Instruments checks on ground

[Giulicor12]

Hi all ! These days I had some questions from my instructor concerning the checks of instruments while on ground. I've been looking for the answers but no results...

The questions are :

1) what is the maximum difference between the QFU and your compass when lining up for take off ?

2) the max difference between your compass and your heading on the HSI ?

3) In IFR, 2 altimeters are required, what is the max difference between both altimeters readings ?

Does someone can help me ? And most of all, does someone can give the source of the information found ? For example Jeppesen, ATPL books, ICAO annexes or whatever !

Thanks

[stepwilk]

You're on guard...I mean aviation history and nostalgia. You need to post in a flight-instruction or private-flying forum.

I'd try to help anyway, but we don't use any of those funny Q-things in the U.S.

[Giulicor12]

Sorry I'm new on this website and I made a mistake ...

Oops !

[Background Noise]

Hi, I see you've added the questions elsewhere. You can delete the old thread by deleting the first post (select EDIT then delete) - if you are the thread starter it deletes the whole thing.