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Today's Paper | December 05, 2024

Updated 25 Jun, 2020 10:10am

ANALYSIS: A litany of fatal errors

ISLAMABAD: Preliminary findings in the government-commissioned probe into last month’s crash of Pakistan International Airli­nes’ aircraft have pointed towards errors committed by the pilot and the air traffic controllers (ATCs) during the landing of the plane.

The report tabled by Aviation Minister Sarwar Khan in the National Assembly on Wednesday contains several unanswered questions. PIA’s flight PK-8303 from Lahore to Karachi crashed on May 22. Ninety-nine people, including eight crew members, were on board the ill-fated flight, 97 of whom lost their lives in the crash, while two miraculously survived. A woman was killed on the ground because of the burns she suffered when the aircraft crashed in Karachi’s congested Jinnah Gardens locality.

The events during the botched landing attempt by the pilot of the Airbus A320-214 aircraft, which carried the tail number AP-BLD, explain what really went wrong.

Briefly, the chain of events goes like this, to quote the report: “At 14:35 hrs the aircraft performed an ILS approach for runway 25L and touched down without landing gears, resting on the engines. Both engines scrubbed the runway at high speed.”

It further said: “Flight crew initiated a go-around and informed ‘Karachi Approach’ that they intend to make a second approach. About four minutes later, during downwind leg, at an altitude of around 2000 ft, flight crew declared an emergency and stated that both engines had failed. The aircraft started losing altitude. It crashed in a populated area, short of runway 25L by about 1340 meters.”

Report tabled in NA narrates sequence of events leading to tragedy

Multiple errors were committed not just by the pilot, but also by air traffic controllers in the six to seven minutes after the start of descent by the aircraft culminating in the tragedy just days before Eidul Fitr.

Pilot’s errors

Going by the findings of the report, the pilot was distracted and what Aviation Minister Khan told the National Assembly “he was not focused”. The report said: “The crew did not follow standard callouts and did not observe CRM (crew resource management) aspects during most parts of flight.”

It did not state how may callouts were missed, but definitely suggested that something was pre-occupying the mind of the pilot.

The pilot had over 17,000 hours of flying under his belt, including 5,000 hours on A-320, and his record seen by Dawn for the past few years showed no incident. The report stays silent on the factors that could have made him commit the fatal errors.

The aviation minister said the pilot was “overconfident” and had been talking all along about coronavirus disease.

The International Federation of Air Line Pilots’ Associations (IFALPA) had back in April warned that Covid-19 pandemic was putting pressure on the crews, which could affect safety with thoughts of job loss and financial pressure affecting their “regular operational decision-making”.

The first mistake apparently committed by the pilot while making the initial attempt at landing was that of coming in ‘hot and high’ — or in other words had higher altitude and high speed than what’s prescribed for landing.

The report tells us: “The aircraft ended up higher than the required descend profile. At Makli the aircraft was at 9780 ft and at about 245 knots IAS. In order to manage the descent and lose the additional height, ‘OPEN DES’ mode was selected via the FCU, both autopilots were disengaged and speed brakes were extended.”

It further says: “Karachi Approach inquired ‘confirm track mile comfortable for descend’ and later advised to take an orbit, so that the aircraft can be adjusted on the required descend profile. No orbit was executed and the effort to intercept the glide slope and localizer (of ILS) was continued.”

One can’t precisely tell why the pilot chose to descend from a higher altitude and at high speed despite controller’s caution, but aviators, who had flown same aircraft — AP-BLD — say that the Flight Management Guidance Computers of that plane and two others in PIA’s Airbus fleet had software issues, which included the appearance of ‘holdover’ at Makli when they selected Karachi Airport for landing. This causes the computer to show extra ‘track miles’. The problem, they believe, could have delayed ‘top of descend’ — the point from where pilot transitions from cruise phase to descent.

Though commercial pilots prefer automated landing, the report says “auto-pilot had been disengaged”. Pilots sometime do this to get a quicker deceleration than is possible with auto-pilot and that could have been the reason in case of PK-8303 as well.

At this point started the real problem. The report says the pilot had lowered his landing gear at 7,221 feet and applied speed brakes, when the aircraft was around 10.5 nautical miles away from the runway, but then pulled the gears back at 1,740 feet, followed by retraction of the speed brakes.

This action of pulling back landing gears just five nautical miles short of runway needs to be further scrutinised. There is apparently no logic for a pilot to pull back the landing gears so close to runway and that too when he is coming ‘hot and high’.

Theoretically, there can be two scenarios — first at high ‘indicated speeds’ (AIS) of 260 knots or above, hydraulics connected to landing gear sometime get cut, secondly pilot could retract the gear because of some ‘unsafe indication’ but then forgot to deploy it again. The first scenario can be ruled out because the aircraft speed was around 245 knots, but there is a real possibility of the second situation.

The pilot, however, from the events, somehow looked to be confident that his landing gears were down.

As far as the apparently contradictory finding of the report is concerned, it states that the pilot applied the reverser. The reversers can be applied only when landing gears are down and locked. A former PIA director flight operation told Dawn: “Few things defy logic. At 7500 feet landing gear was down, then at 1700 feet they go up and pilot on touchdown applies reversers.” Touching down without lowering the landing gears was the real fatal mistake by the pilot as it caused the engines to scrub the runway. The pilot belatedly aborted the landing after realising that he was down without his landing gears. Opting for a ‘go around’ at this stage was the second major mistake.

The damaged engines were on fire and the aircraft could not keep itself in air and crashed about four minutes later.

Controllers’ blunders

Notwithstanding the fact that the pilot ignored the controller’s advice for a ‘go around’ at the very start of the events when he was approaching ‘hot and high’, the crucial mistake committed by the controller was that ‘Karachi Approach’ did not transfer the aircraft to ‘Aerodrome control’.

The report said: “Karachi Approach instead of changing over the aircraft to Aerodrome Control, sought telephonic landing clearance from the Aerodrome Control.” The two controls are different components of air traffic control system.

As a result of the bypassed procedure, aerodrome control did not notice that the plane was landing without lowering its landing gears and the pilot too wasn’t warned about it, although visually inspecting the incoming aircraft on this count is one of its primary responsibilities. Secondly, aerodrome control observed that the plane’s engines had hit the ground, but it didn’t communicate this to the pilot.

Published in Dawn, June 25th, 2020

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