Unless of coarse it's a noe raid, a vulch fest is pretty easy to see coming. It usually starts when 1 or 2 come in, hit dar and get a few guns. They'll usually try to take out the VH. This is when you want to start getting alt. Especially if a big dar bar is growing.
CV attacks produce a good vulch fest too. Once I realize a CV is off shore I'll 1st look for a SB to see if I can get guns on it. If not, I'll up bombers from the next closest field and head that way.
The bottom line is, if you want to avoid the enemy vulching you, you have to take the fight to them. Too many people want to fly around their own field hoping the ack will protect them and when the ack is taken down, they become fish in a barrel.
If the enemy is already at your field jump in a field gun to check to base out first before just jumping in a plane and sitting on the runway. If you can get up, take something fast or something that turns good...or both. Stay low and get as fast as you can, make a slow climb away from the direction the cons are coming. Once you have enough speed and alt to engage, try baiting as many as possible to pull them away from the field so that more friendlies can get up to help you. Do not go for the HO shoots. It's important that you stay up as long as possible to allow for others to get up and defend. Always stay fast and keep your head on a swivel.
If you can't get up at all and the VH is down. Take off from the closest base and head to theirs. Try to put them in the position to defend. Also they'll be upping from there 1 by 1 which will allow you to engage them as they'll be low and slow.