Before Iraq invaded Kuwait, business had been kind of sluggish at Herndon-based WorldCorp Inc.

The charter airline company headquartered near Dulles Airport had reported several quarters of losses in 1990, its stockprice had fallen and there were costly delays in renewing a major military charter contract. But ever since President Bush decided to send U.S. troops to the Persian Gulf, World's phones have been ringing off the hook.

Last week, World began flying troops to Saudi Arabia, one of several airlines helping to ease the government's transportation crunch as an estimated 200,000 U.S. troops are ferried to the Persian Gulf.

Another charter company, New York-based Tower Air Inc., also began shuttling military personnel to Saudi Arabia last week, according to spokesman Rosalind Ellingsworth. The Department of Defense also has chartered two airplanes from Delta Air Lines, according to company spokesman Neil Monroe.

To ensure access to commercial planes, the government also maintains the Civil Reserve Air Fleet, activated last night by the Pentagon for the first time in the program's 38-year history. All airlines and charter services with government contracts commit a specific number and types of planes to the fleet, which the military can call on in a national emergency.

It was not clear last night what impact the Pentagon move to activate the civil fleet will have on the charter business. Before the fleet was activated, however, the military had preferred to work with airlines under existing contracts. That way the military could contract out needed wide-bodied aircraft, including 747s, McDonnell Douglas DC-10s and Lockheed L-1011s. In contrast, many airlines commit narrow-bodied aircraft to the civil reserve fleet.

The increased government business thus far has been a boon to small charter companies such as WorldCorp, which have been struggling in a depressed airline market.

William F. Genoese, director of the Teamsters union's airline division, which represents World's flight attendants, said the trips to Saudi Arabia made flight crews nervous. "There's a lot of anxiety," he said. "They have a right to say they don't want to go."

Flight crews that make the journey have war-zone insurance coverage with special benefits for prisoners of war, Genoese said.

Experts said it is the scale of the operation, rather than the military's use of commercial carriers, that makes Operation Desert Shield unusual. The government routinely relies on commercial aircraft for troop transportation -- a service that can be a steady source of revenue for airlines with government contracts. Even during peacetime, some commercial airlines shuttle thousands of soldiers to U.S. military bases around the world.

"It's one way of doing business. If the military had to maintain all this stuff organically, it would cost a fortune," said Lawrence J. Korb, who served as assistant secretary of defense for manpower and logistics from 1981 to 1985. Korb estimated that commercial airlines will transport about one-fourth of the troops heading to the Persian Gulf.

Some commercial airlines have been contacted by the government but have not been told when they will need aircraft. Military officials have notified Northwest Airlines that they may need three Boeing 747s, but have not said when they will need them, said spokesman Doug Miller.

United Airlines, Continental Airlines, Federal Express and several other major carriers declined to comment on whether they were participating in troop movements. USAir, based in Arlington, and American Airlines said they had not been contacted by the military.

T. Coleman Andrews III, president of WorldCorp, refused to comment on his airline's participation in troop movements. But several sources close to the airline and military experts said that World is involved.

World has made secrecy paramount, sending a message to its employees that it does not want them talking publicly about flights to the Persian Gulf.

Officials at the Military Airlift Command, which coordinates transportation of troops and equipment to Saudi Arabia, are tight-lipped about the operation. "We are contracting out some of the airlift for Operation Desert Shield," said Staff Sgt. Mark Johnson, a spokesman for Military Airlift Command at Scott Air Force Base, Ill.

Although Johnson would not identify which airlines were involved, what they were carrying or any other details of the airlift for security reasons, he did say commercial airlines make up a small percentage of the total number of aircraft in use by the military.

"Two weeks ago, a lot of these airlines were seeing business dry up. A roller-coaster is the best way to describe it, rather than a windfall. They are now scrambling to meet military requirements," said Paul Hyman, director of cargo services for the Air Transport Association.

WorldCorp, which owns and operates World Airways and Key Airlines, has a three-year contract with the Department of Defense to provide transport and cargo services. The company's stock has plummeted in recent weeks, which Andrews attributed to three quarters of losses. But the company's fortunes may be changing as it settles into a familiar niche in the air transport business.

Founded in 1948, World became known for evacuating soldiers from Vietnam. Transporting military personnel has remained a large portion of its business.

After the war, it moved into scheduled passenger service, where its World Airways subsidiary was known for its discount fares. However, ensuing fare wars nearly destroyed the company, causing it to shift back into charter service and undergo a major restructuring.

Last year, the company had $223.8 million in revenue and $11.1 million in earnings.

Analysts predicted that some of World's military contracts would vanish as the United States reduces the number of military personnel in Europe. But that scenario has been put aside for now as World helps move U.S. troops to the Persian Gulf.

"They're going to make a lot of money," Korb said of World.

Staff writer Paul Farhi contributed to this report.