Cessna 310 1975 Owner's Manual page 25

Most of the engine warm-up should be done during taxi-
ing, with just enough power to keep the aircraft moving.
Engine speed should not exceed 1000 RPM while the oil is
cold.
BEFORE TAKEOFF (Use the Pilot's Checklist}
Use the Pilot's Checklist in the aircraft to prevent the
possibility of overlooking an important check item.
Most of the warm-up will have been conducted during
taxi, and additional warm-up before takeoff should be re-
stricted to the checks outlined in Section I.
Full throttle checks on the ground are not recommended
unless there is good reason to suspect that the engines are
not operating properly. Do not runup the engines over loose
gravel or cinders because of possible stone damage or abra-
sion to the propeller tips.
If the ignition system produces an engine speed drop in
excess of 150 RPM, or if the drop in RPM between the left and
right magnetos differs by more than 50 RPM, continue warmup a
minute or two longer, before rechecking the ~stem. If there
is doubt concerning operation of the ignition system, checks
at higher engine speed will usually confirm if a deficiency
exists. In general, a drop in excess of 150 RPM is not
considered acceptable.
If instrument flights are contemplated, a careful check
should be made of the vacuum system. The minimum and maximum
allowable suctions are 4.75 and 5.25 inches Hg., respective-
ly, on the instrument. Good alternator condition is also
important for instrument flight, since satisfactory operation
of all radio equipment and electrical instruments is essen-
tial. The alternators are checked during engine runup (1700
RPM) by positioning the selector switch in the L ALT and R
ALT position and observing the charging rate on the volt-
ammeter.
A simple last minute recheck of important items should
include a quick glance to see if all switches are ON, the
mixture and propeller pitch levers are forward, all flight
controls have free and correct movement, and the fuel selec-
tors are properly positioned.
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