The air war in El Salvador, an object of mixed military reviews and heavy criticism from human rights groups, is growing in intensity as the armed forces here acquire more and more weaponry.
The bombs dropped by the country's small fleet of jet fighters are heavier than those dropped last year. More rockets are being fired from increasing numbers of helicopters that also are armed with rapid-fire machine guns. Slow-flying propeller driven planes pepper the countryside with thousands of bullets.
The combat fleet is expected to grow further, a reflection of Salvadoran and U.S. military opinion that the air war has crippled the five-year old leftist insurgency here. Virtually the entire Salvadoran air force is U.S.-supplied.
Increased firepower, coupled with sophisticated aerial reconnaissance by U.S.-piloted planes, has had one major achievement: discouraging the rebels from massing troops for large-scale attacks. But it is not clear whether aerial attacks, especially bombing, actually kill many guerrillas.
A side effect of the air war--some say it may be a primary objective--has been that civilian backers of the guerrillas have been terrorized and have taken flight from rebel-dominated areas.
Human rights groups charge that the Salvadoran air force engages in "indiscriminate" bombing of civilians.
It is difficult to verify any of these charges because the guerrillas have mined many of the approaches to the areas they control and ambushes by both sides have made other parts of the country insecure.
Interviews by The Times with refugees from three frequently bombed regions and with relief workers with access to battle zones yielded little evidence to support the charge of widespread bombing. There are many tales of bombing and strafing, but such attacks do not seem to be indiscriminate and few civilian casualties have been reported.
Most of the witnesses are civilians who sympathize with the rebellion and have relatives under arms.
Nonetheless, given the increasing power of the bombs and the stepped-up strafing plus the rebels' penchant for living with or near their families and supporters, the menace to civilians appears real.
"The bombing announces death," said Ramon Ardon, a resident of Corozal, in the region of Guazapa mountain, a target of air attack.
The Salvadoran air force is dropping an average of 129 bombs a month this year, compared to 140 in 1984, according to U.S. figures. However, last year, most of the bombs dropped were 500-pound explosives. This year, more than half weigh 750 pounds.
The workhorses of the bombing fleet are nine A-37 Dragonfly attack jets. Three of them were delivered here in January. Delivery of another one is expected soon, and Western observers expect the fleet to eventually number an even dozen.
Each A-37 is also equipped with rockets and a rapid-fire "mini-gun" in its nose. The mini-gun can spray an area with up to 6,000 bullets a minute. The effect on trees and buildings was once described by a pilot as like "hay going through a threshing machine."
During the Vietnam War, U.S. pilots used the Dragonfly for low-level attacks on villages thought to harbor guerrillas. Salvadoran pilots, on the other hand, often drop their bombs from high altitudes, making the attacks less accurate.
The air force also flies five O-2 "Push-Pull" propeller planes that fire 2.75-inch rockets.
The use of combat helicopters has added greatly to the monthly fusillade. Between the O-2s and the choppers, an average of 900 rockets a month rain down on the countryside this year, compared with 500 last.
The Salvadoran combat helicopter fleet consists of 43 UH-1H gunship and troop transport helicopters, each armed with a pair of machine guns. Six Hughes 500 choppers also are equipped with mini-guns.
The United States is sending six more UH-1H choppers this summer, and the Salvadorans have requested four UH-1M helicopters that are fitted with night-vision equipment.
This year, two AC-47 "fire support platforms" made their debut in El Salvador. The AC-47s are revamped, twin-engine DC-3s, armed with a pair of .50-caliber machine guns. The planes circle combat zones at a slow pace and pour fire on targets selected by special reconnaissance equipment. They are most often used to protect helicopter landings of troops.
The Salvadoran air force recently bought three more reconditioned AC-47s to operate in rotation when the other planes are being repaired. Two more are on the way.
Rebel officials have long said that air strikes discourage their troops from massing for attack. And, as a result, large-scale assaults on military installations or towns are now rare in El Salvador's civil war.
During a recent interview, Shafik Handal, one of five top rebel commanders, said the insurgents "reserve the right" to obtain anti-aircraft rockets. He declined to specify the type or the possible source.
In any case, now that rebel units are dispersed, the effectiveness of bombing is questionable. During a recent visit to Morazan province, guerrilla leaders told reporters that the bombing does little more than tip off the rebels that the army is set to launch an offensive.
No Casualties Seen
In February, Salvadoran commanders sent up helicopters, bombers and an AC-47 to disperse a group of rebels who were burning civilian vehicles on a main highway. There were no signs of guerrilla casualties.
The helicopters, however, present some problems to guerrillas on the move. Unlike the bombers, which drop their load and return to base, the helicopters pursue and fire for a longer period.
They can be especially effective if they surprise a guerrilla unit. Rebel commander Nidia Diaz was captured this spring after a Hughes 500 helicopter strafed the unit she was leading.
Diaz, who suffered four wounds, was the only survivor of the attack.
The Salvadoran armed forces are convinced of the air war's effectiveness.
"The subversives would not be complaining about bombing if it wasn't hurting them," said spokesman Maj. Carlos Aviles.
Aviles said that pilots may have mistakenly hit civilians, but he denied there was a government policy to target noncombatants.
American military advisers working in El Salvador fret that the Salvadorans might rely too heavily on air power. "One of the concerns is that the Salvadorans not develop a firepower mentality," said a military observer. "An air system is not going to win this war."
Poor Target Selection
Retired U.S. Army Col. Edward King, a private defense consultant, said that on a recent visit to El Salvador, he found scant evidence of indiscriminate bombing. "Some of the targets may be badly selected," he said. "They knock down lots of abandoned buildings."
King also predicted that the Salvadorans might try to replace dangerous ground patrols with air power.
Interviews with refugees and residents of battle zones suggest that while bombing runs and helicopter attacks often accompany ground advances, sometimes the air force is used alone to soften up guerrilla positions.
Many refugees arriving in San Salvador say that the danger of air attacks prompted them to flee their homes. Refugees from Guazapa, who fled their village in April, were interviewed at the Betana refugee camp near San Salvador.
They knew of one case of a civilian hit by a bomb--the mother of a man named Vicente Quevedo.
"It's only by luck that we weren't killed," said Antonio Rodriguez, 69. "The aviation comes day and night."
Marta Arias, 40, from Cerros de San Pedro, a mountainous guerrilla-populated area, said that bombing from the air and burnings by foot-soldiers had destroyed most houses in her village.
"The bombs come and then the soldiers," she said. "We can't stand it anymore."
At the Domus Mariae refugee camp in the San Salvador suburb of Mejicanos, Guazapa refugees who arrived last week told much the same story. Some said the bombings occurred daily, some said four times a month, some twice a month.
"These are not ordinary bombs," said Yolanda Hernandez, 45. "These are bigger."
Alicia Landaverde, 28, recalled that a woman and child were hit by a bomb and died a year ago. No one else gave concise information on civilian deaths.
In any case, the refugees all said that when an attack started, they fled to mountainside hand-dug shelters called tatus .
"The rockets and the bombs come because the soldiers think there are guerrillas," said Jose Rivera, 50, from Mirandilla. "But the guerrillas have already fled."
Salvadoran human rights officials contend that aerial bombardment and strafing have replaced death squad killings as a tool of the armed forces. The object of both is to erase civilian support for the rebels.
"The guerrillas are touched little by the bombing. The civilians suffer," said Maria Julia Hernandez, an official of the Roman Catholic Church's legal aid office.
Hernandez concedes that aerial bombing is in one sense more controlled than in past years. No longer does the air force bomb outside of battle areas.
"But within the conflict zone, the bombing is still indiscriminate," she asserted.
The U.S. human rights group, Americas Watch, charges that the air war is part of a concerted effort to drain civilian support from rebel-dominated territory.
Aerial bombing was first criticized as indiscriminate in 1983 by Cardinal Arturo Rivera y Damas, following air force bombings of the towns of Tenancingo and Berlin. Such attacks on towns have not been repeated since.
The air war has also become a propaganda dogfight. The government of President Jose Napoleon Duarte maintains that the complaints of massive bombing are overblown, especially when the level of bombing is compared with the U.S. war in Vietnam or the Israeli invasion of Lebanon.
Last fall, Duarte publicized a list of restrictions on bombing designed to avert random attacks. Under the guidelines, pilots are supposed to assault only targets designated by spotters on the ground or in the air.
The guerrillas counter that the bombing is meant only for civilians and sometimes stretch the truth to prove the point.
During a recent visit to Perquin, reporters and a delegation of U.S. Latino activists were shown the City Hall and told that it had been hit by a 500-pound bomb--although there was no characteristic crater visible.
A rebel sentinel later let slip that it had been destroyed by guerrilla sappers who blew the roof off, and a guerrilla spokesman apologized for the misunderstanding.