101–110 of 223 posts
I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel. Get a fleet of 2-4 seater unpowered glider planes [1] Get a bunch of rural properties spaced ~100km apart. Put little glider landing and launch strips on each propert…
Earlier quoted context omitted.
LNA, an aviation industry newsletter, recently came to a very different conclusion [1]. The biggest difference to Wendover Productions's numbers is a hugely higher estimate in the cost of replacing the battery every 5-10 years due to battery degradation. [1] https://leehamnews.com/2021/07/01/the-true-cost-of-electric-...
So, by that article, a fully-loaded turboprop (let's say 19 100 kg passengers, 4900 kg airframe, 320 kg fuel, 308 kg reserve fuel) flying 200 nm weighs ~ 7500 kg and consumes just under 4 MWh of fuel, of which 1 MWh is useful work. The battery model will weigh at least twice that for the same useful work, so how the hell does it fly as far ? Could it actually fly the mandated 100 nm + 30 min contigency*
I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel. Get a fleet of 2-4 seater unpowered glider planes [1] Get a bunch of rural properties spaced ~100km apart. Put little glider landing and launch strips on each propert…
Wouldn't landing be the hardest part?
I am mainly curious if the general physics and economics of the idea are remotely feasible, assuming the software is solvable.
I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel. Get a fleet of 2-4 seater unpowered glider planes [1] Get a bunch of rural properties spaced ~100km apart. Put little glider landing and launch strips on each propert…
Gliders are able to bypass this limitation in certain scenarios (such as updrafts) but this only works in specific cases. It also usually takes more than a launch to bring them to sustainable altitude, and they are slow.
Interesting that the routes they name are 119 and 78 miles. Kinda surprised Americans have flights so short. But then again the aircraft might beat CAFE for a vehicle with a single driver in it, plus aircraft usually carry a load of cargo too, as the passengers pay for the plane to go somewhere and the cargo is the profit. Wonder how much cargo this elegy plane can carry. https://en.wikipedia.org/wiki/Fuel_economy_in…
It's all connecting to bigger flights. Plus 78-119 miles means either paying a lot of money for a cab, paying gas & parking fees for the duration of your trip at the bigger airport, or asking a friend/family member very nicely to take that trip to drop you off/pick you up. The smaller cities in question for these routes aren't going to have any sort of usable bus service for making a flight on time. To answer your ca…
I actually think you the cargo aspect will be somewhat significant as well- The regional airports I checkout on flightaware appear to have several fedex/UPS feeder flights a day.
I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel. Get a fleet of 2-4 seater unpowered glider planes [1] Get a bunch of rural properties spaced ~100km apart. Put little glider landing and launch strips on each propert…
Wouldn't landing be the hardest part?
I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel. Get a fleet of 2-4 seater unpowered glider planes [1] Get a bunch of rural properties spaced ~100km apart. Put little glider landing and launch strips on each propert…
Flying in good conditions may be an easier problem to solve than driving in good conditions but the issues seem to move towards what happens in the bad conditions. It's not like you can just hit the brake or park on the side of the road and continue later when the system detects a current or upcoming problem. Even if you get it so 99.99% of flights are in favorable weather and wind without piloting issue a 1 in 10,000 chance your glider is going to make an emergency landing or worse is not good enough odds, especially if it's multiple flights each way. And that ignores the problem of the service being unavailable if certain weather conditions aren't met, so the backup transportation option is still needed at a moments notice in full force anyways.
Then, much like self driving, there are the regulation issues https://www.ssa.org/glider-pilot-ratings/ which would be their own challenge to change and require you solve them before the business can even get it's chance to get going.
That being said I like the concept, just not sure it's really any easier. Perhaps we should just build the missing rail instead :).
I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel. Get a fleet of 2-4 seater unpowered glider planes [1] Get a bunch of rural properties spaced ~100km apart. Put little glider landing and launch strips on each propert…
As a software developer, this part is what I don't like.
We're still quite a ways from fully autonomous driving cars (as in: don't rely on a human taking over for backup). A bad bug in an autonomous car could drive you at high speed into a wall, but there can at least be an "emergency stop" button that disables the main processor and jams on the brakes.
Planes have no such ability to just "stop". At best, they could deploy a parachute, but even then landing safely is by no means guaranteed.
I think we need a decade or so of fully autonomous cars being accepted into daily life before this can be attempted with anything that flies.
Earlier quoted context omitted.
LNA, an aviation industry newsletter, recently came to a very different conclusion [1]. The biggest difference to Wendover Productions's numbers is a hugely higher estimate in the cost of replacing the battery every 5-10 years due to battery degradation. [1] https://leehamnews.com/2021/07/01/the-true-cost-of-electric-...
That sounds like a ridiculous assumption. Airplanes are basically guaranteed to not discharge the batteries lower than 20% for safety reasons. I’m guessing they’ll also not charge to fully 100%, like some BEVs. On fixed routes they could charge only what they need to get to where they’re supposed to go plus the required buffer for emergencies. The batteries will probably also be cooled. So it could be an ideal scenar…
They talk about regional flight. Does anyone have any sign that battery-powered planes carrying a hundred people will cross the Atlantic, Pacific, or the U.S.? The physics in Tom Murphy's textbook https://dothemath.ucsd.edu/2021/03/textbook-debut suggests it's impossible. I've talked to people at electric plane companies who have offered no hope. I originally thought since we engineered from the Wright brothers to 74…
The Youtuber Real-Engineering (aerospace engineering background) has a good video discussing the viability of electric aircraft. Barring some dramatic revolution in battery energy density, electric aircraft beyond a certain range are simply not-feasible. They are very feasible for short-range routes though. https://www.youtube.com/watch?v=VNvzZfsC13o
It's not inconceivable that fuel cell electric planes could become a thing as well, especially if these early BEV show other benefits around maintainability, noise reduction, etc. I think its a long shot though, as jet fuel + carbon capture will probably be price competitive before fuel cell airliners become a thing.