"Mike Rapoport" wrote
It is going to depend a lot on the individual airplane and what features it
has. On an airplane with boots, the boots ARE eventually going to have to
be replaced and the cost is going to be over $15k and they probably won't
last ten years, so boots alone will cost $7.50/hr...

Boots are not a high priority on the Gulf coast (where I do most of my
flying and all of my business flying) because IMC combined with
freezing levels down to the MEA's happens once every couple of years.

The bottom line is that it is not realistic to extrapolate two or three
years of experience, you need to either use at least a thousand hours of
experience or estimate the life time of every part.

For me, three years of experience is over 600 hours. Note that I gave
the maintenance breakdown for a reason - did you note the $4200 for
gear AD and associated maintenance? That's a 1000 hour AD, and many
of the parts replaced were original - meaning they lasted 6000+ hours.
It is unlikely that they will be replaced again in the lifetime of
the airplane. The same is true of the gear trunion, exhaust stack,
and cylinders. None of those expenses are likely to recur in the next
couple of years, but other expenses will. It all averages out.

With regard to vacuum pumps - yes, I certainly do wait for them to
fail, and one already has. The repair cost is part of the breakdown I
gave. Given that I only need one pump to run my gyros, and given that
I have an indicator that immediately tells me when one fails, I think
this makes sense.

Michael