Having ruled out all the mechanical malfunctions that could cause a C-130 to fall from the sky in that manner, the American team left it to the Board to conclude "the only other possible cause of the accident is the occurrence of a criminal act or sabotage leading to the loss of control of the aircraft".

This conclusion was reinforced when an analysis of chemicals found in plane's wreckage, done by the laboratory of Bureau of Alcohol, Firearms and Tobacco in Washington, found foreign traces of pentaerythritol tertranitrate (PNET), a secondary high explosive commonly used by saboteurs as a detonator, as well as antimony and sulfur, which in the compound antimony sulfide is used in fuses to set off the device. Using these same chemicals, Pakistan ordinance experts reconstructed a low-level explosive detonator which could have been used to burst a flask the size of a soda can which, the Board suggested, probably contained an odorless poison gas that incapacitated the pilots.

But this was as far as the Board of Inquiry could go. It had not had autopsies done on the remains of the crew members to determine if they were poisoned. It acknowledged in its report that it lacked the expertise to investigate criminal acts. What was needed was criminal investigators and interrogators. It thus recommended that the task of finding the perpetrators by turned over to the competent agency, which meant, as one of the investigators explained to me, Pakistan's intelligence service--the ISI.

I also spoke to an American chemical warfare expert about poison gases that could have been used. He explained that Chemical agents capable of knocking a flight crew, while extremely difficult to obtain, are not beyond the reach of any intelligence service, or underground group with connections to one. He also pointed out that a gas capable on insidiously poisoning a whole flight crew (and leaving the pilot's fingers locked on the radio switch) had been used in neighboring Afghanistan. According to the State Department's special report 78 on "Chemical Warfare in Southeast Asia and Afghanistan," which he sent me, corpses of rebel Muejadeen guerrillas were found still holding their rifles in firing positions after being gassed. This showed that they had been the victims of "an extremely rapid acting lethal chemical that is not detectable by normal senses and that causes no outward physiological responses before death." This gas manufactured by the Soviet would have done the trick. But so would American manufactured "VX" nerve gas, according to a scientist at the U.S. Army chemical warfare center in Aberdeen, Maryland. "VX" is odorless, easily transportable in liquid form, and a soda-sized can full would be enough, when vaporized by a small explosion, and inhaled, to causes paralyzes and loss of speech within 30 seconds. According to him, the residue it would leave behind would be phosphorous. And, as it turned out, the chemical analyzes of debris from the cockpit showed heavy traces of phosphorous.