Electric airplane

True. Given the choice, I think everyone would have preferred to have feedback. Yet, I've rattled off a series of examples where there is none. Whether the experience of a NASA study, that apparently later appeared in the F16, is applicable to general aviation (actually experimental aviation) should be decided by the pilot. If the alleged benefits are sufficient, it might be worth tolerating the loss of feedback.

I wasn't thinking so much about takeoff and landing as maneuvering (flying donuts) and possibly aerobatics. The RPV's I tinkered with has gyro stabilized platforms to stabilize the cameras. I have no idea how well they would do aerobatics. I suspect fairly badly as feedback to the yoke and pedals is fairly important.

Think pot holes, sand dunes, hills, washboard, ruts, etc. Maybe 2.5 dimensions?

Is this is quiz or credibility check? In a cross wind, I have to crab (side slip) the aircraft on landing. I had to do that anyway on a Cessna 150 because the engines torque center is not on the aircrafts center line. For a short field landing, I would do a power off landing. I've never tried it with both a short field and a crosswind.

Sure. With the trim tabs and the trim wheel. Keep the nose up and all that.

To save you the effort of a cross examination, I do not have a pilots licence. I took a few lessons in about 1968 where the idiot instructor had me land in a cross wind with about 10 hours of time in the log book. I noticed the windsock was all wrong, but didn't say anything. When I hit the runway, the Cessna 150 bounced. The crosswind got under the wing and tried to flip the plane over. Both the instructor and I instinctively over compensated, grinding the opposite wingtip into the runway. If I had hit the grass, we would have cart wheeled. After that mess, I gave up flight skool. Most of my subsequent flying was with friends. I've been invested in an avionics shop for about 20 years.

Ok. You're right. They won't kiss the ground after landing.

One of my former bosses worked on the ill fated Microwave Landing System:

I learned quite a bit about it listening to his stories. I recall that he mentioned that they successfully tested hands off landings using it. However, I don't believe that the subsequent WAAS/LAAS GPS landing systems were ever as good at landing as MLS. There were plenty of reasons not to do this on a regular basis, but it is possible to do a smooth hands off landing.

Another credibility check (which incidentally has nothing to do with my previous comments)? Yes, the terms mean landing on a short runway, a grass field, or a muddy dirt road. I've never done any of these.

What does your question have to do with force feeback in airplane controls? Sure, it's more difficult to land on these limited runways, where hands off landings are probably a bad idea. However, I'm not so sure that force feedback is going to be the determining factor for a sucessful landing. Methinks much depends on the abilities of the pilot. If they are experienced in zero feedback landings, methinks they can do it well enough.

Hmmm... no force feedback on most (not all) of these simulators:

(examples) This one uses pneumatic dampers and an air compressor for force feedback:

I'm not talking about practising hand-eye coordination to keep yourself the right way up in zero visibility, important though that is, but about the procedural stuff. Did your "simulator" require you to fly SIDs and STARs and airways, holds and missed approaches? Did the simulator keep issuing new levels and headings?

Sure. And in your universe, everything's a SMOP and all problems can be solved by adding another level of indirection. And in that universe, emergent complexity and scalability issues simply don't exist.

The issue I was alluding to is maintaining separation under IFR in IMC, or, more colloquially, "pushing tin". Consider what happens to the infrastructure that manages this if every airliner is replaced by several hundred "safe, efficient, electric-powered single-seat, ultra-long range aircraft", all of which have to be prevented from colliding.

There are regular stories in comp.risks about failures of computerised ATC systems under current levels of loading, let alone the hundredfold increase you're suggesting.

I think everyone gave up when we reached ULSI more than a decade ago.

Dirk

There are stick-and-rudder folks that want to fly the airplane and there are others that view the airplane as a transportation vehicle. The latter crowd would want the airplane to fly a nice glide slope to touch down, no slips allowed. The VLJs are not hand flown. Look at the Citation SP, you have to have a working autopilot for single pilot operation. I had the opportunity to fly jump seat on a 737 a few years back. From the time the gear came up until on short final their hands did not touch the yoke (nor feet the pedals). In fact, the only thing they touched (other than their reading material) where the autopilot and radio knobs.

Can you do something similar for GA, feet on the floor, hands on a simple joy stick? I dont know. Could be. As long as you dont kill yourself or anyone else and dont go broke, it's worth a try (actually the FAA will gladly let you turn yourself into a smoking hole in the ground).

The big problem is, can you do this at the cost and level of safety required. It would make for a very bad day if your computer system decided up was now down while traveling along at 200+Kts.

You make a good point here. During landing, and especially a short or muddy field landing, there is a point where pressure feedback is useless or non-existent anyhow due to the low airspeed; speed is barely above stall and control input needs to ignore stick and rudder pressures, because the need is to force the plane's attitude to your needs. Also, ground effect will eliminate pressures, because the stall speed is much lower.

Very true.

Stall/spin (recovery) practice, at altitude, is good to do and will give a pilot a much higher survival rate. The FAA used to require such training for a Private rating, but instructors complained about the numbers of students that terminated their training after the first power-on stall, so the FAA eliminated the requirement. I opted to do them anyhow. It's cool... You're in a spin before you recognize what happened.

Lacking that training and practice, a student will probably encounter their first stall and spin entry while they are in the pattern for landing, probably while turning onto final. Since the untrained reactions are completely wrong (they will increase the stall), the plane will likely crash.

Yeah, it is possible and has been for a long time; so what's your point?

You obviously don't know why slips are performed.

There are two types, and without a lot of detail one is used to lose altitude quickly without gaining airspeed and the other is used to keep the airplane aligned with the runway in crosswinds.

Not following the glide slope tends to result in a bad landing or a request to call the tower after landing or both.

In calm air in a properly trimmed airplane it is not necessary to touch any control.

Most of the time my feet are just resting on the rudder pedals and I have two fingers on the yoke to null out minor bumps.

It doesn't take a computer system or an autopilot.

All it takes is trimming out the airplane.

A lot of student pilots develop a death grip on the yoke and the cure for that is to have them trim the airplane and fold their arms.

GA airplanes are required by law to be stable.

I would not use the ATC. I would use a combination of aircraft and ATC. Each machine would maintain a virtual grid of the 3D-sky highway as it knows it. There would be rules about flying, just as there are rules about driving. With typical GPS device, it is not difficult to write software that alerts the pilot if these rules are viloated [or about to be violated].

I would imagine it would be more dangerous to crash in prop-driven, ICE-loaded machine than with something else where these elements were not present.

-Le Chaud Lapin-

I think that's called wheel-barrowing. With just the nose wheel on the ground, the aircraft acts like a wheel barrow. I haven't flown enough to have run into the problem. However, like all beginners, I have managed to overcompensate several times. My first attempt at simply maintaining altitude was an exercise in overcompensation until I got the feel of the airplane.

No mention of force feedback. That was filmed in 1978 on an aircraft that was probably designed a few years earlier. My guess(tm) is that since this was a research project, the initial configuration would have been very Spartan and without any feedback to the pilot to see what could be done with a minimal configuration. Force feedback was probably added later. Dunno for sure.

Yeah, that would be a problem. If the actuators protect themselves and are hard limited to some max rate at which they can move, there's a real possibility of resonance or under-damping when operating at the limits. That's a problem even in model airplanes, where a slow moving servo and an overly aggressive pilot can easily cause PIO (also known as porpoising). The trick, which is quickly learned, is to intentionally shove the control well beyond the desired position and quickly return it to normal, at just the right moment. If you're too slow to recover, you get PIO. There's no need for force feedback as this is really an exercise in timing.

Yep. So what's your opinion? Can a general aviation (production, not experimental) airplane be built that flys using a joystick and limited force feedback? Is force feedback optional, desirable, or mandatory? Is PIO such a major technology killer that practice and training are insufficient ineffective?

Perhaps thats why, in the show about Blue Angels I mentioned, the pilots were required to know calculus and basic theory of complex variable, or at least that's how it appeared. I did see an H(s) written on the whiteboard during the show, and several Blue Angels pilots sitting watching the instructor.

I think once a pilot understands the basics of control theory, it is hard to not trust the math after that.

My bike has no steering damper, so around 138 mph, the front end starts to vibrate strongly, and the first time I got it into that range, I knew instinctively not to fight it, but to wait, and "watch the humps".

-Le Chaud Lapin-

I designed my first radio when I was 9 or 10.

For certain applications, it probably will.

It is especially attractive in HAM circles where things are always changing, but, one more time, aviation radio is cast in international treaty concrete and is NOT going to change.

Since you don't seem to know what much of anything means, I was dumbing it down for you.

I'm well aware of what is in a modern radio.

The independant testing lab will charge way more than that.

That is for Part 15 toys.

Aviation is covered by Part 87.

My god you are ignorant.

No, you implied that you were going to.

Babbling idiot; it can't be proprietary since all you would have to do is look at it and you would know what the TECHNOLOGY is.

The TECHNIQUE used can be proprietary, but the TECHNOLOGY can't.

So which is it, aluminum, composite, or hybrid aluminum/composite?

There aren't any other choices for a pressurized airframe.

What is is that your home build fly-by-wire airplane will be able to do that any modern GA aircraft such as a Cirrus SR22 can't do?

If you encounter significant turbulence, what is the first thing you do and why?

By design, I mean actually design, like employing the concepts of semiconductor physics, electrodynamics, theory of complex variable, etc. I did not mean putting together a kit, if that's what you mean.

Hmmm...well it appeared that you had become out of touch with field of electronics, for at least 30 years.

Are you 100% sure about that statement?

-Le Chaud Lapin-

Maneuvering flight is easy and pretty trivial.

Landing where you are moving at high speed and are close to the ground is a bit more critical of precision control of the airplane.

A little of both.

Actually, the torque is centered and would cause the airplane to spin around the axis of the propeller shaft, but all the aerodynamic forces result in a turning moment, generally to the left.

A short field landing is done with power at just above minimum controllable airspeed.

What you do is set up the airplane then use the trim wheels to eliminate any control force.

If you try to do it without the force feedback from the controls 9 times out of 10 you will wind up oscillating around for a while before getting it trimmed out.

Sorry to hear that. Where's the shop?

I went through 5 instructors; one got a better job so that one doesn't really count, but the other 3 were probably good buddies with the one you had. The one I finished with I still go to for flight reviews.

Yeah, I remember MLS.

I think the two big factors that killed it were the cost of the ground equipment required and international politics.

Thin skin because I've dealt with far too many naifs that have read a couple of web articles on aviation and think they know everything there is to be known about flying.

Again, just because something CAN be done doesn't mean it SHOULD be done.

Having force feedback makes flying an airplane easier and ultimately safer.

You don't have to rebuild the firewall on a simulator when you slam the nose wheel on the runway and bend the firewall/nose wheel attach area.

Exactly.

Add to that the common misconception that ATC is somehow and magically actually controlling the movement of all those airplanes.

No, that is not what I meant.

The only manufactured electronic part was the variable capacitor.

Well, since I had to post the definition of "proprietary" because you didn't know what it means, yes.

What materials are you going to use to build your homebuilt's airframe and aerodynamic surfaces?

What is it that your fly-by-wire home built will be able to do that any modern aircraft such as a Cirrus SR22 can't do?

If you encounter significant turbulence, what is the first thing you do and why?

Spin training at the private level was eliminated some years ago, but stall training is still required.

The justification was that the numbers indicated more accidents from spin training than accidents by private pilots who got into spins.

What is now taught is spin avoidance and spin recovery without actually doing a spin.

True.

The emphasis now is stall and spin avoidance since usually if you do stall during the landing phase there isn't enough altitude to recover anyway.

If you are going down the runway on the nose wheel, it is called wheel-barrowing.

If you are bouncing up and down, it is called porpoising.

No, not for a normal category airplane as it would never meet the stability and controlability requirements of Part 23.

As a home built experimental it would get the reputation of being squirrelly and no more than 1 or 2 would ever be built.

The Blue Angels aren't flying GA aircraft, they are flying high perfomance, aerobatic, jets with a huge thrust to weight ratio and wearing G suits.

Then you would go to jail.

ATC is international in scope.

I have often wondered what would happen if a would-be-Blue Angel could not get past the math.

Probably rejected?

-Le Chaud Lapin-