how is boeing 747 deiced on ground?
 

out of curiosity, I would like to know how is Boeing 747 deiced on ground in very cold places?

The same way an A320 is?

Wash her down like a cow. Don't spray the eyes.

https://encrypted-tbn0.gstatic.com/i...fBXnw6MgKKrBQg
try not to spray in any of the orifices either!

With lots of deice fluid.

nice picture.. no wonder, a picture speaks a thousand words!

Suppose wings are ice-free, you taxied out for take-off. there is a long queue for takeoff. now there is frost on the wings. is there a provision to provide deicing service on the taxiways with engines running? or the aircraft has to come back to the bay?

The de-icing fluid has what is call a 'holdover time' which means that it will continue to keep the aircraft frost free for a period of time, on the ground this can stretch to hours.

In the air I believe there are systems using engine bleed air and electronics to help keep the aircraft frost and ice free.

yes and no, depends entirely on the airport.

Do you know some airport where deicing service is available to the airplanes in takeoff queue on taxiways?

Not exactly in the queue but DFW and PIT both deice on pads at the departure end of the runway.

and malpensa