This Boeing 737 wound up dumping some of its fuel during takeoff from Düsseldorf airport earlier this week (March 15).

Footage of the takeoff shows how an emergency fuel vent was releasing fuel from the left wingtip after lifting off the ground. This was not strictly an emergency but a necessary failsafe when a plane's is over-fuelled.

The filmer commented on the sight: "Every airplane has fuel overflow vents but I have only filmed three planes losing fuel through the overflow vents within the past 15 years. It's kinda rare to see this happen.

"These vents are quite important to make sure the pressure inside the fuel tanks doesn't get too high. Especially when the wings bend during takeoff it might happen that the fuel doesn't have enough space anymore inside the wings."

This Boeing 737 lost some fuel during its departure at Düsseldorf this week. Every airplane has fuel overflow vents but I have only filmed three planes losing fuel through the overflow vents within the past 15 years. It` s kinda rare to see this happen. These vents are quite important to make sure the pressure inside the fuel tanks doesn` t get too high. Especialy when the wings bend during takeoff it might happen that the fuel doesn` t have enaugh space anymore inside the wings. Too avoid high pressure inside the wings the fuel has a possibitly to leave the wings via the fuel overflow vents which is clearly visible in this video.