The F-16A, a single-seat model, first flew in December 1976. The first operational F-16A was delivered in January 1979 to the 388th Tactical Fighter Wing at Hill Air Force Base, Utah. The F-16B, a two-seat model, has tandem cockpits that are about the same size as the one in the A model. Its bubble canopy extends to cover the second cockpit. To make room for the second cockpit, the forward fuselage fuel tank and avionics growth space were reduced. During training, the forward cockpit is used by a student pilot with an instructor pilot in the rear cockpit.
Block 1 and Block 5 F-16s were manufactured through 1981 for USAF and for four European air forces. Most Blocks 1 and 5 aircraft were upgraded to a Block 10 standard in a program called Pacer Loft in 1982.
Block 10 aircraft (312 total) were built through 1980. The differences between these early F-16 versions are relatively minor.
Block 15 aircraft represent the most numerous version of the more than 3,600 F-16s manufactured to date. The transition from Block 10 to Block 15 resulted in two hardpoints added to the chin of the inlet. The larger horizontal tails, which grew in area by about thirty percent are the most noticeable difference between Block 15 and previous F-16 versions.
Block 20 aircraft incorporate significant avionic and structural enhancements. Many of these enhancements are supported by a modular mission computer that replaces three other computers and has faster processing and a large growth capacity. The aircraft¡¯s improved version of the APG-66 radar, called the APG-66(V3), has many new features, such as increased detection and tracking ranges and the ability to track more targets simultaneously.
These F-16s also have an improved data modem, a ring laser inertial navigation system, a digital terrain system, an advanced interrogator for identifying friendly aircraft, wide-angle head-up display, color multifunction cockpit displays, up-front controls (a set of programmable pushbuttons placed just below the head-up display), and Block 50-style sidestick and throttle controllers. Cockpit lighting is compatible with night-vision systems.