Alt Bug Color sequencing

[johnb]

4500s

Can someone explain the logic of the color sequencing of the Alt Bug?

The MINS bug makes sense. On descent > 100' to DH/MDA , I'm in the 'blue' (cyan), DH/MDA < 100' I'm within 'sight' (white), < DH/MDA is a cautionary yellow and Alert.

The color sequencing logic of the Alt bug box escapes me.
Goes from white to yellow when passing through 1000' (Text typo says 100') of Bug Alt and then to cyan passing within 200' of Bug Alt.

Seems like sequencing and the Target color should be the same for both ceiling and MDA targets. Easier to remember and eliminates the interpretive step of climb color vs. descent color.

Maybe the logic is 'climb into the blue' and descend from the blue with CAUTION

[chardks]

The altitude bug colors on all the AF EFIS systems operate in the following manner:

WHITE: Bug setting is more than 1000' above or below the current altitude

YELLOW: Bug setting is between 200' and 1000' above or below the current altitude

CYAN: Bug Setting is within 200' of the current altitude

The altitude bug audio operates in the following manner:

ARRIVAL ALERT: There is an audio alert issued when the the current altitude gets within 220' of the bug setting to indicate the arrival at the desired altitude.

DEVIATION ALERT: There is an audio alert issued when the current altitude moves more than 180' from the current setting to indicate a deviation from the set altitude.