Section 906
Digital RPM Indicator
906 - 4
Page Date: 20. April 2002
Pilot´s Operating Handbook
EXTRA 300L
Ignition switch position:
RIGHT
Status area:
Left red LED illuminates
Display:
shows RPM drop
Ignition switch position:
BOTH
Status area:
Right and left red LED OFF
The middle LED should be OFF,
otherwise the difference is more than
permissible.
N O T E
During the short circuit (grounding) of a single magneto, the respective red LED has
to be illuminated. The maximal allowed RPM drop at 1800 RPM is 175 min
-1
. The
maximal RPM difference between the magnetos should not exceed 50 min
-1
(identified by the illuminated yellow LED).
906.5
PERFORMANCE
Not affected.
906.6
WEIGHT AND BALANCE
Not affected.
906.7
DESCRIPTION AND OPERATION OF THE SYSTEM
The operation of the indicator is straight-forward. After power is supplied to the indicator, the
engine is started, and the self tests are performed, the default display of the engine RPM
appears on the display. The default display is insured via the use of internal timers that will
restore the display to the current RPM even in the event that one of the panel buttons
becomes stuck or defective.
Internally, two independent tachometers watch the pulses received from each magneto. Each
tachometer is accurate to less than 1 RPM and can be individually enabled/disabled via
buttons on the face of the indicator.
Magneto-Control
Operation placard:
Press-and-release
Operation placard:
Press-and-hold
Hours Clear Trap
L DIM R
Status
RPM-
restriction
RPM range
buttons
Display
Page Date: 19. April 2012
Summary of Contents for 300L
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