IN the wreckage of a small Cessna airplane that crashed Saturday in the eastern part of the country was cargo that has sent a chill through many military men here - the first shipment of surface-to-air missiles presumably destined for the leftist rebels battling the United States-backed government. So far, US-supplied air power has given the Salvadoran Army an edge in the decade-long war. But heat-seeking missiles could knock down the Army's helicopters and planes, and take away that advantage.
President Alfredo Cristiani suspended diplomatic relations with Nicaragua over the incident, accusing them of supplying the missiles. Still, he played down the military importance of the missiles, saying the Air Force would be able to keep the rebels under control, regardless of whether they had missiles. Others were less optimistic, though.
``This completely changes the panorama of the war,'' says Major Mauricio Chavez Caceres, an Army spokesman. ``The guerrillas had two problems in the recent offensive - the Air Force and armored vehicles. In this shipment we see missiles which can shoot down airplanes, and a recoilless rifle with antitank capabilities.''
``If the guerrillas can knock out the government's air power, the war would change completely,'' says a Western diplomat, adding that if there was one shipment there would be others.
In fact, the same day as the Cessna crashed, another light aircraft was found abandoned and burned 35 miles southeast of the capital. Peasants in the area reported seeing boxes unloaded before the plane was set fire. It is not known what the shipment contained.
US-supplied air power played a critical role in preventing a rebel victory in 1982 and 1983. During that time, Vietnam-generation, troop-carrying UH-I helicopters, known as Hueys, increased the Army's mobility, allowing the Army to penetrate rebel strongholds in remote mountain areas. The guerrillas reacted by using land mines to reduce the Army's mobility and by expanding into new parts of the country.
The rebels are now trained to mass small-arms fire against helicopters, which are thus forced to fly higher, where their guns are less effective. The guerrillas have also acquired a long-range Soviet-made sniper rifle.
Rebel peasant fighters are taught to lead the target when aiming at helicopters by ``five or six body lengths.'' The rebels also train by aiming at a silhouette of a helicopter, which is carried on a stick. ``They've [Salvadoran troops] found hundreds of silhouettes on sticks recently, when they've searched guerrilla camps,'' says a US military source.
Such target practice has begun to pay off. Helicopter mechanics say that it is rare for helicopters to come back without fresh bullet holes. And more and more helicopters are being shot down or disabled. During the recent rebel offensive, a Huey helicopter and an A-37 bomber were both shot down in San Miguel. Two journalists riding Saturday in a military helicopter were wounded as the helicopter came down to land at the site of the crashed Cessna.
Although the rebels have long asserted their right to use surface-to-air missiles, similar to those provided to the contras by the US, they apparently never used them for fear of being seen as escalating the conflict. The Cessna's cargo, though, indicates that the rebels may be reevaluating their position, observers here say.
One Salvadoran analyst says that the Salvadoran Air Force's bombardment of guerrilla-occupied residential districts allows the rebels to justify the acquisition of more sophisticated technology to shoot down the government's aircraft.
And if the rebels make a new push in the capital, the anti-aircraft missiles could give them the ability to neutralize the government's advantage in the air.