Airplane propeller blades are crafted out of several different materials, including wood, metal, and various composites. Wooden propellers seem to be romanticized by the pilots who prefer them. As a 2003 article from Air & Space magazine bemuses, “Wooden propellers are like Louisville Sluggers.”
While we don’t work on wooden propellers at our shop, we can certainly admire the craftsmanship. So today, we’re sharing a few tips on the care and maintenance of your aircraft’s “Louisville Sluggers”: wooden propellers. This care and maintenance plan includes, of course, knowing when you should have a propeller inspection.
If you know that your composite propeller is ready for a propeller inspection or repair, give us a call. Stockton Propeller is a full-service propeller overhaul and maintenance facility with the needed equipment and expertise to perform static and dynamic balancing. Get inspection and maintenance before failure!
Wood Choice
The wood choice itself doesn’t make much difference when it comes to caring for your wood propellers. Wood propellers could be crafted from almost any type of hardwood.
Historically, the most popular wood choices were mahogany, oak, walnut or black walnut, black cherry, yellow birch, or sugar maple. Almost all wooden propellers are also strengthened in some fashion (like lamination) to add strength. Fabric or metal coverings can also add to the propeller design and reinforce stability.
The Case For Wooden Propellers
Wood propellers are not certified for many planes these days. But for those for which they are certified, there are some definite advantages:
- Wood propellers are lighter and increase payload.
- Wood propellers can get up to speed much more quickly than most metal propellers.
- Wood propellers cause less vibration. Metal propellers accumulate invisible flaws from vibrations and flexing.
- Wood propellers are generally the less expensive choice.
What You Can Do To Care For A Wood Propeller Yourself
All propellers are subject to wear, fatigue, corrosion, and erosion. Wooden propellers are especially at risk for erosion and distortion.
A damaged propeller cuts your speed, diminishes your airplane’s performance, and increases your take-off distance. At worst, severely damaged propellers can cause engine failure and catastrophic airplane crashes.
Read Your Owner’s Manuals
Hey, your plane is a considerable investment. Of course, you’ve already done this! But, just on the off chance that you haven’t read them, make sure you read your owner’s manuals on each piece of equipment and the plane itself.
Take inspection and overhaul recommendations to heart. Keep a calendar or record of everything.
Park It Horizontal
When your plane is parked – or if you have to remove your wooden propeller from the aircraft – make sure the propeller is horizontal. If you store it vertically, any moisture in the air around it or on the propeller could migrate to the lower half and cause a disproportionate weight balance or warping of the wood.
If you’ve removed the propeller from the plane entirely, make sure it is horizontal, flat, and out of direct sunlight to keep the wood at its best. Do not ever store a propeller vertically!
Pre-Flight Propeller Inspections
Make sure you conduct your own pre-flight propeller inspections before every flight. It’s essential to routinely check for bruises, scars, or other damage to wood propellers and leading-edge protection. And, remember, more frequent inspections may be necessary when climate changes are extreme.
Clean The Propellers
During flights, propellers can pick up several different problems – including bugs, dirt, debris, and pollutants. All of these can not only cause problems on their own but can also mask issues that you’re trying to spot.
Washing the propellers with a good, old-fashioned soap and water solution and soft brushes or cloths can easily take care of this after every flight. Just be sure you don’t get any liquid dripping down into the propeller’s hub.
If you’ve subjected your plane to saltwater, the propellers may need a little extra TLC. A freshwater flush or two should get rid of all traces of salt. While this may seem like a pain, it’s imperative to take the time to do this to avoid warping and erosion.
Wax The Propellers
Wax your wooden propellers as often as is suggested and with whatever type of wax your owner’s manual recommends. If you don’t have a recommendation, ask your “propeller guy” (like ours here at Stockton Propeller).
Don’t Push Or Pull
Do not ever grab the propellers to push or pull the aircraft. Use the tow bars to move the plane by hand. Exerting any force (pushing or pulling) on the propellers can affect the positioning of the blades. This incorrect positioning can harm flight performance.
When It’s Time For A Professional Propeller Inspection Or Repair
If you notice anything amiss in your pre-flight checks or you’ve hit the mandatory number of hours for an inspection or overhaul, make sure you get your appointment scheduled.
Do not attempt to fly anywhere if your wooden propeller shows any of these damage signs:
- Any cracks in the hub bore (small or large)
- A long, deep, wide crack parallel to the grain in any spot on the wooden propeller
- An oversized or elongated hub bore or bolt holes
- An appreciable warp (discovered by inspection or through rough operation)
- An appreciable portion of wood missing from the propeller blade
- A deep cut across the wood grain
- A separated lamination along the length of the wooden propeller
Finally, sometimes, the damage is beyond repair – whether the propeller is too damaged or the repair costs more than a new propeller blade.
If you’re doing pre-flight inspections and paying close attention, it’s much easier to schedule an inspection and maintenance before that happens, though!
If you know that your composite propeller is ready for a propeller inspection or repair, give us a call. Stockton Propeller is a full-service propeller overhaul and maintenance facility with the needed equipment and expertise to perform static and dynamic balancing. Get inspection and maintenance before failure!