Islamabad, Nov 20 (PTI) Nearly four years after a Pakistan International Airlines’ flight crashed in Khyber-Pakhtunkhwa province, killing 47 people, a probe report has said that the aircraft had three “technical anomalies” for which the airline’s engineers were responsible, according to a media report.
The plane crashed near Havelian in Khyber-Pakhtunkhwa province on December 7, 2016, killing all 47 passengers and crew on board the ATR42 aircraft of the national carrier.
Junaid Jamshed, a singer-turned-preacher, was among the people killed in one of the most disastrous air crashes in the country’s aviation history.
The Aircraft Accident and Investigation Board (AAIB) completed its investigation into the crash and revealed that the aircraft had three “technical anomalies” for which the airline’s engineers were responsible, the Dawn News reported.
Head of the AAIB Air Commodore Usman Ghani submitted the report on Thursday to a bench of the Sindh High Court (SHC) after repeated directives by the bench in a petition filed about various incidents involving ATR planes.
A spokesman for the aviation division, senior joint secretary Abdul Sattar Khokhar, said in a press release that the investigation was carried out under the guidelines provided by the International Civil Aviation Organisation and were aimed at improving the safety of air travel.
According to the investigation report, the air crash was the result of three “latent technical factors”, including fracture of one of the power turbine blades of Engine 1; a broken/fractured pin inside over-speed governor; and probable pre-existing contamination inside Propeller Valve Module.
The AAIB report, which held the PIA engineers responsible for the disaster, said the aircraft remained in air for about 42 minutes before the crash.
Analysis of the digital flight data recorder indicated that the aircraft’s Engine 1 was degraded, the daily said.
“The flight took off with two pre-existing technical anomalies. One anomaly was a fractured Power Turbine (PT-1) blade and the second was a fractured pin inside the Over-Speed Governor (OSG) of the same side. The probable latent pre-existing condition was contamination external from the engine observed in Propeller Valve Module (PVM),” the report said.
It said most probably the PT-1 blade had fractured during a previous flight. However, this defect is not observable during regular operations.
“It was determined that the pin inside the OSG was fractured due to improper re-assembly. Metallurgical evaluation of the OSG pilot valve pin fracture surface, at Woodward, USA, determined that the pin had failed due to overload resulting from the valve being forced together using an improper re-assembly method during some unauthorised/undocumented maintenance activity,” the report said.
“It has been established that any of the latent pre-existing technical anomalies and probable latent pre-existing condition … alone may not lead to such a catastrophic/hazardous situation except in the presence of unusual combination and/or additional contributing factor(s),” the report said.
It suggested that the simultaneous existence of the three “technical anomalies” made it extremely difficult for the cockpit crew to tackle the situation effectively.
“The event was unexpected and the crew was not trained for this specific sequence of events,” said the report.
It said the captain and the first officers were well-trained and had a good overall total flying hours. They led a normal family life. Responding to the report, the management of PIA said the airline had already incorporated immediate safety recommendations, including PT blade modifications and inspections of OSG at the manufacturing facility.
Spokesman for PIA Abdullah Hafeez Khan said the management had reviewed the crash report and acknowledged that there were three latent factors that aligned together at the time of the crash.
Had any of these factors happened in isolation, the consequences would not have been so devastating, he said. PTI SH PMS AKJ PMS