Standby Attitude Indicator
The standby attitude indicator provides attitude information that is independent of
the primary attitude displays. The indicator is powered by the battery bus and
remains powered after the loss of all normal AC power as long as battery power
is available. The gyro reaches operational speed approximately 60 seconds after
power is applied. The indicator requires three minutes to achieve accuracy
requirements.
Standby Altimeter/Airspeed Indicator
Standby altitude and airspeed are displayed on a single indicator.
The standby altimeter receives static pressure from the alternate static ports.
Current altitude is displayed digitally. A pointer indicates altitude in hundreds of
feet. Barometric setting windows display the barometric setting in both millibars
and inches of mercury as set by the barometric setting control. The altimeter has
a range of -1000 to 50,000 feet. The standby airspeed indicator receives ram
pressure from the auxiliary pitot probe and static pressure from the alternate
static ports. It provides current airspeed in knots.
Standby Radio Magnetic Indicator
The standby radio magnetic indicator (RMI) displays magnetic heading and
VOR/ADF bearing to the station. The RMI is powered by the AC standby bus and
remains powered after the loss of all normal AC power as long as battery power
is available.