There used to be 3 broadly-defined expertises for GAs, aka TAs -
Technical Assistant - in my time: firing-data (FD) calculation,
recce n' survey, & arty-fire planning (i.e. assisting FO/FSO).
The 1st two are taught at SOAY; the latter also touched on there,
but IMO learnt more ad-hoc while at the active unit.
I understand, though, the recce n' survey side has been phased out
with the advent of GPS sophistication & also the newer Arty
weapons.
So, of the remaining two, the FD side is physically cushy but quite
mentally taxing; you're vehicular-based but will be finger-tapping
keyboard/calculator keys all the time.
The arty-fire planning side can, I believe, be split into 2 further
subgroups:
- the HQ appointments where you're basically based in an air-con
office in camp (generally tagging along for field exercises as BN
Ops, though occasionally get attached to FSO/FO's too);
- the line-troop appointments where you pack a signal set &
follow the FO/FSO when they do support for the infantry exercises,
which was a lot & usually on weekends during my time.
The latter (as FO/FSO GA or TA) is the most siong, esp. if you're
not even PES B in the 1st place. You could even end up going to
Brunei for jungle-training, like I did!
Tip: Unless you're garang or absolutely hates to work with numbers,
you can try to persuade for a change from the "tougher"
appointments during the initial getting-to-know-you interview with
your commander. That's what I did, & even then I did an
about-face come reservist (didn't fancy chiong suah with the
infantry until age 30something).