Re: MT Propeller
I talked to Mark @ Memphis Propeller this morning in regard to maintenance, overhauls, etc. He said that composite overhauls are more expensive in their shop by 10-50% (so if a typical Hartzell/McCauley aluminum 3 blade overhaul with no damage is 3500 bucks, the typical composite overhaul of a similar prop will be 4k to 6k). He said they are more delicate, obviously, if you ding it with the tool box or tow cart it is gonna cost. Field repairs are possible for cosmetic dings but hard dings resulting in structure damage will require removal and sending it off. He said standard wear-and-tear overhauls in the field are no big deal, they do them locally, whereas structural repairs due to serious damage will have to go to Florida.
He said the MT props are a wooden core with a fiberglass or carbon fiber exterior. He said the difference in glass vs carbon is not that much of a consideration, longevity is similar.
He said time between overhauls is similar as well. At 100 hours a year part 91, he said 10 year overhaul intervals should be fine.
He said inspections are slightly different, you have to check for de-lamination on your annuals, and be more pro-active about fixing paint/gel coating loss, since water getting in can harm the wooden core.
He said the lower weight results in far less stress on the crankshaft, less motor mount wear, less noise, just generally a better running prop, so over time in his opinion the benefits outweigh the negatives. He also said in a worst case gear-up scenario the delicate nature of the composite/wood structure is a good thing, it won't be as violent a shock for the engine, the blades will just splinter and 'go away'.
