If you have a few K of altitude, the Hellcat will escape from the George with a 0G dive to very high speed. That's about your only "out" card. The George is definately the most dangerous plane to the Hellcat, specifically for it's excellent accelleration. Your the E fighter vs. the George, but it's accelleration means that your E advantage will vanish very quickly. If you have a decent E advantage you can make 1 pass on a George, maybe 2, then it's time to bug out.
I love the Hellcat, it's a great little E fighter and it can turn some. It's the best accellerating single engined plane in the US stable. It dives very well, and accellerates in a dive at what must be one of the best rates in the game. One other thing the Hellcat has going for it is it's toughness. It's almost as tough as the Jug, and it will get you home many times when lesser planes would be fluttering to earth in bits.
The ticket with the Hellcat is E and hiding it. It's an E fighter and a damn good one, but you really need an E advantage at the start of a fight to expect to win. The Kitty can turn some, but she only really turns well if you can afford to burn up some E to do it. The best way to engage in the Kitty is to shallow dive into combat to gain speed, and level out nice and early so you "hide" your speed. I'll also not head directly for the enemy if I've got more E, I'll angle off him a bit as we approach to cut down the closure speed. You want to come in slightly lower but faster than him, and manage your closure as you approach so that he mis-judges your energy state. If you can accomplish that, you've all but won.
BTW, if you are getting hassled by La7's, the Hellcat is a great ride. It's my La7 killer.
It will out-turn the La7's and for some reason they never seem to expect that. If you can get close to them in terms of energy state, you'll eat 'em up. The second they try to dive away you can eat their lunch. The La7 will escape eventually, but for the short term in a dive the Hellcat will gain fast and get you close enough for a shot. In the early stages of a dive, the Hellcat may be the best in the game, so use that to surprise folks who think they can run away from you in their "faster" planes. The guys in F4Us, P-51s, P47's and FW's will under-estimate your diving ability most times and when they try to dive away you eat them. Just make your shots count, because once you are level on the deck, the faster planes will start to pull away fairly quickly.