Aircraft Propeller Maintenance

Aircraft Propeller Maintenance

Aircraft Propeller maintenance stars with careful and regular inspection. Even the smallest of areas that may have damage such as nicks and stone chips can allow for stress points that can often and commonly lead to corrosion or cracks. It certainly pays to be vigilant and deal with these small areas of damage before they soon become big ones.

Making simple and minor repairs to propeller blades is not commonly or particularly challenging task, but the technique is fundamental. It’s certainly not something that owners can or should do by themselves. An experienced professional is usually required.

Aircraft Propeller Maintenance

Careful planning and patience is key. It can be typically very easy to remove aluminum from the outside of a propeller blade and nearly impossible to place back on. This is important when you soon realize that each propeller blade has dimensional limits that will restrict the amount of metal that can be take off during repairs before the entire propeller becomes unairworthy.

It’s recommend to use a hand file to carefully remove any damaged material until you eventually reach the bottom of the nick, stone chip, etc. None of the original or primary damaged surface should be left. Only a minimum amount of material should be removed to achieve this.

Next, dress out the repaired area, making sure to create a smooth transition into the surrounding material. The typical rule is to dress out the repair up to an area 10 times the original depth of the damage. For example, if you need to file down one eighth of an inch to enable you to get to the bottom of a nick or chip on the leading edge, you must be prepared to dress out the repair up to five-eighths of an inch on both sides of the center of the repair, which becomes a total repair span of around 1.25 of an inch. It’s recommended that you try to maintain the original airfoil shape, by blending the repair around and into the surrounding area.

You can easily remove file marks by using an emery cloth until the surface becomes smooth. Inspect the area carefully, by using a dye penetrant that will reveal any remaining cracks or marks.

Regular oil changes are fundamental when it comes down to aircraft that house constant-speed propellers. Since engine oil allows for the power source in controlling propeller pitch; it means making sure that the oil is free of dirt and is clean will considerably reduce the chance that the propeller will experience problems caused by water contamination or sludge. It’s recommended to leave constant-speed propellers in a horizontal position or, in the case of a three blade propeller, in a “Y” position to reduce any possible water collection on the hub.

Wooden propellers are most certainly pieces of art, they should be treated with care. Pay particular attention to any metal tips on the ends of the propeller; looking for loose rivets, screws, or solder. The coating of varnish serves a crucial part in protecting the propeller from any moisture damage and should be delicately maintained. If the propeller needs to be removed for any reason, the hub bore and bolt holes should be inspected for any damage. The holes holes should ideally be treated with a preventive against moisture such as varnish.

Nevertheless, regardless of the kind of propeller that you may have, it’s always recommended to perform a tracking check on your propeller. This is a simple procedure that many owners can do.

Copyright AeroBase Group, Inc. 6/1/2015