Dark grey clouds in background.
dark grey smoke coming from wings of plane.
blueish grey clouds in sky.
smoke trailing behind the airplane
the smoke is dark grey
the sky is grey
a patch of darker cloud
The smoke billowing from the jet.
The sky the jet is flying in.
a stunt jet is flying at an air show
the smoke is billowing behind the jet
the smoke is black and gray
the sky is blue with white clouds
The sky is overcast. 
a black helicopter flying in cloudy sky next to a helicopter with a cloud of smoke coming off it