In article ,
Dan Luke wrote:
One finds many 20+ year old aircraft advertised with engine time =
airframe time, both in the neighborhood of 1000-1600 hours. Now, it is
my undersatanding that aircraft engines have a calendar TBO as well as a
tach TBO. however, prices for these aircraft do not seem to reflect
engines that are beyond TBO.

Most sellers don't factor in engine time properly. If they've never done
an overhaul (or did it 10+ years ago) they're probably not aware of the
cost. So high time engines don't get discounted like they should. Low
time engines tend to be marked up TOO much (since the owner just felt the
sting) especially since "0" time engines are suspect to a buyer so he's
not willing to pay the full markup.

The calendar overhaul times are pretty short compared to tach time for
anything but a rental/charter. You'd have to fly about 200 hours/year
to use up the tach time in the calendar time, and not many owners do
that. On the other hand you could fly it 100 hours/year (a "good" amount
for the engine) and that would take twice the calendar overhaul time.

The way I factored it in when buying was to assume that the engine I was
looking at (O-540 or IO-540) was a type that "typically" needed a top OH
sometime, and that an engine well beyond calendar overhaul would not be
worth topping.

--
Ben Jackson

http://www.ben.com/