Just picked up this plane, and was wondering if anyone had built/flown one previously. Drawings that came with it indicate that it was produced by Southeast Model Productions, who still appear to be in business, but no longer producing the kit.

Here are some of the stats on the plane:
- 35" wingspan
- 50" long
- balsa/ply construction
- fixed gear
- Kress/Aerojet fan unit
- K&B engine (haven't had a close enough look to see what it is)

Construction seems pretty straight forward and light, so it seems like it should be a good flyer.

Thanks in advance,
Steve

Nice looking F4. If you decide not to tackle this project , I will take it off your hands. I would convert it to electic, but thats just me! Good luck with it and keep us posted with some video if you decide to keep it
Jim

I'm pretty sure that would be Larry Epifanio and he does check into this forum periodically. I can't recall his RCU handle but he's pretty helpful. Good luck with your project.

Neat airplane...This was the first ducted fan jet I built in the late 1980s. It is a Southeast Model Products F-4 Phantom designed around the OS .25 ducted fan I believe. Many folks put the Kress RK 740 in them. I still have plans for mine to put in an electric ducted fan. They have advanced far enough to where a person could put one in that F-4. Did you get directions or plans with yours? I am looking for the CG in particular. Here is a picture...

MACE

Hi Mace,

Looks exactly like mine, other than the thrust tube that you appear to have coming out of the exhaust at the rear of the plane.

I did get the plans with mine. I'll take a picture of the section showing the c of g location and post it here if you want. Or I can email it to you, just let me know.

Steve

Well, here is the finished product. An old F-4 with a new engine. It has an MW44 Gold autostart with 32 usable oz. of fuel.

MACE

Steve,

Did the fella you got this F-4 from ever say that if flew? Did he ever put any flights on it or give an indication of how it flies?

MACE

Hi Mace,

I bought the plane through the local hobby store, so they didn't know much about it really. The controls had been completed, so there is no way that it could have flown previously.

Sorry I can't give you more help than that.

Steve

I am pretty sure that was the Nick Ziroli designed model, which was kitted by the company mentioned previously. I built one too from the Ziroli plans - a nice little model. My model flew awful at the CG per the Ziroli plans - it was way tail heavy if I remember correctly.

Hi,

Did you change the CG and try again? How did it fly otherwise? Steve sent me the recommended CG off of the plans. It is hard to tell with this type of wing and airfoil where the CG should be. My thoughts were that the CG is too far forward for this wing.

MACE

I flew it with the OS.25 VFDF/Axiflow, and the OS.46 VFDF/KressFan, assuming I was dealing with a thrust issue. I played around with spinner fairings, etc. The plans originally showed a cheater hole on the bottom, just fwd of the spar if I remember correctly. I later found out (after getting rid of the model) that it was a CG issue. The model would "hang" literally at about 45 deg AOA, with no effective roll control. It was bizarre. I think I was eventually able to fly the model, but this was also around 1990. I probably still have the drawings. I could check the drawings and see where the CG is shown, then see how it corresponds with your location. From what I remember, the MLG will then be a bit aft. They appeared already aft even with the model I built...

Ron,

Thanks for the information thus far. I intentionally installed everything as far forward as I could in anticipation that CG would be an issue. If I had to guess this plane weighs about 8 lbs dry. This would put me around a bit heavier weight after fuel of course. I still think it is lighter than what I had in it before. It originally had an RK-740 and K&B 7.5 with 16 oz of fuel. Full of fuel it seemed like a pig on the ground. It never flew as I did not get the fan to produce enough thrust to fly.

MACE

Mace, I found my Ziroli F-4 plans. I did write down notes on it too, believe it or not, regarding CG. Actually, I'm not surprised, since I was surprised how off it was for me... You may want to compare this with your plans, because it is possible the CG location was adjusted before it got to Larry. I'm guessing here. And if Larry chimes in, I'd take his word first. But this is what I noted regarding CG location. As you can see per my sketch, I moved it about 1" fwd of the spot called out on the original plans, after numerous takeoffs, rotates to about 45 degrees, then the airplane "hang", where the tail is totally blanked from flow, and very little fwd velocity.

My model was just a tad over 4.5 lbs - it was quite lightweight - Dave Brown lite wheels, no rudder, etc... When I switched to the OS 46 / KressFan, I'm sure it picked up another 5 oz (pure guess). This was like 1989-1990 for me. I've considered building another, possibly for electric if I could get a canopy. Lightweight retracts would also make it fun. I also found my single, lone photo of the model - I'll see if I can scan it tomorrow and add it here for fun. [8D]

Ron,

I checked my CG against your sketch and my forward CG mark is the same as yours. The current CG location on the jet is 1/4 inch behind the forward mark, dry, less the receiver in the nose. So I think once I have installed the receiver and fueled it up, it will be where I need it for takeoff. My fuel tank is centered slightly forward of the CG and the engine is in the duct at the rear of the jet. I plan on doing some taxi tests tomorrow.

Thank you,

MACE

Sounds like you'll be in better shape than I was atleast from a CG standpoint then. Good luck with your first flight! I scanned a bad pic of mine, from 1989. My camera skilz were 10% less than they are now...

Here is video of the taxi tests after installing new tires. Everything checked out ok.

MACE

http://www.vimeo.com/4283018

I remember more about the model now, after watching your taxi video. After moving CG forward, I was getting nasty landings, as in, MLG touches down, and next maneuver most predictably slams nose downward due to (now) a MLG position waay aft of the CG. So careful on landings. [8D]

I also looked at some of your HUD videos... Boy I shouldn't have looked at that! I remember using HUD video stuff for a UAV demonstrator ~15 years ago... A fun project, and I always wanted to try that again on my own...

Ron,

I'll try to keep it off the ground as long as possible on landing. Thanks a lot for all of your input thus far. I will hopefully get the first take off on a better quality video camera. After watching full scale F-4 landings, I doubt this little one is going to be pretty.

PM me with some details on the demonstrator you worked on?

MACE

Ron,

Thanks for the info. Were you around when "Mr Mac" was still alive i.e. did you get a chance to meet him?

I spent some time working on an A-4 and will always remember what I saw stamped on the rudder pedals and can imagine the same was on all their aircraft. Would hate to take a ride in one of their ejection seats though.

The next hud down the pipe has an artificial horizon and GPS return to home/autopilot, if rc link is lost using thermal sensors.

MACE

Mister Mac was before my day. I was there from 1988-1997. Now I'm with the "other company" working mostly on F-35. [8D]
Artificial horizon would be be nice! I remember some times, we'd have video camera dropouts, but still have the working HUD if I remember correctly...
Nicer stuff is available now...