Tesla Model S - Curb weight 4,647 lbs Audi A8 - Curb weight 4,751 lbs BMW 7 series - Curb weight 4,244 - 4,848 lbs
Tesla Model 3 - Curb weight 3,627 to 4,072 lbs Audi A4 - Curb weight 3,450 to 3,627 lbs BMW 3 series - 3,582 to 4,010 lbs
I've been wondering if this offers any escape. Suppose that you have a power supply from the ground during the initial acceleration, and the final cruising velocity is not much higher. Or just build a huge ramp.
It sounds like a joke at first, but it might not be impossible. You just need some kind of reverse linear induction motor that doesn't require much weight on the plane side. Perhaps the fuselage is the magnet? If the takeoff acceleration is 2g, you need a 1 km ramp. The varying lift of the wings will be an obstacle, though this might be manageable with flaps. Of course, a 2g takeoff would be a dramatic experience for the passengers.
An object dropped at 30,000 feet would be traveling at about 3,000 mph when it impacted the earth, ignoring the atmosphere.
Maybe launch at 4,000 mph to overcome drag to throw something into cruising altitude? We'll just wear some noise canceling headphones to block out the OVERSPEED alarms.
A220 and 737 both carry roughly 100-150 passengers and have wingspans of 115-120' and the lightest versions weigh around 130,000 lbs.
Seems doable if the jet and catapult system were specifically designed for this purpose. Maybe less plausible for jumbo jets.
> Plus, I doubt you'd ever get a lot of civilians to fly off a catapult...
I'm sure many short-sighted people said that about passenger air travel in general. Plus, if you actually watch a video of a modern catapult launch, you will see that it would be mostly invisible to passengers.
Plus, if you actually watch a video of a modern catapult launch, you'd realize that you're speaking out of your ass. Going from 0-170mph (the rotation speed of an A320), in a short amount of space is going to impart huge G forces on both the aircraft as well as the crew and passengers. Catapults also fail, and a "cold cat" on an airline sized plane (without zero/zero ejection seats for everyone) means a mass fatality event.
Man, HN is just full of people suffering from Dunning-Kruger.
If that's not good enough for you, here's what fucking Airbus has to say:
"In the report, Airbus explains that the initial power required for a passenger plane to take-off is only needed for a brief part of the total flight. This therefore poses an opportunity for a ground-based device to provide the propulsion needed and free the plane of its additional burden. With this in mind, the engineers at Airbus came up with an idea dubbed "eco-climb" which appears to draw inspiration from the catapult-assisted take-off system utilized on aircraft carriers."
Dunning-Kruger indeed.
Engineers come up with all kinds of ideas all the time. Most don't result in more than some PR piece, like the one you quoted above...
Airbus's "Eco Climb" was greenwashing at its finest, and despite them touting it in 2012, here we are over a decade later without ANYONE doing something this dumb. The comment above misses out on some basic aircraft fundamentals. One, most of the energy used by an aircraft is in flight, not in rolling off a runway. So the amount of energy saved compared to the added complexity makes it a dumb idea.
Sure, you could make the catapult the length of a runway, mitigating the G force etc. Then you have a Rube Goldberg device that needs to accommodate every aircraft that uses the runway. And this device can't interfere with landing or taxiing either. Then you need to get this device adopted by most airports, otherwise you've immediately gimped your airliner when it lands somewhere that lacks this device.
This idea reminds me of crap I used to read in Popular Mechanics and Popular Science (RIP) that had great ideas that were never developed because their underlying assumptions didn't match with the real world.
You might as well off up the idea of using a blimp/dirigible to lift the airliner up to altitude then drop it off...
Oh and I believe referring to the Airbus quote is an appeal to authority? Considering that Airbus design flaws killed a lot of people, maybe reconsider?
My non-credible idea would be to just use an Apple-style magsafe charger on the back of the airplane that disconnects midair at 30,000ft and falls on the helpless people below.
I do like the magsafe charger idea. However, I anticipate some regulatory issues.
There's a big caveat there though. Current aircraft engines are extremely expensive to operate and maintain, regardless of fuel costs. Even a simple GA piston engine would cost more to operate than a small commercial EV aircraft's motors. Replacing turbines with electric motors will provide cost savings that actually make small commuter flights economical again. Kerosene and jet engines aren't going anywhere for the long haul flights. But the future for electric aviation is in the sub 300 mile regional commuter market, where it's faster than a train and has the simplicity of catching a bus.
See Eviation Alice for an example: https://www.popularmechanics.com/flight/a41453056/eviation-e...
Today's battery tech is just barely good enough at this point to start becoming useful for these kinds of flight profiles.
Note that I said should above. The reality is North America has terrible train service, and management (congress!) doesn't care: so airplanes end up better despite all reasons they are worse for short trips.
The TSA requirement is nil for 10 person flights and these would be VFR only anyways. You would avoid a vast majority of the need for added ATC by operating between uncontrolled fields and relying on enhanced automation. The traditional airport model doesn't really apply when flights can be made so casually. Imagine a world where tiny runways that only service EVs are integrated into the city and you can hop between them as easily as catching a bus. Crosscountry travel would be also be possible via smaller hops, and cost less than a direct long haul jet liner ticket.
All of that is enabled by the orders of magnitude reduction in operating costs. EV Alice is claiming $200/hr to operate an aircraft that has the equivalent performance to a $1k+/hr turbine within the range limitation.
I mean, that sounds like a massive shift in infrastructure and city planning. I am not sure how efficient and affordable this would need to be to achieve that level of integration into daily society. Currently nothing, in the US at least, is setup to function this way. Whereas rail and roads are already deployed.
And again, this ignores any of the issues brought on by scale. If this is the way we want people traveling at a 10x or 100x rate, the airspace is going to be busier and likely will need some sort of coordination, whether ATC or some other mechanism.
But just like, reading this comments about everything from batteries to from-ground power sources for ascent to dragging dead batteries after use... like, what if we just flew less? Yes for international travel that needs to happen at speed, a plane is basically the best option. But for... basically everything else, what if we just sacrificed some convenience to not be dumping industrial amounts of waste into the atmosphere?
I'm reminded of how much air quality improved almost worldwide when covid first hit and offices were shut down, offices that, I remind you, continued to function largely just fine after a period of adjustment to remote work. I'm obviously extremely for making all transportation tech more efficient, but an under-discussed element I feel in this is just... doing less shit? Moving fewer people when moving said people isn't really needed? Maybe not growing all the pineapple in one country and shipping it over to a different country to be packaged in plastic and then shipping those all over the world so everyone on the planet has ready access to pineapple, a ton of which is just going to go straight in the garbage because we don't actually need all that damn pineapple?