767/757 question

[Turbine Cowboy]

Hi agin,

Does the VSI in the 757/767 get information from systems other than the IRS?
Is it by any way connected to the ADC?

thank you much

T.C

[Ka8 Flyer]

Yes its connected to both the IRS and the ADC. Both need to be operational for the VSI (or rather IVSI) to work.
IRs provides (short term) acceleration information while the ADC basically always resets the drift error by using the pressure difference as in a basic aircraft.
Regards

Mark