IFR vs VFR fkight routes

IFR vs VFR Flight Rules, What is the difference?

IFR and VFR are very popular terms in aviation, we hear a lot about them in flight planning and when we try to read and decode the airport’s approach plate.

In this article we will learn about IFR vs VFR Flight Rules, What is the difference between them, what they mean for a pilot, and in what conditions they’re used. So let’s see What is the difference between IFR vs VFR and compare them.

In aviation, IFR (Instrument Flight Rules) and VFR (Visual Flight Rules) are the two governing rules regulations governing all aspects of civil aviation aircraft operations. Both of these regulations could be flown by a pilot in specific technical and metrological (Weather) conditions. IFR is used to fly below 1,000 feet AGL ceiling and/or visibility less than three miles with special instruments equipped onboard. VFR is used to fly above 3,000 feet AGL ceiling and visibility greater than five miles with no special instruments required.

Table showing IFR vs VFR requirements.
IFR vs VFR requirements table

IFR vs VFR Flight

VFR flight rules set is required for a pilot to fly under it, enabling the pilot to operate the aircraft under clear calm weather conditions. This weather should be clear enough for the pilot to be aware visually on the flight, and better than VFR weather minima that are specified in the rules and regulations by each national civil authority.

On the other hand, IFR flight rules are set required for a pilot to fly under it, enabling the pilot to operate the aircraft under difficult weather conditions or simply low visibility weather.

When flying an IFR flight plan, the pilot depends on the instruments onboard the aircraft to navigate and fly his route. For landing, the pilot may use types of precision approaches or no precision approaches depending on the instruments equipped on the aircraft see the VOR/DME vs RNAV vs ILS approach for more information about these Nav aids.

IFR flight may also be required from the pilot to land or fly in class A airport.

IFR vs VFR Flight

VFR requirements

To fly VFR, a pilot would need at least a Private Pilot License (PPL), with specific VFR weather minimums, VFR weather minima are identified in the visual meteorological conditions, known as VMC. Which is essentially any weather condition less than VMC but in which aircraft can still operate safely.

In some countries, the civil aviation authority flying VFR at night could be permitted, and it’s known as Night VFR. Authorities add more regulations to flight at night like, minimum safe altitudes to fly and special training (night rating) for the pilot to make him able to fly VFR at night.

What are the minimum fuel reserves for day/night VFR flights?

One hour of fuel reserve on the aircraft is required regarding day or night VFR flight.

What is the minimum radio equipment to operate in an aircraft to fly VFR?

  1. Radio communication equipment to communicate with ATC
  2. Transponder (In some Airspaces)

VFR weather minimums

If the VFR weather minima don’t meet the visual meteorological conditions, the pilot must get an IFR clearance to fly. In some airports, like a class A airport, VFR is prohibited and pilots should fly IFR only. Use of instrument flight rules is also required when flying in “Class A” airspace regardless of weather conditions.

The minimum weather conditions for ceiling and visibility for VFR flights are defined in FAR Part 91.155.

 According to FAA, on the 14 CFR 135.205 VFR: Visibility requirements.

(a) No person may operate an airplane under VFR in uncontrolled airspace when the ceiling is less than 1,000 feet unless flight visibility is at least 2 miles.

(b) No person may operate a helicopter under VFR in Class G airspace at an altitude of 1,200 feet or less above the surface or within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport unless the visibility is at least:

(1) During the day – 1/2 mile; or

(2) At night – 1 mile.

IFR Requirements

To fly IFR, a pilot would need at least a Private Pilot License (PPL) with an instrument rating, with specific IFR weather minimums, IFR weather minima are identified in the instrumental meteorological conditions, known as IMC. There is also a requirement for special instruments to be equipped in the aircraft and functioning to fly IFR;

IFR Instrument Requirements

To make it easy for our students, try to remember the letters “GRABCARD”, and you will never forget what IFR equipment is required.

  • Generator or alternator
  • Rate of Turn Indicator
  • Attitude Indicator
  • Ball (inclinometer)
  • Clock (second-hand sweep or digital)
  • Altimeter (pressure sensitive)
  • Radio/Navigation (appropriate for flight)
  • Directional Gyro/Heading Indicator

IFR Weather Requirements

The main factor to choose the type of flight plan to file for clearance (VFR or IFR), after the file and submission of the selected flight plan, weather conditions themselves do not affect anymore. For example, an IFR flight that encounters visual meteorological conditions (VMC) en route does not allow the pilot to change to a VFR flight, and the flight must still follow all IFR procedures regardless of weather conditions.

During flight under IFR, there are no visibility requirements, so flying through clouds (or other conditions where there is zero visibility outside the aircraft) is legal and safe. However, there are still minimum weather conditions that must be present for the aircraft to take off or to land; these vary according to the kind of operation, the type of navigation aids available, the location and height of terrain and obstructions in the vicinity of the airport, equipment on the aircraft, and the qualifications of the crew.

Special VFR

Sometimes, in airports where the weather can be changed fast from VMC to IMC, VFR pilots on the sky that haven’t an IFR rating could be granted a special VFR permission to fly in the airport’s airspace.

To operate safely in IMC (“actual instrument conditions”), a pilot controls the aircraft relying on flight instruments and ATC provides separation. Not all IFR flights are flown with IMC. A significant amount of IFR flying is conducted in visual meteorological conditions (VMC).

So, when an IFR flight is flown with VMC, there is probability VFR flights are operating in the same airspace, in that case, the crew is responsible for seeing and avoiding VFR traffic; however, because the flight is conducted under instrument flight rules, ATC still provides separation services from other IFR traffic, and can in many cases also advise the crew of the location of VFR traffic near the flight path.

Although large airliners, and increasingly, smaller aircraft, carry their terrain awareness and warning system (TAWS), these are primarily backup systems providing a last layer of defense if a sequence of errors or omissions causes a dangerous situation. During flight under IFR, there are no visibility requirements, so flying through clouds (or other conditions where there is zero visibility is possible.

IFR ATC Separation

The distance by which an aircraft avoids obstacles or other aircraft is termed separation. The most important concept of IFR flying is that separation is maintained regardless of weather conditions. In controlled airspace, air traffic control (ATC) separates IFR aircraft from obstacles like NOTAMs and other aircraft using a flight clearance based on the route, time, distance, speed, and altitude.

ATC monitors IFR flights on radar, or through aircraft, position reports in areas where radar coverage is not available. Aircraft position reports are sent as voice radio transmissions.

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