REFLECTOR: Aerocomposite Prop
HYTEC45 at aol.com
HYTEC45 at aol.com
Tue Apr 4 16:35:16 CDT 2006
In a message dated 4/4/2006 11:10:53 A.M. Pacific Standard Time,
ajlz72756 at yahoo.com writes:
haven't purchased my prop yet and am interested in hearing more about your
problems with your MT prop. I thought this was the best prop that you could
buy and know that this is the suggested prop to use by Velocity. If others are
having the same problems that you are, I sure don't want to invest 11K on a
piece of crap. Please tell us what kind of problems that you are having.
After I purchased my prop in 2000, I developed a fatigue crack in one of the
blades. mt said that there is now a AD that restricts the operating RPM on
non-counterweighted engines like mine between 2250/2550. Even though mt
never sent the AD out to owners on file, I had to fight tooth and nail for them
to repair the crack. After that, even though I operated the propeller out of
the "restricted" range, I developed massive grease leaks. American propeller
who services mt told me that mt has a big problem with grease leaks, and now
has a another modification that is needed to be done to address that. I had
that mod. done, and continued to have grease leaks, along with bearing wear
requiring the replacement of bearings twice. My average operation of the
prop between "return for repair" is around 44 hours. I have under 290 hours of
operation on the prop, and it has been off five times. mt admitted that the
blade design as shipped on mine in 2000 is not applicable to my four banger,
so I have to PURCHASE new blades otherwise I will continue to have
bearing/seal/cracking problems. This cost me 5K, as I had to pay for installation,
along with of course new bearings, and a pitch change yoke even though the prop
was just overhauled 45 hours prior. After I ran those blades for a little
over one hour, they developed almond like blisters on 2 of the three blade
tips. These were decided by mt caused by sap trapped within the wood core. The
fix was to drill holes in the blisters, fly it a while to sling the sap out,
then seal with 5 min. epoxie. This still left these blisters (de lamination
areas) on the top side of the airfoil where the airfoil is critical. Even
though the prop only operated for a little over one hour, they will not pay to
remove the blades, but will fix them if I pay to have the prop once again
disassembled ($700.00) to send the blades back. This of course does nothing
for my time of installation and removal of the prop, or the down time on the
plane.
My prop is also an electric controllable pitch, and probably 75% of my
additional problems are due to the electrical mechanism. This includes three
pitch change motors replaced, three RPM sensor replaced, plus my time
troubleshooting and installing these items.
As I sit, I am developing grease seal leaks again with the "new and
improved" blades, along with RPM sensor problems which I was assured world not happen
with the new blade design.
mt now tells me the problems are related to either that I am running 10 to 1
pistons, and or I am running a light speed electronic ignition. They only
tested the prop on a "standard" lycomming and since mine is not standard, I'm
on my own.
The reason that Velocity recommends the mt is because it's the ONLY constant
speed prop that will fit due to weight. With the standard Velocities, you
could get away with a fixed pitch prop. With the XL and /-5 a constant speed
is a must, and they (Velocity) would not have a viable/safe product in the XL
line without one.
I know that Velocity is very interested in the aerocomposite, and another
option may be soon available. I hope so.
TEC
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