Integrated Standby Flight Display (ISFD)
The battery bus powers the ISFD. Selecting the battery switch ON activates the ISFD. After
10 seconds, an initialization sequence begins that requires 90 seconds to complete. ATT
and INIT 90s messages are displayed during initialization. Upon completion of the
initialization sequence, attitude information is displayed.
- Note: Any change in airplane position during the initialization sequence may result in
an inaccurate alignment. Inaccurate alignment is not annunciated and may result in
the display of inaccurate attitude prior to, and during flight. Re-initialization can only
be accomplished through maintenance action.
Detection of a momentary out-of-limit ISFD condition may cause the attitude display to
blank and the WAIT ATT or ATT:RST message to display. Operation of the attitude reset
switch is required in response to the ATT:RST message. This will reset the horizon line with
the airplane symbol.
- Note: Operation of the attitude reset switch will not correct an inaccurate alignment.
On the ground, operation of the attitude reset switch must be performed with the airplane
stationary. In flight, operation of the attitude reset switch must be performed with the
airplane in wings level, non-accelerated flight. During the process, the ATT 10s message
displays. Failure to maintain straight and level flight for 10 seconds may result in an ATT:
RST message. If the reset attempt is unsuccessful, the ATT:RST message remains
displayed and the ISFD does not enter normal operation.
