Practical aircraft for everyday use -concept

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karoliina.t.salminen

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I have been talking about long range concepts before but there is another category where there is a hole on airplane market, such plane does not exist today (that would be available):

- Practical everyday commuter that is geared towards the fact that airports are closing and also airports are not where the actual destinations are
on daily commute. Ability to operate without airports.

Background: In Finland many Finns own summer cottages next to a lake. It is possible to have a seaplane on the lake. In the Southern Finland
and in many other coast cities, there is also the sea nearby, and in fact my work office is located next to the sea. The closest airport to office is EFHF
and it takes 50 minutes to go from the work to the airport with bus and on heavy traffic, it can take one hour by driving car. There is also parking fee
at the airport and leaving car there is extremely costly. Landing fees and navigation fees and what not are also eating the earned salaries which make
the airport not usable for daily commute unless your job title is very high in the ladder of a big corporation and those guys often don't have the time
to learn flying, to build a plane and so on. And in addition to that the city wants to close the airport down, making the closest airport to be not so close
anymore. Instead of the 50 minutes travel time, the airport can be hence more like 1 hours 30 minute travel away, and the uncontrolled airfield is not usable
in darkness because night flights can be only flown from controlled ones which have runway lights. And that kind of airport anyway is not for getting somewhere,
but getting up into the air.

I personally (like many Finns), have summer house which is not exactly next to the work place, but also not that far away. It takes 1 hours 30 minutes to travel to work
by car. That is by keeping around 85 km/h average speed for the trip. That is quite long time to invest per day twice, but that's what I have been doing
for couple of last years almost every day in the summer time. Still this distance is quite short, especially by airplane terms. Travelling that distance with our
Diamond takes a lot less time and the only problem is that it is not possible to land the thing there. Or it is but the plane can be landed only once and never again ;).
Even in the rainy Finland, there are lot of days where VFR conditions prevail, and it would be safe and convenient to commute this trip by air and not needing thus
any IFR approach procedures which would ruin the commute time as flying the procedure would take the time difference between car and the plane.

Our car is Toyota Prius and that is a reference commute method. 1.5 hours of travel time and around 4 liters fuel spent for the commute to one direction,
making 8 liters of gasoline per day. The fuel cost per day is hence around 12 euros (with 95E10 autogas price).

The requirement specification for the plane would be hence this:
- airplane which would be capable to make STOL takeoffs and landings from/to water.
- airplane which would also be able to land on airport whenever needed
- the airplane should have reasonable range to not require refueling on every trip because fuel is not available on either end but
fueling needs to be arranged by a flight to airport or by filling tanks from canisters anyway. Ideally the fuel would last for 5 days of commute.
(the reference car lasts for the work week approximately between refuelings).
- the airplane must not use more fuel than the Toyota Prius. So the commute should only use 4 liters of 95E10 autogas for the 100 kilometer trip.
This is the fuel consumption for the whole airplane and not a mpg rating per hypothetical passenger. This way it matches the reference car.
This can be achieved by high cruise L/D, which calls for sailplane-like wings.
- The STOL-capability would be achieved by active boundary layer control and slotted fowler flaps.
- Because of the low fuel consumption, the weight of the fuel would be low. Roughly only 60 liter tank would be large enough to fullfil this criteria and it would have
even reserve fuel.
Of course the plane would be more versatile if it had larger tanks, and it could be also used for other purposes than just commuting this typical distances.
- The commute time should minimally be cut to around 1/2 ... 1/3. This would result in required cruise speed of around 200-250 km/h, which is
very similar to the reference airplane: the Diamond DA40.
- The pre-flight check should be as simple as possible and as automated as possible, for not spending time for preflight. It would need to just work to be
car replacement for the commute.
- It should be able to be docked next to sailboats on nearby harbour.

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.

Just mentioning this spec because I have thought that this could be quite useful for many. Any thoughts?
 

radfordc

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Seems to me that Alaska if full of airplanes being used as described.
 

jedi

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Sahuarita Arizona, Renton Washington, USA
.......

The requirement specification for the plane would be hence this:
- airplane which would be capable to make STOL takeoffs and landings from/to water.

.....

Any thoughts?
Your requirements are quiet demanding. Which are you willing to compromise with. For example, can you haul auto fuel and carry only two round trips? One for normal operations and a second for contingencies, weather diversions, etc.

Please be more specific about the above requirement. How STOL and why.
 

Victor Bravo

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KWHP, Los Angeles CA, USA
Here is your best solution, assuming you can afford it:

http://www.do-sray.de/index.php?home

If you want to build or modify something less expensive, then:

Avid Flyer on floats or wheels, not quite fast enough but very inexpensive
Flight Design CT modified for floats, more efficient design but more expensive
Pereira Osprey 1 with SMART car engine, small Diesel, etc. could be built from your beautiful Finnish woods


And if you want to do it in the minimalist way:

Fly-NANO Finnish ultralight seaplane
 

Vigilant1

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Would a Coot Amphibian get the job done? It's going to burn more fuel than the Prius, but I think anything taking off from the water with two people aboard is going to require some non-trivial thrust, and having a hull/floats is also going to reduce your flight efficiency compared to a plane that always takes off from the ground. The Coot takes a 180 HP engine (designed for a Franklin, Continental, or Lycoming), at least two have flown using a Mazda 13B engine (if I recall correctly, one builder employed NO2 injection to aid in getting on the step quickly).
Also, will it be practical to get the plane out of the weather when it is docked? Maybe lifted up out of the water and under cover (it might weigh just 1600 lbs with fuel, a small electric winch could do that easily if the plane had convenient attachment points). If the plane is going to be exposed lake water, snow, rain, sun--well, that's a challenge for a "daily driver."

Trying to get this done in an efficient/minimalist way (clean airframe, small engine, etc) is probably going to be a challenge just due to the hydrodynamics.

Not to be a wet blanket, but I think if we look realistically at the time it would take to drive to the origin airport/dock, get the plane ready to fly, fly, land, taxi, tie up, move to the ground vehicle for the last few miles to work, etc, that we'll find that the real door-to-door time is about the same unless the driving time is more than about 2-3 hours or the roads are very indirect/slow. And if you drive to work in the morning, you'll know that you can get home the same way, even if the afternoon weather forecast was wrong. If we do the math on the cost of maintaining the airplane--well, it will be a fairly expensive way to save time.
 
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BBerson

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There is no seaplane as fuel efficient as Prius.
If your lake cottage was say 20 miles direct across a fiord then a seaplane makes sense. But if you are flying the same highway route, then no.
Need folding wings to use most marinas. And they usually need to be designated as seaplane bases.
 

Sockmonkey

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Does it have to be a plane? Because if traveling by water will provide a shortcut, a hovercraft would be a good choice. Usable year-round on any sort of reasonably flat terrain. Far easier to build than a plane.
 

Aesquire

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Autonomous Drone Delivery system. You call for a lift, climb in your Volvo F ( with special roof rack mating system that doubles as a ski rack ( mandatory in Norway )) and a multi rotor drone picks up your car and gently deposits you in the car park nearest work, releases your car, and goes on to the next job or refueling/charging station.

Or a Rotorway Exec. If you want to actually fly it yourself.
 

Riggerrob

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Can you dock your seaplane at a marina within walking distance of your work?
Can you taxi up a boat-launching ramp?
Will they rent you space at the marina to store your airplane?
Will the marina sell you 100 octane fuel?
What exactly is your route?
How long is a straight line between your office and your summer home?
How many people do you want to carry?
How much baggage?
How much shorter is the trip by air?
How many bridges will your airplane miss?
How many twisty roads will your airplane miss?
How many ferry boats will your airplane miss?
How many air traffic controllers will you have to talk with?
How far above sea level is your summer home?
Will you need to fly over any mountains?
Will you be able to pull your seaplane out of the water at your summer home?
Are you willing to settle for the 160 kph cruise speed of most small seaplanes?

No need for fancy boundary layer blowing or double-slotted flaps because that sail-plane like wing will be big enough for STOL take-offs. All seaplanes are STOL to reduce take-off distance, take-off speed and waves pounding on your hull.

Most twin-floatplanes will fly your mission and a few of them have folding wings (Avid Flyer) to reduce storage space whether tied to a dock or stored in the back of a marina?

A recent issue of "Plane and Pilot" magazine had an article on small seaplanes: Petrel, Icon, Aventura and a couple that have not even flown yet, like Vickers.
There are also stacks of older small seaplanes: Anderson Kingfischer, Avid Catalina, P. Osprey, Volmer Sportsman and that new design made of Finnish plywood that is light enough to power with a Rotax engine.... sorry but I cannot remember the name.

I see your mission as similar to the Icon's mission. Some enterprising investor could purchase a fleet and lease them out to qualified customers who want to fly from a downtown marina to a mountain lake for adventurous weekends.
 

karoliina.t.salminen

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Some answers:
- 100 octane fuel is not available at all.
- The Prius fuel consumption is must.
- Existing planes except SkiGull do not meet performance nor fuel consumption requirements.
- Yes the marina with the long wings may be a problem
- How many air traffic controllers need to talk: zero for whole route
- 160 kph would be still better than car yes
- no mountains, Finland is flat as pancake.
- straight line is somewhat shorter than road
- the lake is large enough, no problem on the size
- no ferries, no bridges
-
 

karoliina.t.salminen

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Basically without running the numbers, my expectation for required cruise L/D would be >25:1. And also the engine power would be such that for takeoff there is good power to weight ratio while in cruise the power is like 25% of total available. We can assume a fuel injected Rotax 912 is sufficiently powerful.
 

karoliina.t.salminen

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And especially in Helsinki the only place to land is water, there are absolutely no other free spots of land without buildings or trees or lamp poles. And also landing on water is legal, landing on street or even field owned by someone else is in violation of regulations.
 

karoliina.t.salminen

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The distance to the plane if it was on water, would be 20 meters at summer house. Near workplace the marina is 10 minute walk away. The original list of requirements had fast or better automated preflight check, ideally as simple as starting Prius or Tesla.

Yes I know the Finnish plane made of Finnish plywood, Atol. Yes it is nice but it does not meet the fuel consumption criteria. It is ULC/EU LSA. I have no such requirement. It can be as heavy as it takes and short span for saving weight is not needed compromise like in others.
 

karoliina.t.salminen

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Helicopter will not meet performance nor economy criteria. Helicopter meets takeoff and landing distance criteria but that's all.
 
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