On Jan 3, 9:21*am, "Viperdoc" wrote:
Actually, your premise about babying an engine may not be true. Is there
data that supports this "gentle" use of an engine adds to longevity?

My own plane, as well as others with the same type (an Extra 300) are
essentially operated in an on/off mode. It generally is full power (2700RPM
and full throttle) on TO, cruise to the practice area, and then on/off, with
no regard to shock cooling or heating- full power straight up, power off to
spin, then full power on the recovery. Gyroscopic maneuvers (with a
composite prop)- no problem with cranks.

Yet, with 400 hours of this operation on my plane (and many/many others
according to the reps), none have required an overhaul, with some up to
1,000h of similar operation.

Likewise, Lycoming and Continental always gave some hand waving response to
questions about running LOP, yet, Cirrus, with now many thousands of hours
of *LOP operations now mandate operating *in this realm.

So, a lot of what is considered "safe and prudent" operating may be more of
an old wive's tale, and not supported by actual data.

You could be right. Never the less, our TBO is determined by tach
hours, and we are happy to run at 1950 at altitude instead of 2600. It
could be a old wives tale, but rapid temp change does different things
to metals than does more gradual changes as well. We'll continue to
fly with a gentle hand -- it pleases us to do so, even if there's a
possibility it doesn't prolong engine life or reliability. I am pretty
persuaded it does, but can offer no evidence. It would be interesting
to have a mechanic examine enough engines flown with different flight
algrithyms to see if he could detect a difference or estimate service
life -- a single blind protocol, if you will.