Air New Zealand is challenging aircraft makers to come up with alternative fuel planes for its domestic network by 2025.
The airline is today taking the unusual step of making public a Product Requirement Document (PRD) outlining its detailed requirements for zero emissions planes to replace traditional aircraft used on its regional network.
The airline has set out an ambitious timetable with a purchase order in 2023 and the delivery date two years later but there is a big rider - the schedule is ''indicative and dependent on technology evolution''.
Baden Smith, head of fleet strategy and transactions, said that Air New Zealand was throwing open the challenge and trying to shake out the serious suppliers of what the airline is calling ''novel propulsion'' aircraft.
While there has been a flurry of activity around battery-powered and hydrogen-powered planes in the past few years, he said they were still in the prototype phase.
Sending out the PRD was aimed at sorting the ''wheat from the chaff'', he said.
''As is always the case in startups and new technology there's always a bit of noise, but there's some real gold in there as well. This, for us to be able to help figure out is what's the gold and what's the noise.''
While the PRD had already gone out to some plane makers, he said Air New Zealand had made it public so all parts of the aviation sector and even rival airlines could see it.
Anything to help build the knowledge pool was helpful for developing zero emissions planes for the aviation sector under increased pressure to reduce pollution.
The airline wanted turbo-prop planes fully electric or hydrogen-powered and progress as a result of PRD would work with an existing agreement with Airbus for larger short-haul jets. Air NZ is also working with the Ministry of Business Innovation and Employment and the fuel industry on sustainable aviation fuel (saf) for its bigger long haul aircraft.
Smith said around the world battery-powered planes are further down the development track but have considerably less power for their weight than existing aircraft.
These could work for very small aircraft on short range.
• Mid-2022: Increased Collaboration
eg: MOU / letter of support
• End of 2022: Possible aircraft commitments
eg: Letter of intent (LOI)
• 2023: Firm order contract
eg: Purchase order
• 2024: NZ pilot/ demonstrator
eg: Demonstration missions, infrastructure tests
• 2025: Aircraft delivery
'You need to put 50 times the weight on an aircraft for the same amount of energy. The technology is quite advanced and we could get there quickly.''
Hydrogen had more development time needed but it has the opportunity to provide aircraft with much more performance.
''Weight is the biggest thing you're trying to overcome in aviation - the mass energy density of hydrogen is three to four times better than jet fuel. The downside is it takes up three times the volume,'' said Smith.
The PRD contains detailed specifications of what these are, including average adult passenger weight of 80kg, arrived at following a five-yearly survey last year. The maximum weight of 110kg includes all baggage..
''We think hydrogen has got a better long term future. But we think we might be able to get there faster on battery-electric.''
The refueling network was another important factor and there was no green hydrogen production at scale and any reticulation to airports at present.
Air New Zealand was working with MBIE and hydrogen firms on production and future infrastructure.
Smith said there were only tiny battery powered aircraft that had been certified but nine and 19-seater planes were in development.
In this country ElectricAir flew continued development of its two-seater electric plane with a demonstration flight across Cook Strait in October.
Hydrogen planes were in the test bed, so several years away from flying in any numbers. New Zealand, with its large supply of renewable energy and uncrowded skies, would be attractive to plane makers to trial planes and some of the airline's short low routes linking small towns would be ideal for the resulting aircraft.
The PRD highlights the role 19-seater Beechcraft planes played in the Air NZ fleet until 2016.
''We would be willing to consider aircraft on that sort of scale, possibly even smaller,'' said Smith.
''We can see routes in the network that could work with a really small aircraft. They might not be massively profitable but we're going learn a lot about how to operate this kind of technology and as we add this to our road map.''
Deployment options listed have planes with up to nine seats in the fleet by 2025, up to 50 seats by 2030 and more than 50 seats by 2035.
Early adoption aircraft (by 2025) could be used for freight, training and demonstration flights.
While the cost of planes may initially be more and fuel more expensive, airlines were facing steep increases in the cost of carbon. In the PRD, Air New Zealand assumes it will increase from US$70 ($NZ103) a tonne to $300 a tonne by 2035.
The PRD says suitable novel propulsion engines could be retrofitted, depending on the complexity of the modification required to existing aircraft.
Air New Zealand currently operates 52 turboprop aircraft made up of 23 Q300 aircraft with 50 seats and 29 ATR72-600 aircraft with 68 seats. These aircraft are the likely candidates for replacement with novel propulsion technology.
''Air New Zealand expects to begin phasing out the Q300 fleet towards the end of this decade and we see significant value in acquiring novel propulsion aircraft to initially supplement, and then ultimately replace/modify the Q300, to support ongoing services to existing Q300 markets.''
The airline has also made available to potential suppliers details of what features it would expect aircraft cabins to have. Smith said the airline would not compromise on customer requirements.
''Air New Zealand would be willing to discuss the options to retrofit an existing turboprop aircraft for demonstrator purposes with novel propulsion technology. Aircraft may be available for retrofit as they exit the operational fleet over time,'' the document says.
Any novel powered aircraft would have to meet passenger expectations of product aboard planes, said Smith. The airline would not compromise on products or service.
Air New Zealand alliance partner United Airlines has taken an equity stake in ZeroAvia, a firm focused on powering electric motors by utilising hydrogen fuel cells.
In a sign of how quickly moves to emissions-free planes are, United said it expects to purchase up to 100 of ZeroAvia's engines it described as zero-emission and completely hydrogen-electric.
The airline said the engine was expected to be used in pairs as a new power source for existing regional aircraft. United said it plans to pursue a conditional purchase agreement for 50 of the engines, with an option for 50 more.
They could be retrofitted to aircraft from 2028, CNBC reports.
Earlier this year, Rolls-Royce's first all-electric aircraft completed its maiden flight, taking to the skies in Britain. Meanwhile last September, a six-seater hydrogen fuel-cell plane from ZeroAvia undertook its first flight. The same month saw Airbus release details of three hydrogen-fueled concept planes, with the European aerospace giant claiming they could enter service by 2035.
In Britain budget airline EasyJet has partnered with the aviation start-up Wright Electric to design and develop such a prototype 180-seat plane that could fly for around 500km.