Some national security experts believe the streaks in the sky witnessed by scores of people on Long Island just before TWA Fight 800 crashed into the Atlantic Ocean in July could have been a rocket launched by a hobbyist.
Government research has determined that a number of active amateur rocketeers live in the area near where the plane plunged into the Atlantic Ocean, killing all 230 people on board.
Experienced amateur rocketeers said it was virtually impossible that a non-military projectile hit the plane, and even if it did, no damage would have occurred.
But an official involved in the TWA probe said that large projectiles fired by amateur rocketeers easily could be mistaken from a distance for military missiles.
The theory that a missile downed the jet has been bolstered by the eyewitness reports of streaks in the sky. The possibility that witnesses really viewed a hobby rocket is an intriguing new factor that could strengthen the other two theories of what caused the crash: mechanical failure or a bomb placed aboard the craft.
So far, no hobbyist has admitted to firing a rocket, the government official said, and no military or civilian missile parts have been recovered by divers combing the bottom for debris.
Federal regulations require people planning to launch high-power rockets weighing more than 3.3 pounds to receive permission before the flight from the Federal Aviation Administration. In some cases, it is necessary to notify the nearest Air Traffic Control Center before smaller rockets are sent up.
An FAA spokesman said Friday the agency's files were being reviewed to determine whether anyone had requested permission to fire a rocket on July 17, the night the plane went down.
Meanwhile, the National Transportation Safety Board urged caution Friday about rushing to judgment in deciding what caused TWA Flight 800 to explode.
"We are still stymied as to what the initiating ignition was," said Peter Goltz, an NTSB spokesman.
NBC Nightly News reported Friday that just before the crash, the plane's pilots were attempting to transfer fuel from a wing tank on one side of the plane to feed engines on the other. The maneuver was undertaken to correct an imbalance of fuel in the plane's many tanks, NBC said.
The network said the revelation was of great interest to investigators who are more and more inclined to believe something mechanical brought down the plane.
Boeing Co. spokesman Doug Webb said the balancing of fuel would occur by using fuel in the fullest tank until the tanks were level. The fuel would not be transferred from tank to tank, nor through the center fuel tank.
Shelly Hazle, an NTSB spokeswoman, said the transfer of fuel is a routine function carried out by pilots to improve a plane's balance and efficiency.
Sources close to the investigation Friday played down a Washington Post report that tests on plane debris point to damage consistent with a slower explosion than would be produced by a bomb or missile.
The Associated Press source confirmed that such "low order" damage patterns are present on the fuel tank debris but said no conclusion can be drawn.