What should members be doing before returning to flight if their aircraft hasn’t been used in a while? Don’t rush Ensure all scheduled maintenance requirements that are due are completed. Carry out a thorough pre-flight inspection Possibly the first thing to check before anything else, and certainly before the aircraft is moved, is the fuel system for contamination. Water can get into a fuel tank through poor fuel cap seals or even cap locking mechanisms. Any substantial movement of the aircraft may disperse water and other contaminants away from the fuel drain points. One of the attributes of Avgas is its ability to remain ‘within spec’ for a fair length of time. With the advent of Mogas being used in many aircraft, extra care should be taken to ensure that the fuel is still usable. With long storage periods, especially if stored in warmer weather the petrol can oxidize to form peroxides. These compounds can attack rubber and metal, stripping away the liner on fuel lines or copper from fuel pumps and attacking rubber hoses. Generally, the summer volatility of petrol is 30% lower than the winter volatility which means that the loss of lighter components in summer can be quicker. However, this is not usually an issue due to higher temperatures but can create problems in Autumn and Winter if the Summer fuel is held over. To avoid this, fresh fuel should always be used in the Winter period.
Engine There isn’t a lot you can do with the engine apart from give it a good look over for bird nests and corrosion and to remove any bungs etc. The engine should not be run without the intention of flying as it’s rarely possible to get it to normal operating temperature on the ground in a bid to boil off any moisture. Ground running tends to promote formation of condensation as the engine cools again. It is important to note the engine should not be rotated by hand unless you are going flying as this can wipe off any residual oil coating on the various surfaces and leave them prone to corrosion. It may be wise to change the engine oil as this can absorb moisture. In an ideal world, everyone would change the oil prior to a lay-off as this will remove any of the harmful combustion process by-products and contaminants from the oil. Check the external surfaces of the cylinders and other components for corrosion. Keeping the cowlings nice and clean will show up any oil leaks that have appeared and give an indication as to where a leak has occurred.
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