The airspace

It starts from the first metre above the ground. It is divided into 2 large separate spaces. Above 150 metres (500 feet) above the ground, it is reserved for aircraft and other inhabited aircraft. Below 150 meters (500 feet), it is reserved for drones.

The area reserved for drones is subject to numerous restrictions ( : (i) Prohibited area (of the sensitive site type), (ii) Army tactical flight corridors, (iii) CTR (areas near aerodromes).

The French Civil Aviation Authority (or DGAC)

The mission of the central office of Civil Aviation is to guarantee the safety and security of air transport: (i) Definition of French aviation regulations, and (ii) Security of air traffic control using primary and secondary radars. In order to ensure the control of the airspace, the DGAC relies on two types of radar:

Primary radars.  These are conventional radars that illuminate a large portion of space with a magnetic wave and receive in return the waves reflected by targets in that space. The term therefore refers to a radar system used to detect and locate non-cooperative potentials.

Secondary radars. These are air traffic control radars that “interrogate” the sky. The electronic equipment on board aircraft (transponders) within range of the radar then returns the flight information of the aircraft; position, flight level, speed, etc.. The responses of the aircraft are: (i) Captured by the secondary radar antenna, (ii) Analyzed and processed electronically, and (iii) Displayed on the air traffic controllers’ screens.

Surveillance tools unsuitable for drones

The experience has shown that its two types of equipment are unsuitable to the airspace surveillance (below the 500 feet) particularly for the surveillance of the drone’s flight drive :

  • Primary radar coverage has a “dead zone” near the ground, which is accentuated in the case of relief and major obstacles.
  • Drones aren’t equipped with transponders.

Deploying them on drones is impossible because this equipment is heavy and emits a power of 160-250 W , which is not in conformity with the free frequency band regulations (500 mW) especially in urban areas.

The palliative put in place

In order to compensate for the lack of technology allowing the surveillance of the airspace below 500 feet, the DGAC has put in place very restrictive regulations.

Drone flights are authorized in certain conditions (risk taken well identified and very limited (low mass drones flying close to the ground outside inhabited areas most generally in view of the remote pilot).

Since January 1, 2018, any drone weighing more than 800 g. is considered a professional drone. Operators must systematically obtain a flight authorisation from the DGAC before each mission.

These administrative authorizations are time-consuming and require and plan a flight well in advance. This one requires: (i) To carry out certain declarations of activity (ii) To obtain authorisations from the prefecture prior to flights, and (iii) To be able to show certain documents in the event of an inspection.

The attached website describes these obligations in detail: