Warning: thread drift to answer piperboy84 question.
Sound like an amazing bit of kit, is it subject to errors and if so how do you recalibrate it enroute?
TBH there's are a few shortcomings in descriptions of how they work in some posts I've seen here ...
however FWIW:
INS/INAS 101: Yes, it is an amazing bit of kit, FWIW they've been around since the 60's, if not earlier ... they do "drift" away from an accurate position/velocity but these days you generally don't "recalibrate" the INS itself in flight ( though some systems do or did allow it....oh, that was fun......) but they're normally only one of several data sources into the nav systems on modern airliners, along with GPS and ground based radio aids so they're not usually the only source of info/data on position etc.
....Next week we will discuss Schuler tuning.....
and back to the thread: I think SSD had it in one, back permalink #47.