Beechcraft Baron G58 Pilot Operating Handbook page 478

the combustion heater. This 2-minute cool down function oper-
ates even with the airplane battery and alternator master
switches turned off. The 2-minute cool down function can be
interrupted by turning the Master Heater Fan Switch to the
"OFF" position. The Master Heater Fan Switch is located on
the left-hand subpanel. The Master Heater Fan Switch should
normally remain in the "ON" position at all times even when the
airplane is shut down and the Master Battery and Alternator
Switches are turned off. Note that during flight operations
when the landing gear is retracted, heater operation and
heater cooling is provided by ram air instead of the heater/
fresh air blower. This applies to the heater 2 minute cool down
period if that is required during flight: the automatic heater/
fresh air valve remains open for 2 minutes to cool the combus-
tion heater using ram air.
FAA Approved
Issued: March, 2017
16 of 24 P/N 58-590000-0091