Search results

Agreed. "Unless." (Computerized control systems for powered control surface aircraft is what I do for a real job. And one of my main accomplishments over the past ten years has been making that true.)

Are you sure there was a prop in front? Could be someone sticking a trike under a Woopy Fly. (Which goes under the heading of "I've had worse ideas, but can't think of any right now," in my mind.)

Pulling It All Together reserved for future post

Flying Wing For the purposes of this discussion, a flying wing is an aircraft with only a single surface acting aerodynamically in the vertical direction -- an aircraft with no conventional horizontal tail, canards, etc. The design under discussion has a conventional vertical tail (stabilizer...

Statically Unstable All aircraft must be stable to fly. That is, when encountering a disturbance, it must tend to return to its previous state. This can be achieved passively, by the aerodynamics of the aircraft itself; or, the aircraft can be stable only under closed-loop control, whether by...

Low Aspect Ratio The design under discussion has an aspect ratio of 3.0. For the purposes of discussion, I will consider this a low aspect ratio, but not extremely low aspect ratio. At extremely low aspect ratios some aerodynamic effects (such as vortex lift) come into play that are...

Greetings. I'd like to present some ideas around a design that I've been working on, on and off, for a little over ten years now. I want to say, up front, that not a single piece of this aircraft currently exists -- some analysis has been done, but this is a pure paper design today. The design...

It's pretty cool. Some Silicon Valley vibes (which I rather enjoy, having lived there voluntarily for 17 years), but not too much on the startup side -- the company is ten years old, so a lot of the rough edges have polished off. And the product is super cool, super real, and fun to get to...

Yes, working remotely since last March, and through the foreseeable future. This one? How bad can it be... only 383 pages. :-O

It's been a long time. Real life has been intruding... but at least real life includes building flying things at this point! I've been working at Wisk.aero for the past two and a half years, and recently moved to Kanab, UT, so lots of life changes. Hoping to get back to some personal design...

I'll be there this year. Driving in and camping. Is there a particular day that people are meeting, or is this a "most mornings" thing? I know I've been nonexistent the last couple years, but looking forward to seeing some faces from way back when! Look for the big guy with a few owls nesting...

If you want a really rough approximation, choose a Vmc speed (Vs is a good target); at that speed, assume 100% thrust on one engine, windmilling drag on the other (at most the drag of a disk the size of the prop disk). Calculate the yaw moment from this (which is where engine offset comes in)...

Yep, OEI = one engine inoperative. You'll need more vertical control authority than a single engine plane for this case; potentially substantially more, depending on how far laterally offset your engines are. More offset is structurally good, but ups the tail size drastically. Slotted flaps...

Is that an 0.03 vertical tail volume coefficient? Seems a bit light; what's the rudder deflection OEI? With a chord below 0.6 m, your Reynolds number is below a million... CLmax of 2.5 seems optimistic, even with high-complexity flaps.

Why would contra-rotating props driven by a single power source have to have pitch controlled separately?

I don't think many pilots would consider a 37 hp Aeronca C3 to be acceptable performance in this century...

I'd be surprised if the engine were that light... the Nano is designed for cost over all else, is my understanding, and building a heavy engine is easier than building a light one. Don't be surprised by at least 120 lbs w/o transmission. The good news is that the power rating and output speed...

In my mind, flat-bottomed = not single surface (concave bottom), not symmetric (overly convex bottom). Something where the weird AC103 camber definition actually roughly corresponds to 2x the airfoil camber, basically.

I haven't seen any external confirmation, but one of the nice points of his book is that all of his changes are backed by measurement... I'd lean towards strongly believing his claims, although how generalizable they are is less clear.

For the record, my understanding is that the NACA 2414 and NACA 4414 are considered "relatively flat bottomed" as used on a bunch of designs. Also both reasonable airfoils for a wide range of ultralights.