RWY Mode

RWY mode is used at take-off to guide the aircraft along the runway centre line using LOC. When aircraft is airborne, the RWY guidance law aims to maintain the sideslip indicator cantered.

RWY engagement conditions –

• V2 is inserted, and
• aircraft is on ground, and
• slats are extended, and
• LOC is valid and deviation is below ½ dot, and
• aircraft heading is withing 20 degree of ILS course, and
• no lateral mode already engages, and
• TOGA/FLX is selected

RWY disengagement conditions –

• LOC is lost below 30 ft RA
• NAV is armed, and aircraft reaches 30 ft RA, NAV engages
• NAV is not armed, and the aircraft reaches 30 ft RA, RWY TRK engages
• Another lateral mode engages
• Aircraft deviates from more than 20 degree from ILS course

RWY TRK Mode

RWY TRK mode is used to guide the aircraft along the track the aircraft was following at the mode engagement. RWY TRK automatically engages at 30 ft RA, if RMS flight phase is take-off, and NAV is not engaged.

RWY TRK disengagement conditions –

• Flight crew pulls the HDG/TRK knob: HDG/TRACK engages
• NAV is armed, and the aircraft reaches the capture zone of the active leg: NAV engages
• The flight crew inserts a DIRECT TO.