I once read a report about carb heat use published by the NTSB (which, of
course, I can't lay hands on now). In it, they pointed out the hazard of
having disparate methods of carb heat use depending on engine and airframe,
and suggested that full carb heat be applied any time the power was reduced
below cruise power...no matter who made the engine or airframe. They felt
that this standardization would have a positive effect on accident rates.

With regard to your transition into a Cessna model that I have not seen, is
the carb heat control still to the left of the throttle? Can it not be
pushed in with your thumb while the throttle is being pushed in by the base
of your palm?

Bob Gardner

"Mitty" wrote in message
...
Gents,

Though this is not strictly an IFR question, I am pretty sure that you
have opinions that I would like to get.

Subject is Lycoming O-360 engines. I have flown behind a number of them
in Pipers and the POH instruction on carb heat is always "as required."
Specifically there is no requirement for carb heat on the landing
checklist. This makes sense to me as the intake charge is routed through
the oil pan cum intake manifold and, with the throttle nearly closed hence
low flow velocity, should get adequately warmed up. At least that is my
rationale for why the POH does not call for heat.

I am about to get checked out in a Civil Air Patrol 172 that has an STC'd
O-360 installed in place of the original Lycoming O-320. The 172 POH
wants carb heat on approach. This makes no sense to me. If I have to do
a go around it is just one more workload item/one more thing to forget
and, from my Piper experience, it does not appear to be necessary. My
guess, without benefit of any actual facts, is that this POH requirement
comes from Cessna's Continental roots and has no engineering
justification. So it seems wise to ignore it.

Comments? (Please, let's not go to the FARS with this question. That is
not my interest.)