Conflicting info on Primary/Supporting IR scan ...

[bobbysamd]

Part 25 aircraft instruments

Bobbysamd brought up a good point. He said:

"So, what if vacuum failed? The answer is turbine equipment has enough backups so vacuum failure is a non-issue. "



Except that most turbine equipment does not use a vacuum system for the flight instruments. They have electric instruments . . .

That is absolutely correct. Sorry, I should have made that more clear in my original post.

Not only are turbine equipment flight instruments electrically-powered, I understand there are ways to switch data sources betwen panels meaning if the the captain's attitude instruments fail that data can be obtained from the FO's side. Finally, turbine aircraft have a third, smaller attitude indicator that is powered independently from the main panel(s).

Here again, my point was we were teaching our Alitalia students to be DC-9 and higher pilots, not Cessna and Piper pilots, so, hence, the emphasis on using the AI. We still taught them partial panel and gave them enough training to obtain their instrument ratings.