KARACHI (Afzal Nadeem Dogar) Although the problem in the air traffic system has been fixed, the backlog of flights in the UK has not been eliminated. Another 2,700 flights were affected for the fourth day on Friday, taking the number of affected flights to 15,000 in 4 days, according to airport data. According to the flight schedule 7 more Heathrow flights canceled 554 delayed, 2 more Gatwick flights canceled 469 delayed, Manchester 341, Stansted 236, Edinburgh 190 Birmingham 153, Bristol 85 Glasgow 88 Belfast 38, Luton 175, City 64, Newcastle 44, Liverpool 57, East Midland 37 flights from 62 Aberdeen were affected. According to aviation experts, it may take several more days to restore flight operations.