There is a bit more to post winter flight preparation than simply charging your dormant batteries and flinging all your gear into the back of the car and heading for the field. Yet…for a good number of flyers that’s exactly what they do…and then they wonder why nothing works properly and they spend the whole day sorting stuff out or even worse, losing a model through poor preparation. Best case scenario is a frustrating day at the field, worst case scenario is that someone gets hurt or injured. With that in view, perhaps it is worth highlighting a few points to jog our memories and make our late winter / early spring trips to the field a more relaxing, pleasurable and satisfying experience. I am very fortunate in that I am able to keep my models inside in a centrally heated room and as a result I don’t have to contend with the savage effects of damp on my models and equipment. If you keep your models in a shed, garage or cold/ damp environment then the first thing you need to do is check for any signs of damp or corrosion on any of the radio gear and batteries. Damp and corrosion of electrical components is a very significant model killer. If you have left batteries connected and unused over the winter there is a chance of corrosion. Check the negative (black Futaba , Brown JR) wires particularly. Black wire corrosion makes the wire brittle and if it is hidden behind a plastic insulator you may not see it until it is too late. Any signs of intermittent contact or poor connections should be thoroughly investigated and the cause tracked down. If you don’t, it WILL come back to bite you….don’t ask me how I know! Check servo extension leads and pins. Switches are notorious for being the source of poor connections and many a precious model has bitten the dust prematurely for want of a decent quality switch. This is one area not to skimp on, do yourself a favour and buy good quality switches and extension leads. It is madness to save a couple of quid here and jeopardise a well loved or expensive model as a result. Batteries is the next area to look at closely. Most Nickel Metal Hydride batteries NIMH, lose their charge and capacity if they sit dormant over time. It is advisable to cycle them a few times on a decent charger to check that they are holding capacity and are still healthy. A battery load tester is a good investment. This simple device can show if a battery is not up to pushing the current that it should. Check out some of the battery diagnostic gizmos from CML for modern, high quality reassurance in this area. Lipos and A123 batteries are better at holding their charge and capacity and tend to keep their ability to push out current better than most Nimh batteries. It is important to check their voltage is as it should be (no damaged cells) and to balance them regularly to maintain their useful, reliable working life. I try to keep an eye on how often I charge and service batteries. I don’t push them to the limit and I have got into the habit of changing receiver batteries on my large and expensive models every 2 seasons at least. I work on the premise that if I am flying a large model at a show, I owe it to everyone to thoroughly check my model and ensure that it is using the best equipment I can find and that it is all reliable and fit for purpose. On 50cc and above models, I always use a dual rx battery system of some sort and try to keep it as simple as possible. Let’s now move on to your transmitter. It needs checked for damp, dust, grime, ariel and above all, the battery. Have a look in the back and check for corrosion, particularly if it has been lying out in a shed all winter…if it has…what are you thinking? Bring it in the house man! You wouldn’t leave your ipod or laptop in the garage all winter…would you?! When was the last time you changed your transmitter battery? Think about how old your transmitter is and how many times you’ve charged it. They don’t last forever. At the first sign of it losing its capacity, it’s time to change it. Assuming now that all your radio and electrical components are checked and are in good working order or have been replaced, it’s time to start moving on to look at the airframe and power source. Check your airframe for any kind of damage. Things like un-noticed cracked or broken mylar hinges, loose control horns, worn or broken linkages or missing nuts, bolts etc can all lead to grieve when you are least expecting it. Look closely at the seems of all film covering to check that everything is still properly stuck down. Five minutes going over the model with an iron on any unstuck, loose or wrinkled covering and trim will always be well worth the effort in terms of both looks and safety. On i.c powered models, particularly check for fuel seepage under covering. If the wood is oil soaked, that’s not a good sign. The best way to stop this is through prevention rather than cure when your model is new. Use something like a two part epoxy finishing resin or a fuel proofer to paint exposed balsa or ply that could get fuel soaked. This also has the benefit of sealing the join between the wood and the film covering if you paint that join. Check things like retaining bolts for stress and wear and replace as necessary. If your model has had a knock, check things like nylon wing bolts to make sure they have not been stressed or weakened. Finally, we come to the engine. This is potentially an article in itself, but I will keep it fairly brief for the moment. Glow, petrol and electric are the main power sources we all use and each has its own set of checks and potential problems. Much of what I said earlier about checking radio gear etc can be applied to your flight system if it is electric. Since I don’t tend to fly much glow these days apart from other people’s trainers etc., I will concentrate on petrol power. Most petrol engines tend to be pretty reliable but nevertheless they still require regular maintenance to keep them at their best. The main things to check after a winter lay-up is the fuel tubing and all plumbing, plug and ignition system and any signs of stress / vibration damage particularly to the mounting system, header and can / muffler. Unless you are using good quality, branded petrol tubing, the stuff supplied in a number of Far Eastern kits tends to be of poor quality and is susceptible to becoming rigid over time. This is a particular issue if it is inside a fuel tank on a fuel feed line! It will pay you to check and replace it. It is a gamble too far to just hope it will be Ok! Make sure your plug is still in a healthy condition. Check it is not sooty or pitted and replace as necessary. Only use a good quality branded replacement plug. It is also important not to let diaphragms on petrol carbs dry out. They should be OK if a little petrol is left in them. Speaking of petrol, do yourself a favour and find another use for the couple of litres you had left that have languished in your can over the winter. Mix up some fresh petrol/ oil at the correct ratio before you go flying. If you haven’t had the cowl off for a long time, it might be wise to take it off and have a look at your engine mounting bolts, carb bolts etc. Finally, check over your manifold, can/s and joiners to make sure they are free from cracks and fractures. All these little checks will give you peace of mind and might prevent a more serious failure of some sort in the air. A good day at the field starts with good preparation. I hope these few pointers will jog a few memories and will prompt all of us take a little more time and care over models that have not been flown for a while. Good luck with your new season’s flying and I wish you many happy landings. Ally