I assume you mean “plane.” The FBI seemingly located a test of the subject plane in St. Louis. A handler placed a test packet (actually several) on a plane being cleaned for a routine test for his dog. The handler siad it was not the same plane and cites time logs at the airport to support his position. The FBI never extensively debriefed him and seems to have grasped at this straw to support a convenient theory.

This I had never heard.  I always though TWA800 was caused due to a faulty wire sparking the fumes in main fuel tank, and that the airline industry reacted to this explanation as if it were real.

The official FBI/NTSB determination. Of course the NTSB was immediately muscled away from the investigation when the FBI feared a crime had been committed and treated the wreckage as a crime scene – never mind that the NTSB does crash investigation for breakfast and would have a huge leg up on the FBI in capability. No other aircraft of this type or similar type ever crashed under similar circumstances, a faulty wire sparking to ignite fuel vapors. Of course Boeing strongly protested the finding. Granted that they have a vested interest, but they did not protest strongly when they had to re-design rudders and cargo doors when the NTSB found defects that led to crashes. Their engineers tend to be proud of their work and as a group they rejected the sparking wire theory.  Boeing was brow beaten into submission by the threat the NTSB could pose to continued operations.

Not only was Boeing upset with the finding, but flight crews also were skeptical. How would you as a flight crew like to fly on any plane that could blow up mid-air at any minute? How would you as a passenger feel about the prospect? I don’t remember hearing the NTSB issue an order to immediately ground all aircraft to repair the ticking time bombs that were flying the friendly skies. 

While I admit the possibility of President William Clinton lying his butt off so he doesn't have to deal with a terrorism problem, I doubt the truth could have been hidden in an investigation this size.  Too many people involved.

Actually an investigation of this nature is among the easiest to cover up. This type of CSI is extremely technical and the ability of outside investigative reporters to conduct even limited research is almost impossible. Two independent reporters did secret some tiny swatches of fabric to have them tested for bomb residue. The FBI went so anal that they had the reporters arrested and threatened a lawsuit unless the swatches were returned, newspapers agreed to not run a story on the results and the reporters never discuss their findings. If the FBI got the results back from the independent investigation and they were negative it would make sense to release the findings. Unless – the swatches had explosive residue, and or the FBI could not risk having a crime scene compromised by amateur Sherlock Holmes. Another interesting point is that the reporters were arrested for removing evidence from a “crime scene investigation.” If the plane blew up from a wire short, what crime is there? I’ll refer this question over to Scooter Libby, he is a little more up to speed on this issue at present.

Another thing to keep in mind is the benefit we have of hindsight. We assume today that the FBI is conducting counter-terrorism investigations with extreme vigor. In 1996-1997 this was not the case. The FBI efforts to uncover the plot to bomb the WTC in 93, Oklahoma City, TWA 800, the Bojinka plot, 911,all in the U.S. not to mention the information that they should have obtained that may helped prevent the Cole bombing, and embassy bombings in Africa and night club bombings in Germany all bespeak of a counter-terrorism department in the FBI that was non functional. 

While the FBI and NTSB were running in circles trying to sort out claims by witnesses that they saw “streaks of light” angling upwards toward the plane and that the streaks merged with the plane just as it exploded one person took less than 24 hours to take advantage of the opportunity. He was on trial in New York