Cessna FT337GP - 3 blades prop

[DaveM]

Hi, Dave McFarlane Here,
McFarlane Aviation products is a North American distributor for the German MT composite props and hold a lot of STCs for the props. The MT blades have a very special wood core that actually dampens or absorbs vibration. The core is then laminated with a composite outer structure to add strength and protect the core. This construction gives the props a lot of advantages over aluminum or hollow core composite blades. Field Reparability is one of them. The owner or mechanic is allowed to make repairs from nasty rock damage in the field by simply sanding the rough edges of the crater and applying J/B weld from the auto parts store and sand and paint. Sever damage requires applying a layer of fiberglass in the field over the epoxy repair. The generously allowed repairs are outlined in the MT owners manual. Quick and easy without removing the prop. I do not know where this wives-tale about difficult repairs and taking the prop off for repairs comes from. Other manufacturers hollow core props are very limited in reparability as they strictly rely on the strength of the composite. MT is the easiest prop to repair. When repairs are done the airfoil is always maintained and material is never taken away. Repairs do not take strength away. The leading edge is nickel-cobalt and bullet proof. We have a video on our website of a guy shooting the leading edge with a 22 rifle without damaging it. https://www.mcfarlaneaviation.com/re...T%20Propellers
Rocks can't touch it. Aluminum blades are very sensitive to vibration stress concentration from rock damage. Stress concentration and cracks are not an issue with wood and composite. The MT props do save a lot of aircraft weight and improve performance.

The hub centrifugal load is drastically reduced by the fact that the blades weigh 1/3 the weight of aluminum and put a lot less gyroscopic loading on the crankshaft in turns. The MT props are built for up to 4,000 HP and up to 11 blades and have never had a blade failure. If a prop strike happens, the blades take the damage and the engine and hub generally are saved.