Zeeshan Sallahuddin
Note: This is an expert analysis of what may have happened to PL-8303 by a flight operations professional with 36 years of experience in Pakistan International Airlines (PIA). Full disclosure: he is my father, Salahuddin Gul.
PK-300, 1986
On February 4, 1986, around 8:30 in the morning, PIA flight PK-300 was in descent into Islamabad, arriving from Karachi. My father was the duty controller at the airport at the time. The pilot and co-pilot had already had their breakfast, while the flight engineer was having his food, and was consequently distracted. The pilot and co-pilot also forgot to lower the landing gear before landing. It would be the last flight the captain would fly.
The inevitable catastrophe was, however, without fatalities.
As the plane approached the runway, nose tilted in the air, the tail struck the runway with a sickening thud, immediately signaling to the cockpit crew that something had gone awfully wrong. The pilot made a split-second decision, the only critical one he needed to make, training kicking in during a state of adrenaline and emergency, and lowered the landing gear. The jet, a Boeing 747-282B, has 18 wheels, two beneath the nose, and the remaining 16 in sets of four beneath the wings and the fuselage. It was too late for these to be of any use (they would not be able to lock in time due to ground impact), but as the nose lowered, there was just enough time for the nose wheels to descend and lock into place.
The plane underwent something called a belly-landing, and the descended front two wheels allowed the pilot to steer the plane as it slowed down, thus avoiding a much larger catastrophe. Of the 247 passengers and 17 crew, the only minor injuries came during the evacuation process using escape slides. The captain accepted the blame unconditionally, and was let go, his flight career ending abruptly. Two of the four engines were completely destroyed, with additional damage to the fuselage and the keel beam – a “backbone” steel beam that runs the length of the aircraft. The 747 eventually returned to service after repairs by Boeing.
From what we know of the crash of flight PK-8303, the two situations have stark similarities, with obviously very different endings.
What do we know so far?
We know that the flight tried to land, but the landing gear was not lowered and locked upon the first attempt at landing. We know that both engines physically came into contact with the runway during the first attempt, roughly at the 4,500 feet mark for the first engine, and 5,500 feet mark for the second engine. The pilot then made a second approach, and owing to engine failure and lack of power, crashed before he could make it back to the runway.
We also know that the flight was asked to re-ascend to 3,000 feet. We know that the damaged engines and the ram turbines were caught on camera by plane spotters during the second landing attempt (ram turbines will automatically engage if the engines fail). Finally, we know that the air traffic controller was expecting a belly-landing from the conversation.
Technical jargon
A few technical terms need to be understood here. First, if a flight has to take off during an attempted landing, the pilot has to pull back the throttle and supply power to the engines to help build the momentum to take off again. The engines take time to spool up, which can explain the engine marks on the ground for a significant distance. Second, when an unusual incident like this happens, the flight is asked to ascend to 3,000 feet before making another attempt, which is precisely what the controller asked the flight to do. This is standard procedure for the Instrument Landing System (ILS), and the primary reason for this will become apparent in a moment. Third, all planes have something called a stall speed. Below this threshold, the plane will drop like a rock, but if there is sufficient height, it may be glided into a safe landing; this is why the 3,000 feet height is essential. Finally (and as stated above), if both engines in this particular aircraft fail, ram turbines automatically descend, providing electric power to essential functions.
It is important to remind readers at this point that the following is expert analysis, theorizing what may have happened using currently known facts and nearly four decades of flight operations experience in PIA. The final answers will be provided by the formal investigation that is made part of any and all air crashes, which takes into account the recovered flight data recorder and the cockpit voice recorder.
Why was the landing gear not lowered?
There are three reasons this could have happened. First, much like PK-300 in 1986, it could have been pilot error. This is an extremely unlikely and rare occurrence in large planes (though fairly common in small aircraft). Second, it could be that landing gear was lowered too late and it did not descend, and with the commitment made to land a few hundred feet above the ground, the cockpit crew could not pull out of the landing in time. Third, it could be equipment malfunction in the form of a hydraulics failure. We know from the recording that the warning system in the cockpit for the still-retracted landing system was functional from the distinct ding-ding-ding-ding in the background.
Why did the pilot take off again?
Once the engines made contact with the ground, there are effectively two options for the pilot/copilot. The first is to commit to and execute the belly landing. This is extremely difficult and dangerous as the pilot has no control over the steer direction of the fuselage, and the engines, full of combustible fuel, are at risk of catching fire. The second option it to attempt to take off, keeping in mind that part of the aircraft may have been damaged, but potentially saving the flight altogether with a miracle or two.
There is but the tiniest window of time to make this decision, and you cannot switch from one to the other once committed. The pilot/copilot elected to go with the latter option, possibly in the hopes that the landing gear would descend during the second approach, allowing them to land safely, though damaged. Neither decision is good or bad, and most pilots let their training and gut reaction guide their decision. It would be impossible at this stage to say the pilot/copilot made the wrong call in such a grave and psychologically challenging situation.
Why did this plan not work?
The key is in the engines striking the ground, by one account, for 7,000 feet of runway. The runway is not as smooth a surface as normal metaled roads. They are coarse, with grooves cut in them to help aircrafts brake faster. Contact with the body of the aircraft would inevitably cause heavy damage, even if the contact was for a brief moment. The engines came into contact with the ground, scraped for a while, and then the airplane took off again. This implies not only that the engines were damaged from the impact and the subsequent friction, but that they initially continued to function, as the plane would not be able to ascend again at all without engine power.
Once the decision to take off again was taken, the pilot pulled back on the throttle – while the engine still functioned – increasing engine power to ascend again. The engines initially aided the effort, but then as the pilot attempted to rise to the height of 3,000 feet, they both shut down, leaving the plane with ram air turbine power for basic functions, but no lift power. The second, ill-fated approach to the runway was made with a) no functional engines (as the ram turbines were out), b) minimal power from the ram air turbines, and c) insufficient flight altitude.
What happened in the end?
In the absence of power, the plane crossed the dangerous stall-speed threshold, and started dropping altitude rapidly. It is unclear from the currently known facts if the pilot ever made it to 3,000 feet, though evidence suggests that he never did. According to one report, he told the air traffic controller that they were struggling with the height during the second attempt. Once the stall threshold was crossed, it was only a matter of time before the plane came down. It cannot rise, and the weight will not allow it to maintain its altitude (an A-320 is 37.2 tons when completely empty; it was likely 60 tons closer to the destination). In such a desperate situation, the only hope is to use the wings to glide the plane from a sufficient height onto an available landing surface.
The air traffic controller cleared both runways for the flight to land, recognizing that it took priority over everything else in the sky at the moment. However, the plane was likely not high enough to glide into the vector needed to successfully land, and it eventually crashed right next to the airport, in Model Colony, killing all but two on board. One expert believes that the plane may have needed as little as another 100 feet of altitude to clear the buildings and attempt the belly-landing at Karachi airport.
As stated before, the above is a calculated guess, based on decades of flight operation experience. What actually happened to flight PK-8303 will be revealed by the comprehensive investigation into the crash.
The author is an Editor-at-Large for MATRIX MAG. He also serves as a Senior Research Fellow at the Center for Research and Security Studies, Islamabad, holds a master’s degree in strategic communications from Ithaca College, NY. He can be reached via zeeshan[dot]salahuddin[at]gmail.com and tweets @zeesalahuddin.
