Complex sentence: The new radar will support the AAM-4 missile, the Japanese answer to the AMRAAM, and the helmet-mounted sight will support the AAM-5 dogfighting missile, which will replace the AAM-3.
Split into simpler sentences: The new radar will support the AAM-4 missile, the Japanese answer to the AMRAAM. The helmet-mounted sight will support the AAM-5 dogfighting missile, which will replace the AAM-3.