On August 17, 1988, at 3:58 PM, Pak One, an American built Hercules C-130b transport plane,
carrying its VIP capsule the President of Pakistan, General Zia-ul-Haq, most of his top generals,as well as two American guests– US Ambassador, Arnold L. Raphel and US military missionhead General Herbert Wassom– crashed to earth only 18 miles from the airport in centralPakistan from where it took off. It had been a. bright clear day, and dozens of eye witnesses could see the giant aircraft lurch up and down three times in the sky, as if were on an invisible roller coaster, and then plunge straight into the desert and explode in a fire ball. All 30 persons on board, including four crew members, were dead. Within hours, army tanks sealed off public building and television stations, signifying the change in power. Zia’s reign, which had begun with his own military coup on July 5, 1977, now had ended with his death. But even though the crash altered the face of politics in Pakistan in a way in which no simple Presidential assassination or coup d'etat could have done, its cause remains a mystery.
Former Prime Minister Benazir Bhutto, whose father he had allowed to be executed (and who
herself was assassinated in 2007,) said in the epilogue to her book, Daughter of Destiny "Zia's
death must have been an act of god". But divine intervention is not what brought the plane
down. According to the 365-page report of the forensic investigation done by six American Air
Force experts, headed by Colonel Daniel E. Sowada, no evidence of a accidental mechanical
failure or pilot error had been found. A conclusion of assassination was all but inescapable.
The aviation investigators, following the precepts of Sherlock Holmes, used on a process of
elimination. First, they ruled out the possibility that the plane had blown up in mid air. If it had exploded in this manner the pieces of the plane, which had different shapes and therefore
resistance to the wind, would have been strewn over a wide area-- but that had not happened. By re-assembling the plane in a giant jigsaw puzzle, and scrutinizing with magnifying glasses the edges of each broken piece, they could established that the plane was in one piece when it had hit the ground. They thus concluded structural failure--ie. The breaking up of the plane-- was not the cause. Next, they eliminated the possibility of a missile attack. If the plane had been hit by a missile, it would have generated intense heat which in turn would have melted the aluminum panels and, as the plane dived, the wind would have left tell-tale streaks in the molten metal. But there were no streaks on the panels. And no missile part or other ordinance had been found in the area.
They further rule out the possibility that there was an inboard fire while the plane was in the air since, if there had been one, the passengers would have breathed in soot before they died. Yet, the single autopsy performed, which was on the American general seated in the VIP capsule, showed there was no soot in his trachea, indicating that he had died before, not after, the fire ignited by the crash.
If it was not a missile or fire, the power might have somehow failed in flight. If this had
happened, the propellers would not have been turning at their full torque when the plane crashed, which would have affected the way their blades had broken off and curled on impact. But by examining the degree of curling on each broken propeller blades, they determined that in fact the engines were running at full speed when the propellers hit the ground.
Had the fuel been sabotaged? They ruled out the possibility of contaminated fuel by taking
samples of the diesel fuel from the refueling truck, and, by analyzing the residues still left in the fuel pumps in the plane, they could also tell that they had been operating normally at the time of the crash. They then ruled out any problem with the electric power on the plane because both electric clocks on board had stopped at the exact moment of impact, which they determined independently other evidence.
The final possibility of mechanical failure was that the controls did not work. But the Hercules
C-130 had not one but three redundant control system. The two sets of hydraulic controls were
backed up, in case of a leak of fluid in both of them, by a mechanical system of cables. If any one of them worked, the pilots would have been able to fly the plane. By comparing the position of the controls with the mechanisms in the hydraulic valves and the stabilizers in the tail of the plane (which are moved through this system when the pilot moves the steering wheel), they established that the control system was working when the plane crashed. This was confirmed by a computer simulation of the flight done by Lockheed, the builder of the C-130. They also ruled out the possibility that the controls had temporarily jammed by a microscopic examination of the mechanical parts to see if there were any signs of jamming or binding.
That left the possibility of pilot error. But the crash had occurred after a routine and safe take
off in perfectly clear daytime weather and the hand-picked pilots were fully experienced with the C-130 and had medical check-ups before the flight. Since the plane was not in any critical phase of flight, such as take off or landing, where poor judgment on the part of the pilots could have resulted in the mishap, the investigators ruled out pilot error as a possible cause. Based on this investigation, Pakistan’s Board of Inquiry concluded that the only other possible cause of the crash of Pak-One was a criminal act “leading to the loss of control of the aircraft." It suggested the pilots must have been incapacitated but this was as far as it could go since there was no black box or cockpit recorder on Pak One and no autopsies had been done on the remains of the pilots.
What had happened to the pilots during the final minutes of the flight? When I went to
Pakistan in February 1989, I attempted to answer that question. There were three other planes in the area tuned to the same frequency for communications– the turbojet carrying General Aslam Beg, the Army’s vice chief of staff, which was waiting on the runway at Bahawalpur airport to take off next; Pak 379, which was the backup C-130 in case anything went wrong to delay Pak One; and a Cessna security plane that took off before Pak One to scout for terrorists. With the assistance of the families of the military leaders killed in the crash, I managed to locate pilots of these planes-- all of whom were well acquainted with the flight crew of Pak One and its procedures-- who could listen to the conversation between Pak One and the control tower in Bahawalpur. They independently described the same sequence of events. First Pak One reported its estimated time of arrival in the capital. Then, when the control tower asked its position, it failed to respond. At the Same Time Pak 379 was trying unsuccessfully to get in touch with Pak One to verify its arrival time. All they heard from Pak One was "stand by" but no message followed. When this silence persisted, the control tower got progressively more frantic in its efforts to contact Zia's pilot, Wing Commander Mash'hood. Three or four minutes passed. Then, faint voice in Pak One called out "Mash'hood, Mash'hood". One of the pilots overhearing this conversation recognized the voice. It was Zia's military secretary, Brigadier Najib Ahmed who apparently, from the weakness of his voice, was in the back of the flight deck (where a door connected to the VIP capsule.) If the radio was switched on and was picking up background sounds, it was the next best thing to a cockpit flight recorder. Under these circumstances, the long silence between "stand bye" and the faint calls to Mash'hood, like the dog that didn't bark, was the relevant fact. Why wouldn't Mash'hood or the three other members of the flight crew spoken if they were in trouble? The pilots aboard the other planes, who were fully familiar Mash'hood, and the procedures he was trained in, explained that if Pak One's crew was conscious and in trouble they would not in any circumstances have remained silent for this period of time. If there had been difficulties with controls, Mash'hood instantly would have given the emergency "may day" signal so help would be dispatched to the scene. Even if he had for some reason chosen not to communicate with the control tower, he would have been heard shouting orders to his crew to prepare for an emergency landing. And if there had been an attempt at a hijacking in the cockpit or scuffle between the pilots, it would also be overheard. In retrospect, the pilots of the other aircraft had only one explanation for the prolonged silence: Mash'hood and the other pilots were unconscious while the thumb switch that operated the microphone had been kept opened by the clenched hand of a pilot..
The account of the eyewitnesses at the crash site dove-tailed with the radio silence. They had
seen the plane slowly pitching up and down. According to a C-130 expert I spoke to at
Lockheed, C-130's characteristically go into a pattern known as a "phugoid" when no pilot is
flying it. First, the unattended plane dives towards the ground, then the mechanism in the tail
automatically over-corrects for this downward motion, causing it to head momentarily upwards. Then, with no one at the controls, it would veer downward. Each swing would become more pronounced until the plane crashed. Analyzing the weight on the plane, and how it had been loaded on, this expert calculated the plane would have made three roller-coaster turns before crashing, which is exactly what the witnesses had been reported. He concluded from this pattern that the pilots had been conscious, they would have corrected the "phugoid"-- at least would have made an effort, which would have been reflected in the settings of the controls. Since this had not happened, he concluded, that they were paralyzed or unconscious
One hypothesis he advanced was that the flight crew might have been incapacitated by an
extremely rapid acting chemical agent, such as "VX" nerve gas. It is odorless, easily
transportable in liquid form, and a soda-sized can full would be enough to causes paralysis and
loss of speech within 30 seconds. Nerve gas would leave behind traces of phosphorous, and, as it turned out, the chemical analyzes of debris from the cockpit showed such traces of phosphorous.
So why were autopsies not performed on the bodies of the flight crew to determine whether a
nerve gas or other toxic agent had paralyzed them? The explanation given in the report was that Islamic law requires burial within 24 hours. But this could not been the real reason since the bodies were not returned to their families for burial until two days after the crash, as relatives confirmed to me. Nor were they ever asked permission for autopsy examinations. And, as I learned from a doctor for the Pakistan Air Force, Islamic law not withstanding, autopsies are routinely done on pilots in cases of air crashes. I was further told by doctors at the military hospital in Bahawalpur that parts of the victims' bodies had been brought there in plastic body bags from the crash site on the night of August 17, and stored there, so that autopsies could be performed by team of American and Pakistani pathologists. But before the pathologists had arrived, the hospital received orders to return these plastic bags to the coffins for burial.
These orders to literally bury the evidence came directly from the Army which was now
under the authority of General Beg, who, after having his turbojet pilot circle over the burning
wreckage of Pak One, few immediately back to the capital, Islamabad, to assume command.
For its part, Pakistani military authorities concentrated their investigation on the possibility
that Shi'ite fanatics were responsible for the crash. The co-pilot of Pak One, Wing Commander
Sajid, was a shi'ite (as are more than ten per cent of Pakistan's Moslems), as was one of the
pilots of the back-up C-130. This pilot, though he protested his innocence, was kept in custody
for more than two months and roughly interrogated about whether Wing Commander Sajid had discussed a suicide mission. Finally, the army abandoned this effort after the Air Force
demonstrated that it would have been physically impossible for the co-pilot alone to have caused a C-130 to crash in the way it did.
The government then appointed a commission headed by Justice Shafiur Rehman, a wellrespected judge on the Supreme Court, to establish the cause of the crash. Five years later, in 1993, it issued a secret report concluding that the Army's had so effectively obstructed the
investigation that the perpetrators behind the crash could not be brought to justice. The one
uncounted casualty of Pak One was thus the truth
elimination. First, they ruled out the possibility that the plane had blown up in mid air. If it had exploded in this manner the pieces of the plane, which had different shapes and therefore
resistance to the wind, would have been strewn over a wide area-- but that had not happened. By re-assembling the plane in a giant jigsaw puzzle, and scrutinizing with magnifying glasses the edges of each broken piece, they could established that the plane was in one piece when it had hit the ground. They thus concluded structural failure--ie. The breaking up of the plane-- was not the cause. Next, they eliminated the possibility of a missile attack. If the plane had been hit by a missile, it would have generated intense heat which in turn would have melted the aluminum panels and, as the plane dived, the wind would have left tell-tale streaks in the molten metal. But there were no streaks on the panels. And no missile part or other ordinance had been found in the area.
They further rule out the possibility that there was an inboard fire while the plane was in the air since, if there had been one, the passengers would have breathed in soot before they died. Yet, the single autopsy performed, which was on the American general seated in the VIP capsule, showed there was no soot in his trachea, indicating that he had died before, not after, the fire ignited by the crash.
If it was not a missile or fire, the power might have somehow failed in flight. If this had
happened, the propellers would not have been turning at their full torque when the plane crashed, which would have affected the way their blades had broken off and curled on impact. But by examining the degree of curling on each broken propeller blades, they determined that in fact the engines were running at full speed when the propellers hit the ground.
Had the fuel been sabotaged? They ruled out the possibility of contaminated fuel by taking
samples of the diesel fuel from the refueling truck, and, by analyzing the residues still left in the fuel pumps in the plane, they could also tell that they had been operating normally at the time of the crash. They then ruled out any problem with the electric power on the plane because both electric clocks on board had stopped at the exact moment of impact, which they determined independently other evidence.
The final possibility of mechanical failure was that the controls did not work. But the Hercules
C-130 had not one but three redundant control system. The two sets of hydraulic controls were
backed up, in case of a leak of fluid in both of them, by a mechanical system of cables. If any one of them worked, the pilots would have been able to fly the plane. By comparing the position of the controls with the mechanisms in the hydraulic valves and the stabilizers in the tail of the plane (which are moved through this system when the pilot moves the steering wheel), they established that the control system was working when the plane crashed. This was confirmed by a computer simulation of the flight done by Lockheed, the builder of the C-130. They also ruled out the possibility that the controls had temporarily jammed by a microscopic examination of the mechanical parts to see if there were any signs of jamming or binding.
That left the possibility of pilot error. But the crash had occurred after a routine and safe take
off in perfectly clear daytime weather and the hand-picked pilots were fully experienced with the C-130 and had medical check-ups before the flight. Since the plane was not in any critical phase of flight, such as take off or landing, where poor judgment on the part of the pilots could have resulted in the mishap, the investigators ruled out pilot error as a possible cause. Based on this investigation, Pakistan’s Board of Inquiry concluded that the only other possible cause of the crash of Pak-One was a criminal act “leading to the loss of control of the aircraft." It suggested the pilots must have been incapacitated but this was as far as it could go since there was no black box or cockpit recorder on Pak One and no autopsies had been done on the remains of the pilots.
What had happened to the pilots during the final minutes of the flight? When I went to
Pakistan in February 1989, I attempted to answer that question. There were three other planes in the area tuned to the same frequency for communications– the turbojet carrying General Aslam Beg, the Army’s vice chief of staff, which was waiting on the runway at Bahawalpur airport to take off next; Pak 379, which was the backup C-130 in case anything went wrong to delay Pak One; and a Cessna security plane that took off before Pak One to scout for terrorists. With the assistance of the families of the military leaders killed in the crash, I managed to locate pilots of these planes-- all of whom were well acquainted with the flight crew of Pak One and its procedures-- who could listen to the conversation between Pak One and the control tower in Bahawalpur. They independently described the same sequence of events. First Pak One reported its estimated time of arrival in the capital. Then, when the control tower asked its position, it failed to respond. At the Same Time Pak 379 was trying unsuccessfully to get in touch with Pak One to verify its arrival time. All they heard from Pak One was "stand by" but no message followed. When this silence persisted, the control tower got progressively more frantic in its efforts to contact Zia's pilot, Wing Commander Mash'hood. Three or four minutes passed. Then, faint voice in Pak One called out "Mash'hood, Mash'hood". One of the pilots overhearing this conversation recognized the voice. It was Zia's military secretary, Brigadier Najib Ahmed who apparently, from the weakness of his voice, was in the back of the flight deck (where a door connected to the VIP capsule.) If the radio was switched on and was picking up background sounds, it was the next best thing to a cockpit flight recorder. Under these circumstances, the long silence between "stand bye" and the faint calls to Mash'hood, like the dog that didn't bark, was the relevant fact. Why wouldn't Mash'hood or the three other members of the flight crew spoken if they were in trouble? The pilots aboard the other planes, who were fully familiar Mash'hood, and the procedures he was trained in, explained that if Pak One's crew was conscious and in trouble they would not in any circumstances have remained silent for this period of time. If there had been difficulties with controls, Mash'hood instantly would have given the emergency "may day" signal so help would be dispatched to the scene. Even if he had for some reason chosen not to communicate with the control tower, he would have been heard shouting orders to his crew to prepare for an emergency landing. And if there had been an attempt at a hijacking in the cockpit or scuffle between the pilots, it would also be overheard. In retrospect, the pilots of the other aircraft had only one explanation for the prolonged silence: Mash'hood and the other pilots were unconscious while the thumb switch that operated the microphone had been kept opened by the clenched hand of a pilot..
The account of the eyewitnesses at the crash site dove-tailed with the radio silence. They had
seen the plane slowly pitching up and down. According to a C-130 expert I spoke to at
Lockheed, C-130's characteristically go into a pattern known as a "phugoid" when no pilot is
flying it. First, the unattended plane dives towards the ground, then the mechanism in the tail
automatically over-corrects for this downward motion, causing it to head momentarily upwards. Then, with no one at the controls, it would veer downward. Each swing would become more pronounced until the plane crashed. Analyzing the weight on the plane, and how it had been loaded on, this expert calculated the plane would have made three roller-coaster turns before crashing, which is exactly what the witnesses had been reported. He concluded from this pattern that the pilots had been conscious, they would have corrected the "phugoid"-- at least would have made an effort, which would have been reflected in the settings of the controls. Since this had not happened, he concluded, that they were paralyzed or unconscious
One hypothesis he advanced was that the flight crew might have been incapacitated by an
extremely rapid acting chemical agent, such as "VX" nerve gas. It is odorless, easily
transportable in liquid form, and a soda-sized can full would be enough to causes paralysis and
loss of speech within 30 seconds. Nerve gas would leave behind traces of phosphorous, and, as it turned out, the chemical analyzes of debris from the cockpit showed such traces of phosphorous.
So why were autopsies not performed on the bodies of the flight crew to determine whether a
nerve gas or other toxic agent had paralyzed them? The explanation given in the report was that Islamic law requires burial within 24 hours. But this could not been the real reason since the bodies were not returned to their families for burial until two days after the crash, as relatives confirmed to me. Nor were they ever asked permission for autopsy examinations. And, as I learned from a doctor for the Pakistan Air Force, Islamic law not withstanding, autopsies are routinely done on pilots in cases of air crashes. I was further told by doctors at the military hospital in Bahawalpur that parts of the victims' bodies had been brought there in plastic body bags from the crash site on the night of August 17, and stored there, so that autopsies could be performed by team of American and Pakistani pathologists. But before the pathologists had arrived, the hospital received orders to return these plastic bags to the coffins for burial.
These orders to literally bury the evidence came directly from the Army which was now
under the authority of General Beg, who, after having his turbojet pilot circle over the burning
wreckage of Pak One, few immediately back to the capital, Islamabad, to assume command.
For its part, Pakistani military authorities concentrated their investigation on the possibility
that Shi'ite fanatics were responsible for the crash. The co-pilot of Pak One, Wing Commander
Sajid, was a shi'ite (as are more than ten per cent of Pakistan's Moslems), as was one of the
pilots of the back-up C-130. This pilot, though he protested his innocence, was kept in custody
for more than two months and roughly interrogated about whether Wing Commander Sajid had discussed a suicide mission. Finally, the army abandoned this effort after the Air Force
demonstrated that it would have been physically impossible for the co-pilot alone to have caused a C-130 to crash in the way it did.
The government then appointed a commission headed by Justice Shafiur Rehman, a wellrespected judge on the Supreme Court, to establish the cause of the crash. Five years later, in 1993, it issued a secret report concluding that the Army's had so effectively obstructed the
investigation that the perpetrators behind the crash could not be brought to justice. The one
uncounted casualty of Pak One was thus the truth
