The avionics were upgraded on some E-models as part of an Avionics Modernization Program. Boeing Helicopters manufactures and integrates the fuselage, cockpit, avionics, and flight controls. The modernization is aimed on improvements in aircraft's avionics and armament. The A-7 had more modern avionics and systems than contemporary aircraft. The aircraft was equipped with TAWS made by Universal Avionics Systems of Tucson. ARINC 429 is a data transfer standard for aircraft avionics. However, this aircraft doubled in cost with demands for an upgraded engine and new avionics. The squadron develops operational tactics and evaluates new avionics and weapons systems. However, the ban is due to potential radio interference with aircraft avionics. Other enhancements included upgrades to avionics and performance such as a new flight management system. These were updated as F-5N/Fs with modernized avionics and other improved systems. The base model Su-25 incorporates a number of key avionics systems. Subsequent variants have updated systems, avionics, and higher weights. By 2013, IAF AH-64As were receiving a comprehensive upgrade of their avionics and electrical systems. This version also incorporates upgraded avionics and a redesigned interior.