Jose Cremades grimaced when he saw the CIA's graphic animation of the final 49 seconds of TWA Flight 800, which burst into a fireball 10 miles off the coast of Long Island 16 months ago.
He lost his teenage son in the crash. Yet he now says the FBI's decision this week to formally end its criminal investigation has created an odd sense of relief.
"We now know that 230 passengers did not die because somebody wanted to kill them," says Mr. Cremades, president of the Association of Families of Victims of TWA Flight 800.
But the FBI's formal conclusion that the plane wasn't downed by a bomb or a missile raises unsettling questions about the safety of hundreds of older airplanes that are still flying.
The Boeing 747 that blew up because of what's now believed to have been mechanical failure was more than 25 years old.
"We will spare no effort to find the cause of the TWA explosion," said National Transportation Safety Board (NTSB) chairman James Hall at the FBI press conference on Tuesday.
Next month in Baltimore, his agency will hold five days of public hearings on the investigation and its ramifications for the airline industry.
Experts and investigators have spent months scrutinizing and reassembling more than a million pieces of Flight 800's wreckage. They've determined the center fuel tank blew up and are now looking at whether damaged wiring could have provided the deadly spark. The fuel tank was empty of fuel, but full of fumes.
"If you take a can of gas and throw a match in, nothing happens," says a Boeing engineer who helped design the 747. "Dump the gas out, throw a match in, the fumes will blow up."
LAST fall the NTSB, which has advisory capacities only, made four recommendations to the Federal Aviation Administration to help ensure no other fuel tanks explode. They include measures to flush flammable gases out of empty fuel tanks. The industry balked at what it said was the high cost of such changes. The FAA also hesitated, saying more tests were needed.
"While there has been some disagreement over them, I have been heartened by the fact that both the FAA and the industry have undertaken an inspection of every aircraft ... flying in commercial aviation in regard to the wiring probes and other things around the center fuel tanks," says the NTSB's Mr. Hall.
The FAA finally asked for comments on the recommendations last April. In June, Boeing issued a service bulletin calling for inspections of the fuel tanks and related systems in all of the estimated 1,100 747s still in service.
In August, the industry responded to the FAA and called for creation of an international fuel tank agency that could check the integrity of all wiring, fuel pumps, fuel lines, and all electrical equipment related to fuel tanks.
But Hall insists that more needs to be done. Beyond simply eliminating possible sources of ignition, he wants the industry to ensure that no flammable fuel gases are ever left in empty tanks. The FAA is expected to make its determination in several weeks.
During its hearings next month, the NTSB will go into "great detail" on the issue of aging aircrafts and their systems. More than a quarter of the domestic commercial fleet is at least two decades old. With the fierce competition brought on by deregulation and the advent of smaller, cut-rate airlines, the number of older aircraft in service is expected to continue to grow.
Boeing 747s, like most aircraft, are designed for a 20-year lifespan, experts say. Under certain circumstances, however, they can operate for 25 to 30 years.
"When you take a plane like 800, in excess of its optimum age..., it means you must have very, very close inspections," says the Boeing engineer. "If you ... get a 30-year-old automobile and crawl underneath it, especially if it was owned by several people over the years, it's not necessarily going to look the way the manufacturer built it in the first place."
The NTSB has not formally determined a "probable cause" in the crash of Flight 800, and officials don't expect one by the end of next month's hearings. They say it could be another six months or more.