On Sat, 19 Oct 2002, Angus Gordon wrote:

> This is nonsense. There is no one universal mandated TBO for aircraft engines.
> Here is an example of the recommended TBO for Lycoming engines -
>
> http://home.earthlink.net/~tbo/SI1009.pdf
>
> Many of the turbocharged models (those with a T in the prefix)
> have recommended TBO's that are as long or longer than some normally
> aspirated engines.

Those recommendations are also just that -- recommendations, though most
people follow them.  They do not carry the force of law.  Turbine engines
tend to have some parts that *do* have mandated lifespans after which
replacement is required.  This is also often true of helicopter rotor
blades.

What I have heard is that turbocharged aircraft piston engines are
considerably less forgiving than normally-aspirated ones.  They require a
bit more skill and attention to operate.  (Many have manually-controlled
wastegates, for example, and the fuel mixture (also manually controlled)
is a bit more critical than in NA engines.) A ham-fisted pilot can destroy
a turbocharged engine in relatively few hours.  It takes someone with
skill to get the engine to last until its TBO.

             _ _
  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti, MI
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