Roger,

The U.S. distributor for MT propellers is in Deland, FL
http://www.mt-propellerusa.com/.   They are very helpful and experienced.
Experimental propellers have no requirement to adhere to the 6 year, 2000
hour overhaul recommendation legally (MT puts an experimental tag on your
propeller if it goes on an experimental aircraft).  However, I asked MT
about the on-condition versus calendar time issues when I had my overhauled.
Gaskets, seals, and O-rings are calendar limited based of time of
manufacture, time that they sit in the shop at MT, and time they sit in your
propeller.  After a while, these rubber parts begin to degrade.  After 6
years, you are probably beginning to see some wear issues on your propeller,
such as the phenolic shims that keep the blades from moving.  You should be
checking for radial and longitudinal play in the blades on your preflight.
They have specific tolerances on the amount of play allowed.  My shims on my
electrically governed propeller needed replacing at about 1000 hours.
Likewise, if you're running an electric propeller, the brushes wear out
about then too.  Electric governed propellers also begin to throw grease
when they are having wear issues (like mine did).  They (MT) have a general
rule of thumb about how much grease it can throw before you need an
inspection.  Overall, it's a good propeller.  However, it's unlikely to make
it to TBO without at least some maintenance.  You really don't want to skimp
on propeller maintenance.  It's one of the most flight critical components
on your aircraft.


Don Gordon
Lancair 320, 1600 hours - Electric MT propeller
Orlando, FL