Minister of National Defense Kao Hua-chu promised Thursday to consider a proposal to mothball the Air Force's Mirage fighter jets in light of their low performance and high maintenance costs. Kao said the Ministry of National Defense (MND) will carefully evaluate issues such as how to maintain the balance of combat capabilities across the Taiwan Strait, before making a decision on the matter. In the meantime, the Air Force will work with the French manufacturer in an effort to fix the problems with the turbine blades of the jet engines so as to upgrade the aircraft's performance, he said. The proposal to mothball the Mirage fighters was put forward by ruling Kuomintang Legislator Lin Yu-fang during a meeting of the Legislative Yuan's Foreign and National Defense Committee. According to Lin, the rupture of the engine turbine blades on Mirage 2000 fighters in May resulted in a drop of pilots' average flight hours to six hours that month, which was only 40 percent of the minimum 15 hours required by the MND. Lin also pointed to the exorbitant costs involved in maintaining the Mirage fleet. While the maintenance costs of the F-16 fighters and the Indigenous Defense Fighter (IDF) are NT$160,000 and NT$250,000 per flight hour, respectively, it costs NT$800,000 per flight hour to maintain the Mirage jets, he said. Also during the meeting, Kao denied an Apple Daily report that a F-5E aircraft was almost shot down by an F-16 fighter in a recent aerial gunnery training exercise. Kao told lawmakers that fire from the F-16 fighter hit only the cable to which the aerial gunnery target on the F-5E jet was attached. The F-5E was serving as a towing aircraft in the training exercise, he added. He said when the cable was hit, the F-16 fighter was 2,000 feet away from the towing aircraft, and it is untrue to say that the F-5E 'was almost shot down.' 