The TF-104G (Lockheed Model 583-10-20) was the combat-capable two-seat version of the F-104G. It had a cockpit canopy similar to that of the F-104D, with a fixed transparent area separating the two separate leftward-opening canopies. It was fitted with the NASARR fire control system of the single-seat F-104G and was equipped with underwing racks which could accommodate many of the same offensive weapons that the single-seat F-104G could carry. However, the TF-104G did not have the centerline bomb rack of the single seat F-104G version. As in the case of the F-104B and D two-seaters of the USAF, the 20-mm Vulcan cannon that the single-seat F-104G carried had to be deleted, some internal equipment had to be rearranged, and the internal fuel capacity had to be reduced.
All of the TF-104G two-seaters were built by Lockheed, although some used components supplied by the European Starfighter consortium. Since the TF-104G aircraft was so similar to the F-104D two-seater of the USAF, no prototype was built and the first machine was actually a production machine. Including 48 aircraft assembled from components supplied by the European Starfighter consortium, Lockheed built a total of 220 TF-104Gs in six versions, generally distinguished from each other by the nation which was to receive them. These versions were identified by adding a letter after their Model 583 company designations. Models 583C through H were respectively versions destined for MAP delivery to Germany and Italy, and for direct delivery to Holland, Germany, Belgium, and Italy.
One of the Model 583Ds was retained by Lockheed as a demonstrator. It carried the civil registration number N104L and was nicknamed *Free World Defender*. It was used by the well-known aviatrix Jacqueline Cochran to set three women's world's speed records. On May 11, 1964, she averaged 1429.3 mph over a 15/25 km course, on June 1 she flew at an average speed of 1303.18 mph over a 100-km closed-circuit course, and on June 3 she flew at an average speed of 1127.4 mph over a 500-km closed-circuit course. Ms. Cochran's Model 583D was eventually delivered to the Koninklijke Luchtmacht (KLu) with the Dutch serial number D-5072.
Two ex-Luftwaffe TF-104Gs were acquired by NASA in July of 1975 and were given the civilian registration numbers N824NA and N825NA.
Many of the TF-104Gs were purchased with MAP funds, and those that were were assigned USAF serial numbers for record-keeping purposes, even though they never carried USAF insignia. In addition, numerous Luftwaffe TF-104Gs operated with training units in the USA and carried USAF insignia and serial numbers even though they remained German property.