Airspace

Airspace is a portion of the atmosphere controlled by a country above its territory, including its territorial waters or, more generally, any specific three-dimensional portion of the atmosphere. This is not to be confused with the term ”Aerospace”, which is the general term for Earth’s atmosphere and the outer space in its vicinity.

ATS airspace is classified and designated in accordance with the following:

• CLASS A : IFR flights only are permitted, all flights are provided with air traffic control service and are separated from each other.
• CLASS B :  IFR and VFR flights are permitted, all flights are provided with air traffic control service and are separated from each other.
• CLASS C : IFR and VFR  flights are permitted, all flights are provided with air traffic control service and IFR flights are separated from other IFR flights and from VFR flights. VFR flights are separated from IFR flights and receive traffic information in respect of other VFR flights.
• CLASS D :  IFR and VFR flights are permitted and all flights are provided with air traffic control service, IFR flights are separated from other IFR flights and receive traffic information in respect of VFR flights, VFR flights receive traffic information in respect of all other flights.
• CLASS E : IFR and VFR flights are permitted, IFR flights are provided with air traffic control service and are separated from other IFR flights. All flights receive traffic information as far as is practical. Class E shall not be used for control zones.
• CLASS F : IFR and VFR flights are permitted, all participating IFR flights receive an air traffic advisory service and all flights receive flight information service if requested.
• CLASS G : IFR and VFR flights are permitted and receive flight information service if requested.

IFR ( Instrument Flight Rules)

IFR stands for Instrument Flight Rules – the set of rules that govern aircraft that fly in IMC, or Instrument Meteorological Conditions. In general terms, instrument flying means flying in the clouds. More specifically, IMC is defined as weather that is below the minimums prescribed for flights under Visual Flight Rules.

It’s called instrument flight because the pilot navigates only by reference to the instruments in the aircraft cockpit. Flying in the clouds (IMC) requires an IFR flight plan and an instrument rating. More on flight plans and instruments later!

VFR (Visual Flight Rules)

VFR stands for Visual Flight Rules, and the term refers to a set of rules created by the FAA for flight in VMC, or Visual Meteorological Conditions. These are terms that even pilots sometimes use incorrectly.

Air traffic controllers aren’t always required to keep VFR aircraft separated from each other like they do for IFR traffic. The responsibility for traffic separation lies solely with the pilot during VFR operations, which means he needs to be able to see in front of and around his aircraft while in the air. For this reason, VFR rules also cover visibility requirements and cloud clearance criteria required to fly with visual reference to the ground and/or horizon.

Airspace infringement

Airspace infringement occurs when an aircraft enters notified airspace without previously requesting and obtaining clearance from the controlling authority of that airspace, or enters the airspace under conditions that were not contained in the clearance.

All classes of aircraft are prone to airspace infringement, but the majority of incidents recorded involve General Aviation (GA). This is unsurprising, as most GA VFR flights are conducted outside controlled areas and zones, and are in general flown by less trained and less experienced leisure pilots.

Possible effects

• Mid-air collisions
• Loss of separation from other aircraft
• Exposure to danger from military hazards – radiation, gun firing etc.
• Disruptions to flight operations

Sources

• https://en.wikipedia.org/wiki/Airspace
• https://www.skybrary.aero/index.php/Classification_of_Airspace
• https://www.skybrary.aero/index.php/Airspace_Infringement
• https://pea.com/blog/posts/vfr-ifr-mean/#:~:text=IFR%20stands%20for%20instrument%20flight,means%20flying%20in%20the%20clouds.
• https://www.schaeffler.ch/content.schaeffler.ch/en/products-and-solutions/industrial/industry_solutions/aerospace/index.jsp (Cover photo)