into 18 brigades at its height) and the Self-Defense Workers' Cooperatives. Aside from the BLIs and BLCs, the SPA also sported the following units: Multiple Duty Battalions Permanent Territorial Defense Company Corps of Engineers Medical Corps Tactical Battle Groupings composed of: Armored battalions Mechanized Infantry battalions Field artillery battalions Air defense artillery battalions Communications battalions Operational Support Bases Ground Forces Reserve Battalions (formed in the early 1980s) Equipment Type 58 assault rifle Air Force When the Sandinistas assumed control in 1979, the Sandinista Air Force/Air Defense Force (Fuerza Aérea Sandinista/Defensa Anti-Aérea—FAS/DAA) inherited only the remnants of the National Guard's small air force. Equipment included a few AT-33A armed jet trainers, Cessna 337s, and some transports, trainers, and helicopters. The time required to train pilots and construct airfields precluded a rapid FAS/DAA buildup. Beginning in 1982, the Sandinistas received from Libya the Italian-made SF-260A trainer/tactical support aircraft and the Czechoslovak Aero L-39 Albatros, a subsonic jet trainer that could be missile-armed for close-in air defense. In addition to light and medium transport aircraft, the air force acquired a fleet of helicopters from the Soviet Union that served against the Contras. They included Mi-8 and Mi-17 transport helicopters and later the Mi-24, followed by its export variant, the Mi-25, a modern armored assault helicopter. After Humberto Ortega revealed that Nicaragua had approached France and the Soviet Union for Mirage or MiG fighter planes, the United States warned against introducing modern combat jets to the region. Although Nicaragua began construction of a new airbase with a longer runway and protective revetments, it did not succeed in acquiring new fighter aircraft. A series of radar sites were constructed to give the Sandinistas radar coverage over most of Nicaragua, with the added capability of monitoring aircraft movements in neighboring countries. A Soviet-designed early-warning/ground-control intercept facility gave the air force the potential to control its combat aircraft from command elements on the ground. After 1990 the FAS/DAA was no longer able to maintain its full aircraft inventory without Soviet support. The personnel complement fell from 3,000 in 1990 to 1,200 in 1993. Airbases at Bluefields, Montelimar, Puerto Cabezas, Puerto Sandino, and Managua remained operational. Combat aircraft were reduced to a single mixed squadron of Cessna 337s, L-39s, and SF-260As. However, the serviceability of all these aircraft was doubtful. In 1992 a number of helicopters and six radar units were sold to Peru. A small fleet of