Who is he, what does he do, and what does he talk to the crew about, the man with headphones standing under the plane before departure? A pilot explains it to TFC
Many of you, before and during the departure of an airplane from its parking position, will have paid attention to [...]

Many of you, before and during the departure of an aircraft from its parking position, will have paid attention to A 'little man' with a headset and microphone connected through a cable to the plane same. Who is he, what does he do, and what is said with pilots during departure operations?
In this article:
The Flight Club asked the first officer of a major European low-cost airline., who explained that "each flight has a ground team that is captained by what we in the vernacular call a 'ramp,' but is referred to in English as a 'dispatcher'.
He is the one who coordinates the ground operations ranging from loading baggage and cargo to sending passengers on board through the finger or the interstage bus and is responsible for the cargo 'sheet' on which the quantity and positioning of cargo, baggage, men, women, and children, which is essential for us to define the aircraft's center of gravity, which affects, for example, the pitch, i.e., to the inclination we give the nose of the aircraft as it leaves the runway avoiding so-called tailstrikes, the touches on the runway with the rear of the fuselage."
The first officer explains that "the 'ramp' or dispatcher is also the one who before pushback and after the doors are closed does an inspection around the plane to check that all the doors are closed properly and then connects to the plane via a plug that is next to the front undercarriage compartment".
In jargon the 'little man' is referred to as the 'ground cockpit'. The pilots, from the cockpit, ask them if the check, the external check, is okay after receiving confirmation, they tell them that they have the brakes on. They then ask the control tower for permission to be pushed back and once they get it they communicate it to the 'ramp,' adding at that point that they have released the brakes.
"Done that, we ask the ground cockpit for confirmation that we can turn on one or both engines, because everything is safe, and when he gives us the okay we start the engines and tell him 'ground cockpit, good engine start,' meaning that the startup was successful."
"At that point he removes from the front carriage the 'pin,' which is A metal retainer attached to a strip of fabric with the inscription 'Remove before flight' (that so appeals as a keychain to aviation enthusiasts, ed.) and shows it to us by walking away from the plane after removing the headphones from the compartment next to the undercarriage."
The 'pin' actually serves to disable pilots from any action on the front wheel steering mechanism while the plane is being pushed back by the tractor, an action that could severely damage the undercarriage. "At that point, we ask the tower for taxi clearance, and when we get it, we wave to the ramp, who waves and then heads for the terminal, since his job, with us, is done".