Here are are some comments from MT Propellers Gerd Muelbauer regarding reversing- blade damage and repair.  

 

"Any professional pilot know, that he shall not use reverse below 40 KIAS, because he may pick up all kind of FOD ( stones ) with will also be ingested by the engine, so not only prop damage will occur. Also, you may see not many professionals, taxiing backwards with the prop in reverse. It is certainly possible to do this and nothing is totally wrong, if the power is selected carefully. But some of these amateurs know only two power setting: Idle and Full Power. And if a propeller is damaged, a big cry comes.

We have now flying about 11.000 propellers on all parts of the globe and every now and then, we hear about such things. Again, we do not care anymore, because it is useless. The every day increasing population tells us, that our product is right and if carefully operated and maintained, a life long investment.

Regarding the stainless steel erosion sheat, it was select over Nickel, because it is not so brittle and we do believe, that steel is better. Far better than aluminum. And what is even more important, it can be replaced as many times as required, without loosing its original dimensions, unlike aluminum blades, which must be scrapped after two or three nicks from a stone. And not any nick or bulg must immediately be removed. We have no fatigue problem, like the aluminum blades.

In summary, it is the old story, which goes on and on from such persons, unwilling to learn. We europeans never had a problem with wood composite propeller blades, developed in Germany in 1928 and ever since used. In WW II, almost all nations and airplanes used wood composite propeller blades, like the Russian YAK-3, Britsh Spitfire and Hurricane, German Focke Wulf 190, Junkers 88, Japanese and a lot more of these high performance aircraft. And what they did about 80 years ago, is still valid, certainly with new materials even better. And the saga about it will take 3 month to get it back and it will cost almost as much as a new prop to overhaul one is a simple lie. We have fixed prices and it shall not take more than 3 weeks to repair/overhaul one. I checked several cases in the past and it turned out that such statements were always false."

Charlie K.