Rolf Blom wrote:

There was a jumper club at ESCN a few years ago, and they never shut
down their plane either; something about the turboprop engine start/stop
cycles being counted towards maintenance intervals instead of just
running time, but I'm not sure about how it worked exactly.

/Rolf


That is EXACTLY what its all about. Thermal stresses are caused by
temperature changes. Major temp changes are caused by startup/shutdown.
So, keep the turbines turning and burning and you reduce the maintenance
cycles incurred. That was one of the reasons that helicopter EMS guys
used to "hot load" (they still do in some places, particularly if its
the "second bird in, and can grab the patient and go")

Most turbines have to run for a few minutes after landing before
shutting down.. and then on startup have to run a few minutes again to
stabilize the temps to minimize the thermal stresses.

What I do NOT know for a fact is if total time, or total cycles, or a
combination of both is used for determining TBO (or I believe for
defining when periodic inspections - Hot Sections I think they call em)

Dave