I've just finished building a discovery and the following may of of interest to others who are either in the process of deciding which trainer to purchase or are about to start building one.

Firstly, the fuel tank is too thin, especially at the corners and it's not worth taking the risk by using it. Remember, your expensive electronics are likely to get soaked in glow fuel if it should burst or leak. Throw it away and buy a good quality tank. I purchased a Ripmax 10oz tank and it fits perfectly. Cost £2.85.

The wing band supplied in the kit are too thin. Buy a pack or two of good quality bands. Costs around £1.75 per pack.

While you are in the shop, buy a length (only about 6 inches will be used) of 6mmx12mm medium hardness balsa strip. Comes in very handy to hold items such as the fuel tank in place. Cost around £0.50.

I used a small ball link to connect the supplied threaded rod to the throttle control on the engine. It works very well. It's probably worth having a good look at the engine and planning this connection in advance in order to save another trip to the shop. Cost around £0.75.

Whilst in the shop, also buy a pack of high-density foam to put around the fuel tank and under the Rx etc. as packing and to isolate these items from the vibration of the fuselage.

Apart from the above items, I only needed to purchase 30-minute epoxy and cyano as per the instruction manual.

I did use a couple of swing keepers but that was out of personal preference rather than being absolutely necessary.

The key decision after purchasing the discovery is which engine to use. I intended to use an OS FP40 with the optional OS mute kit. But, just for interest, I also tried a number of alternatives. Basically, any engine of 420g to 450g including silencer - with the radio battery appripriately positioned - will give perfect balance without the need for additional ballast. VMAR have been quite smart here in that 2 stroke engines such as their own VMAX, GMS, SC and ASP will give correct CG withut having to add additional weight. Also, 52/61 size four strokes can be used as they fall within this weight range. I tried my ASP 61 4-stroke - it gave perfect ballance and fitted well in the pre-installed monunt. If you do use a lighter engine, lead will need to be added as far forward as possible under the engine in order to bring weight up to the above level. An RMX40 is a heavy engine and would have needed some lead at the tail end. The OS FP40 and the LA40/46 are very light engines and I ended up using about 100g of lead plate mounted under the engine, secured to the side cheeks with screws.

The total weight, without fuel, is 5lb 8Oz. It would be difficult to deviate too far from this provided you stick to the standard build process. This is light for the wng area (719 Sqinch measured) and explains why the Discovery has a reputation for being a very easy to fly trainer with a slow, vintage style flight capability. Just what's needed from a first trainer.

Overall, the plane cost £55 and around £10 for the additional items listed above.

It really is very easy to put together - about as easy as a manufacturer can make an ARTF. Taking time with the building an forward planning of the radio installation and servo connections pays dividends.

My only gripe is that the covering is a bit thin and in places not stuck to the wood that well. But given that this is a trainer I expect it to see me through learning to fly and possibly beyond.

Would I buy another should this one suffer a mishap - without a doubt.

Hope this helps some potential flyers.