 Complete the following phrase:  In 1985, the FABF also acquired two ex-Soviet Mi-4 transport helicopters from an unknown supplier, followed by an additional two Mi-4s. The Mi-4s were operated by the FABF until the late 1980s, when they were taken out of service. Five Mi-817 transport helicopters were later added to the Escadrille dHélicoptères. While supervising the ceasefire after the 