Speed Reference Selector (Outer Knob)
Sets the reference airspeed bugs on the Mach/airspeed indicator:
- AUTO – the reference airspeeds and gross weight are
provided automatically through the FMC.
- V1 – used to manually set decision speed on the ground; in
flight, displays “INVALID ENTRY”.
- VR – used to manually set rotation speed on the ground; in
flight, displays “INVALID ENTRY”.
- WT – allows manual entry of reference gross weight.
- VREF – used to manually set the landing reference speed
in flight; on the ground, displays “INVALID ENTRY”.
- Bug 5 – used to manually set the white bug 5 to the
- desired value.
- SET – removes the speed reference display.
Speed Reference Selector (Inner Knob) (Two speed slew)
ROTATE –
- Manually sets the appropriate reference airspeed or gross
weight.
- The digital display appears below the airspeed indication.