Fuerza Aérea Hondureña
Late in the afternoon of 14 July 1969, the concerted military action began. El Salvador was put on a blackout and the Salvadoran Air Force, using passenger airplanes with explosives strapped to their sides as bombers, attacked targets inside Honduras. Salvadoran air-raid targets included Toncontín International Airport, which left the Honduran Air Force unable to react quickly. The larger Salvadoran Army launched major offensives along the two main roads connecting the two nations and invaded Honduras. The invasion phase was perpetrated by three main contingents: the Chalatenago Theater, the North Theater, and the East Theater. The Chalatenango Theater was based on the northwest side of El Salvador, including the departments of Santa Ana and Chalatenango, across the mountain range close to the border, and the Sumpul River. This was a strategic region due to its rich soil and climate; however, this Theater would not see any fighting as it was to deploy only in case of Honduran penetration into El Salvador. The North Theater was composed of a small unit of armored vehicles and a large amount of manpower. The East Theater was to deploy in the departments of La Unión and Morazán. This Theater was composed of a large mechanized division, armored fighting vehicles such as the M3 Stuart and a large amount of artillery such as the 105mm M101.