Originally Posted by
kijangnim
there is only TRANSITION ALTITUDE, you have to use it as transition level during descent although it is referenced to transition altitude.
Incorrect. You
may want to use it as a TL reminder (STD flashing on PFDs) modified to the value applicable for given runway / pressure. Or, you may want to keep/correct it as appropriate to relevant TA, so that you get the flashing reminder during GA when climbing, so not to bust your GA FL. It is a tool and well educated operateur
will use it as (s)he sees most benefical.
Of course, generally, one is better off following employer's standards (a.k.a. SOPs). Of course, there are ten in a dozen aircraft not equipped with such feature and all flying gets performed safely. It is better that automation guidlines do not become obstructing to procedure planning and situational awareness.
FD (the un-real)