Crucial part of PK-661 was broken before it took off: report

ISLAMABAD: An investigation report of Pakistan International Airlines (PIA) plane PK-661 that crashed near Havelian while returning to Islamabad from Chitral on Dec 7, 2016, has been presented to Prime Minister of Pakistan.

All 47 people aboard, including Deputy Commissioner Chitral Osama Ahmad Warraich embraced martyrdom in the accident.

The report said the most crucial part of the plane was broken before it took off, while the other was faulty. A metallic analysis of the plane revealed that its OSG pin was fitted incorrectly that had broken down before the crash. The last maintenance job of the ill-fated jet was carried out in Canada, where not only the OSG was modified but also the part number was changed.

When the ATR aircraft took off from Chitral for Islamabad, the stage one blade (PT 1) of the engine’s power turbine was broken and dislocated, causing the power turbine shaft to rotate, while OSG pin was also broken.

The investigation team suspects that the PT 1 blade and the pin had broken when the plane was on the way to Chitral from Peshawar before the accident. It was, nonetheless, diverted for the next flight.

According to the report, the malfunctioning started at 4:05 pm, mainly due to fuel contamination in the engine oil which combined with the broken OSG pin PT 1 blade reduced the speed of the propeller after which the propeller electronic control malfunctioned.

Five minutes into the process, the engine number one failed at 4:10 pm, and at 4:11 pm, the OSG stopped working. All these faults together caused a new type of malfunction that had never been seen before in ATR planes. Before the captain could figure out anything, the plane crashed at 4:20 pm at Havelian.

The report also identified that the change in engine design was the manufacturer’s fault who proposed a corrected design, but PIA management was too lazy to get it done in time. The Civil Aviation Authority (CAA) also did not properly monitor the process.

The investigation team has suggested that the national flag-carrier should hold an audit of the airline and strictly follow the rules regarding aircraft maintenance and be very careful in the future to avoid such mishaps.