Piper SEMINOLE 2013 Pilot Operating Handbook page 126

SEcTION 4
NORMAL PROcEDURES
4.5j cruise checklist (continued)
cRUISING (continued)
Use of the mixture control in cruising flight reduces fuel consumption
significantly, especially at higher altitudes. The mixture should be leaned
during cruising operation above 5000 ft. altitude and at pilot's discretion at
lower altitudes when 75% power or less is being used. If any doubt exists
as to the amount of power being used, the mixture should be in the full
RICH position for all operations under 5000 feet. To lean the mixture, pull
the mixture control aft.
Best economy mixture is obtained by moving the mixture control aft
until peak EGT is reached. Best power mixture is obtained by leaning to
peak EGT and then enrichening until the EGT is 100F rich of the peak
value. Under some conditions of altitude and throttle position, the engine
may exhibit roughness before peak EGT is reached. If this occurs, the EGT
corresponding to the onset of engine roughness should be used as the peak
reference value.
For maximum service life, cylinder head temperature should be
maintained below 435°F during high performance cruise operation and
below 400°F during economy cruise operation. If cylinder head temperatures
become too high during flight, reduce them by enriching the mixture, by
opening cowl flaps, by reducing power, or by use of any combination of
these methods.
The pilot should monitor weather conditions while flying and should
be alert to conditions which might lead to icing. If induction system icing
is expected, place the CARB HEAT control in the ON position.
The LEFT ALTR amd RIGHT ALTR switches should be ON for
normal operation. Certain regulator failures can cause the alternator output
voltage to increase uncontrollably. To prevent damage, overvoltage relays
will automatically shut off the alternator(s). The CAS Warning messages
L ALTR FAIL and R ALTR FAIL will warn of this tipped condition.
Alternator outputs will vary with the electrical equipment in use and
the state of charge of the battery. ALTR AMPS should not exceed 60
amperes on the ground or 75 amperes in flight. The VOLTS indication will
flash red if bus voltage drops below minimum requirements.
IFR operation is not recommended with a single alternator.
REPORT: VB-2307
4-20
PA-44-180, SEMINOLE
ISSUED: June 5, 2013
REVISED: October 27, 2014