When the B-58 was required to change to the low level bombing role, it rapidly became apparent that it lacked range, leading it to be withdrawn from the bomber role by 1969. However Convair/General Dynamics engineers had been studying way to increase the range of the aircraft, and surmised that in the near future more economical engines could give the aircraft a useful range. Such was the support within the company and the USAF for this concept that rather than the airframes being scrapped they were placed in storage. However budgetary constraints, along with the lack of a clearly defined role prevented any work being done on the stored aircraft, and it is only now that they have reappeared in a far different guise than was originally envisaged .the FB-58F missile truck.
Gone are the four wing mounted engine pods, replaced by a twin F119 engine installation under the fuselage based on the engine pods of the B-1. Subtle reshaping of the undercarriage doors, along with widespread use of RAM on the leading edges are reputed to have reduced the airframes RCS by over 70%. Four wing pylons, located where the engines used to be, are each capable of carrying three AIM-120 missiles, and the aircraft retain the tail mounted 20mm cannon. Though the FB-58F does carry a version of the APG-77 radar, its size and lack of manoeuvrability dictates that it stays as far away from enemy fighters as possible, so target acquisition for the missiles is normally via data-link from other aircraft such as F-22 Raptors and F-35 Lightnings.