I see and understand the thinking behind hurting the engine upon ground strike but this is at landing or take off and as of now I have never seen an engine hurt with a strike. I'm still using a .40 OS LA engine for trainers that has been going strong for so many years I don't even remember how old it is?? Hundreds of ground strikes. MASTER AIRSCREW props: I trained three students to fly on one MAS prop. At one point I figured it was getting a little short so I pulled it and put it on my ballancer, it was still dead on?? Guess it was wearing down both sides on ground strikes??
Mode, using props within the manufactures recomended range would imply reading the instructions. How about just making a sticky of this question with one good answer??? It has worked very well on the question of covering.