning's flight.
A passenger plane has completed a two-hour test flight partly powered by fuel derived from a tropical fruit.
Air New Zealand hailed the flight as a "milestone" in the development of sustainable fuels that could lower aeroplane emissions.
One engine of the Boeing 747-400 was fuelled by a 50-50 mixture of jatropha plant oil and standard A1 jet fuel.
A Virgin Atlantic test flight in February used fuel derived from a blend of Brazilian babassu nuts and coconuts.
In Auckland on Tuesday, a range of tests were completed both on the ground and during the flight, said Air New Zealand chief pilot David Morgan.
He said the oil from the plum-sized jatropha fruit performed "well through both the fuel system and engine".
Air New Zealand chief executive Rob Fyfe said the completion of Tuesday's flight was "a milestone for the airline and commercial aviation".
The International Air Transport Association says it wants a 10th of aviation fuel to come from biofuels by 2017.
Critics of biofuels are opposed to turning arable land over to the cultivation of biofuels at the expense of growing food.
However, the fruit from jatropha trees is toxic to humans and the plant can be grown in poor, marginal soils.
But questions have been raised about the plants' suitability as a biofuel because harvesting the fruit is labour intensive and the quality of the yield can be inconsistent.
Tuesday's flight was the first time the fuel had been used partly to power an aircraft, but the biodiesel has been used in cars and trains in Asia for a number of years.
