Please understand that I sent the initial e-mail to the LML based upon
what I believed was good information as the only thought I had was
concern for those of us flying the MT propellers.  With only 620 hours
on my prop and the prop shop telling me that the blades needed replaced,
I was concerned with safety.  The final analysis is not complete but it
appears that the overhaul manual and initial response to the overhaul
shop by MT left American Propeller with no choice but to say the blades
were not serviceable.  The initial response from MT via email was
"Blades, which are cracked in the root, are reject. There is no
possibility to repair them."

Further amplification by MT suggests that the overhaul manual might need
some revision and the communications improved.  This was and is a safety
issue as far as I am concerned, not an indictment of either MT or
American Propeller.  Both have been very professional.  

I don't have a final decision on the blades yet, but I am comfortable
that MT will make it right if there is an issue.  The following was
received by me from MT:

"It looks to me that there is a misunderstanding from one of our Service

Stations. In our blade root area inside the aluminum blade ferrule it is

normal that there are small cracks extending from the lag screws. These
cracks are normal and of no concern because the high plastified beech
wood
is compressed in this area between the outer aluminum ferrule and the
inner
aluminum bushing where we install the blade balancing weight. This small

cracks in the plastified beech wood can do nothing as they are pressed
between 2 aluminum parts. Our  propeller overhaul station should send a
digital picture of what they found.

In any case, I am to 100% sure that there is no problem at all and we
have
more than 35000 blades flying since 25 years and we never lost a blade
in
flight and therefore you should not worry because definitely this is not
an
airworthiness issue but just a wrong information. We will also update
our
blade overhaul manual  which addresses this issue that no service
station
is confused.

The 1/16 lines are normal due to the different composition of our blade.

Hope this information helps and please keep in mind that MT-Propeller is

the only certified propeller manufacturer with no valid AD on hydraulic
propellers and also the only one who never lost a blade in flight."

American is sending photos of the blades to MT and has suggested that,
because of the differing opinions as the serviceability of the blades,
we send the blades to Germany for their visual inspection, which I am
inclined to do.  Both American Propeller and MT have been responsive and
factual with their presentations.  I believe both parties will be better
able to service our community after the resolution and we should be able
to sleep easier. I know I will.  

Pat Brunner
N98PB