[ARC5] Wire antenna on Dreamliner ?

[Hubert Miller]

My brother says he saw a video of a 787 Dreamliner taking off and it had some kind of wire
antenna hanging from the vertical stab. He says it looked guessing about 15 foot long and 
ended in a ball shaped drogue. He said at liftoff this wire was not horizontal but still dragging
at an angle, in other words not extended fully horizontal at takeoff speed.  This was not a 
military 787; it was painted in some airline's logo. 
So, what's this about ??
-Hue Miller