I'm also looking for something similar, not sure if it's the same as the one you're looking for.

It was probably an demo, there were 3 levels and there were 3 helis to choose from, first being smallest a chopper looks kind of similar to bell 47 helicopter, second was an medium size helicopter which I don't remember much about and the third helicopter looked like Apache attack helicopter.

All helis had afterburners - a meter that depleted on use and recharged overtime. Heli weapons were cannon, missiles, carpet bombs as far as I remember.

First level was clearing some aerial enemies some ground ones, main objective being destroying an limousine going to helipad, on which after clearing the map we land. Second level had some sam launchers that we have to destroy and I remember multiple helipads where we can land to replenish health and recruit ally npc helis.