C172SP engine start with battery switch only?

Check in the section on operations in cold weather. It will probably refer
to the split switch start there. If you can do it cold weather, and they
don't give a maximum temperature at which it is "permissible" you are in
compliance with the POH.

Of course, if you fly your (at least older) Cessna in strict compliance with
the POH, you'll screw up your engine.

--
Roger Long
David Brooks wrote in message
...

"Peter Duniho" wrote in message
...
"Bob Gardner" wrote in message
news:_tkec.120289$K91.333719@attbi_s02...
It's common sense, when you think about it. With both halves of the
switch
ON, the alternator field windings are connected across the battery,
creating
a drain in addition to that drawn by the starter

It's worse than that, too. Not only is the battery being used to
energize
the alternator field circuit, but having that circuit energized creates
drag
on the engine, making the starter work harder.

It makes sense to me, too, but I've always been told to follow the
procedures in the POH. My 172 POH's don't contemplate the split switch
start. Also, I'm concerned that if I change my routine now, I'll be taking
off with a rapidly draining battery one day.

Having said that, I split the switch to do the flaps and lights check
early
in the pre-flight.

-- David Brooks