close-up of duck ! - discharge from aircraft !!

 Face-off    -  getting closer to a duck ! 

This morning photographed a Cargo aircraft (bigger than usual passenger jets) – from a Cricket ground in Mylapore.  One could observe a discharge (gas or water) from the wings ! 

1)                                      Wingtip vortices are associated with induced drag, an unavoidable consequence of three-dimensional lift generation. The rotary motion of the air within the shed wingtip vortices (sometimes described as a "leakage") reduces the effective angle of attack of the air on the wing. The cores of the vortices can sometimes be visible when the water present in them condenses from gas (vapor) to liquid. This water can sometimes even freeze, forming ice particles. 

2)   Whenever snow, ice, or even frost has accumulated on the aircraft, the pilots call on the airport deicing facility to have it removed. Deicing fluid, a mixture of a chemical called glycol and water, is generally heated and sprayed under pressure to remove ice and snow on the aircraft.  

Typically aircraft systems prevent ice buildup in one of two ways. On most jet aircraft, hot air from the engines is routed through piping in the wings, tail and engine openings to heat their surfaces and prevent icing. 

Not sure of what it is !!!