Electric planes

[EVer Hopeful]

it'll be like drones (now called SUAVs)

Started off as a free for all, but now requires a Part 107 sign off (mostly)

 

[nativewolf]

you can do similar with ultralights, there are basically no rules or regs other than it being light (250lbs or less for a powered vehicle). So, the only new thing here is that these are basically more like a little helicopter than a plane.

 

[Earl]

With better aero, weight goes up.

Not really. One can make very light, very aerodynamic fixed wings. These have been around since the '70's

The First Human-Powered Flight

The Gossamer Condor relied on pedal power.

www.smithsonianmag.com

The problem here is that the wings are tiny propellers that have to spin very fast to generate all lift. Then they try to control forward speed, turning, and climb/descent by changing the speed of those tiny props so they will seldom be at their efficient airfoil/pitch speed which is bad to begin with.

This will probably be good for a 10-15 minute flight, so not really suitable for commutes.

Which means 5 - 7 minutes of safe flight time. At 60 mph, this means 5 - 7 miles (~7 - 10 km) range. Yep, you could probably drive a car or bike there just as easily and it would take less space to park.

However, I can imagine a future where landing a manned drone will be as easy as landing a pro/consumer drone: just point the stick downwards and sensors and the flight controller will figure it out themselves.

I can imagine it, as have cartoon writers (The Jetson's). Carrying enough energy to carry much load any distance will be a ;physics challenge.

But I do wonder how the FAA will handle redundancy

Redundancy is really a solution for Reliability. Reliability is the key aspect for flight since, if something goes wrong while flying high and fast, hitting the ground tends to be catastrophic. Multi-rotors tend to lend themselves to redundancy nicely since one can design the control system to compensate if one or more rotors go out. Unfortunately, however, the reliability of the control system, which is a single-point-of-failure becomes a challenge.

manned drones

I think these are sort of conflicting terms, unless, of course, you're thinking of no pilot flying it, but carrying passengers.

 

[oldsport]

Is it even legal to take off and land these things in populated areas like cities? And what happens to the regulations the first time two of these collide, crash, and kill someone on the ground, or fall onto somebody's house? I would vote to ban flying these things over my city.

Yes, I'm sure people said the same about early airplanes, but there's a reason it's illegal to fly low over houses. The difference is that airplanes, by law, only approach the ground near airports. Both helicopters and airplanes require all sorts of certifications and licensing for pilots. This contraption is intended to take off and land in people's yards, and supposedly requires no license to fly.

idk all the details but for 100k and w usa engineering behind it i think it s a steal...

 

[EVer Hopeful]

I bet you can still get a pretty nice 182 for 100k

AND make money throwing skydivers out of it

 

[daniel]

I believe the makers of the Jetson One claim that it is very easy to fly. Presumably the computer does most of the work and the pilot just points it where they want it to go. But that does not address the fact that most people don't pay sufficient attention to their surroundings. And in an aircraft you're dealing with three directions, not just two, and you don't have roads with marked traffic lanes.

 

[oldsport]

I believe the makers of the Jetson One claim that it is very easy to fly. Presumably the computer does most of the work and the pilot just points it where they want it to go. But that does not address the fact that most people don't pay sufficient attention to their surroundings. And in an aircraft you're dealing with three directions, not just two, and you don't have roads with marked traffic lanes.

you are so right on this one... this is not a toy to be taken lightly...

 

[petit_bateau]

These are exactly the regional routes that shorter range EV-flyers need to work up the technology ladder. Clue : Europe and China will likely go high speed rail (more) , likewise likely India. So ..... no prizes for guessing that the lobbyists will block USA high speed rail. Just as they always have.

forecasts that an additional 21,000 kilometres of high-speed rail can be built between now and 2050. That is the key finding of a new study presented over the weekend. It would mean tripling the length of the current European high-speed rail network. ......... The study that DB and its partners have drawn up envisions connecting all of Europe’s metropolitan areas via rail. These are conglomerations with 250,000 inhabitants or more. Some 60 per cent of Europeans currently live in these areas, and expanding the high-speed network would mean giving those people access to fast connections.

DB sees potential for tripling European high-speed network, but investments insufficient

Deutsche Bahn forecasts that an additional 21,000 kilometres of high-speed rail can be built between now and 2050. That is the key finding of a new study presented over the weekend. It would mean tripling the length of the current European high-speed rail network. However, without additional...

www.railtech.com

 

[mycroftxxx]

But I do wonder how the FAA will handle redundancy in manned drones. It's OK to have only one flight controller and non-redundant sensors in a toy drone, but how do we go about with manned drones?

”manned drones“ is a bit of an oxymoron

As someone else said, the FAA mandates reliability: how many loss of control and loss of aircraft accidents per flight hour, where the causal factor is failure of the aircraft, not pilot error, poor maintenance, etc. Redundancy is one way to achieve reliability, assuming you’re smart enough and experienced enough to do it right, which is much harder than you may think. (See, for example, Complex System Reliability for details). Depending on the aircraft size, purpose, etc., it will fall under one or more regulatory classes, and the reliability requirements will fall out from there. Whatever methods the manufacturer chooses to use to achieve the required reliability, said manufacturer will have to satisfy the FAA, by analysis and test, that the requirements have been met prior to a type certificate being issued, and a commercially-sold aircraft without a type certificate isn’t really an aircraft in the legal sense of the word.

 

[wooter]

”manned drones“ is a bit of an oxymoron

Maybe not. Whereas in a fixed-wing airplane or helicopter the pilot directly controls the surfaces to steer the aircraft, a "multicopter" with 4 rotors is controlled by a flight computer which controls the speed of each of the 4 rotors, while the pilot doesn't have 4 separate dials to control the speed of the 4 rotors but probably employs a joystick (or could even use a game controller) to control the aircraft.

My point about redundancy is that in classic aircraft there are hard links or redundant hydraulic systems to control the surfaces, but a multicopter with fixed rotors has only the flight computer and cabling to power the rotors. If the flight computer is not redundant, the power dies or anything else, there is no way for a pilot to induce an autorotation because the pilot cannot control the angle of the blades of the rotors.

 

[Earl]

Maybe not.

Perhaps English is not your first language so you're missing the point.
The term "Drone", in English 2.0 (American English), generally refers to an aircraft (or ship or land vehicle) with no people onboard operating it.
While many "drones" are multi-rotors, these are generally the cheap consumer devices that are generally toys or used for photography. There are drones that are fixed wing aircraft and can be quite large.

There are also, of course "drone ships"

Familiar to most Tesla enthusiasts.

However, you're technically wrong in your statement that:

a fixed-wing airplane or helicopter the pilot directly controls the surfaces to steer the aircraft,

Sure, some fixed-wing airplane or helicopters allow the pilot to directly control the control surfaces but very few designed since the 1960's are this way. Nearly all have flight computers that talk directly to servos that move the control surfaces while the operators put control inputs in to the computers. Some may have mechanical or hydraulic backups but the machinery does most of the work.

 

[mycroftxxx]

My point about redundancy is that in classic aircraft there are hard links or redundant hydraulic systems to control the surfaces, but a multicopter with fixed rotors has only the flight computer and cabling to power the rotors. If the flight computer is not redundant, the power dies or anything else, there is no way for a pilot to induce an autorotation because the pilot cannot control the angle of the blades of the rotors.

And your point is…?

Again, the FAA primarily mandates reliability. If you can demonstrate to the FAA via rigorous design review and testing that the failure likelihood of your simplex vehicle management system (that’s what the fly-by-wire system is called) meets the FAA’s probability of loss of control and probability of loss of aircraft requirements, then you’ve met one of the requirements to get a type certificate. (I haven’t looked at the FAA docs in quite a while, and they may actually require some level of redundancy for certain classes of aircraft, regardless of your simplex reliability, but the gist of my statement stands - there is flexibility on how you meet the PLOC/PLOA requirements.)

Yeah, a simplex system can have lots of failure modes. Or not - depends on the engineering behind it. But focusing on redundancy confuses the trees for the forest. Redundancy is a means to an end; reliability is the end result.

(FWIW, designing reliable FBW systems is one of the things I get paid to do in my day job…)

 

[oldsport]

very interesting discussion...

 

[Earl]

Again, the FAA primarily mandates reliability. If you can demonstrate to the FAA via rigorous design review and testing that the failure likelihood of your simplex vehicle management system (that’s what the fly-by-wire system is called) meets the FAA’s probability of loss of control and probability of loss of aircraft requirements, then you’ve met one of the requirements to get a type certificate.

Of course, a friend of mine, who's a giant in the world of aircraft design, reminds me that nearly, if not all, type certified aircraft for passengers rely on data that started being collected long before the FAA began certification. Collecting enough data today, on aircraft that are not making revenue, would be extremely expensive.
Bert Rutan complained about this to no end because of the efforts he went to to get Starship certified.

I don't know that it ever was certified to the same qualifications as airliners are.

 

[petit_bateau]

Of course, a friend of mine, who's a giant in the world of aircraft design, reminds me that nearly, if not all, type certified aircraft for passengers rely on data that started being collected long before the FAA began certification. Collecting enough data today, on aircraft that are not making revenue, would be extremely expensive.
Bert Rutan complained about this to no end because of the efforts he went to to get Starship certified.
View attachment 958240
I don't know that it ever was certified to the same qualifications as airliners are.

Indeed Starship certification was a bit of an issue, but was by no means the only cause of failure.

Why the Starship was such a disaster : Air Facts Journal

When one examines a failure of such monumental scale as the Beech Starship program, the inevitable question is, “Why did they do that?” As in almost every instance where things go badly wrong, it was a series of decisions made under shifting circumstances that led to the ultimate disaster.

airfactsjournal.com

Beechcraft Starship - Wikipedia

en.wikipedia.org

This summary may be relevant in todays world,

"But the Starship was a disaster for all of aviation in terms of lost opportunity. The billion bucks — closer to two billion in today’s dollars — that Raytheon spent going down the wrong technology paths could have been, and should have been, spent on an improved conventional turboprop. Today’s King Air 350 is a terrific airplane, and a best seller, but if that billion dollars had gone into building on the King Air instead of chasing a dream we would have an airplane now that is several inches larger in cabin section, more fuel efficient because of a newer wing design, and less costly to maintain because of modern system design and materials use.

I cringe still when the Starship is described by so many as high-tech, and futuristic. It was a failure in every respect. Raytheon shot for the moon and ended up with an exotic looking airplane that didn’t do anything as well as airplanes already there, and costing much less. And all of aviation was robbed of the really terrific airplane that a billion dollars could have created."

 

[mycroftxxx]

Of course, a friend of mine, who's a giant in the world of aircraft design, reminds me that nearly, if not all, type certified aircraft for passengers rely on data that started being collected long before the FAA began certification. Collecting enough data today, on aircraft that are not making revenue, would be extremely expensive.
Bert Rutan complained about this to no end because of the efforts he went to to get Starship certified.
View attachment 958240
I don't know that it ever was certified to the same qualifications as airliners are.

Burt Rutan is not really any kind of expert in type certification of aircraft; pretty much all of his designs were one-offs and/or designed for kit building, not production aircraft. And Rutan didn’t certify the Beechcraft Starship - Rutan built an 80% scale demonstrator for Beech, then Beech tried to scale it up and certify it. Rutan may have consulted on it but wasn’t responsible. One of my college professors who was familiar with the program and the rigors of getting a new aircraft type certification told us that Beech underestimated the drag because they didn’t properly account for scale effects - in particular, according to my professor, Beech assumed the laminar-to-turbulent boundary layer transitions in cruise flight would happen at the same locations on the full-scale aircraft, which of course they won’t. Another of my mentors had a saying that “Burt Rutan designs the best bad aircraft out there”, and I tend to agree

 

[Earl]

“Burt Rutan designs the best bad aircraft out there”, and I tend to agree

I can't disagree.
I've heard that quote extended to "Burt Rutan designs the best bad aircraft without a finished cockpit out there" since he always lost interest once the plane had flown. IIRC, the Boomerang had a lawn chair for the pilot seat.
When "Giggle Factor" and CDDTU (Coefficient of Drag due to Ugliness) were critical factors determining what projects get funded (Higher is better), what can you expect.
He did push new designs though while certified aircraft design pretty much froze in 1958 after the 707/C135.

 

[mycroftxxx]

He did push new designs though while certified aircraft design pretty much froze in 1958 after the 707/C135.

Agree, but too many were “new for the sake of new” IMO. Maybe things are starting to unfreeze a bit with the blended wing-body stuff, at least for cargo and tanker aircraft; I’m not sure that passengers would take well to sitting way off the centerline in roll maneuvers though.

 

[Earl]

too many were “new for the sake of new” IMO

True,
However, to his credit, one reason he loved the canard design was its 'inability' to stall. One of his obsessions was to make a plane that was so stable and safe anybody could fly it (VarEZ, LongEZ). He really did want to make personal air mobility accessible to everyone. Not unlike a big theme on this thread.
Maybe he was off in his approach but his heart was in the right place in this regard. He also offered to let me charge my EV1 at his house in Mojave once when I was going there for a meeting. His "Sparky" was the first EV1 in the Antelope Valley.
See, this got back to the EV topic even

 

[GSP]

Dutch startup has plans for 90 passenger 500 mile battery-electric aircraft. Instead of electrifying a modern turboprop, they looked to the 707 and DC-8 narrow body jets. They were fuel guzzlers designed for long range, so they also needed to carry a high energy mass, about 50% of total mass.

It has a turbine generator for the "reserve fuel" function. Lighter than batteries and not zero emission, but only used for less than 1% of flights.

Dutch Startup Elysian Pursues Large Battery-Electric Airliner | Aviation Week Network

Subsidiary of Fokker owner Panta claims 90-seat aircraft is feasible on near-term battery technology.

aviationweek.com

https://pure.tudelft.nl/ws/portalfiles/portal/173363843/de_vries_et_al_2024_a_new_perspective_on_battery_electric_aviation_part_ii_conceptual_design_of_a_90_seater.pdf

GSP