[AJCoholic]

Originally Posted by black

Very cool project.
I think you are overly concerned about residual thrust. Turbine powered but still driving a prop. It should not have the same residual thrust as turbine jet. What is the idle rpm of the prop? If it's close to a piston driven prop then flight should be similar.

I’m not overly concerned, lol. I saw Marc Thompson fly this engine in a very slick Comp ARF Extra. It certainly didnt have flaps.

I’m putting in flaps because I want to... its not much extra work, and I already purchased the servos to do it.

Another few hours of work. I am not sure of the idle rpm but it is low enough as to allow the plane to taxi without brakes on grass. I suspect that in the air it would be similar to, possibly a bit higher, than a typical reciprocating engine.

[black]

I too, have seen Marc fly that. It was quite a while ago! You're a very experienced pilot so I trust your judgment on the construction. Touch and go's are great fun with a plane that flies at walking speed.

[AJCoholic]

Originally Posted by black

I too, have seen Marc fly that. It was quite a while ago! You're a very experienced pilot so I trust your judgment on the construction. Touch and go's are great fun with a plane that flies at walking speed.

I’m hoping to do many touch and go’s

[Cat 1]

Looking at the structure Andrew and I think your plain flap idea will be the easiest - if you set up for lots of deflection you are golden in the drag department.
I have done a split flap with a stiff flat skin (balsa thin ply lam) and secondary ribs that matched and slightly offset the wing ribs hinging was "at the skin" and the drive was straight in through the back spar.. Tried to find a picture but couldn't ...
Your solution will work great....

[Mike Sebastien]

Interesting project. My biggest concern heat in the fuselage. You are going to vent it to let the hot air out.

[reo]

Originally Posted by Mike Sebastien

Interesting project. My biggest concern heat in the fuselage. You are going to vent it to let the hot air out.

I didn't find this to be an issue. The 'hot' parts of the engine will normally be in the cowling. Only the intake of the turbine would be exposed to the fuselage.

[stegl]

I agree with Ron. Here is my installation and pretty much totally within the cowl.

[AJCoholic]

On this plane, I was planning to mount the flange of the turboprop through the thick plywood firewall. There is plenty of room for this, and yes, it will place the turbine portion inside of the fuselage.

I haven’t given it that much thought yet - but in the instruction manual they do show the option of having a metal screen (painted to match the plane colours) over a cutout near the engine, on the underside. If required, it would be easy to have a few vent openings in the firewall, and venting either below the core turbine or in the top hatch, to allow hot air to exit. I can always run it (as I plan to) before flying, to get familiar with the operation - and see how warm things get. Its something that can be assessed later on in the build...

Glued up the ailerons this afternoon. The next step is to bring the wings to my woodworking shop, and mod for the flaps, build the flaps, finish the ailerons and sheet the wing and shape the leading edges, and sand. And make up a few more servo mounts. Much easier in the shop VS home, I can make all the mess I want to and all my tools are there.

Hopefully tomorrow or the next day, I will have the wings finished up and I can get started on the fuselage or tail group next.

[AJCoholic]

Went to my shop today (my wife had a rare afternoon off work, so she could watch the kids) and did some work on the wings.

Removed the tails of the ribs where the flaps will go, glues a strip of ply on the backside and cut and glued in the hinge mounting blocks.

Then I finished up the stock ailerons, and cut the flaps from solid light balsa (will hinge on the bottom edge so there isnt need for a tapered leading edge).

Started sheeting the wings, got both done on the bottom, one mostly done on the top. And one leading edge glued and shaped. Will try and go back later this week to finish the sheeting and cap strips, and sand.

I can start the fuselage next or the tail group. Here at home. But heavy sanding and shaping is so much easier at work. I’m still closed down for the time being so it was nice and quiet all afternoon, just me and the radio.

[stegl]

Not sure where you firewall is on the plans , but sounds like a good plan. Any chance you could post the front side view of the plans as not much on the AMR site other than a picture . You could consider leaving the back side windows open for fresh air to the turbine intake. Not really a lot of warm air around the turbine to worry about . My glass cowling gets barely warm but the aluminum foil helps reflect some.
A lot of air moving around behind that prop.
The screen is a good idea to keep the grass and stuff from getting sucked up.