Past air disasters saw waves of civil suits against airlines, security companies and manufacturers, but the scope and nature of the September 11 terrorist attacks prompted special legislation which created a legal landscape as unprecedented as the attacks themselves.

Tacked onto Congress's $15 billion airline bailout is a blueprint for victims' families to collect money. The legislation gives survivors the choice of applying to a taxpayer-financed compensation fund, where money will be distributed relatively quickly, or pressing their case in Manhattan federal court, where settlements are expected to be larger for a few, but nonexistent for others and longer in resolution for everyone.

Deciding which path to take, lawyers say, is likely to turn on how the victims were situated both physically and financially at the time of the attack. But lawyers who met with victims last week said they were cautioning their clients to go slow. Many aspects of the new compensation program, including its nuts and bolts workings, are still undecided. And lawyers say potential targets for civil suits, such as flawed airport security companies and foreign governments that sponsor terrorism, will only become known as the massive international investigation continues.

The federal fund, known as the September 11th Victim Compensation Fund of 2001, is designed to compensate victims for "economic and noneconomic losses," but it does not assess blame or award punitive damages. Families and survivors who apply to the fund are barred from pursuing suits, including those against the airlines. A "special master" appointed by Attorney General John Ashcroft will evaluate each case and determine how much a family should receive. And the Association of Trial Lawyers of America has stepped forward to offer free representation to families seeking compensation from the fund.

To fix the amount, the special master considers "economic losses" like the victim's future earning potential at the time of death. Taken into account are the victim's salary, age and chances for advancement. But the special master also considers "noneconomic" factors such as the physical and emotional pain suffered by family members and their "loss of enjoyment of life." The amounts determined by the special master will vary dramatically from person to person, even among those who worked on the same floor of the World Trade Center.

"That's standard. In a typical plane crash ... [the amount of compensation] would be all over the ballpark," said Anthony Tarricone, a Boston lawyer consulted by several victims' families.

The final figure is lowered if the victim had life insurance or received death benefits from his or her employer. Those payouts are subtracted from the special master's award.

"Let's say your case is worth $5 million. If you already had $5 million in employment benefits, you get nothing," said Bob Clifford, a Chicago lawyer specializing in aviation.

The insurance exception, known as "collateral compensation," may encourage families with generous death benefits to opt for federal court instead of the compensation fund.

"I don't know if you can say they have more to gain in litigation. It's that they had nothing to gain" from the fund, Clifford said.

Typically, families with large insurance packages are wealthier. Poorer families, whose concerns are month-to-month expenses rather than shoring up college savings or retirement plans, are more likely to apply to the compensation fund, experts say.

The compensation legislation stipulates that fund be ready to operate within three months, and that once underway, victims' families will be told how much money they will get within 120 days of applying.

Don Nolan, a Chicago lawyer representing families on all four of the hijacked airplanes, said settlements reached in federal court will almost certainly be larger than the compensation fund, but for families struggling to make ends meet now, the difference in awards is unimportant.

"For some people, getting a much lesser sum earlier is better. Those are people with real economic needs," he said.

Some lawyers speculate that only airline passengers and not victims on the ground will be able to successfully sue the carriers. The duty to protect the safety of passengers is well defined, but the airline's duty to those on the ground in the face of unprecedented acts of terrorism has not been established.

"[The airlines] will argue that they could not have foreseen people driving planes into buildings and the acts of criminals exculpates them," said Nolan.

The civil suit procedure is also spelled out in Congress's airline bailout. All cases stemming from the attacks are to be handled in Manhattan's federal court, and airline payouts are capped at the amount for which the planes were insured, reportedly $6 billion. The legislation does not address whether other institutions sued in the court, such as airports, their security companies, and building owners, would also be capped at the amount of their insurance.

The airline caps mean there are limited funds available, and families who choose court instead of the government fund will have to compete against other victims' relatives and those who suffered property damage, such as business owners, whose only recourse is a suit.

Under the circumstances, said New York aviation lawyer Lee Kreindler, running out of money "is a serious possibility."