For the second time in 2003, the U.S. Air Force has cancelled a Red Flag training exercises. This exercise was to he held in late March. The Red Flag exercises, which were developed right after the Vietnam war, use realistic representation of enemy aircraft and tactics to train American pilots to the highest level possible. The air force holds several Red Flag exercises annually, each one lasting 2-6 weeks and employ over a hundred pilots. A network of electronic devices record every aspect of the simulated air battles, so that post exercise critiques are able to accurately determine what worked and what didn't. The exercises are held at Nellis Range, an isolated, 5200 square mile area in Nevada. The air force didn't get to see the results of their Red Flag work until the 1991 Gulf War, when some pilots praised Red Flag by observing that the Gulf War air operations were "almost as intense as Red Flag." After the Cold War ended, many air force pilots noted a decline in the quality of Red Flag exercises. The "enemy" pilots were not as experienced and more of the aircraft used to represent the enemy were down because of poor maintenance or lack of spare parts. In the last few years, attempts have been made to address these problems.