London - PM Yousuf Raza Gilani's special plane was kept on hold for 18 minutes at Heathrow Airport in order to accommodate other flights. The special plane was allowed to land after ground was cleared. The PM's plane was scheduled to land at terminal 4 of Heathrow Airport at 5: 28 pm according to Pakistan standard time but it was kept on hold because runway was not vacant and other flights have to be accommodated. Usually in UK, heads of other countries are given protocol and VIP flights are allowed to land at the airports and routine flights are stopped for time being. But PM Gilani's plane was not given any such VIP protocol. Pakistani authorities said PM Gilani visit to UK was an unofficial one and that might be the reason for not giving him VIP protocol at the airport.