The Difference Between VFR and IFR
There are two sets of rules for flying any aircraft: VFR and IFR. VFR stands for Visual Flight Rules and IFR stands for Instrument Flight Rules
IFR and VFR are terms which are commonly used in aviation, but what is the exact difference between VFR and IFR?
To fly any aircraft there are two different sets of rules: VFR and IFR. IFR stands for Instrument Flight Rules and VFR for Visual Flight Rules. To fly VFR there are some criteria which must be met. These criteria are for example that the VMC (Visual meteorological conditions) must be met. So it depends a lot on the current weather, whether a pilot should fly VFR or IFR.
Let’s take a closer look to the exact difference between VFR and IFR:
What is IFR?
IFR should only be used if it’s unsafe to fly VFR (With visual contact). This has been defined by the FAA (Federal Aviation Administration).
Instrument flight refers to the control of aircraft in which the flight situation is kept on board with the help of flight instruments such as navigation instruments and flight monitoring devices without reference to external, visually perceptible clues (Exception: The circling and visual approach are instrument approaches that are under Visual conditions are carried out). Air traffic controllers on the ground support flight operations and flight navigation. An instrument flight must be carried out according to instrument flight rules (IFR), and in almost all cases coordinated with air traffic control.
In the case of instrument flight, the flight position is maintained exclusively by means of instruments in the aircraft, and navigation is carried out using aids which allow the intended flight path to be observed regardless of the outside view. It is also possible to fly in clouds and with limited visibility. Instrument flight makes air traffic largely independent of the weather and is a prerequisite for adhering to flight plans. Weather conditions that only allow instrument flight are called Instrument Meteorological Conditions (IMC).
For commercial air traffic in Europe, the Operating Instructions Part A (Operations Manual Part A in accordance with EU OPS 1) stipulate the conditions under which visual or instrument flight rules apply. The country’s regulatory agency must approve the airline’s decision.
What is VFR?
A visual flight is a flight that is carried out by the pilot by sight according to the applicable visual flight rules (VFR).
Visual flight is mainly used in general aviation at low altitudes, in small aircraft and with air sports equipment, but also in military low-altitude flights. Commercial flights with larger commercial aircraft are usually carried out as instrument flights (IFR).
In visual flight, the pilot visually checks the position of his aircraft in space and also assesses its position relative to other aircraft. For the flight situation in space, he uses clues outside the aircraft, usually by looking at the horizon. The basic requirement for visual flight is therefore that the weather permits certain minimum visual ranges and the pilot does not fly through clouds, so that the necessary clues can be seen outside the aircraft. He must also maintain certain horizontal and vertical minimum distances from clouds to avoid collisions. Where these conditions (Visual Meteorological Conditions, VMC) cannot be met, no visual flight is allowed to take place. The principles of the process of visual flights are laid down in the so-called visual flight rules (VFR). Typically, the flight takes place according to visual flight rules, without an air traffic controller staggering other air traffic — the principle See and Avoid applies. Correspondingly, the visual flight rules also define alternative rules, similar to the right of way rules in road traffic. In certain airspaces, however, VFR traffic is also controlled by air traffic control (controlled visual flight, CVFR) and staggered by IFR flights. Under certain conditions, visual flight is also permitted above closed cloud cover or at night (NVFR). A control zone can be flown through under unfavorable visibility conditions with appropriate approval, also according to special visual flight rules (SVFR). It is crucial in any case that the horizon is recognizable and the visual flight rules (obstacle detection, cloud distances) can be observed depending on the air space flown through.
In air law, visual flight is defined by the application of visual flight rules. These stipulate certain minimum conditions that must be met for visual flight. The visual flight rules have been standardized across Europe in the Standardized European Rules of the Air (SERA) since 2014.
