block 15
In November 1981, the Block 15 introduced MSIP Stage I changes to the F-16A/B starting with subblock 15Y and continuing through subblock 15AZ. More than a year earlier, in February 1980, these modifications were already effective on the F-16C/D production. The changes expanded the F-16s growth potential by allowing improved capabilities in the air-to-ground and BVR missions.
One major modification was the addition of two hardpoints to (and structural strengthening of) the chin of the inlet, designated hardpoints 5L and 5R. To offset the shift in center of gravity caused by the weight of these two additional hardpoints (and eventual stores attached to them), the extended horizontal stabilator (the so-called "big tail", 30% increase in area), was fitted. The new tail also provided better stability and more authority for out-of-control situations. It changed lift-off rotation speeds and allowed stable flight at higher angles of attack.
The AN/APG-66 radar on the Block 15 Fighting Falcons was provided with an early version of a track-while-scan mode for greater air defense capability. The F-16s were also equipped with Have Quick I secure UHF radios, and internal provisions for the AIM-7 were made. Additional structural strengthening was performed to allow an extra 1000 pounds of ordnance to be carried on the underwing points. Last but not least, pilot comfort was enhanced by improving the cockpit air conditioning.
The production run of the Block 15, saw 983 aircraft produced over a 14 year time-span, and took place on 3 production lines. The first Block 15 F-16 (#80-0541, the 330th F-16 built) rolled out in 1982. In 1996, the last block 15 was delivered to Thailand, the 11th Block 15 customer. Early USAF Block 15 aircraft were later (1987-1993) retrofitted to Block 15OCU specifications.