Air navigation

The speed triangle graphically represents the relationships between the speed vectors used for air navigation

Air navigation is the set of techniques and procedures that allow an aircraft to be flown efficiently to its destination, ensuring the integrity of the crew, passengers, and those on the ground. Air navigation is based on the observation of the sky, the terrain, and the data provided by the flight instruments.

Types of air navigation

Air navigation is divided into two types (depending on whether the aircraft needs external facilities to be able to navigate):

• Autonomous air navigation
• Non-autonomous air navigation

The autonomous air navigation is one that does not need any infrastructure or external information to be able to successfully complete the flight. In turn, this is divided into:

• Observed navigation: it is based on the direct observation of the necessary references on the ground by the sailor or pilot, in order to know the position of the aircraft.
• Navigation at estimation: the sailor or pilot estimates the current position, known the direction and speed with respect to the terrain.
• Navigation by position fixation: this in turn is subdivided into astronomical air navigation, Doppler air navigation, inertial air navigation (INS).

Non-autonomous air navigation, on the other hand, does require external facilities to carry out the flight, since the aircraft itself is not capable of navigation. The necessary facilities for its guidance during the flight are called navigation aids. These aids can be divided in turn depending on the type of information they transmit, as well as the channel through which they do so. Thus, the aid can be:

• Visual assistance for navigation: they are the set of installations for the visual guidance of an aircraft.
• Radioayudas: These are radioelectric signals received on board, usually issued in terrestrial facilities.
• Satellite navigation.

Regulations

Depending on the minimum visibility conditions, distance from the clouds, and the type of airspace crossed, there are two sets of mandatory rules: the visual flight rules (visibility greater than 5 [kilometres] [8 km] and cloud ceiling above 1500 m) and instrument flight rules (instrument operated). Airlines, for safety reasons, only operate under instrument flight rules, regardless of weather conditions.

The element responsible for air navigation on the ground is air traffic control, supported by information provided by pilots and by radar systems.