The International Cessna 170 Association

Yesterday after 2 trips around the pattern didn't notice anyting but got bad feeling so taxied back and checked over AC. My MT composite prop on constant speed 0=360 had delamed and peeled up on blade from blade root about 6" or more up on trailing edge of blade. Could look inside and see 6" of wood core. I had a few light surface cracks that were only finish and had noticed very similar small cracks in root area but at annual we determined they were just surface too which is common and sealed as Mt instructions. Must not have been. I was amazed blade stayed together and amazed had no vibration. Laminated epoxy and spruce core I guess stronger that imagined but discering to say least. Checking options. A tip delamed on Husky in USF&W a week earlier. Any one else flying Composite props had problem? Not interested in arguement for or against Mt or Hartzell at this point just interested in other similar situations from those actually flying them.

Think I like traditional even better now.

Friend of mine had what sounds like the same issue on his Glasair with an O-360 and ended up spending a very pretty penny getting it repaired.

This is a big may be , but some models of the o-360 have inherent vibration issues.and that's why Sensenich props have bands of limited operation . So this begs the question does this vibration issue could translate across types of propellers. But ALL props are not made the same . this includes the metal props also.however Hartzell and MT props are classified composite they are totally different the way they manufactured .