 Featured in the sensor suite was the AN/ALR-23, an Infra-red search and track sensor using indium antimonide detectors, mounted under the nose; however this was replaced by an optical system, Northrop's AAX-1, also designated TCS (TV Camera Set).The AAX-1 helps pilots visually identify and track aircraft, up to a range of for large aircraft.The radar and the AAX-1 are linked, allowing the one detector to follow the direction of the other.