
Source: flightradar24.com
The aircraft due to some technical issue was unable to depart from Karachi and around 5:15 AM all 159 passengers of the aircraft were moved to transit lounge at Karachi Airport.
flydubai technical team and replacement crew arrived in Karachi on a flight from Dubai. After removal of the technical problem, the aircraft with replacement crew was able to leave Karachi at 1:21 PM to resume flight FZ501 to Dhaka. The aircraft stayed in Karachi for ten hours.

Source: flightradar24.com
Abbas