I guess this has to do with the planes ages and safety records. Well most of the planes that go there, Im pretty sure they are in the 7 plane allowed list, and secondly the safety record of PIA has been pretty darn good actually, before this recent fokker crash, there were no major crashes, for more info goto
www.historyofpia.com I hope its acceptable as per forum rules to show this link as its an informative link about PIA run by a PIA fan.