New high-speed aeronautical digital communication technologies will be required to cope with for increasing volumes of in air traffic. The Aeronautical Mobile Airport Communication System (AeroMACS) is a technology based on IEEE 802.16e which can use Multiple-Input Multiple-Output (MIMO) antenna systems to increase channel capacity. We experimentally evaluated the angle dependency of the MIMO effect around an aircraft in an airport environment by calculating the channel capacity around the aircraft using measurements from conventional Single-Input Single-Output (SISO), 2x2 MIMO, and 2x6 MIMO antenna systems. The 2x6 MIMO configuration gave the greatest channel capacity because of displacement of masking by the aircraft's empennage. It was thereby confirmed that an optimized MIMO antenna configuration provides greater channel capacity than conventional communication systems. © 2012 IEEE.