A Case for an Electric Gyroplane Seaplane

[ultracruiser41]

200 lbs worth of batteries and I couldnt take a passenger!!!!!

 

[Hodag]

PW-Plack,
Thanks for the response. I will try to respond and add some other insights.



1) Floats are rated by displacement. If someone is using a 1200-pound displacement set of floats (100 lbs) on a 300-pound aircraft, it is overkill on buoyancy and weight. Unfortunately, there are no good float options presently in that weight class to my knowledge, and not many options in the 1200-1300 pound range either, and something needs to be built. Two-place aircraft are in much higher demand than singles, and are easier to use to make money commercially.

2) Thank you for sharing your knowledge and experience. My section on drowning was specifically aimed at currently-certified seaplanes, but that is a weak defense. I do not dispute your experience with current gyroplanes with floats added-on, but there are two basic problems with them-
a) They were originally designed to be excellent land-based gyroplanes, not seaplanes.
b) Like the difficulties of the first gyroplanes pilots, none of the pilots today likely earned their seaplane rating in a gyroplane. (Although, Sportcopter is currently building a two-place gyroplane seaplane trainer for some strange reason.)

3) Rotax abandoned the single place market below 67 HP, and while they are state of the art, it is a dying art for small aircraft.

4) No designer of electric aircraft should ever use lead-acid batteries, I agree.

5) Never did I suggest that regenerative braking be used for descents on the rotor, only possibly through a special direct-drive propeller, ideally at CLT, and even then, possibly only on taxiing. Regenerative rotor braking would only be used where rotor braking is currently being used. There would be no real change there, except a little energy recapture, or a lot if you need to stop the rotor every 15 minutes. To go from a positive thrust state to a drag state would enhance safety and control when water taxiing.

A new, well-engineered design could possibly be achieved through grants from the U.S. government or NGOs. Tesla was awarded $4.9 billion in grants, but if a design team could only garner $20 million in grants- $10 million for a design budget and another $10 million for certification, the end-unit cost could remain competitive with the median price of a current turn-key gyroplane, and the design would be tried and tested without resorting to backyard modifications and risking pilots’ lives. $20 million is small price to open new markets, especially if it is given to us. What a small price to change the face of civil aviation with electric aircraft! Also, most countries have a National Park system and could benefit from a quiet, zero-emissions vehicle. A FLIR-equipped gyroplane could serve as a search and rescue vessel in these areas.

An electric land-based gyroplane could see a growing number of governmental or scientific uses, even without certification. Beach police could save in fuel costs and still have the ability to swoop down with some accuracy to save a drowning victim, or to reach an accident site. Even a gyroplane seaplane could outrun most boats. Experimentals today can be used in a flying club with fractional ownership and for flight instruction and some other uses. Even though some are over the mandatory retirement age for commercial pilots, electric technology is coming, and it will affect every small aircraft pilot.

 

[EI-GYRO]

I had the pleasure recently of attending a presentation by Dr Tine Tomazic of
Pipestrel, on the Challenges of Electric Flight.

The presentation was essentially a statement of the current state of progress
in the area of electric-powered flight.

The primary challenge is energy density. With current battery technology, energy density of a generally useful amount for general purpose aircraft,
is essentially unobtainable.

Current practical limits are self-launching gliders, and quite limited circuit trainers.

A hybrid aircraft is in development which is probably the most practical implementation of electric power in aircraft, as in cars.

The presentation was quite remarkably free of marketing hype, and wishful
thinking.

In the context of this fanciful thread, it can be fairly said that a float-equipped gyroplane is likely to be very nearly the last type of aircraft to
be equipped with electric power.

Pipistrel, for those who are not aware, have won several NASA-sponsored
competitions for flight efficiency using electric powered aircraft.
They know their stuff.

 

[Hodag]

EI-GYRO,

Thanks for the post,

Seimens, Pipistrel and Airbus are at the forefront of electric aircraft technology. Energy density and battery efficiency are indeed the weak links, motors are much more efficient. Airplanes are designed to go far, or fast, or in the case of gliders, most efficiently. That is not the purpose of owning of gyroplane. We do not need to make general statements about what an electric gyroplane would look like- It's 45 minutes worth of flight before landing to change batteries or charge up, unless flying solo with extra batteries. That's the current state of electric gyroplanes. I do not think it would be comfortable, even in a low-vibration electric gyroplane to fly for 6 hours non-stop. I already stated hybrids should be used for those who desire duration similar to recprocating engines. I am not marketing anything, I am giving away million dollar ideas. I am like Steve Jobs, if he were alive, unknown and penniless. In 1965, landing on the moon seemed fanciful. Also, to argue that we need funding for new markets in reserve areas, a pure electric would be required. A Pipistrel can't perform search and rescue like a gyroplane, or many other things.

 

[Hodag]

The key for any useful electric powered range is to sip, not gulp. Even an electric helicopter, which gulps, would be much louder than a gyroplane due to its downwash.

 

[WaspAir]

Noise is a very complex issue

Noise is a very complex issue

The key for any useful electric powered range is to sip, not gulp. Even an electric helicopter, which gulps, would be much louder than a gyroplane due to its downwash.

Gyroplanes have downwash, too, as argued at length recently on another thread. If you're keeping 1500 pounds of aircraft up, whether the rotor is powered or unpowered, you'll be pushing air down to do it.

Noise is a really, really messy thing to model, and has components that pop up unexpectedly. The original production version of the A&S18A gyro was deafening in large part because of an interaction with the prop blades passing near the sharp vertical edge of the cowl, which was later cured by an STC mod that put a concave arch in the edge, but had nothing to do with the rotor system. Helicopter noise has components that come from the tail rotor and from interaction with the flow from the main rotor; fenestron-style shrouding can radically change that. Classic Bells have a wop-wop sound from the design of the rotor system. The NOTAR MDs have their own sound pattern.

Noise also has significant perception issues, as to what is pleasant to the ear and what is less so. I think if I flew my old McCulloch J-2 gyro past a ground observer and another pilot flew a Robinson by at similar speed and altitude, that some would find the gyro more objectionable.

 

[Hodag]

WaspAir,

Thanks for the post,
I am fond of the NOTAR system, I wrote a little speech on it once.

Most of the noise from a gyroplane comes from the engine and propeller, which could all but be eliminated with a low-RPM direct-drive assymetric propeller powered by an low-RPM electric motor, just from observing the Zigolo link. I do not think it is too much of a generalization to say a helicopter's rotor makes more noise to wildlife.

Further, gyroplanes are a little cheaper and more efficient than helicopters. And since rotorcraft are typically best at ground, or close-air, support roles, the gyroplane wins my vote to get electric first.

 

[Hodag]

Unmanned Aerial Vehicles (UAVs), or drones, can and should be used as much as possible for search and rescue, and especially fire-spotting. But sometimes manned-flight can be more useful for search and rescue particularly. Two people in a clean, silent, open cockipit aircraft can see in color(as opposed to FLIR), hear cries for help or smell smoke.

 

[hillberg]

Thanks for the reply, hillberg.
It would cost less - see "It's cheaper"
It is eco-friendly -see "Eco-Friendly"
Probably will not get certified in the USA, but it might happen everywhere else.
I will remain hopeful.

Every 'new' electric toy is NOT cheaper - Historic fact. (unless it's a golf cart)

Eco-friendly? Heavy metals Lithium mixes exotic electrolights , power unless hydro is toxic to life = nuclear - coal -gas -solar is too costly and over it's life time can't even pay for it's self (heavy gov subsidized -)

Keep dreaming in the 50s Kaman had an electric helicopter (with a long cord to a big ground based generator too)

$$$$ cost less???? Are you that gullible ????

 

[WaspAir]

Most of the noise from a gyroplane comes from the engine and propeller, which could all but be eliminated with a low-RPM direct-drive assymetric propeller powered by an low-RPM electric motor, just from observing the Zigolo link. I do not think it is too much of a generalization to say a helicopter's rotor makes more noise to wildlife.

Further, gyroplanes are a little cheaper and more efficient than helicopters.

A gyroplane rotor is NOT inherently quieter than a helicopter rotor, which is what you seemed to be comparing. Consider an electric Hughes 269 vs. an electric J-2 (you've been proposing Standard Airworthiness so that's a reasonable pair to compare). The rotor systems are about as close as you can get for a helicopter and a gyro. Running one in autorotation and the other in powered mode doesn't automatically make the gyro quieter.

And you really need to let go of that notion that gyros are more efficient. That's just plain wrong. When you drive the rotor by first using the powerplant to spin a prop, to push the aircraft forward, to let the air spin the rotor blades, you will ALWAYS be less efficient than directly driving the rotor with the powerplant. The losses in going through that fluid connection are big. Gyros are the masters of generating drag and are at the bottom of the efficiency list. Truly comparable gyro and helicopter efficiency face-offs will be taken by the helicopter.

 

[kolibri282]

Truly comparable gyro and helicopter efficiency face-offs will be taken by the helicopter

If we take "truly comparable" to mean equal payload and cruise speed and design the gyro to have a tip speed as low as the old tractors (150 rrpm) with the best profile we can muster (perhaps an ONERA OA212) and a very large tractor propeller for the job would that still be true? (just asking without even a back of the envelope calculation..;-)

 

[Hodag]

hillberg,
Thanks for the reply.
On cost, I will repost this analysis of the gas-powered Alpha vs. the Alpha Electro. Not many studies like this exist, so it is important. I do not like the fact that they infringed on the useful load with the Electro for this study, however. I still feel they should instead offer a solo tank. Also, I do not believe they are using a low-RPM direct-drive system. (https://www.avweb.com/blogs/insider/Will-2015-See-Deliverable-Electric-Airplanes-223695-1.html) It would cost a buck or two to "fill up" an e-Cavalon battery. The inconvenience of returning every 45 min for a hot-swap is the other price. The reason Europe is starving for electric aircraft is because they do not heavily subsidize the oil industry, and its fuel prices are more accurate.

I cannot imagine that washing your hands with petroleum then huffing the fumes all day is more healthy than sitting in a compartment isolated from externally vented batteries of any kind, unless they are radioactive- which I am not suggesting. The type of battery used would simply be whatever is safe and efficient at the time, best left to the designated EE. There will be no clear winner for a very long time. There is a reason pure electric EVs are called "zero-emission." Are extraction, transportation and manufacturing filthy? You bet!

WaspAir,
Thanks for the reply,
My assumptions on sound were based on the principle of having two equal noise boxes, with one that is relatively upwind from a mating group of Pandas and one that is downwind...sound follows wind currents, and downwash.

The other, perhaps more difficult assumption, is comparing a helicopter's rotor noise only, and the quietest tail rotor technology to a gyroplane's rotor noise only, assuming the electric motors are equally silent. No study like this has been done, and I do not think it would be worthwhile financially to pursue, since in time, both will be electric, therefore I will drop this issue of sound. Thanks for being a good sounding board.

Would you say that the fuel burn rate of a helicopter is more, less or the same as a gyroplane after 45 minutes of flight, including one takeoff and landing? An Autogyro Calidus seems more aerodynamic than a side by side... anything.

I also feel that tandem seating- not generally found in civilian helicopters but is not out of the question, I suppose- is not only better for visibilty- allowing both occupants to see on both sides at all times, but better hydrodynamically for a seaplane- and the same would hold true for two-place tandems over single-place gyroplanes, although anything is scalable. Floats are not necessarily worse than flying boat hulls, but if used, I would contract a float specialist. Not many floats were designed with rotorcraft in mind. Much cost savings on R&D could be achieved through partnerships. I am not 100% happy with any of the current enclosures for seaplane use however, and some study on that would be needed primarily for escape reasons. From what is currently available for S&R, I would just fly day VFR in an open cockpit MTO Sport, better to hear and smell and no glass distortion or grime- which would add terrible drag, I know. Otherwise a drone would have the advantage for the market, but a reflection from a signal mirror might also be more apparent to the naked eye, rather than a monitor. What are the most aerodynamically efficient open-cockpit designs in aircraft?

Again, I have absolutely no skin in the game and I feel my thoughts are objective. (Unless someone wants to hire me to be a relentless dreamer, or start a co-op)

 

[Hodag]

Also, tandem seating would be better for dock loading, without the need to ever jump over throttle (or rheostat ) controls.

 

[Hodag]

I like the idea of a tandem with removable doors and windows, shaped like a long Vortex or Mosquito. It would eliminate much of the drag and still give a largely unobstructed view. It would also provide easy entry.

Splash rails would be needed with lower side walls. Something like an exaggerated cargo pod from an M-22 Magni Voyager.

 

[Arnie Madsen]

Hodag ... I enjoy your enthusiasm !!! . For a couple of thousand dollars you could do your own preliminary testing . Familiarize yourself with the power ratings of electric motors in todays cars , find a suitable one from the junk yards or insurance salvage , buy or borrow a used battery that still has some life in it .

Adapt a prop drive to the motor , mount the whole affair on wheels or a trailer to measure the thrust , time how long the battery lasts , and calculate how much everything weighs.

You would come up with some real-life numbers that would tell you if it could power a gyro or whatever. It would be a fun experiment and you would have a lot of followers and advisers with you all the way.

 

[Arnie Madsen]

Hodag ... Sikorsky built an electric powered Hughes 269 using off-the-shelf batteries and motor . Unfortunately they did not fly it , apparently they only wanted the patents . Probably used components from the Tesla car or similar. (from memory) the Tesla motor can produce 260+ horsepower which could lift 2600 pounds of helicopter and battery.

.

 

[Hodag]

Arnie,

Thanks for the encouragement. Nice ride you have there.

I would love to buy a Vortex on floats sans engine, which Sportcopter said was possible, only to save costs building hours in a two seater. It would be more practical though, to buy a Dominator with the CLT kit without floats or engine, especially with my current location.

For me to buy anything at all is not feasible at the moment, I am seasonal and between gigs. The small scale testing just for the motor would not be required. I would call Aeromarine-LSA and buy the system from the Zigolo. Testing after installation would still be revealing. I would like to see a commercially certified two-seat pure seaplane gyroplane though, so I could possibly afford to pay for it.

I have seen the electric Hughes, pretty sweet! The new Seimens 50kg motor may be better for the chopper, and it would take a tall stack of batteries with a Super Big Gulp lIke that. I think there are fewer variables with flying a gyroplane and it would seem more straightforward, no pun intended, and also easier to fly.

If any experienced gyro pilot with a single-seat has the ambition to try that power plant, I would love to hear the results.

 

[Jean Claude]

...little energy recapture, or a lot if you need to stop the rotor every 15 minutes.

You just need basic physics to also extract this false idea of your mind.
Energy expended to 15 minutes of flight = 45,000,000 Joules
Recoverable kinetic energy in stopping the rotor J = 1/2 I ω2 = 140,000 Joules or 0.3%
It is the same benefit by entering your head into shoulders, so reduce the drag.

 

[Hodag]

Jean-Claude,

Thanks for the response, and the math.

Regenerative braking on the rotor brake would require a more thorough cost/weight benefit analysis, especially since I have no idea what it would look like, and like regenerative braking for amphibious gyroplane wheel brakes, it may not be so useful. The term “a lot” should have been “a little more.” Sorry for the exaggeration.

What would this energy recapture be for fast-taxiing to resist high relative winds? I imagine Beach Police may have to stop more frequently than 3 times in a 45 minute period, and could spend much time taxiing.

My head creates tremendous drag and lifts my CG horribly, but sometimes it is useful.

 

[Hodag]

If floats are used, the gyroplane should have a low wide stance, like a Challenger II on Puddlejumper floats, to raise the CG and provide maximum balance with a tall mast. The mesh skirting used on the Full Lotus floats would be useful, as would a shroud around the propeller.