Flaps on a delta?

Yes, I think it has split elevons that can be mixed to work together as normal elevons or can be set up to go to a crow mix for landing. Remember, it also has the canards, which could easily counteract the "flaps" on their own too.

Inboard flaps, outboard elevons, plus canards for elevator.

I'd have to go back and look but I dont think the inboards flaps will go up

Originally Posted by TTRotary

Flaps on a delta?

From inspecting my just delivered kit, and reading the "instruction manual" I'm guessing that there is a breakdown in vernacular and language usage between Vietnamese and English.....
I think "flaps" ought to read "canards"? Just my opinion that they are really talking about the canard defection for takeoff or landing.

¿quién sabe?

- Mike

Thanks for the hands on info Mike. Does it have one or two control surfaces per wing? If you have time, some end user pics sure would be interesting.

Yes, two surfaces on each wing plus canards.

You didn't read my first post?

I've slept since then

Lee,
Had the EDF Jet Jam last week, now I'm out of the country for a week at work, will have more time to examine the kit once I'm back home on days off.
The trailing edge is separated into two sections, inboard and outboard like a full size Mirage III

The instruction manual is pretty basic as you might surmise, no real info on setup of the flight surfaces except for throws and a CG.
I'll probably treat it like a classic Mirage/ Kfir, the real Gripen is a fly by wire deal with computer mixed flight controls so that is not much help.

I'll post a couple of pictures when I get home and have time.
- Mike

Originally Posted by Knife Liddle

I've slept since then

LOL nice!

I'm not speculating, I have one as well. And yes, the instructions are of the, shall we say, basic variety

Originally Posted by Knife Liddle

Thanks for the hands on info Mike. Does it have one or two control surfaces per wing? If you have time, some end user pics sure would be interesting.

+1 Yes please chaps, some detailed walk around and inside pics would be great.

There is one here that keeps staring at me every time I walk into the LHS - I have to hide my credit card! It's not cheap so I'm a bit reluctant to splash out...

Busdriver

Thanks Mike and BH for the early owner info, any pics and description about the jet will be appreciated. I have many more jets than time or space right now, but always enjoy reading about the new stuff.

Originally Posted by Mike Warren

From inspecting my just delivered kit, and reading the "instruction manual" I'm guessing that there is a breakdown in vernacular and language usage between Vietnamese and English.....
I think "flaps" ought to read "canards"? Just my opinion that they are really talking about the canard defection for takeoff or landing.

¿quién sabe?

- Mike

Could the instructions reflect LEFs that did not make it into the final kit?

Trailing edge "flaps" on a delta are just down-elevator, and they will introduce significant down-moment that the canards may not be powerful enough to counteract. Attempting to "crow" the TE on landing with the outboards up will cause pitch and roll axis instability that will worsen as the AOA increases i.e. as you approach ground. You won't need them anyway. As long as the build stays light and the CG is not too far forward, you can bring the nose up and slow it down plenty for landings.

I would also be very careful with those canards. The jet guys have had serious headaches with them on the JL Gripen. I believe one guy got them to work to increase AOA on landings via small deflections in flight mode, to slow the plane down. Others crashed. I would start with them fixed with about 1-2deg positive incidence relative to the wing, with ability to quickly trim and not fool with them, but that's just me. Large actuations may stall the wing by disrupting vortex lift since the control surface is very large...

That said the plane seems like a solid flier from what I've seen.

The rigging for the canards on this thing is pretty solid but I would definitely make sure you're using good servos on them.

If by LEF you mean Leading Edge Flaps, or slats, then no, there are none.

I was puzzled by the inclusion of flaps for the same reason you stated.

I have an old CARF Eurosport airframe. It also has split elevons and of course canards.

Originally Posted by Knife Liddle

I have an old CARF Eurosport airframe. It also has split elevons and of course canards.

Split control surface is standard practice on full scale (Mirage, Gripen, Rafale Eurofighter)to maximize flexibility, but the surfaces move primarily as traditional elevons or ailevators only.The inboards function primarily as pitch controls, and the outboards as roll control. I am not aware of any crow configurations on full scale. Standard landing or HA configuration is to deflect the inboards up to counteract LEF downmoments, with the outboards preserving full roll authority / dynamic reflex as needed. On the Gripen, the inboards are also heavily deflected upwards to keep the boundary layer attached under significant canard deflections.

I have tried splitting elevator and aile function, and though a decent solution in theory, it does not work that well. I have best results using both as elevons, with more aile mixed to the outboards and more Ele mix to the inboards. It is also great for redundancy in case you lose a servo.