Thought I'd do a build thread on this as it's a great kit that's worth showing. The kit, turbine and all the other bits have been purchased from Al's Hobbies who have been really helpful with a good price to boot.. Ali has been great and very quick to help on a few little issues with the kit so overall I'm really happy, thanks Al.

So then...........

Skymaster L39

Length: 86" (2200 mm). Wingspan: 68" (1750mm).

Power: 17~27Lb (7 ~12kg) thrust

The ARF pro version of this model is a very comprehensive kit. Included is a very well finished composite airframe, wings, stab fin etc... The control surfaces are all live hinged except the rudder which uses standard pin hinges and is also the only surface that doesn't come pre installed. All parts come pre painted with molded panel lines and rivets. One thing that really impressed me was the fit of the wings, stab and fin to the fuz, its perfect! The wings and horizontal stabilizers are removable for transport. The fin is removable but only for access to the rudder servo.

Its not my favorite L39 scheme but is growing on me, should look great once I've finished with it

There's loads of scope for extra detail but I think I'm only going to give the airframe a wash to bring the detail out. The detail itself has been nicely molded with crisp flush rivets and hatches. The hatches seem a little to prominent for my liking but for an ARF it's very good.

All the retracts, oleo's, wheels, brakes, associated air lines and valves are included. The quality is very good, my only concern is that the spring in the nose oleo is very soft. The first thing I'll do is fit the retracts and check the models stance is OK bearing in mind the extra weight that will be on the mains. I really want it to sit with zero AoA or at least slightly positive one. Air rams and the stuff associated with the gear doors is also included. Just a note on these doors, all will require strengthening as they're a touch on the flimsey side. I'll be using an Airpower digital valve for all the pneumatic functions instead of the supplied mechanical and Jetronic valves. The jet pipe is also included. The extras that I have are the Kevlar fuel cells, full depth cockpit plus pilots and a bypass although I'm undecided if that will be used.

Going into the model is a JetCat P120SX with close to 30lbs of thrust, all control surfaces will have JR DS8411's and the receiver is a Spektrum 12100 with two 3300 nimh's.

There are a few small issues with the kit supplied.

• the bottom of the intake at the turbine end is cracked
• the forward gear door is distorted
• the former the pipe sits in at the back end is too big
• the front oleo spring is too soft

All that's left now is to build the thing................

I'm starting off by installing the retracts and gear doors. This has to be my least favorite part of any build more so with this model as I was expecting them all to be pre hinged. Instead I was confronted with 5 loose fiberglass doors, a pack of offset hinges and no guidance as to how to fit them!

I placed the main retract units and oleo's into the wells and made a temporary fixing with a few self tappers. I had to pack the outside edge of the units with 1/32 ply to get the main gear doors to close, I'll make a hysol fillet so the retract sits on something solid. The retracts will eventually have captive nuts and M4 screws securing them.

It wasn't possible to position the supplied offset hinges pivot point correctly as there isn't enough room between the central reinforcement plate and the gear door. I didn't want to use pin hinges as I don't like the look of them when the doors are closed. Instead I cut the ply plate out and installed two 3mm sts studding at the correct point for the hinges to pivot around. I used some double sided tape to test the inner doors actuated properly. I then added some carbon sheet just above the studding for strength. The center fuz between the gear doors is now rock solid. The outer gear doors were supplied as one plate with no cut lines. I had to add some fixing points for the retract hatch as well as work out the shape of the gear door. I've fixed these outer gear doors via a hardwood block hysoled onto the oleo. I made some plates to fix the air rams and the door gets actuated via the hinge.

The next dilemma was the gear door on the nose. This was supplied as one long gear door, if left like this it would have to remain open when the gear is down this in turn would mean more valves and work. Something I wasn't keen on doing especially as it's not scale. The solution is to cut the gear in two. The area around the oleo will be fixed when the gear is extended with the main nose gear door closed. I've also added two little doors to the fixed part so when the gear is retracted there's no gap. This is the scale arrangement. I've seen loads of pictures of this model with no gear doors I now know why. I'm pleased with the results and I think functioning gear doors add allot to the overall appearance so all in all its worth the effort.

I wanted to fully assemble the model early on in the build to check it's 'sit' when on it's wheels. It became apparent that the nose spring is way too soft and the oleo itself wasn't really long enough. I decided to pack the retract bearer as much as I could to lift it slightly. Ideally it needs a 110 degree retract but I think I'll stick with what I have. I just need to source a new spring. I'm sure the application of thrust would bottom out the oleo creating a negative AoA making the rotation a real jerky jump into the air. I'm also flying off grass so I really want it sorted before It fly's.

Will try and post some pictures of what I've done on my days off.

Cheers, Alex