Anticipated growth in avionics features and parts obsolescence issues drove the need for an AIMS upgrade, says Dan Murray, Boeing’s 777 systems and equipment manager. It has gotten difficult and expensive to obtain parts for the original 100-megabit/sec (Mbit/sec) Fiber Distributed Data Interface (FDDI) local area network. Called Planenet, the fiber optic LAN–used on the ground–carries traffic between AIMS and both the maintenance access terminal (MAT) and the portable MAT, and is used in software data loading. With AIMS-2, Boeing replaced the FDDI LAN with 10-Mbit/sec Ethernet 10BaseT. (AIMS-1 actually used less than 10Mbits/sec of FDDI’s bandwidth, so the Ethernet link will allow for future growth.)