KARACHI: A day after the Pakistan International Airlines (PIA) turbo prop plane ATR-42 crashed near Havelian, a PIA pilot refused to operate another ATR-42 aircraft which was bound to fly from Karachi to the archeological site Mohenjodahro. According to reports on a TV channel, the pilot refused to operate the flight after identifying a problem in one of the engines. According to the Standard Operating Procedures (SOP), before every flight, the pilot has to sign the air worthiness certificate and therefore cannot be forced to operate an aircraft which may create a technical issue during flight. It is pertinent to mention that a PIA ATR-42 plane with 47 people on board crashed on Wednesday while operating a scheduled domestic flight from Chitral to Islamabad.