Mike Rudd's Keep Fit Checklist

This is a checklist that was handed out at one of the Microlight Aviation Club meetings, in Popham, England. In this area, Mike Rudd is fairly world famous for his microlighting abilities, having designed various modifications, and built his own microlights and even designed and built microlight trailers! This is just a checklist of the sort of stuff you can check every time you fly, that will help keep your aircraft in tip-top condition. This was originally written for the Thruster microlight, but I've tried to adapt it to apply to more or less any type, so if something doesn't make sense, don't worry. These checks were supposed to be as well as the checks in your owner's manual.

Your Mileage May Vary :)

Engine and Prop

• Check that prop bolts are torqued per the manual, and that lock nuts are retightened.
• Check the gearbox oil level (and condition).
• Check the gearbox oil casing - the nuts should be tight, and there should be no oil on the casing.
• Check the spark plugs are clean, the gaps are set, the plugs should be tight and the caps pushed fully home... tip here: see if it's possible to get a bungy cord to hold the plug caps down tight, as they have been known to vibrate loose - on the 503 you can drill small holes in the airscoop that bolts on over the finning.
• Carbs should be upright, check the mounting rubbers are undamaged, and are clamping the collars tight. Throttle cables should be unkinked and set level.
• Fuel pipes should be secure, with no nicks or chafes.
• Exhaust and crank case bolts should be tight, and there should be no leaks.
• The engine mounting bolts and mounts should be secure and tight.
• The silencer (muffler) mounts should be whole, and the mounting nuts tight.
• Check that the cylinder head nuts/bolts are tight, and the cowl bolts are secure.
• The ignition coils and other wiring should be secure and free from damage.
• The fuel pump mounting and casing screws should be tight, and there should be no fuel leaks.
• Check the engine mount frame (usually steel tube) for missing paint, rust and cracks, especially near weld joints.

Airframe

• Using the correct spanners (not an adjustable!) check the tightness of all bolted joints between the tubes that form the airframe structure. All should be easily accessible, except within the wing frame, which should be stripped every now and then to be checked.
• Pay special attention to the spring to axle beam bolts and any "A" frame junctions, but do not tighten so much as to crush tubes.
• Check the mountings for the fuel tank, and that the tap moves easily.
• Tube ends should be checked (small animals like to nest in there!) and rivets in the main spar should be checked to make sure they're tight.
• Seat rails should be tight, and all the bolts secure.
• Control cables should be checked and cleaned... cables have a tendency to pick up grit which then acts as an abrasive. Check the crimps on cables... these are prone to suffering unseen corrosion, so look for "salting" or, in serious cases, looses strands. Check that the pulleys are turning properly, and aren't damaged.
• Check the stick and pedals, for free movement, and the mountings to make sure that they're tight.
• Check throughout the airframe for rust on bolts, rivets and screws.
• Check that all plug-ends are in tight.
• Check the wheel nuts, both the spindle and the nuts to hold the wheel together. These are often found to be very slack.
• Check all moving parts. Also look for any flexing of the welds in tubes where applicable.
• Check all wing (and tail) surfaces, the integrity of internal frames, hinges and safety clips.
• Check the nose or tail wheel... the castor bolt should be only just loose enough to allow turning. The spring fixings have also been found to be loose.
• Check the rudder mounting bolts.
• Whilst checking the moving parts, lubricate where necessary.

Coverings / Skins

• Any damage to the skins should be properly repaired, surfaces should be tight and any misshapen battens removed and re-profiled... tip here: retighten the skins with some (or all) of the battens removed.
• Certain skin materials, notably Dacron, degrade in UV light, causing weakness. To form ajudgement on the serviceability of the skin covering material, call in expert help... if you can poke a finger through it - get it recovered.
• Algae / green microbes like to colonise on the wing skin... they rot the material, so strip it off occasionally and wash in a mild, soapy solution.