Contrails or condensation trails
Contrails
That is an airplane equipped with a smoke generator. The pilot maneuvers the plane to form letters and symbols with the smoke trail.
A contrail or a vapor trail. See the related link for confirmation.
Smoke trail is the trail of smoke left behind by an aircraft as it flies in the sky.
Carbon monoxide and other left overs from combustion. However, the trail you see behind a plane flying high up is called the contrail, and it consists of water vapor that freezes behind the plane.
The white trail you see behind an airplane in the sky is called a contrail. It's an artificial cloud made by the exhaust of jet aircraft or from the wingtips.
It is called a contrail. The 'con' in contrail is derived from condensation, because mostly, airplane vapour or 'smoke' trails are made of water. Concorde's contrail was the purest with something like 99% of it being water at cruising altitude. As the air is accelerated over the wing, the water vapour present in the ambient air can't stay suspended so it condenses, forming a long thin 'cloud'.
The stream behind a jet is called a contrail. It is actually water vapor that condenses in the cold.
You are not allowed to smoke ANYTHING on an airplane.
That line of smoke is called a vapor trail. You can still see it on low flying planes, but it must be a jet plane.
The chemtail from an airplane is the also called a vapour trail when it can be seen. Inside the vapour is all the products of combustion from the engines, thus a "ChemTrail"
The smoke is actually ice that freezes in the air