The 70 kilo single person plane | Hacker News Reader

The 70 kilo single person plane

physorg.com

9 pointsph0rque10 comments

I went to the http://www.flynano.com/ website, I have to say that the main image isn't exactly inspiring. Sure it looks like the guys having a good time flying, but he also appears to be flying in some post-apocolyptic scene.

I'm curious how much pilot weight affects a craft with such a low weight already, and why they would start with a water based craft, as I assume it takes more energy to get up to take-off speed from the water than from land.

and why they would start with a water based craft

My guess would be related to minimizing things, no need for landing gear speeds up the process to get to release. The only moving parts appear to be the prop, otherwise it's all chassis.

Also crashing in water is at least a little more forgiving that landing on concrete.

I want one.

I agree that it minimizes moving parts. HOWEVER. Takeoff and landing on water is more difficult than land, because the water actually sucks the hull downwards, thus takeoff is more challenging than with wheels. Wheels would add some manufacturing complexity, but inexpensive and lightweight landing gear is a solved problem for ultra-light aircraft. I'd certainly like to hear their rationale for this. If they are real, I'd guess that they are going after a market--such as people who own cottages--where access to water is plentiful but access to prepared runways surfaces is not.

The quoted stall speed is 70 kmh (~43 mph), water feels a lot like concrete if you hit it at that speed

All of the illustrations I can see appear to be just that: Illustrations. I have real trouble believing that they will be shipping an aircraft, even a hobbyist aircraft, without at least one honest-to-goodness picture of a prototype. (UPDATE: http://www.eaa.org/news/2011/2011-04-14_aero.asp has a picture of a prototype that has not been flown yet).

And manufacturing with carbon fibre is non-trivial. The bicycle industry is full of horror stories about design firms that outsourced the manufacturing and wound up (heh) shipping frames that cracked or split. It's a wonderful material, but it isn't a no-brainer. I would expect that having designed such a thing, they would need to build a succession of prototypes, followed by choosing a manufacturer very carefully, and then doing some prototypes with the manufacturer to iron out the issues involved when scaling up to production processes.

So where are the pictures of the prototypes?

And about what they call "Tech:" They. Must. Be. Joking.

Where is the discussion of the airfoils chosen or how the hull is designed for takeoff from water? What's the maximum wave height this craft can deal with before you say "Too choppy, can't fly?" What's the takeoff speed? "Runway" distance required? Stalling speed? Where is the designer bragging and boasting about the unusual wing design and what problem it solves?

This web site does NOT satisfy my sniff test.

It appears to at least have been built: http://www.eaa.org/news/2011/2011-04-14_aero.asp

The craft hasn't yet had it's maiden flight. It's an interesting concept. I've always liked the joined-wing concept from a structural standpoint but, if the wing nuts in my graduating class were to be believed, stability and control of that layout isn't trivial.

Thanks for the link!

This striking box-wing airplane is all carbon fiber composite and can start only from water. It is probably the most interesting airplane proposal at this fair. The maiden flight is planned in a few weeks. Because of severe winters in Finland, flight testing was made only with scale R/C models.

I'm mystified as to how they can promise deliveries this summer if they haven't even had a full-scale flight yet. Can you comment on their production optimism?

Also, I can't see any control surfaces for pitch or roll. What am I missing?

You know what's important here? Deliveries start Summer 2011. There is so much vaporware with small vehicle companies. Well okay, not vaporware, but years of delays at least. It's a great MVP, not perfect, but still awesome.

Anyone have a video? What kind of certification and/or testing is needed for a craft like this?

Looking into how to buy an order option (provided it's not vaporware).

Depending on where you are, this plane may possibly fit in the Ultralight category ( http://en.wikipedia.org/wiki/Ultralight_aviation ) - i.e. none or very little paperwork required. Not sure about max/stall speed requirements - seems like it doesn't fit in US definition of ultralight, it's LSA ( http://en.wikipedia.org/wiki/Light-sport_aircraft ) in US probably.

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