The Anonymous Widower

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.

 

 

 

December 7, 2021 - Posted by | Hydrogen | , , , , , , , , ,

2 Comments »

  1. I don’t think there is a need to absolutely match the current route block time/speed in the future. Commercial aviation has been getting slightly slower since the 1970’s (taking Concorde out of the discussion as an exception to test the rule). I suspect passengers would tolerate an additional 60-90 minutes on a over 10-hour route if the plane is kind to the environment and the onboard experience is good.

    Outright speed is more of interest for shorter flights (many of which should become train journeys anyway), certainly the routes that are a bit too long to be an attractive train journey but where there is an expectation of having half a working day at destination on flight days (or an evening for leisure), so adding time to the 3.5-5.5 hour routes would be unattratcive

    Comment by MilesT | December 8, 2021 | Reply

    • I’ll go along with what you say.

      Pre-pandemic, I did four four-hour trips to Amsterdam on Eurostar. Several passengers said, they’ll always use Eurostar, as check-in and check-out is so much quicker. Many passengers like me, effectively go city centre to city centre.

      Heathrow must be gagging for Crossrail, as it will give them better connections than St. Pancras.

      Comment by AnonW | December 8, 2021 | Reply


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