Maidened my CMP C-160 Transall today. Flew very well. I bought the plane in 2006 on eBay for under $130 and was sitting on it until last month. I've read all the threads on this plane and thought I should add my experience to the mix. Got in two flights before it started raining. 8 minutes on the first and 9 minutes on the second. Take off roll and landing speed were about the same as an average glow powered sport plane. Initially I had all control throws set to the maximum and used expo to keep it tame around the center of the stick on the first flight. This is my normal practice on a new plane to ensure I have plenty of control authority in case of unexpected trim issues. I noticed a tendency to balloon with large pitch changes that I attributed to the expo curve kicking in and/or the short coupling between wing and tail. The second flight was on low rates without expo and I still found the pitch to balloon unexpectedly with larger inputs. Nothing scary, just a little more reaction then expected. Normal elevator inputs resulted in predictable pitch changes. I didn't notice any tendency to porpoise with large or small inputs. The CG is currently at 75mm. I have read that a number of people have used 75mm or more on this plane for CG, so it could just be the short coupling causing it.

Looped from level flight just fine, but don't think it will have enough power for large diameter loops. Didn't roll it yet, but aileron response indicates it will roll just fine. 60-70% power seemed to provide very scale like flight. During my stall tests I found it to be very tame. With the motors turning at a very slow idle speed and the nose held level it didn't drop a wing. It just seemed to descend slowly with very little forward speed while maintaining a level attitude. Ailerons remained effective and the glide was straight. It did not drop a wing until I abruptly applied full up elevator (I had substantial throw available). It broke to the right. The flat glide with near zero forward speed would seem to indicate that the 75mm CG is spot on.

I converted it to electric flight with the following components:

- Motors - 2 Turnigy 35-42c's (equal to an Axi 2820)
- ESC - 2 Turnigy Plush 40 esc's
- Batteries - 2 Turnigy 4000mah 3s Lipo's rated at 30C (One for each motor)
- Prop's - 2 APC 10x7 sport prop

This motor/esc/prop combo draws 36.4 amps at full throttle per my watt meter. The plane weighed in RTF at 8.5lbs. This works out to around 95 watts per pound.
After an 8 minute flight with average throttle position at 70% each battery had depleted only a hair over 2000mah, so with this setup 12-14 minute flight times should be reasonable with a little power in reserve.

I modified the kit as follows:

The NLG is junk. It consists of a very soft aluminum axle pushed onto a 5/32 hardened steel shaft and locked on with 2 set screws. No way this is going to last on a grass field. The nuts used to secure the wheels to the axles were the wrong size and would not tighten. There is no suspension or movement permitted with this setup. I grass field will transmit a whole lot of pain to the mounting bulkhead and its attachment to the fuselage. I bought a Dubro 5/32 Nose gear strut, added a Dubro EZ adjust axle, cut down the strut to size and used the trimmed off portion as an axle for the nose wheels. It fit securely and with the spring wound into the strut provides a little relief to the bulkhead when hitting the bumps on the field.

The fuselage has 3 full bulkheads in the kit I received. One at the nose, one at the trailing edge of the wing and a 3rd a couple inches behind the wing trailing edge. I managed to pull the last one loose a little with light hand pressure. I re-glued all of them with 30 minute epoxy and added a 3/8 x 1/4 hardwood longeron from the NLG bulkhead to the MLG front mount and then on to the MLG rear mount. This should distribute some of the NLG load.

The fuselage wing mounting area and hardware are not up to the job. The wing lead edge mount area of the fuselage is very week and does not have a bulkhead to help support the wing. I could flex the fiberglass that the wing front mount screw attaches to easily. In addition after the the initial installation of the wing, cracks formed on the fuselage in the center join area at the lead and trail edge of the wing mount area. I added 3 layers of 2oz fiberglass with 30 minute epoxy in this area wrapping half way down the inside of the fuselage. I also added one layer of glass to reinforce the trailing edge bulkhead attachment area. I replaced the small single wing leading edge attachment screw with a 1/4" allen bolt. The trailing edge screws provided will do in that position because there are two of them.

The engine nacelles are very light and each has a separate access cover for use with access to a glow engine. I found that the complete nacelle can be installed and removed with the electric motors in place. Since I don't need the access hatches and in the interest of adding a little more rigidity to the nacelles I epoxied the hatches in place on the nacelles. If I need motor access I can pull the prop, 4 screws and remove the entire nacelle cover in one piece. I opened up the scale turbine exhaust outlet and air inlet to permit cooling air for the motors and ESC's. I also trimmed the prop shaft opening a bit to allow more air through to the motor. I am not using spinners because they will block the cooling air needed to keep the motor/ESC happy.

My batteries would not fit in the nacelles, so I had to locate them in the fuselage. In order to do that I needed to extend the battery leads about 12" to each ESC. I read a lot of stuff here and elsewhere about surges causing failure of ESC's due to extended battery leads. It's generally recommended to extend the ESC to motor leads if an extension is needed. But long ESC/Motor leads can generate noise which can impact radio operation. One work around I read about was to add a 220uf capacitor at the ESC for each 4" of battery lead extension. The voltage capacity of these capacitors should be at least as much as the capacitors already found on the ESC. I initially thought my extensions would be 16" so I added four 220uf 50v capacitors to the battery leads on each ESC. They are soldered in parallel to the battery leads. They help absorb the surges generated by the long leads. Since my leads ended up being only 12" the protection afforded by the extra cap is good insurance. Larger gauge wire is also supposed to help a little, so the extensions are 12GA noodle wire. I had a CG problem with the battery position. The best place would be between the MLG, but that made for a tail heavy condition. I tried them at the lead edge of the wing and ended up with a nose heavy situation. My solution was to install them at an angle so they did not extend as far forward in the fuselage. The batteries are velcro'ed together and mounted in a balsa box that installs at an angle in the fuselage between the rear of the wing lead edge mount and fuselage bottom. The upper part is attached at the wing leading edge attachment mount plate and the lower part attaches on the longeron I installed to support the NLG bulkhead earlier. It's about 1 1/2" longer then the batteries to permit shifting the CG by placing foam pads behind the battery to move it aft. I cut 8 large diameter holes in the box to vent/lighten it. Its function doubles as a structural support for the wing lead edge mounting as well as the battery holder. The only downside is that the wing must be unbolted for the batteries to be installed/removed. I didn't want to cut a big hole in the fiberglass just to get at the battery easier. It's pretty light weight glass and I wanted to keep it intact for strength.

The biggest issue with this kit by far is the problem with some kits having the incorrect incidence in the precut horizontal stab mounting slot. Mine was WAY off. I had 5 or 6 deg of positive incidence in my stab slot. I had to remove a 3/8 thick wedge from the top trailing edge of the mounting slot and add that same amount of wood under the stab to fix it. After gluing the stab in position I discovered that I still had a little over 1 deg of positive incidence in the stab. Nothing I could do at that point but shim the wing or be prepared to add some nose up trim after take off the first time. I elected to do the latter.

My kit was the all white version with blue wing leading edges, red wing tips and Turkish army decals. The decals include the windows for the cockpit and side windows. They were completely unusable. The inner and outer layers separated and looked like the windows had air bubbles trapped over the black. I made some new windows from trim monokote. I had a plan to make the plane look like one of the Southern Air Transport C-130's that used to stage for Honduras out of my area in the '80s. Rather then recover the wing trim, I painted the blue/red wing/stab/rudder and lower half of the fuselage with gray Krylon and added 1/4" black pin stripping at the edges. Looks good and so far the paint is sticking without problems on the covering material of the wing and tail. I printed up the "Southern Air Transport" for the fuselage, N number and the corp logo for the rudder onto some Testors decals sheets and it looks pretty good.

I hope this info helps anyone else considering this kit. It gets a lot of attention at the field, looks great in the air and it flys pretty good too

Here is a video of the 4th flight.
[youtube]http://www.youtube.com/watch?v=XgRLQx8M2uo[/youtube]