Standard electrical accessories include a starter, a key lock ignition, an
electric fuel pump, an audible stall warning, fuel gauges, an ammeter, and an
alternator warning light.
The system provides for the addition of such optional accessories as
interior and exterior lights, a heated pitot head, and communication and
navigational equipment. The anti-collision and landing lights are controlled
by rocker switches on thc switch panel.
WARNING
Strobe lights should not be operating when
flying through overcast and clouds since re-
flected light can produce spacial disorientation.
Do not operate strobe lights in close proximity
to ground, during takeoff and landing.
The master switch is a split rocker switch. One side of the switch is for
the battery (“BAT”) and the other is for the alternator (“ALT”). The words
“master switch” as used in this handbook and unless otherwise indicated,
refer to both the “BAT” and “ALT” switches, and they are to be depressed
simultaneously to ON or OFF as directed.
The ammeter is mounted in the instrument cluster to the right of the
engine control quadrant. The ammeter as installed indicates the electrical
load on the alternator in amperes. With all the electrical equipment turned
off and the master switch on, the ammeter will indicate the charging rate of
the battery. As each electrical unit is switched on, the ammeter will indicate
the total ampere draw of all the units including the battery. For example, the
maximum continuous load for night flight with radios on is about 30
amperes. This 30 ampere value plus about 2 amperes for a fully charged
battery will appear continuously under these flight conditions. The amount
of current shown on the ammeter will tell immediately if the alternator
system is operating normally, as the amount of current shown should equal
the total amperage drawn by the electrical equipment which is operating.
The overvoltage relay protects the electronics equipment from a
momentary overvoltage condition (approximately 16.5 volts and up) or a
catastrophic regulator failure. If no output is indicated on the ammeter
during flight, all unnecessary electrical equipment should be turned off to
reduce the electrical load. The 5 ampere field circuit breaker should be
checked and reset if open. If the breaker is not open, the “ALT” half of the
SECTION 7
PIPER AIRCRAFT CORPORATION
DESCRIPTION & OPERATION
PA-38-112, TOMAHAWK
REPORT: 2126
ISSUED: JANUARY 20, 1978
7-10
REVISED: MARCH 1, 1979
Standard electrical accessories include a starter, a key lock ignition, an
electric fuel pump, an audible stall warning, fuel gauges, an ammeter, and an
alternator warning light.
The system provides for the addition of such optional accessories as
interior and exterior lights, a heated pitot head, and communication and
navigational equipment. The anti-collision and landing lights are controlled
by rocker switches on thc switch panel.
WARNING
Strobe lights should not be operating when
flying through overcast and clouds since re-
flected light can produce spacial disorientation.
Do not operate strobe lights in close proximity
to ground, during takeoff and landing.
The master switch is a split rocker switch. One side of the switch is for
the battery (“BAT”) and the other is for the alternator (“ALT”). The words
“master switch” as used in this handbook and unless otherwise indicated,
refer to both the “BAT” and “ALT” switches, and they are to be depressed
simultaneously to ON or OFF as directed.
The ammeter is mounted in the instrument cluster to the right of the
engine control quadrant. The ammeter as installed indicates the electrical
load on the alternator in amperes. With all the electrical equipment turned
off and the master switch on, the ammeter will indicate the charging rate of
the battery. As each electrical unit is switched on, the ammeter will indicate
the total ampere draw of all the units including the battery. For example, the
maximum continuous load for night flight with radios on is about 30
amperes. This 30 ampere value plus about 2 amperes for a fully charged
battery will appear continuously under these flight conditions. The amount
of current shown on the ammeter will tell immediately if the alternator
system is operating normally, as the amount of current shown should equal
the total amperage drawn by the electrical equipment which is operating.
The overvoltage relay protects the electronics equipment from a
momentary overvoltage condition (approximately 16.5 volts and up) or a
catastrophic regulator failure. If no output is indicated on the ammeter
during flight, all unnecessary electrical equipment should be turned off to
reduce the electrical load. The 5 ampere field circuit breaker should be
checked and reset if open. If the breaker is not open, the “ALT” half of the
SECTION 7
PIPER AIRCRAFT CORPORATION
DESCRIPTION & OPERATION
PA-38-112, TOMAHAWK
REPORT: 2126
ISSUED: JANUARY 20, 1978
7-10
REVISED: MARCH 1, 1979