Pitch Channel – Autoland
Multichannel engage is initiated when one channel is engaged in CMD and one or more A/P channels are manually placed in CMD with APP selected. The switches remain in CMD only if APP is selected. Pitch multi-channel engage occurs at 1500 feet radio altitude if G/S and LOC are captured and two or more channels are armed.
Since multichannel engage occurs at 1500ft or below, with the above conditions, there will be no bus isolation request and no drained battery.