Difference between IFR and VFR flights

What are flight rules? #

Flight rules are stated on the flight plan filed by the pilot. There are two categories of flight rules. These are IFR and VFR. Most general aviation flight plans are filed as VFR, but sometimes flight plans with IFR are also filed. VFR stands for Visual Flight Rules, while IFR stands for Instrument Flight Rules.

The two flight rules are very different from one another. Visual Flight Rules rely mostly on flying the aircraft visually, while Instrument Flight Rules rely primarily on the aircraft instruments on how to fly the aircraft.

During a pilot’s training phase, VFR is mainly applied for the duration of the flight training, but they have scheduled basic IFR training in preparation for wide-body aircraft or more complex aircraft. Pilots without an Instrument Rating on their license cannot file an IFR flight plan. The pilot with an Instrument Rating must be the pilot-in-command when an IFR plan is filed.

Pilots may file a single flight plan with a combination of IFR and VFR, but the pilot can only activate one flight plan at a time; the pilot-in-command will initiate a call to the Air Traffic that they will switch the flight plans and terminate the current one. For example, the pilot initiated the flight with the IFR flight plan. Once the pilot wants to change to the VFR flight plan, the pilot must initiate a call to the Air Traffic Controller that the IFR flight plan will be terminated and will activate the VFR flight plan. However, the pilot cannot bring back or activate the IFR flight plan unless there is a valid reason for switching flight rules, such as bad weather.

Take note that even big airlines fly an aircraft visually, especially when landing if the airport does not support auto landing. The auto-land system is part of IFR flying since it is a part of the ILS or Instrument Landing System. Multiple equipment systems help the pilot land the aircraft, especially during IFR flights.

Visual Flight Rules #

VFR flight is conducted by reference to outside landmarks and ground features, in contrast to Instrument Flight Rules (IFR), which rely heavily on aircraft instruments and navigational aids. VFR provides excellent flexibility to pilots, and pilots can conduct VFR flights without assistance from air traffic control (ATC). In many countries, VFR flight does not require a specific certification or rating; however, it is generally recommended that all pilots possess at least a basic understanding of VFR principles.

When flying VFR, pilots are responsible for maintaining their situational awareness and avoiding other aircraft, terrain, and obstructions. VFR pilots must constantly scan the sky and ground for other aircraft and be aware of changes in weather conditions that could adversely affect the flight. VFR flights are generally less complex and demanding than IFR flights but can be more challenging in some respects due to the need for more instrument guidance. VFR pilots must have an excellent working knowledge of aircraft systems and performance, weather conditions, and airspace regulations.

Visual Flight Rules, or VFR, must meet regulations governing aircraft operation in visual meteorological conditions (VMC). If the VMC conditions are not met, there is a high chance that the flight will be cancelled.

According to the International Civil Aviation Organization (ICAO), For the conditions to meet the VMC, these are the minimums;

The International Civil Aviation Organization (ICAO) sets the global standards for VFR, which are then adopted by individual countries. In general, VFR aircraft are required to stay clear of clouds, maintain visual contact with the ground, and fly at altitudes that will allow them to land safely in the event of an engine failure or other emergency. Specific VFR requirements may vary from country to country, so pilots need to be familiar with the VFR regulations in their area of operation.

In the United Kingdom, the VFR regulations are set by the British Civil Aviation Authority (CAA). The CAA requires that VFR aircraft stay at least 500 feet (150 meters) away from clouds, maintain horizontal visibility of at least 1,600 feet (500 meters), and fly at an altitude that will allow them to land safely in the event of an emergency.

Some VFR flights are conducted in Class B, C, and D airspace without an ATC clearance, but these flights must still adhere to the VFR cloud clearance requirements. In addition, VFR flights in Class B, C, and D airspace must maintain two-way radio communication with ATC before and during the flight. VFR flights in controlled airspace generally require an ATC clearance, although pilots may conduct some VFR flights under Special VFR (SVFR) rules with reduced visibility minimums.

What are airspace classifications? #

Airspaces are classified into seven based on flight rules limitations, speed limits, radio communication equipment requirements and service provided in the airspace.

Here is a table summary of the airspace classes and their limitations

The summary of the table is that IFR flights can operate in almost airspace, while VFR flights can operate in limited airspace, provided they have ATC clearances. Flight information services provide information to pilots for the safe and efficient conduction of flights. Pilots may inform other pilots during flight to provide additional information, such as weather changes in an area.

What is SVFR? #

Special Visual Flight Rules, or SVFR, allow pilots to operate aircraft in certain visibility conditions below the minimum visual flight requirements.

To be authorised to fly under SVFR, pilots must receive specific training from a certified instructor. This training covers weather conditions that warrant the use of SVFR, how to interpret meteorological reports, and how to manoeuvre the aircraft in low-visibility situations safely.

This type of flying is only allowed in certain visibility conditions below the minimum visual flight requirements. The Pilot operating handbook (POH) contains all of the information needed for a pilot to understand the procedures, limitations, and hazards associated with SVFR flight.

SVFR can be used in both day and night flying operations but is typically only invoked in cases where the visibility is too low for standard visual flight rules (VFR) but is still sufficient for the pilot to see and avoid other aircraft, obstructions, and terrain.

Some advantages of flying under SVFR include flying in otherwise-restricted airspace and having more flexibility regarding route planning. However, it is essential to remember that SVFR comes with its risks and limitations, so pilots must be well-trained and comfortable flying in low-visibility conditions before attempting it.

Can VFR pilots fly at night? #

The answer is yes, pilots can fly VFR during at night it is called Night VFR. Night VFR is possible but must meet the VMC’s minimum. According to ICAO, the definition of “Night” is between the end of evening civil twilight, which is 30 minutes after sunset, and the beginning of the morning civil twilight, which is 30 minutes before sunrise.

A night currency is required when flying night VFR. Pilot trainees must have an endorsement from their instructors who trained them for night operations. A pilot who holds a currency for night flying must have landings and training conducted after an hour of sunset and an hour before sunrise to maintain the night rating currency.

Instrument Flight Rules #

The instrument Flight Rules (IFR) rule allows appropriately equipped aircraft to be flown with low visibility. Any visibility or cloud ceiling below VMC or SVFR standards pilots can only fly IFR-tagged flights in these conditions.

IFR follows a strict procedure whether they are landing or taking off. Pilots follow a standard procedure for everything in IFR, from turns, altitude and heading; everything is in a chart.

These are some of the IFR charts;

• Standard Terminal Arrival - or also called STAR, these charts are used for IFR arrivals. These charts also provide procedures in case pilots must commence a missed approach or go-around.
• Standard Instrument Departure - or SID- these charts are used for departure.
• Enroute Low Altitude Charts - provides information for instrument flight rules flying below 18,000 feet MSL.

Here is a sample of a terminal chart.

This is a SID chart. You can see there are procedures on the lower part of the chart.

Note: If you are using airport or terminal charts, always take note of the validity because some charts may be invalid.

Pilots who wish to fly under Instrument Flight Rules (IFR) must be IFR certified. IFR certification is granted by the Federal Aviation Administration (FAA) in the United States, Transport Canada, Civil Aviation Authority (CAA), or other authorities in other countries.

To be IFR certified, pilots must complete a specific training program that covers all aspects of flying in instrument meteorological conditions (IMC). This training includes ground school and flight training and must be completed with an authorised instructor. IMC has no visibility minimums, unlike the one that VFR has.

Once a pilot has completed the IFR training program, they will receive an IFR rating on their pilot certificate. This rating indicates that the pilot is qualified to operate an aircraft under IFR in IMC.

Pilots must maintain their IFR proficiency by flying a certain number of hours under IFR conditions and completing recurrent training every few years.

IFR-certified pilots can fly in weather conditions that would otherwise ground VFR (Visual Flight Rules) flights. This allows for increased flexibility when planning flights and provides an additional level of safety in case of unexpected weather changes.

Before becoming an airline pilot, an IFR rating is an essential requirement because the flight plan of commercial flights is mostly filed under IFR. The ILS or Instrument Landing System is directly connected to IFR flying because the instruments related to the ILS are practised during IFR training. IFR-rated pilots must be very familiar with the ILS instruments.

Some instruments used for IFR landing #

These are some of the instruments used for the ILS approach and how the instruments function;

• Localizer - • this provides lateral guidance to the landing aircraft. It is used together with the glide slope.
• Glide slope - this provides vertical guidance for the aircraft. It has a range of 10NM, but only some glide slopes have this range.
• Distance Measuring Equipment- this is also known as DME. It measures the aircraft’s distance to the station. The measurement used in this are displayed by Nautical Miles (NM)
• Very High-Frequency Omni Directional Radio - VOR for short, shows the aircraft’s location regarding the station in bearing.

Advantages of VFR and IFR #

Even if there are significant differences in how you fly these flight rules, each one has a unique advantage over one other here are some of the advantages of each flight rule. Of course, it is a very massive advantage if you possess a certification for IFR flights since you can fly both IFR and VFR flights. Being IFR-rated means you have mastered VFR flying to transition to IFR flying smoothly.

Advantages of VFR #

• Views - since VFRs references are visual, you enjoy the view outside your window. A cockpit view is always better than a window view.
• Easier - VFR only follows fewer procedures compared to IFR. It is easier to fly VFR since you follow your route. But always be careful to follow your flight plan.
• Change of intention - you can easily change intention on VFR flight plans compared to IFR flight plans. But when safety is concerned, a valid reason is changing intentions on an IFR flight plan.
• Relies less on instruments - with VFR, you don’t rely too much on your instruments.

Advantages of IFR #

• No weather minimums - unlike VFR, there is no weather limitation for IFR. You can continue the flight if the weather is within the aircraft’s operating range. If the weather is still in the operating range, but the pilot-in-command deems the weather unsafe, the flight can be cancelled.
• Fewer restrictions - certain airspaces do not allow VFR flights within that area, but IFR flights are allowed.
• Precision - IFR flying relies heavily on instrument readings, which is why it is more precise than VFR, which doesn’t follow specific procedures on take-off and arrival.

VFR and IFR application on a pilot’s training #

During the early stages of a pilot’s training, a pilot trainee starts with VFR flying most of the time and only trains for IFR later in training. During a standard training phase, around 70% of the time, pilots fly VFR. After the student receives a commercial pilot license (CPL) only when the student starts training for IFR flights. This is to let students focus on one training phase at a time. IFR flights are very strict on procedures since they rely on instruments. All procedures must be followed, especially the altitudes on the charts.

Some pilots may say that IFR is easier to fly than VFR, but some say it’s the other way around. Each flight rule has its advantages and disadvantages. It depends on the pilot’s personal view of IFR and VFR flights.

Most airlines worldwide require a pilot to be IFR rated before they start flying. Big aircraft such as Airbus rely heavily on ILS when landing. Unlike Cessna and other training aircraft that can either fly on VFR or IFR flight plans.

Having the rating and licenses for IFR is a good step toward being an airline pilot. Even in the general aviation field, this rating is a plus, significantly, if the weather hinders flying VFR.

Simulator training on VFR and IFR flights #

With the advancement of Flight Simulators, flight simulators can replicate VFR and IFR flights on modern flight simulators. For example, a G1000 on a C172 has an active navigation system and ILS in which you can select and adjust the frequency depending on your chosen airport. VFR applications on a flight simulator almost have a good rendering of the terrain, which can be a good reference compared to the actual flight. Flight simulators can even replicate actual weather and time of day. Even actual traffic on the server can be seen if you opt-in to view live traffic on the simulator. Sometimes, even an air traffic controller can be present in a flight simulator server. ATC can give clearances and permissions for requests during or before flights. But there are times when a flight simulator server can be a disaster. Always be mindful when joining a simulator server. In the section below, you can see two screenshots from two different aircraft taken from a flight simulator from a computer.

Here is a screenshot of a G100 on the Flight simulator.

It has the instruments that are used on an IFR flight.

Here is a screenshot taken from a Microsoft Flight simulator of an Airbus A320-neo which is almost an exact copy of the actual A320 cockpit.

How do airlines and civil aviation authorities maximize the use of simulators? #

Not only aviation enthusiasts and student pilots use flight simulators. Even some airline pilots use a flight simulator from their computer for leisure and sometimes for familiarity with an aircraft. Most airlines require their pilot to undergo simulator training from time to time, but the simulator used for this differs from the simulator installed on your personal computer.

These simulators that airlines use are called full-flight simulators. These simulators move and tilt depending on the input on the aircraft control columns. This almost replicates the exact cockpit environment of the aircraft. In these simulators, pilots train for emergency procedures such as radio communication failure, engine failures, engine fires and other emergencies that an aircraft can experience. So that in the event of an emergency, pilots can follow the correct procedure needed to prevent a fatal accident.

Civil aviation authorities also use a full flight simulator to conduct test and proficiency exams for pilots applying for their ratings and certifications. Using an actual aircraft for such purposes is expensive and wastes unnecessary time and resources.

So, no matter how many flying hours you have logged in an actual flight, you will be sitting behind a simulator from time to time. Simulators will always be a part of a pilot’s life.��