Visual flight rules
Encyclopedia
Visual flight rules are a set of regulations which allow a pilot
to operate an aircraft
in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the relevant aviation authority. If the weather is worse than VFR minimums, pilots are required to use instrument flight rules
.
To avoid collisions, the VFR pilot is expected to "see and avoid" obstacles and other aircraft. Pilots flying under VFR assume responsibility for their separation from all other aircraft and are generally not assigned routes or altitudes by air traffic control
. Near busier airports, and while operating within certain types of airspace
, VFR aircraft are required (not in the United States) to have a transponder
to help identify the aircraft on radar. Governing agencies establish specific requirements for VFR flight, including minimum visibility, and distance from clouds, to ensure that aircraft operating under VFR are visible from enough distance to ensure safety.
From a regulatory perspective, airspace is categorized as controlled and uncontrolled. In controlled airspace known as Class B
for example (note that Class B does not exist in the UK), Air Traffic Control
(ATC) will separate VFR aircraft from all other aircraft. In most other types of controlled airspace, ATC is only required to maintain separation to aircraft operating under instrument flight rules
(IFR), but workload permitting will assist all aircraft. In the United States, a pilot operating VFR outside of class B airspace can request "VFR flight following" from ATC. This service is provided by ATC if workload permits it, but is an advisory service only. The responsibility for maintaining separation with other aircraft and proper navigation still remains with the pilot. In the United Kingdom, a pilot can request for "Deconfliction Service", which is similar to flight following.
Meteorological
conditions that meet the minimum requirements for VFR flight are termed visual meteorological conditions
(VMC). If they are not met, the conditions are considered instrument meteorological conditions
(IMC), and a flight may only operate under IFR.
IFR operations have specific training requirements—usually placing a pilot in simulated IMC environment using a view limiting device and recency of experience, equipment, and inspection requirements for both the pilot and aircraft. Additionally, an IFR flight plan
must usually be filed in advance. For efficiency of operations, some ATC operations will routinely provide "pop-up" IFR clearances for aircraft operating VFR, but that are arriving at an airport that does not meet VMC requirements. For example, in the United States, California's Oakland (KOAK
), Monterey (KMRY
) and Santa Ana (KSNA
) airports routinely grant temporary IFR clearance when a low coastal overcast forces instrument approach
es, while the rest of the state is still under visual flight rules.
In the United States and Canada, VFR pilots also have an option for requesting Special VFR when meteorological conditions at an airport are below normal VMC minimums, but above Special VFR requirements. Special VFR is only intended to enable takeoffs and landings from airports that are near to VMC conditions, and may only be performed during daytime hours if a pilot does not possess an instrument rating
.
VFR flight is not allowed in airspace known as class A
, regardless of the meteorological conditions. In the United States, class A airspace begins at 18,000 feet msl
, and extends to an altitude of 60,000 feet msl
.
aircraft under VFR.
separation and minimal guidance are necessary. In this respect, CVFR is similar to Instrument flight rules
(IFR) in that ATC will give pilots headings and altitudes at which to fly, and will provide separation and conflict resolution. However, pilots and aircraft do not need to be IFR rated to fly in CVFR areas, which is highly advantageous. An example of airspace where CVFR is common would be Canadian Class B
airspace.
The CVFR concept is used in Canada and certain European countries, but not in the U.S.
, where the Private Pilot certificate itself authorizes the pilot to accept clearances under VFR.
In Israel and the Palestinian territory, for example, VFR does not exist. All visual flights must be performed under CVFR rules.
500ft provision
An aircraft must not fly closer than 500ft to any person, vessel, vehicle, building or structure.
1000ft provision
If an aircraft is flying over a congested area (town, settlement, etc.) it must fly high enough so that in the case of an engine failure, it is able to land clear without being a danger to people or it must not fly less than 1000ft above the highest fixed object within 600m of the aircraft.
Aviator
An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...
to operate an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the relevant aviation authority. If the weather is worse than VFR minimums, pilots are required to use instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
.
Requirements
VFR require a pilot to be able to see outside the cockpit, to control the aircraft's attitude, navigate, and avoid obstacles and other aircraft.To avoid collisions, the VFR pilot is expected to "see and avoid" obstacles and other aircraft. Pilots flying under VFR assume responsibility for their separation from all other aircraft and are generally not assigned routes or altitudes by air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
. Near busier airports, and while operating within certain types of airspace
Airspace
Airspace means the 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....
, VFR aircraft are required (not in the United States) to have a transponder
Transponder (aviation)
A transponder is an electronic device that produces a response when it receives a radio-frequency interrogation...
to help identify the aircraft on radar. Governing agencies establish specific requirements for VFR flight, including minimum visibility, and distance from clouds, to ensure that aircraft operating under VFR are visible from enough distance to ensure safety.
From a regulatory perspective, airspace is categorized as controlled and uncontrolled. In controlled airspace known as Class B
Airspace class
The world's navigable airspace is divided into three-dimensional segments, each of which is assigned to a specific class. Most nations adhere to the classification specified by the International Civil Aviation Organization and described below...
for example (note that Class B does not exist in the UK), Air Traffic Control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
(ATC) will separate VFR aircraft from all other aircraft. In most other types of controlled airspace, ATC is only required to maintain separation to aircraft operating under instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
(IFR), but workload permitting will assist all aircraft. In the United States, a pilot operating VFR outside of class B airspace can request "VFR flight following" from ATC. This service is provided by ATC if workload permits it, but is an advisory service only. The responsibility for maintaining separation with other aircraft and proper navigation still remains with the pilot. In the United Kingdom, a pilot can request for "Deconfliction Service", which is similar to flight following.
Meteorological
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
conditions that meet the minimum requirements for VFR flight are termed visual meteorological conditions
Visual meteorological conditions
In aviation, visual meteorological conditions is an aviation flight category in which visual flight rules flight is permitted—that is, conditions in which pilots have sufficient visibility to fly the aircraft maintaining visual separation from terrain and other aircraft. They are the opposite of...
(VMC). If they are not met, the conditions are considered instrument meteorological conditions
Instrument meteorological conditions
Instrument meteorological conditions is an aviation flight category that describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules , rather than by outside visual references under Visual Flight Rules . Typically, this...
(IMC), and a flight may only operate under IFR.
IFR operations have specific training requirements—usually placing a pilot in simulated IMC environment using a view limiting device and recency of experience, equipment, and inspection requirements for both the pilot and aircraft. Additionally, an IFR flight plan
Flight plan
Flight plans are documents filed by pilots or a Flight Dispatcher with the local Civil Aviation Authority prior to departure...
must usually be filed in advance. For efficiency of operations, some ATC operations will routinely provide "pop-up" IFR clearances for aircraft operating VFR, but that are arriving at an airport that does not meet VMC requirements. For example, in the United States, California's Oakland (KOAK
Oakland International Airport
Oakland International Airport , also known as Metropolitan Oakland International Airport, is a public airport located south of the central business district of Oakland, a city in Alameda County, California, United States...
), Monterey (KMRY
Monterey Peninsula Airport
Monterey Peninsula Airport is a regional airport located three miles southeast of the central business district of Monterey, a city in Monterey County, California, USA. It was created in 1936....
) and Santa Ana (KSNA
John Wayne Airport
John Wayne Airport is an airport in an unincorporated area in Orange County, California, with its mailing address in the city of Santa Ana, which is also the county seat, hence the International Air Transport Association airport code. The main entrance to the airport is off of MacArthur Blvd in...
) airports routinely grant temporary IFR clearance when a low coastal overcast forces instrument approach
Instrument approach
For aircraft operating under instrument flight rules , an instrument approach or instrument approach procedure is a series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing, or to a point...
es, while the rest of the state is still under visual flight rules.
In the United States and Canada, VFR pilots also have an option for requesting Special VFR when meteorological conditions at an airport are below normal VMC minimums, but above Special VFR requirements. Special VFR is only intended to enable takeoffs and landings from airports that are near to VMC conditions, and may only be performed during daytime hours if a pilot does not possess an instrument rating
Instrument rating
Instrument rating refers to the qualifications that a pilot must have in order to fly under IFR . It requires additional training and instruction beyond what is required for a Private Pilot certificate or Commercial Pilot certificate, including rules and procedures specific to instrument flying,...
.
VFR flight is not allowed in airspace known as class A
Airspace class
The world's navigable airspace is divided into three-dimensional segments, each of which is assigned to a specific class. Most nations adhere to the classification specified by the International Civil Aviation Organization and described below...
, regardless of the meteorological conditions. In the United States, class A airspace begins at 18,000 feet msl
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
, and extends to an altitude of 60,000 feet msl
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
.
Pilot certifications
In the United States and Canada, any certified pilot who meets specific recency of experience criteria may operate an airworthyAirworthiness
Airworthiness is a term used to describe whether an aircraft has been certified as suitable for safe flight. Certification is initially conferred by a Certificate of Airworthiness from a National Airworthiness Authority, and is maintained by performing required maintenance actions by a licensed...
aircraft under VFR.
Controlled visual flight rules
CVFR flight is used in locations where aviation authorities have determined that VFR flight should be allowed, but that ATCAir traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
separation and minimal guidance are necessary. In this respect, CVFR is similar to Instrument flight rules
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
(IFR) in that ATC will give pilots headings and altitudes at which to fly, and will provide separation and conflict resolution. However, pilots and aircraft do not need to be IFR rated to fly in CVFR areas, which is highly advantageous. An example of airspace where CVFR is common would be Canadian Class B
Canadian airspace
Canadian airspace is the region of navigable airspace above the surface of the Earth that falls within a region roughly defined by the Canadian land mass, the Canadian arctic, the Canadian archipelago, and areas of the high seas....
airspace.
The CVFR concept is used in Canada and certain European countries, but not in the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, where the Private Pilot certificate itself authorizes the pilot to accept clearances under VFR.
In Israel and the Palestinian territory, for example, VFR does not exist. All visual flights must be performed under CVFR rules.
Low Flying Rules
In the UK, the Rules of the Air define clearly in the principles of Low Flying Rules in Rule 5. The main principle is that an aircraft must always be able to perform an emergency landing in a case of engine failure. Hence these three criteria:500ft provision
An aircraft must not fly closer than 500ft to any person, vessel, vehicle, building or structure.
1000ft provision
If an aircraft is flying over a congested area (town, settlement, etc.) it must fly high enough so that in the case of an engine failure, it is able to land clear without being a danger to people or it must not fly less than 1000ft above the highest fixed object within 600m of the aircraft.
See also
- ADS-B
- Barany chairBarany chairThe Barany chair or Bárány chair, named for the Austro-Hungarian physiologist Robert Bárány, is a device used for aerospace physiology training, particularly for student pilots. The subject is placed in the chair, blindfolded, then spun about the vertical axis while keeping his head upright or...
- Night visual flight rules
- Special visual flight rulesSpecial visual flight rulesSpecial visual flight rules are a set of aviation regulations under which a pilot may operate an aircraft. It's a special case of operating under visual flight rules .- Use in different regions :...