Section 906
Digital RPM Indicator
Page Date: 20. April 2002
906 - 5
Pilot´s Operating Handbook
EXTRA 300L
Page Date: 19. April 2012
RPM RANGES
Engine operating ranges are indicated by the large green, yellow, and red LEDs.
These LEDs are located on the upper right corner of the indicator face.
MAGNETO-CHECK
Three small LED magneto system alert indicator lights are located within the "Status" aera on
the upper left corner of the indicator face.
The left and right red LED alert indicator lights, when illuminated, indicate, because of loss of
ignition signal to the tachometer, a possible malfunction of the respective left or right magneto
ignition system.
While performing a magneto check during engine run-up, the red alert indicator lights will
illuminate, thus identifying the grounding of the respective right or left magneto systems.
Between the left and right magneto ignition system alert indicators is a yellow
RPM
synchronization indicator
. This small yellow indicator is illuminated when there is a
difference of more than 50 RPM between the right and left tachometers.
This indicator also may flicker during extreme RPM excursions of the engine.
OPERATION BUTTONS
There are three panel buttons. Each button has two modes of operation.
PRESS-AND-HOLD operation mode
(press and hold for more than 2/3 of a second)
This operation mode is placarded above each button.
(Hours, Clear,Trap)
Engine time (Hours)
The left button, upon depression, will cause the tachometer to display the non-fractional
portion (0000.) of the current accumulated engine hours. When the button is released, the
fractional part of the engine hours (.00) is displayed for a short period of time. The clock is
started whenever the engine RPM exceeds 800 RPM and is recorded in real hours.
Clear
(Clear)
The middle button clears the RPM trap. During depression of the switch, the RPM trap is
zeroed. When the button is released, the trap will record the current engine RPM.
Engine RPM
(Trap)
The right button will cause the tachometer to display the current contents of the RPM trap.
This trap records the
highest engine RPM
achieved before the button was pressed.
Summary of Contents for 300L
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