Flying wing as cheap and simple option for basic fun flying.

[Victor Bravo]

PS: I think there may be a market for a tail wheel conversion on a C-172. There is one available for my sons 175 but as you say it’s cost benefit numbers do not work out.

Well this is off topic, but the cost of doing a 175 conversion is high. If you're talking about visiting Fairbanks this is mostly because Dave S supplies brand new Cessna parts in his kit. If you're talking about visiting Porterville then it's because Harry D (RIP) was a crafty old coot of a businessman and needed to pay for a lot of big machinery and the room to operate it

 

[erkki67]

Regarding the Possum and derivations of Sockmonkey, I'm wondering if it could be solar and battery powered, if yes how big should the wing be to accomodate the solar panels?! And what hp should be installed?

 

[Sockmonkey]

Regarding the Possum and derivations of Sockmonkey, I'm wondering if it could be solar and battery powered, if yes how big should the wing be to accomodate the solar panels?! And what hp should be installed?

You can stick solar panels on anything, but they're probably best suited for something more glider-ish.

 

[erkki67]

Too sad!

 

[erkki67]

I don’t know if it’s going to be a cheap option, but solar flight with a bit less optimal aircraft should be possible.
So let’s think about Sockmonkey’s Plank, either the enclosed canine beneath the wing or the on the top fuselage.
the Sunseeker 1 of Eric Raymond had 8,5m2 of solar panels installed. The Surface available for the Plank is in the neighborhood of about 12m2.

The Cockpit of this Fritz Design coupled with the Sockmonkey’s Plank

and Solarpanels would give an interesting combination

 

[Victor Bravo]

A large area plank, with enough wing area to have usable solar panels on it... what a great idea !

 

[Hephaestus]

So 1360w/m² available harvested at an efficiency of 15% - 207w

Possum has ballpark of 18sqm of wing. 3726w.

Is that enough to even offset the extra weight of the solar panels?

Think of glare - you'd never run solar on a low wing.

 

[Norman]

A large area plank, with enough wing area to have usable solar panels on it... what a great idea !

And cheap too... At least compared to a satellite. You guys are concentrating on the cost of the airframe but that's not necessarily what most of the money in a homebuilt airplane budget goes to. The engine and electronics can be much more if you aren't careful. If all you want to do is fly around your local area at low speed and altitude (say less than 5,000ft and 70 mph) in good whether, during the day, you can have a minimal instrument cluster. Higher altitude and higher speed requires more power which can get expencive fast. Getting good climb performance on low power requires low induced drag which only comes from low span loading. Low aspect ratio means that you'll need more power for a given rate of climb thus bigger more expensive engine.

 

[cluttonfred]

FWIW, here is a proven commercial flexible solar panel -- SunPower SPR-E-Flex-110 Flexible 110 watt 12 Volt Solar Panel | Wholesale Solar -- that's about a little under 4' x 2', weighs 8 lb, and costs $225. So a single-seat light aircraft with, say 30' span and 4' chord for 120 sq ft of wing area could fit 15 of those panels on the wing and/or fuselage for a total of 1,650 watts, 120 lb, and $3,375. The problem is that 1,650 watts converts to a theoretical maximum of just 2.2 hp, so it's really not worth bringing the solar panels with you. You'd be much better off with heavier, cheaper rigid panels to create a ground charging station for a battery-powered electric ultralight that can be charged with a day of direct sunlight and just fly local hops.

 

[John.Roo]

Exactly!
As I wrote before...
"... best and cheapest position for solar panels is roof of hangar."

What do you think about "e-soaring"?

Good job :-) And very good empty weight. I asume that 115 kg is with some light combustion engine or with electric propulsion (probably without batteries). So to keep MTOM under 300 kg with "normal" pilot arround 100 kg you can still use 70-80 kg battery. Nice :-)

www.homebuiltairplanes.com

 

[Pops]

Why wouldn't that solar panel work on the top of the cabin roof of the JMR to keep my battery topped off ?

Panels for my hanger.
Do not put panels on roof in snow county.

 

[Hephaestus]

Exactly!
As I wrote before...
"... best and cheapest position for solar panels is roof of hangar."

What do you think about "e-soaring"?

Good job :-) And very good empty weight. I asume that 115 kg is with some light combustion engine or with electric propulsion (probably without batteries). So to keep MTOM under 300 kg with "normal" pilot arround 100 kg you can still use 70-80 kg battery. Nice :-)

www.homebuiltairplanes.com

Even more so if you can get the government to pay for a big hunk of the cost and give you a contracted kwh buyback rate

 

[cluttonfred]

That's a great idea as long as you're using the battery to power avionics and lights and a starter but not an electric motor to fly your plane, though in that case the 110 watt panel is probably overkill and the 50 watt panel at half the price and weight would be plenty.

Why wouldn't that solar panel work on the top of the cabin roof of the JMR to keep my battery topped off?

 

[Pops]

That's a great idea as long as you're using the battery to power avionics and lights and a starter but not an electric motor to fly your plane, though in that case the 110 watt panel is probably overkill and the 50 watt panel at half the price and weight would be plenty.

I have been looking for a flex panel and you are right, my 12V , 9 amp battery needs to be charged at a lower rate if ran direct without a charge controller. I have a couple of charge controllers that I can use.

Added-- Looked at the 50 watt and its just what I have been looking for. Should do the job. I have electric for handheld radio, elevator trim servo, LED position lights and LED strobes if I want to use. With the charging for the solar panel, shouldn't have any problems with a light weight starter on the C-85.

 

[cluttonfred]

That’s a solid panel, that brand is made in France if memory serves.

 

[sming]

FWIW, here is a proven commercial flexible solar panel -- SunPower SPR-E-Flex-110 Flexible 110 watt 12 Volt Solar Panel | Wholesale Solar -- that's about a little under 4' x 2', weighs 8 lb, and costs $225. So a single-seat light aircraft with, say 30' span and 4' chord for 120 sq ft of wing area could fit 15 of those panels on the wing and/or fuselage for a total of 1,650 watts, 120 lb, and $3,375. The problem is that 1,650 watts converts to a theoretical maximum of just 2.2 hp, so it's really not worth bringing the solar panels with you. You'd be much better off with heavier, cheaper rigid panels to create a ground charging station for a battery-powered electric ultralight that can be charged with a day of direct sunlight and just fly local hops.

If you look at how a panel is made, a lot of the weight is the plastic backing of the panel, the actual sensitive stuff is very thin. I always wondered 2 things: if a panel can actually replace the fabric/skin of the wing, offsetting some the weight, or if somehow you could order that thin sensitive layer and laminate it with carbon or something, again to have something structural and light sensitive. I also wonder if you can kind of slice the back of a panel to save some weight if you cannot get the raw film from the factory
Apparently, Sunpower have some factory in France but they are very much a global company and got factories all over the world...

 

[Sockmonkey]

If you look at how a panel is made, a lot of the weight is the plastic backing of the panel, the actual sensitive stuff is very thin. I always wondered 2 things: if a panel can actually replace the fabric/skin of the wing, offsetting some the weight, or if somehow you could order that thin sensitive layer and laminate it with carbon or something, again to have something structural and light sensitive. I also wonder if you can kind of slice the back of a panel to save some weight if you cannot get the raw film from the factory
Apparently, Sunpower have some factory in France but they are very much a global company and got factories all over the world...

If the wing skin is made of something transparent, then you can just lay the panels in between the ribs. Since they would be enclosed, the panels wouldn't have to be structurally strong.

 

[Steve C]

I've kept my eye on solar for quite a while. The kind airplanes need used to be pretty much unobtanium- sponsored or NASA, but not anymore. There are guys flying rc with no battery at all. This was not possible a short time ago.

 

[WonderousMountain]

In reply to Cluttonfred's question on wingletts for
Lower-mid AR planks or fixed rectolinear wings.

Yes, you can basically get all positive results if you
are carrying enough load bearing 'Spar' toward the
tip. You want to bring the tip to something like 1/3
Chord, and that's on the winglets vertical portion.

Ideally, you would have some kind of taper already,
If not, it's better to have ~ 20% of the wing in taper.
That might mean aileron or mounting modification.

Elliptical is the wrong answer, but a good visualization.

THX all,
LuPii

 

[erkki67]

I like simple layouts, as this Plank. It’s like with the Ranger and Piojo of Fritz, it has simple clean lines.

the forward fuselage Section of the Fritz Ranger (cockpit and enginemount) would fit nicely this plank, but the tailcone would require a different design as it incorporates the rudder.

with removable or folding wingtips it would be trainable as well.