Practical aircraft for everyday use -concept

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karoliina.t.salminen

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The fuselage can not be boat hull in any case. It will need to be like sailplane fuselage and there can not be separate floats than the fuselage. Therefore the options are short for the water operation, and Rutan like skis or Lisa airplanes like hydrofoils are must. It can not be conventional float plane and have over 20 glide ratio at the same time at cruise speed of 160 km/h or more.
 

Vigilant1

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Just an observation: Your strict "pass/fail" fuel burn limit ("no more than a Prius") may significantly increase costs/decrease utility in other areas of the design. There may be value in doing a tradeoff analysis in this criteria.
 

BJC

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OK. I give up.

Do you have a design?

What practical airplane meets all of your criteria?


BJC
 

Autodidact

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Do hydrofoils work on aircraft? Also, a water propeller for take off might shorten the run with a significantly smaller engine. The Piaggio PC.7 has/had these two features, but it is probably not what your commuter should look like. Hydrofoils or skis, a streamlined body, high wing with a cabin, a water propeller (or water jet) driven mechanically by a relatively small engine, and possibly several electric flight motors arranged along the leading edge of the wing? I would be very surprised if what you are looking for currently exists, so you would need to design it. Modern electronics and code could smooth out the transition of the power load from the water prop to the flight propellers.
 

Autodidact

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What's so tinfoil hat about this? And if it's my post above, it isn't Karoliina's fault (besides, I'm not an engineer...).

Are you pointing out that acceleration is the same for a water propulsion as for air propulsion?
 

Autodidact

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It seems to me that there may be something to be gained by designing the water propulsion for maximum efficiency in all-out acceleration from zero to lift off speed, and the aero propulsion for an efficient climb and cruise. Hybrid electric for the aero, mechanical for the water.

I wached a video of a v6 powered boat - typical boat you'd see on most American lakes - accelerating 0-60 in 11 seconds; that's roughly 500 ft isn't it?
 

Vigilant1

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It seems to me that there may be something to be gained by designing the water propulsion for maximum efficiency in all-out acceleration from zero to lift off speed, and the aero propulsion for an efficient climb and cruise. Hybrid electric for the aero, mechanical for the water.
Very doubtful that this would be useful. Every ounce added to this thing increases its drag in the water, the mass used to build a prop drive for water would not earn its keep. A regular "in the air" prop is not especially inefficient. And the weight of a hybrid setup will definitely not be worthwhile for this application.

JATO? Maybe a "water rocket"--use the recip engine to pressurize air in a 200 liter container half filled with lake water to about 700 PSI. Blast it aftward through a 22mm nozzle for 4 seconds takeoff acceleration, it's good for about 400 lbs of average impulse (much more at first--hang on tight!). It might be enough, together with the regular prop/engine, to get the airplane up on "the step", the prop/engine can take it from there. Not much weight when empty, makes good use of the readily available lake water, and a hell of a good show for the spectators. The water mist freezing in the Finnish winter will make a picture worthy of the local newspapers.*

Fun water rocket calculator here.

*note to all: water rocket suggestion is made in jest. Though I'd pay to see it tried.
 
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Autodidact

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Very doubtful that this would be useful.
I'm not convinced of that. I have not yet seen any numbers that say this won't work. A jet ski pump is small, simple and light weight. You can hold it in your left hand. A 1.5L, 10.6:1 compression, normally aspirated jet ski is quoted as producing 957 lb thrust; that's three times the static thrust of a 100 hp aircraft engine. STOL is the requirement here and getting off of the water quickly would be worth the small amount of extra weight - similar to a PSRU - of the jet pump, alternator, and 6 17 hp electric motors. The jet pump could be lighter still, because it doesn't need the steering nozzle; docking maneuvers could be handled by the aero props. All of these items currently exist and can be used for this purpose.
 

BBerson

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No simple aircraft can fly safely in all weather and fog.
So as the title requests, there is a problem finding any aircraft for everyday trips to work.
Would the boss allow days off for fog?

Seattle's Seahawks Jimmy Graham is recently famous for flying his seaplane to work. His Dehaviland Beaver is hardly practical. Largely a stunt. I doubt anyone else flies to work every day. http://www.seahawks.com/news/2015/06/03/seahawks-te-jimmy-graham-flying-high-new-nfl-home

A flying car makes more sense because you can drive it home when foggy instead of being stuck for two days in a seaplane.
 

Vigilant1

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I'm not convinced of that. I have not yet seen any numbers that say this won't work. A jet ski pump is small, simple and light weight. You can hold it in your left hand. A 1.5L, 10.6:1 compression, normally aspirated jet ski is quoted as producing 957 lb thrust; that's three times the static thrust of a 100 hp aircraft engine. STOL is the requirement here and getting off of the water quickly would be worth the small amount of extra weight - similar to a PSRU - of the jet pump, alternator, and 6 17 hp electric motors. The jet pump could be lighter still, because it doesn't need the steering nozzle; docking maneuvers could be handled by the aero props. All of these items currently exist and can be used for this purpose.
The 100 HP gasoline engine will not adequately feed 6 x 17 HP electric motors even disregarding thermodynamics, but after conversion losses you can save some money and weight by just buying 4 of them. And don't get rid of the steering on that jet pump, because if the engine is only driving that alternator it is not also driving a prop to send air over the rudder, so we'll need to steer with the water pump. And I guess the real flying prop doesn't start turning until we unhook the alternator, so that will be another bit of adventure on takeoff.
If you want a water jet, probably much better to just use a 60 lb, 60 HP two-stroke that will do just fine >and< allow the 100HP airplane engine to add its own thrust (and propwash for directional control) for takeoff. Less weight, less complexity, and the poor fuel efficiency of a two stroke hardly matters for the 15 seconds it will be running.
 
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autoreply

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The fuselage can not be boat hull in any case. It will need to be like sailplane fuselage and there can not be separate floats than the fuselage. Therefore the options are short for the water operation, and Rutan like skis or Lisa airplanes like hydrofoils are must. It can not be conventional float plane and have over 20 glide ratio at the same time at cruise speed of 160 km/h or more.
Why?

Let's put realistic requirements and boundary conditions on the table first.

Very doubtful that this would be useful. Every ounce added to this thing increases its drag in the water, the mass used to build a prop drive for water would not earn its keep. A regular "in the air" prop is not especially inefficient. And the weight of a hybrid setup will definitely not be worthwhile for this application.

JATO? Maybe a "water rocket"--use the recip engine to pressurize air in a 200 liter container half filled with lake water to about 700 PSI. Blast it aftward through a 22mm nozzle for 4 seconds takeoff acceleration, it's good for about 400 lbs of average impulse (much more at first--hang on tight!). It might be enough, together with the regular prop/engine, to get the airplane up on "the step", the prop/engine can take it from there. Not much weight when empty, makes good use of the readily available lake water, and a hell of a good show for the spectators. The water mist freezing in the Finnish winter will make a picture worthy of the local newspapers.*

Fun water rocket calculator here.

*note to all: water rocket suggestion is made in jest. Though I'd pay to see it tried.
Yeah, it sounded like a good joke.

Until you do the math. Than it's actually a very good idea that makes a lot of sense...

Pressure vessels nowadays are plenty light. A simple high-pressure airflow pumping water via a venturi would even obliviate the need for on-board water storage.
 

Glider

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I had a similar interest.

The interest was to reduce a 7.5 hour drive, one way, from Gulf of Mexico to work. There is one guy in the office who has done this drive every weekend for years (or did at least, might still do) because his wife lives in a condo on the coast (he exceeds the speed limit and does it in 6 hours, each way, he says). When I lived near the San Francisco Bay, I spent a lot of consecutive weekends driving to/from Los Angeles (6 hours each way, arriving at work Monday morning at 9 am).

I thought through the requirements for an airplane that would allow me to commute to work, and back, from the Gulf of Mexico coast once a week, and I couldn't see it happening with anything less than an equivalent to a Lancair Legacy, with an IFR panel. Even then, it would not be workable (about 2.5 to 3 hours door-to-door, one way) and gave up.

Flying commercially would be the most fuel efficient way to go, for my route, but it would be cost prohibitive, take 4-5 hours (TSA) each way, and likely ruin many of my weekends with unexpected occurrences.

It seems that this "use case" is about justifying the purchase of a LISA Akoya (not available to purchase). While I believe the Akoya is the sexiest amphibian ever built, it also exhibits design decisions that could make it challenging if the engine unexpectedly shutdown.

I would rather have something more conventionally unconventional, such as a MFI-10 Vipan
 

harrisonaero

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Before someone points out the Rutan SkiGull, indeed this spec is very near to SkiGull and SkiGull would be such practical daily commuter in fact.
However there is only one SkiGull so it is not mine so it is not a possibility.
?
Yup, very close to the SkiGull mission. Be patient and someday it may be available as a kit (but not by Burt according to past statements he's made to the public). BTW it can be Prius efficient when you consider straight-line travel (usually about 40% less distance). I was in the chase plane for SkiGull 1st flight and in about 2 hours of flying it only burned about 2 gallons of fuel since we were going slow.
 

Sockmonkey

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Why?

Let's put realistic requirements and boundary conditions on the table first.


Yeah, it sounded like a good joke.

Until you do the math. Than it's actually a very good idea that makes a lot of sense...

Pressure vessels nowadays are plenty light. A simple high-pressure airflow pumping water via a venturi would even obliviate the need for on-board water storage.
Do they ever use those in sailplanes to make them self-launching?
 

Autodidact

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.


Yeah, it sounded like a good joke.

Until you do the math. Than it's actually a very good idea that makes a lot of sense...

Pressure vessels nowadays are plenty light. A simple high-pressure airflow pumping water via a venturi would even obliviate the need for on-board water storage.
Vigilant1, I thought it was a good idea, too, but then I saw you meant it as a joke, and since I was already feeling foolish enough I just decided to try and defend my own ideas...:emb:

I thinks it's a matter of details, but the idea of an engine storing up power and then releasing it later in conjunction with the engines power for takeoff is very interesting and could be done in several different ways.
 
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Hot Wings

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What practical airplane meets all of your criteria?
BJC
Phase one:
Canonball.jpg

Phase two:
parachute.jpg

Oh, sorry I forgot the words 'practical' and 'airplane' in the same paragraph :gig:

Seriously, for what she needs the only way is likely to be by using a hybrid drive system, and we just aren't quite there .... yet.
 
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