In general there is a room in the airport dedicated to the reception and assistance of people who need it. It will be the meeting point or the waiting place for you to be picked up to pass security and go to the departure lounge.
For security control, if you cannot get out of the wheelchair to pass the metal detector gantry, a security agent (of the same gender as you) will have to do the control manually. Your chair may be looking for traces of explosives if you have kept it. You will then be accompanied to your departure lounge and wait until it is time to board, you are likely to be the first!
If the plane is stuck to the terminal, you will reach it by a gangway. If the plane is far away, you will be taken down from the terminal to take an ambulift which will take you to the plane while the other passengers will take a shuttle / bus. An ambulift is a wheelchair accessible form of transportation that commutes between the terminal and the aircraft, and has the ability to ascend to the height of the aircraft door. You will keep your manual wheelchair or the one loaned by the assistance in the ambulift but you will then have to transfer to a very narrow wheelchair which passes in the aisle between the seats of the plane and allows you to transfer to your place . It happens that you are installed on this seat from the terminal, fortunately it is quite rare because it is far from being comfortable! If you have kept your wheelchair in the ambulift or on the gangway, it will be directly put in the hold from the plane door.
In general and for security reasons, you will not be placed in the first row or at the level of the emergency doors. The airlines consider that in the event of the plane being evacuated, you risk embarrassing and prefer to place people in better physical condition to help with the evacuation (or at least not to hinder it!).
First come but last out, on landing the assistance will help you disembark once all the passengers have got off the plane.
Procedure in reverse, we bring you the seat that goes in the aisle of the plane and then you get your own manual chair (when it goes well) or an airport chair directly at the exit of the plane. You reach the terminal via a gangway or an ambulift and you are taken to the arrival hall to collect your luggage and your wheelchair if you have not collected it before.
Upon your arrival, a specialized vehicle will be made available to you with a nursing assistant and a nurse.