There are a number of reasons that a player may appear to be hacking. For one, high latency [heavy traffic] on our game servers can delay the apparent space and location of an opponent in AirCombat. Other times, if the latency issue is on the player's end, the player with the better connection may have an advantage.
To determine if the latency is on your end, test the game on another WiFi network [like a friend’s house or a coffee shop] to see if the issue is still apparent. Another occasional cause is low application memory. To get more memory allocated to MetalStorm; double click your home button and remove all the items from your multi-tasking tray (don't worry, this doesn’t delete the apps off your phone). For more info see- http://support.apple.com/kb/HT4211
If, however, you continue to see behaviors in AirCombat that are related to hacking, we would like to investigate further. Please send us the specific Game Center ID (please note: exact spelling, capitalization and spacing is required for looking into GC IDs) of the player so that we can take a further look. You can open up a support ticket.