warlick says if jet fuel prices keep soaring, with fewer passengers flying, airlines may be forced to trim capacity or make cuts in other areas. >> you haven't seen a large number of cost initiatives of that kind so far in 2011 but, certainly, with another round of capacity cuts, you could see an impact on labor and some of the other line items. >> reporter: experts say fuel will continue to be a wild card for airlines. carriers are trying to rein them in better by purchasing more fuel-efficient planes. yesterday, american said it ordered 460 new jets that offer between 15% and 30% better fuel economy than its current fleet. joseph schwieterman studies the transportation industry for depaul university's chaddick institute. he thinks these new planes will determine which carriers survive and thrive down the road. >> in five or six years, it is going to be essential that you have a fuel efficient jet or you just won't be able to compete in the market place. the implications of 5%, 10%, 20% less fuel costs is going to drive fares down relatively speaking. >> reporter: still, it will be a