A320 v/s indicator white

[westinghouse]

hi,

yesterday the v/s indicator line which is normally green was white in colour before pushback.
however once we got airborne it turned to green.
any reasons for the change in colour?
did a search but to no avail.

thanx.

[Fargoo]

Should be green normally or amber with excessive V/S

Did the grey background shading disappear too until the needle turned green? If so it's possible the screen had either not warmed up fully or been starved of cooling for some reason and overheated temporarily.

Do you have the old CRT's or the newer LCD screens on your aircraft?

[westinghouse]

its the newer ones. LCD's.
its normally green but this time it was white. and they grey background was available.

[Lamboo1]

Hi,

Just my 2 cents, I have seen this twice before, one of our friends at engineering said that it might be show up after the a/c had some sort of software update, ( nav data or EIS update i don't know)

Regards

Lamboo1

[safetypee]

Not the same software package, but the Avro RJ has a similar feature.
IIRC the green-white changeover indicates a different source for the information than normal (green = normal), i.e. if air data invalid or unreliable (low speed, on grnd, etc) then the VS display uses inertial velocity (white = alternate).
If memory has failed me, an alternative may be that the air data source has been switched, i.e all on ADC 1 or all on ADC 2. This might also indicate that there would not be any comparator function available for that data.