( CNN ) -- It was n't long after TWA Flight 800 exploded off the coast of Long Island on a warm July evening in 1996 that the conspiracy theorists emerged . Seventeen years later , they 're still here . I have n't seen a new documentary that purports to repudiate the conclusions of the National Transportation Safety Board , which ruled that the crash of the 747 headed for Paris was caused by a center fuel tank explosion likely ignited by faulty wiring . But I do know that -- despite all the media attention the filmmakers are getting -- their essential claim that a missile hit the plane is not new . And neither are aircraft fuel tank explosions . In fact , they were considered enough of a danger that the Federal Aviation Administration has put in place new regulations to prevent such events . And the FAA , heavily lobbied by airlines and aircraft manufacturers who want to keep their costs low , does not enact new regulations without reason . When I covered the four-year investigation into TWA Flight 800 for Newsday , I spent hundreds of hours interviewing investigators , scientists and experts ; I walked around inside the center fuel tank of a Boeing 747 ( yes , it 's that big ) at a plant in Seattle ; and I continued to cover the aftermath of the NTSB 's final report that culminated in an FAA rule to make airlines pump inert gas into fuel tanks to prevent explosions . I remember being surprised when I first learned of fuel-tank explosions on aircraft , particularly those designed with air-conditioning units below the center tank . At first it seemed unbelievable . But when an aircraft 's fuel tank is nearly empty , as is often the case with the center tank , the heat from the air-conditioning packs underneath combined with ambient temperatures can create , well , what seems like a bomb on board . In 1990 , the fuel tank of a Philippine Airlines plane exploded on the ground in Manila , killing eight people . In 2001 , a Thai Airways International plane blew up on the ground in Bangkok when its center tank exploded . And as recently as 2006 , the wing tank of a Boeing 727 exploded on the ground in Bangalore , India . In 2000 , the FAA compiled a list of 26 fuel-tank explosions dating back to 1959 . I also remember the day l learned that the system that tells pilots how much fuel remains includes electrical components located inside the tank . Although aircraft wiring is made to be strong and durable , it is also subject to the effects of aging and abrasion -- so much so that short circuits can occur . On July 17 , 1996 , the conditions -- a volatile fuel-air mix of vapors in the center fuel tank heated to the point of being explosive , a likely short circuit in fuel-gauge wiring and 230 people on board -- came together with a tragic result . I ca n't speak to the motives of the former investigators who are calling for a renewed investigation . But it is important to note that while a poster from the film on epix.com trumpets , `` inside investigators finally break their silence , '' one of the key investigators featured testified about the NTSB 's failings before the Senate Judiciary Committee in 1999 . It would seem that if he had something more pertinent to say he would have said it long ago . As for the missile theory , its main proponents were those eyewitnesses who reported seeing a streak of light in the sky on the night of the crash . That streak has been explained as the still-airborne fuselage of the Boeing 747 after the nose of the plane broke off and fell to earth -- and debris recovery patterns confirm this scenario . Metallurgical evidence showed that the fuel tank , the main structural component between the wings , exploded from the inside , with no evidence of a puncture or outside entry . The filmmakers say they have new radar evidence . I do n't know why it has n't surfaced before now , or how it will contradict the physical evidence that shows the fuel tank exploded from the inside . I do know that when the process turns to fault-finding in aviation accidents , there are many competing interests with a stake in the game -- the pilots ' union , aircraft manufacturers and airlines , all with lawyers ready to battle their side . When I covered aviation safety , it seemed that the NTSB was the only entity with no conflicts of interest . Even the media want a good story -- and what better story than a missile and cover-up ? I imagine the same can be said of people who want to sell an idea for a documentary . Fuel-tank explosions and exposed wiring just are n't that sexy . Conspiracy theories about TWA Flight 800 are a bit like 17-year cicadas . Except they seem to emerge a bit more often . The opinions expressed in this commentary are solely those of Sylvia Adcock .
Sylvia Adcock : Conspiracy theories have long been around story of Flight 800 crash . Documentary says NTSB theory -- crash caused by center fuel tank blast -- was wrong . She says it caused new regulations ; FAA does n't make costly regulations without reason . Adcock : There 's huge amount of physical evidence NTSB right -- where 's investigators ' proof ?