ORIGINAL: Tarhunnas
I usually don't plan on having the enemy surround my units; that's negative thinking[8D]. When it does happen it is usually kind of unforseen [;)].
Seriously, however near the front I have the army airbase it is unlikely it will be in the exact spot to be included in the pocket (unless I manage to get the whole army surrounded, but that is even more negative thinking).
ORIGINAL: Q-Ball
But if you plan ahead enough to put an airbase close to the front where it would supply the pocket, why not plan ahead and just get those guys out of there?
And if you can get an airbase unit IN to the area, why can't you get the troops OUT?
Most pockets aren't really PLANNED is my point. And you need to PLAN ahead to have an airbase in there, generally.
Who does? [:)] With current mechanics, no one. When I said "planning ahead" I was thinking of a situations like the following:

where you "plan ahead" as in:
* I don't want to pull out from there for whatever reason
* I am gathering my reserves to defeat both pincers, but I need time.
* So I move Corps HQ and Airbase into Pogar, and establish a perimeter with infantry until cavalry arrives.
That should give a fighting chance to those divisions, and probably would stall what would be a major push from your opponent.
ORIGINAL: TarhunnasORIGINAL: Bletchley_Geek
That's debatable Tarhunnas. The difficulties of keeping supplied 6. Armee at Stalingrad - where they had 3 different airports - were more a consequence of the STAVKA massing VVS figher regiments to interdict air resupply when it realized what was going on, the inability of 11 PzD to keep the 5th Tanks Army off the airbases on the Chir river - though they managed to keep 5th Tanks from breaking through - and weather. The LW also tried to supply smaller pockets - such as Korsun - but there they were limited to parachute drops (I think) and it was too common that supply fell in the hands of - also starving - Red Army troops.
True, a lot of things were different at Stalingrad compared to Demyansk or Kholm. Still, the fact remains that it proved possible to supply a corps almost indefinitely by air, but not an army, while with the rule as it appears, it risks the opposite simply because the army has an airbase.
Good point Tarhunnas. If you can't do as above, or you just happen not to have an airbase in the right place, you're screwed.