Dart, the first Air National Guard unit to receive this aircraft. With the F-106, the squadron competed in and won its first William Tell, a live-fire missile competition held at Tyndall AFB, Florida. Performed air defense duties along the northern tier of the United States until 1978 when ADCOM was merged into Tactical Air Command. Continued air defense mission for ADTAC component of TAC with the F-106s, transferring to First Air Force when ADTAC was replaced in 1985. The 186th FS converted from the F-106A to the F-16A/B Fighting Falcon in mid-1987. The conversion happened earlier than was scheduled and the 186th FIS was to be the last squadron to lose its F-106s. The first aircraft were older block 5 and 10 models with some block 15 airframes also being delivered to the squadron. Main task for the unit was air defense, as with many ANG units who were equipped with the F-16. In 1991 the F-16s were brought up to the Air Defense Fighter (ADF) variant. This meant a serious leap in performance and capability of this squadron in their defensive role. This situation was maintained up until 2001 when the squadron started receiving more modern F-16C block 30 aircraft with a large intake. This conversion replaced the air defense mission with one of general purpose/air-to-ground as part of the Expeditionary Aerospace Force. With the conversion, unit members felt it was time to consider a change in the aircraft tail markings. The most notable change included the 186th Fighter Squadron's nickname of "Vigilantes". The nickname by the pilots of the 186th is intended to honor the first men in the Montana Territory who organized for the safety and welfare of the people. The squadron once again found itself on alert status after the terrorism attacks in New York City and Washington, D.C. Base personnel implemented the necessary procedures to establish a secure environment while maintaining a 24-hour alert status for aircraft. Throughout 2002, hundreds of unit personnel were activated and deployed to multiple locations in support of Operation Enduring Freedom and the world. As a result of the 2005 BRAC decisions, the unit converted to the F-15C/D during 2008 and revert to an all-air defense unit. In early December 2007 the first F-16 left Great Falls being transferred to the 158th Fighter Wing, Vermont ANG. By the summer of 2008, eighteen F-15C Eagles had been transferred from the 131st