It can be argued that the Avro 504 was one of the most influential aircraft of the 20^th century. It was in production from 1913 through 1932 and over 10,000 were built and the type was used by 39 nations around the globe. It served as a private aircraft, a trainer, a bomber, a fighter, an army cooperation aircraft, a research support craft on an artic expedition and saw service on wheels, floats and skis. In addition, it used 15 different engines during its development through 30 marks. It was a truly versatile aircraft. For a long time the only plastic model of the type was the old Airfix one that dates from 1967 and like its namesake, it has had a long life still being in production today.

Kovozavody Prostejov, or KP as it is sometimes known, is a Czech company that has been making plastic kits for over 50 years. I had my first exposure to a KP kit back in 1971 when I build the only kit available of an L-29. It was pretty basic and primitive, but when completed it generally resembled an L-29. KP has come a long way since then as these two kits show.

The box art for the two models differs in that one, the “K” model, is shown with wheels while the “L” model is shown with floats. However, there are parts supplied in the box so that you can build either version and the instructions show how. Furthermore, there are parts and instructions for a version with skis and you even get a K gun on a Foster mount to add if you want to build a fighter. The only differences between the two kits are the decal sheet and the painting guide on the back of the box. Now, what’s in that box?

There are two sprues of grey injection molded parts with nice detail. There is little flash but there are mold seams to be dealt with and some of the sprue attachment points are pretty heavy so care must be taken with the many smaller parts. The instructions are relatively clear, especially given the current state of the “this kind of goes sort of around here with an arrow pointing somewhere” instructions that have become all too prevalent.

There is a nice interior with a cockpit framework, rudder pedals, control sticks, seats and instrument panels along with some framework molded into the fuselage sides that can be picked out with paint and highlighted. Two accurate windscreens are provided printed on a small acetate sheet, but you have to be careful when cutting them out as they are very small. The engine is, well, there. It’s nothing special but does look the part.

The interplane and cabane struts (all 12 of them) are all individual so I expected some problems with alignment. However, I made a template out of cardboard of their angle to the wing and with its aid and working one by one with fast setting glue, they went into place fairly easily. One note, the locator holes are just little dents, so I deepened them a bit for better “grip”. I was amazed that when it came time to put the top wing in place, it required almost no adjustment and settled in quite easily working from one end to the other.

I decided to build the float plane version. The struts are very thin but fortunately the plastic is not very brittle so you can work with them. I did not use the kit’s instruction sequence here. I first assembled the floats, which took a bit of effort to eliminate joints/seams as they use bevel joints instead of insets. I then made another template of the angle of the front strut set to the floats and used it to get that part in the correct position. I added the rear cross bar and set it all side to set up completely. I did not put the rear “V” struts in place yet. When it came time to mount the floats, I set the front strut assembly in place and then supported the rear of the floats so they were level. I let this all set up. I then measured the distance from the top of the floats to the bottom of the fuselage and cut a piece of thick poster board into a strip wider than the floats. I mounted this on another piece of board so it could stand upright. Remember to compensate for the thickness of this base piece when cutting out your support. To get access to the inner strut area I cut away part of the center of the support strip. I then slid this support under the floats and lightly taped it at both ends to the wings. I then removed the temporary supports I had under the rear of the floats. Now comes the tricky part. Using the kit “V” strut assemblies as a guide, from rod stock I cut a piece the length of the rearmost strut. Cut this long and then adjust as you test fit. When I had it correct, using superglue gel applied to the locator holes I slipped my home-made strut into place. I let this set up and then did the other side. I let this all get good and set. When that was ready, I used the same method to make the diagonal strut of the “V” and get them in place. When it’s all done, it looks pretty flimsy, but it is actually kind of sturdy.

I marked mine as an Australian float plane aboard the HMAS Australia in 1925. It’s a simple scheme of ecru colored linen and a black cowl and rear fin. The decals behaved well, but they are “grabbers” as I call them. Unless you flood the area they are to go, where you first place them they will stay. Make sure they are very loose from the backing paper and using a lot of wetting fluid try to get them as close to where they belong as possible. because moving them afterwards is tricky as they can be brittle and break. Another problem area is that the wing roundels are located so the molded in control horns poke right through them. To eliminate this you could cut off those horns and add them back in later. As I didn’t think of this in advance, I just pushed the decal down over them and it worked…sort of. One on the bottom was damaged.

With the exception of the home-made float struts, this model is out of the box. As such, I have not rigged it for this review although I probably will do so at a later date.

I want to thank Kovozavody Prostejov for the review samples to build and IPMS/USA for the chance to do so.