Electric airplane

I have designed parts of both hardware and software systems that have been used by DoD.

But again, I would aim for the experimental category. I do not subscribe to the notion that, if someone were to design a PAV that met the specifications put forth by FAA/NASA/CAFE, the FAA would simply standby and ignore it. I think that, within reason, there would eventually be an attempt at accommodation.

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At no point did I ever say that I would attempt to design a fly-by- wire C172. In fact, I have stated on several occasionals that the very last thing I would do is take a stock aircraft, C172, kit or otherwise, and attempt to retrofit some kind of fly-by-wire contraption on it.

I stated:

"Suppose that one of the objectives defined by FAA/NASA is low cost, where low-cost is $50,000US. Then, it stands to reason that it would be silly to purchase a $100,000 aircraft and at $15,000 of low-cost electronic equipment, because the end price would be $100,000+ $15,000 =3D $115,000, which obviously moves us in the wrong direction."

A systemic redesign would be necessary, which is why the aircraft would have to start off as experimental. Eliminating the traditional for of the ICE/prop would be a necessity, for example.

-Le Chaud Lapin-

martin

Since subsonic aerodynamics is a very mature technology and there is no way known to science to self propel an object in the air other than accelerating mass, yes.

The only way to make airplanes significantly different than the airplanes that already exist is to invent an "engine" entirely different than that which exists now.

Absent that, airplanes will still have wings or rotors and an engine that accelerates air with a fan of some sort.

But never an entire system? How about ROI calculations? Do you have any clue what the term "burdened labor rate" means?

That means you get to build 1.

You are avoiding the question.

Substitute any GA class airplane you like, whether it exists or not.

Name some things that a fly-by-wire airplane could legally do that the same airplane could not do with conventional cable and pulley systems.

That sequence is silly for what I am proposing. It is also expensive and time-wasting. It implies that I chose to start thinking about these problems as randomly as choosing a type of cereal to buy at the supermarket.

I have flown, although my experience is very limited. Flying an aircraft did not, in any way, improve my insight into aerodynamics or math or computer science or electrical engineering or Newtonian physics. Learning is very important, but the type of learning I require is not to be found on any airfield. Asking questions, yes. I would have extensive interaction with material scientists, etc. I would avoid asking people who are predisposed to insist that whatever I make, it must look like a Cessna.

"Your machine has bugs in it, so I will not insure it under any circumstances. However, given the significant difference in cost, $20,000 vs $100,000, we both know that the external pressure to rid the plane of those bugs so that it can be sold and insured is so significant, it will be a matter of time before it happens, provided, of course, that the bugs really are simply bugs, and not something more profound like gross structural defects."

Then I would wait for the bugs to be out, and when they are out, I would insure both versions. In the meantime, the person making the 1x version will have significant support from multiple factions to polish the product.

A lot of those contraptions look like what the name of the article implies: automobiles that fly.

I think this is am imprudent approach, taking something that is basically a car, and slapping wings and a propeller on it.

Makes me curious as to what he has been working on. Certainly he has access to CAD software. I would never invest in actually building something, using real materials, without vetting the design in software first. If the software tells you that the machine won't fly, there is no point in building it.

I never thought about improving safety. That was not one of my objectives, since safety is automatically a non-negotiable necessity. I was thinking more about the negotiables like, noise, comfort, controllability, automation, cost, size, weight, etc.

This is nice. If only someone could take the COTS approach to the entire airplane, and not just to a relatively small part of it.

-Le Chaud Lapin-

Under those terms (experimental) about anyone who understands airplanes can come up with a more affordable plane. Those with the time, motivation and money do it.

Minimize effects of turbulence against aircraft bu utilizing sophisticated digital filters against stochastic modeling of the turbulence.

-Le Chaud Lapin-

Babbling nonsense and has nothing to do with fly-by-wire.

Do you even know what "fly-by-wire" means?

Do you know what turbulence is?

Obviously not.

For the first item, fly-by-wire means that the control surfaces are not directly mechanically coupled to the controls but rather are driven by motors and the controls provide command inputs to the motors.

A device that "controls" an airplane absent human input is called an autopiltot.

Autopilots for GA airplanes have been around for better than half a century.

Autopilots connect into what ever drives the control surfaces and it doesn't matter if the airplane is fly-by-wire or conventional cable and pulley; they are two separate systems.

For the second item, turbulence is highly localized air movement and mostly vertical in component.

The only thing that can be done to "minimize effects of turbulence" other than avoiding it in the first place is to keep the airplane straight and level and somewhat on altitude.

Most GA aircraft do not have enough power and are not rated for enough G load to keep the aircraft exactly on altitude with anything but the lightest turbulence.

Any off the shelf 3-axis autopilot from the last half century is more than capable of doing everything that can be done about turbulence within the power and stress ratings of GA aircraft and are very common in aircraft that are flown single pilot IFR so the pilot can concentrate on position instead of keeping the airplane right side up.

The question remains:

Name some things that a fly-by-wire airplane could legally do that the same airplane could not do with conventional cable and pulley systems.

Yes.

Actually I do.

Right.

And horrendously expensive compared to how they can be today, in 2008.

The degree of control exhibited by cable and pulley cannot compete with that allowed by fully-electronic servo motors.

Ok.

A computer driving a servo system can do that far better than a computer driving [insert whatever here] driving cables and pulleys.

That does not mean that light turbulence could not be counteracted. Automobiles have been using active suspension for a while now. The same mathematics used in those systems could be employed in aircraft, but not with cables and pulleys.

Those autopilots are typically not designed for counteracting the effects of "light" turbulence.

-Le Chaud Lapin-

Naw, everybody knows that even used, politicians are never reliable.

It sure doesn't seem like it from anything you've said.

It sure doesn't seem like it from anything you've said

The cost of a certified system is irrelevant to the topic under discussion and yet another puerile attempt to avoid the question.

As an aside, if you can build a certified autopilot and sell it cheaper than the ones currently on the market, go for it.

Babbling nonsense.

The "fully-electronic servo motors" eventually wind up moving conventional cable and pulley mechanisms.

You are so ignorant you are laughable.

Do you actually believe that servo motors can be directly, mechanically connected to the flight surfaces without anything in between?

Babble yet again.

How the hell do you think the "servo system" connects to the control surfaces?

Guess what, it is through cables and pulleys.

Well, duh.

Do you understand the difference between keeping the airplane straight and level and holding altitude in an up/down draft that exceeds the capability of the airplane?

Airplanes don't have suspension systems; airplane fly in the air.

Babbling nonsense.

The *ONLY* thing possible to do to "counteract" turbulence is to keep the airplane straight, level, and at altitude.

Autopilots keep the airplane straight, level, and as close to altitude as the airplane performance allows.

Irrelevant as once again, airplanes don't have suspension systems, they are flying through the air.

If I didn't know you had to be older to get a student pilot certificate, I would guess you are about 12 years old from the stuff you say.

head,

Not only that they were not a lot faster then than ocean liners.

In message , Le Chaud Lapin writes

Sure. Now design the infrastructure needed to maintain separation between you and all the swarms of other people doing the same in zero visibility. Done much instrument flying yet?

No. Not any in fact [except for simulator].

This is a software issue, IMO, and not something that is technically insurmountable. It's probably been done already in some other context.

-Le Chaud Lapin-

During the dot.com boom of the late 1990's, there were an amazing array of great ideas to deliver internet access. Tethered aerostat balloons were the most popular.

At one time, I recorded over 300 LEO (low earth orbit) satellite proposals. Teledesic originally wanted to install 840 satellites (later downsized to 288):

but eventually only managed to launch one. The big problem with LEO is that satellite lifetime is a very short 5 to 8 years. The problem with aerostats is that they can't really carry enough weight to effectively cover a city with internet access. They're also not stable enough to use directional, spot beam, or sectored antenna systems. One proposal suggested that the clients rooftop dish antennas would track the aerostat as it wandered around the sky. Lots of other problems. I take personal credit in having shot down (not literally) about 5 such business plans.

technology.

The math is simple. Just calculate the annual amortized cost of construction and launch for the satellite, and compare it with the same criteria for aerostats and aircraft flying donuts. In one report, I demonstrated that it was more financially cost effective to purchase or lease commercial mountain top radio sites, than to launch satellites. The wild card is the FCC which controls frequency allocations and licence fees (and auctions). Cheap frequencies can make or break any scheme. For example, I vaguely recall (not sure) that Skystation was licensed for 68GHz for both uplink and distribution. That's fine, but consumer grade mm wave hardware is neither cheap, reliable, or commodity hardware.

therefore will be

to

Nope. Lose the pilot and it's easy. Just fly above the weather. That was the idea behind the various aircraft built by Dr. Paul McReady:

The trick turned out to be finding a day when the weather was sufficiently cooperative to be able to fly -through- the weather.

night,

Yep. Jet wash will clobber the fragile aerostats and airplanes. The ability to maintain a constant altitude has yet to be demonstrated, so some manner of collision avoidance will be necessary. One nice thing is that the safest place to put an aerostat is directly over an airport. That's where the traffic is the least (as opposed to the approaches).

I beg to differ somewhat. The ridiculous prices wireless service providers are paying for bandwidth should demonstrate that there's a need. However data only services have all lost money (except maybe paging). The only way to make money with wireless data has been to mix it with voice services. Despite predictions of an all digital data future, current profitability is based solely on voice. That will probably change, but in todays economy, short term profit is what drives investments.

Maybe. Research has never been much of a profit maker for its backers.

Optimist. The initial prototypes are here now. The inevitable initial commercial failures will appear in about 3-5 years. They will be underfunded and probably regulated into non-profitability by various vested interests. After they fail, the wreckage (i.e. patents) will be absorbed for peanuts by the big players, who will commercialize such aircraft in a manner that does NOT compete with their mainstream products. That will take care of the early adopters and those with more money than common sense. Meanwhile, paranoid municipalities will pass ordinances restricting their use to "safe" areas meaning that commuting in a battery power airplane isn't going to happen. Eventually, they will become common enough, that small companies can exploit niche parts of the business which eventually will deliver enough clout to disarm the restrictive ordinances and displace much of the general aviation market. My guess is about 50 years. If you think my scenario unlikely, look closely at the electric vehicle business for a parallel example.

Very nice Don, i suspect you are wasting your time typing on an audience that will not engage the thought of his own arrogant ignorance.

I have seen this many times from you, but the bottom line is that i am going to cease buying off on heavier. Perhaps in a couple decades digital fly by fiber (wire) will confer configurability and control advantages affordable at the GA level of perhaps $150,000 normalized to 2001. But i ain't betting on it.

Seek out information on the current size, weight, electrical and cooling requirements of computers that can do that task in real time (as you are talking about here) today. They are probably rather larger than a Cessna 172, are heavier that its maximum load (the computer itself even heavier than gross maximum vehicle weight), require more kW that the aircraft can supply, and need several tons of AC equipment beyond that.

Yeah, heavier.

You can't just bolt a motor shaft to a control surface.

You still have to have all the same cable and pulley stuff with fly-by-wire, it just stops at wherever the motors are mounted instead of going all the way to the yoke and peddles.

So you've replaced some number of feet of fairly light stainless cable with three motors, their mounting hardware, the wiring to the motors, the control system with it's wiring, the sensors on the yoke and peddles and associated wiring, plus if you have any sense at all, there is the extra backup power so the controls always work.