Doing a quick search around the web returns an annual event called Warbirds Over Allaire. The last (and maybe only) date I find is 8/22/09. Maybe they will have another in 2010 that I can go check out.
The main entrance is located off Hospital Road, to the left of the main Allaire SP parking area. You can not drive up the the field unless you have a key to the lock. But you CAN park in the main lot and just walk up to check it out.