The ZEROe Demonstrator Has Arrived
The title of this post, is the same as that of this press release from Airbus.
This is the introductory paragraph.
2022 marks a new and exciting phase for ZEROe – Airbus’ ambition to develop the world’s first zero-emission commercial aircraft by 2035. The multi-year demonstrator programme has officially been launched with the objective to test a variety of hydrogen technologies both on the ground and in the air.
The ZEROe demonstrator will be the first Airbus A 380 aircraft and it is shown in this Airbus visualisation.
Note.
- The four hydrogen tanks in the fuselage.
- The fifth engine mounted in a pod on the fuselage.
- There’s certainly lots of space inside the fuselage for more hydrogen tanks and test and monitoring equipment.
I have a few thoughts.
This Aircraft Will Be A Superb Demonstrator
The press release says this about the use of an A 380 as a demonstrator.
The A380 is the world’s largest and most spacious passenger jet ever built – a size that makes it ideally suited to the role of test platform.
Today, the A380 MSN1 test aircraft is earmarked for a new role: to take the lead on testing the technologies that will be vital to bringing the world’s first zero-emission aircraft to market by 2035.
“The A380 MSN1 is an excellent flight laboratory platform for new hydrogen technologies,” says Mathias Andriamisaina, Airbus ZEROe Demonstrator Leader. “It’s a safe and reliable platform that is highly versatile to test a wide range of zero-emission technologies. In addition, the platform can comfortably accommodate the large flight test instrumentation that will be needed to analyse the performance of the hydrogen in the hydrogen-propulsion system.”
Initially, I suspect the aircraft will fly as a four-engined turbofan aircraft running on standard or sustainable aviation fuel.
The performance of the hydrogen engine will be tested in all phases of operation and at different altitudes.
What Size Is The Fifth Engine?
This layout is clever.
If Airbus want to test a smaller hydrogen engine for say an Airbus A 320-sized hydrogen aircraft like the ZEROe Turbofan shown in this Airbus visualisation, they fit it to the fifth pylon.
Note.
- The fifth pylon on the ZEROe Demonstrator could be the proposed pylon for the ZEROe Turbofan.
- The ZEROe Demonstrator could probably carry a lot of hydrogen to test out the hydrogen engine over a long duration.
- The hydrogen engine could be tested out over the full flight envelop of an Airbus A 380.
I would suspect that the tests on the hydrogen engine would be some of the most comprehensive ever carried out on a new engine.
If Airbus want to test a larger hydrogen engine for say an Airbus A 350-sized hydrogen aircraft, they would probably replace one of the four main engines with the hydrogen engine.
It looks like Airbus will be able to test hydrogen engines for all sizes of plane in their current range.
What Will Happen To Current A 380s?
Consider.
- The production of the A 380 has been stopped.
- There are 251 aircraft in service.
- They appear to be a reliable and safe aircraft.
- The aircraft can run on sustainable aviation fuel.
- The oldest aircraft are only thirteen years old.
- They are still reasonably modern aircraft, that if they needed to be updated to the latest standards could probably be easily done so.
- The aircraft have a lot of volume, which can hold over 500 passengers in a typical configuration.
- The flying characteristics and structure of the aircraft is well known.
I suspect there are a lot of aircraft leasing companies, who feel these aircraft are too good to scrap, just because they are not zero-carbon.
Could Hydrogen Be Stored In The Wing Of An A 380?
Hydrogen storage will get more capable in the next few years and we will see hydrogen stored in strange places in vehicles and aircraft using the gas as a fuel.
The A 380 may well have an advantage in that its wing is relatively thick compared to that of other airliners.
- The A 380 has a wing aspect ratio of 7.53.
- The Boeing 787 has a wing aspect ratio of 11.
- Gliders have wing aspect ratios as upwards of 30.
High aspect ratios are generally more economical on fuel.
But this relatively thick wing, may make it possible to store hydrogen in the wing of an A 380.
Could There Be A Hydrogen-Powered A 380?
I suspect part of the Airbus ZEROe progam will be to investigate the possibility of converting existing A 380 aircraft into a capable hydrogen-powered aircraft.
In Could An A320 neo Be Rebuilt As A ZEROe Turbofan?, I looked at the possibility of turning an existing Airbus A 320 neo into a ZEROe Turbofan running on hydrogen.
This was my conclusion.
I very much feel that there will be a route to convert some or all of the A 320 neo aircraft to hydrogen power.
So what will a ZEROe A 380 look like if it follows the same design route as an A 320 neo to a ZEROe Turbofan?
- There would be a large hydrogen tank in the rear fuselage.
- As I explained earlier, there may be a possibility for some hydrogen to be stored in the wing.
- Both passenger decks would be shortened and perhaps be able to hold the 350-410 passengers of the Airbus A350-1000.
- The cockpit, front part of the fuselage, wings, tailplane and landing gear would be unchanged.
- The aircraft would fit existing jetways at any airport, that can handle an existing A 380.
I believe that converting an existing Airbus A380 to a hydrogen-powered aircraft is possible and the conversion falls within Barnes Wallis‘s rule of problem solving.
There is no greater thrill in life, that proving something is impossible and then showing how it can be done.
The quote comes from a BBC program, where he was interviewed by Chris Brasher, who was another for whom impossible was just a minor hurdle in the way of meeting objectives.
Could There Be A Hydrogen-Powered A 380 Freighter?
Consider.
- I think it is likely, that companies like Amazon will come under pressure over their carbon footprint, as they transport increasing numbers of packages around the world.
- In DHL Express Shapes Future For Sustainable Aviation With First Order Of All-Electric Cargo Planes From Eviation, I talk about how DHL Express have ordered twelve Eviation Alice aircraft to create a zero-carbon service. DHL must feel this would be good for their image. So would they like an intercontinental zero-carbon freighter?
- Some people worry about the air-miles on their food!
There could be a worthwhile niche market for a high capacity intercontinental zero-carbon freighter.
Because it has such a large internal volume, an Airbus A 380 might make an ideal aircraft to convert.
Conclusion
Airbus will learn a lot from the ZEROe Demonstrator.
They may even learn how to develop, a long-range hydrogen-powered zero-carbon A 380 variant that could carry four hundred passengers between Europe and Australia.
Zero-Carbon Emission Flights To Anywhere In The World Possible With Just One Stop
The title of this post, is the same as that of this press release from the Aerospace Technology Institute.
This is the first sentence of the press release.
Passengers could one day fly anywhere in the world with no carbon emissions and just one stop on board a concept aircraft unveiled by the Aerospace Technology Institute (ATI) today.
These three paragraphs describe the concept.
Up to 279 passengers could fly between London and San Francisco, USA direct or Auckland, New Zealand with just one stop with the same speed and comfort as today’s aircraft, revolutionising the future of air travel.
Developed by a team of aerospace and aviation experts from across the UK collaborating on the government backed FlyZero project, the concept demonstrates the huge potential of green liquid hydrogen for air travel not just regionally or in short haul flight but for global connectivity. Liquid hydrogen is a lightweight fuel, which has three times the energy of kerosene and sixty times the energy of batteries per kilogramme and emits no CO2 when burned.
Realising a larger, longer range aircraft also allows the concentration of new infrastructure to fewer international airports accelerating the rollout of a global network of zero-carbon emission flights and tackling emissions from long haul flights.
These are my thoughts.
The Airframe
This picture downloaded from the Aerospace Technology Institute web site is a visualisation of their Fly Anywhere Aircraft.
Some features stand out.
The wings are long, narrow and thin, almost like those of a sailplane. High aspect ratio wings like these offer more lift and stability at high altitude, so will the plane fly higher than the 41,000-43,000 feet of an Airbus A350?
I wouldn’t be surprised if it does, as the higher you go, the thinner the air and the less fuel you will burn to maintain speed and altitude.
The horizontal stabiliser is also small as this will reduce drag and better balance with the wing.
The tailfin also appears small for drag reduction.
The body is bloated compared to say an Airbus A 350 or a Boeing 777. Could this be to provide space for the liquid hydrogen, which can’t be stored in the thin wings?
The fuselage also appears to be a lifting body, with the wings blended into the fat body. I suspect that the hydrogen is carried in this part of the fuselage, which would be about the centre of lift of the aeroplane.
The design of the airframe appears to be all about the following.
- Low drag.
- high lift and stability.
- Large internal capacity to hold the liquid hydrogen.
It may just look fat, but it could be as radical as the first Boeing 747 was in 1969.
The Engines
I suspect the engines will be developments of current engines like the Rolls-Royce Trent XWB, which will be modified to run on hydrogen.
If they are modified Trent engines, it will be astonishing to think, that these engines can be traced in an unbroken line to the RB211, which was first run in 1969.
The Flight Controls
Most airliners these days and certainly all those built by Airbus have sophisticated computer control systems and this plane will take them to another level.
The Flight Profile
If you want to fly any aircraft a long distance, you generally climb to a high level fairly quickly and then fly straight and level, before timing the descent so you land at the destination with as small amount of fuel as is safe, to allow a diversion to another airport.
I once flew from Southend to Naples in a Cessna 340.
- I made sure that the tanks were filled to the brim with fuel.
- I climbed to a high altitude as I left Southend Airport.
- For the journey across France I asked for and was given a transit at Flight Level 195 (19,500 feet), which was all legal in France under visual flight rules.
- When the French handed me over to the Italians, legally I should have descended, but the Italians thought I’d been happy across France at FL195, so they didn’t bother to ask me to descend.
- I flew down the West Coast of Italy at the same height, with an airspeed of 185 knots (213 mph)
- I was then vectored into Naples Airport by radar.
I remember the flight of 981 miles took around six hours. That is an average of 163.5 mph.
I would expect the proposed aircraft would fly a similar profile, but the high level cruise would be somewhere above the 41,000-43,000 feet of an Airbus A 350. We must have a lot of data about flying higher as Concorde flew at 60,000 feet and some military aircraft fly at over 80,000 feet.
The press release talks about London to San Francisco, which is a distance of 5368 miles.
This aircraft wouldn’t sell unless it was able to beat current flight time of eleven hours and five minutes on that route.
Ground Handling
When the Boeing 747 started flying in the 1970s, size was a big problem and this aircraft with its long wing may need modifications to runways, taxiways and terminals.
Passenger Capacity
The press release states that the capacity of the aircraft will be 279 passengers, as against the 315 and 369 passengers of the two versions of the A 350.
So will there be more flights carrying less passengers?
Liquid Hydrogen Refuelling
NASA were doing this successfully in the 1960s for Saturn rockets and the Space Shuttle.
Conclusion
This aircraft is feasible.
First In-flight 100% Sustainable-Fuels Emissions Study Of Passenger Jet Shows Early Promise
The title of this post, is the same as that of this press release from Rolls-Royce.
This is the introductory paragraph.
Initial findings from a world-first study of the impact of 100% sustainable aviation fuel (SAF) on both engines of a commercial jet have provided promising early results.
The study was performed using an Airbus A350, which is powered by Rolls-Royce Trent XWB engines.
This paragraph describes the tests.
In April, the A350 flew three flights over the Mediterranean Sea pursued by a DLR Falcon chaser plane to compare in-flight emissions of both kerosene and Neste’s hydro-processed esters and fatty acids (HEFA) sustainable fuel. The team also carried out compliance tests using 100% SAF and no operational issues were experienced.
I was surprised, when I first read this, that they used a chase plane to measure emissions, as I thought they’d simulate that in a test cell on the ground.
But this is probably, the best way to test the engines, whilst running on sustainable aviation fuel, in real-world conditions.
Conclusion
I believe that sustainable aviation fuel (SAF) will be the interim solution to flying until hydrogen-powered aircraft are developed.
The Anonymous Widower 