ZeroAvia's flight is part of the UK Government-backed HyFlyer II project, which aims to develop a 600kW powertrain to allow zero-emissions flight for 9-19 seater aircraft, and is targeting a 300 nautical mile range. The flight was conducted under a full Part 21 flight permit with the UK Civil Aviation Authority.
The company aims to be serving commercial flights with the technology by 2025. It also aims to scale up the technology to larger 90-seater aircraft, with "further expansion" into narrowbodies in the next decade, they said in a statement. By 2027, they aim to be able to power a 700-mile flight in a 40-80 seater aircraft.
The speed of sound is the speed at which changes in pressure move through the air.
If a bullet is shooting through the air faster than the speed of sound it is said to be "supersonic". (The word "supersonic" literally means above, indicated by the Latin word "super", like "superior", stuck on the front of the word "sonic" meaning sound. "Sonic velocity" means at the speed of sound, and "subsonic" means below the speed of sound, Latin word "sub" meaning below stuck on the front of sonic, like submarine is below the surface of the sea.) A supersonic bullet is moving faster than the sound pressure changes move through the air. So you will not hear the bullet before it hits you.
All the energy in the sound pressure changes that are not going forward from the supersonic bullet has to go somewhere else instead. The pressure changes go into sharp changes in pressure between the air in front of the bullet and the air behind the bullet. These sharp changes in pressure are called "shocks", and they happen when the bullet reaches the speed of sound. Subsonic bullets do not create shocks because the energy can move forward in front of the bullet - you will hear a subsonic bullet before it hits you.
The physics answer has been given, but since this is asked under an Engineering tag it should also be noted that there is something called wind engineering setting standards for the wind speed a building should be able to withstand, and there will be turbulence effects from the neighboring buildings and the height of the window above ground which modify the local wind velocity compared to the wind speed you see on a weather map.
Yes, I agree, it would be good to move traffic onto electric trains. There are also short-range electric aircraft which could reduce the aviation emissions.
This report PDF demonstrates that an 81% emissions reduction is achievable by 2030. This requires immediate and large-scale actions, prioritising short-term ambitious targets for already-available technologies. The report outlines a five-year deployment plan, identifying the most impactful technologies. It will create 195,000 jobs and put Australia on the IPCC scenario SSP1-1.9 (for 1.5 degrees of average global warming). Six existing technologies will do the heavy lifting: solar panels, wind turbines, batteries, electric vehicles, heat pumps, and hydrogen electrolysers.
DisasterousGiraffe OP t1_j55m10m wrote
Reply to Successful test flight of Hydrogen-Electric Airplane could be key to zero-carbon flying. Aim for commercial 700 mile flight with 40-80 seater aircraft by 2027. by DisasterousGiraffe
ZeroAvia's flight is part of the UK Government-backed HyFlyer II project, which aims to develop a 600kW powertrain to allow zero-emissions flight for 9-19 seater aircraft, and is targeting a 300 nautical mile range. The flight was conducted under a full Part 21 flight permit with the UK Civil Aviation Authority.
The company aims to be serving commercial flights with the technology by 2025. It also aims to scale up the technology to larger 90-seater aircraft, with "further expansion" into narrowbodies in the next decade, they said in a statement. By 2027, they aim to be able to power a 700-mile flight in a 40-80 seater aircraft.