请教各位，为什么同一段航线来回时间差那么多

Kuala Lumpur (KUL)

Kuala Lumpur (LCC Terminal) Tue 02 Dec 2014, 1400 hrs ( 2:00PM)

到

Colombo (CMB)

Bandaranayake International Airport Tue 02 Dec 2014, 1450 hrs ( 2:50PM)

50分钟


Colombo (CMB)

Bandaranayake International Airport Sun 07 Dec 2014, 1155 hrs ( 11:55AM)

到

Kuala Lumpur (KUL)

Kuala Lumpur (LCC Terminal) Sun 07 Dec 2014, 1745 hrs ( 5:45PM)

将近5个小时。。。