In aviation, instrument flight rules (IFR) is one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other is visual flight rules (VFR).
In aviation, visual flight rules (VFR) are a set of regulations under which a pilot operates 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 minima, i.e. in visual meteorological conditions (VMC), as specified in the rules of the relevant aviation authority. The pilot must be able to operate the aircraft with visual reference to the ground, and by visually avoiding obstructions and other aircraft.
Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with data about the flight situation of that aircraft, such as altitude, airspeed, vertical speed, heading and much more other crucial information in flight. They improve safety by allowing the pilot to fly the aircraft in level flight, and make turns, without a reference outside the aircraft such as the horizon. Visual flight rules (VFR) require an airspeed indicator, an altimeter, and a compass or other suitable magnetic direction indicator. Instrument flight rules (IFR) additionally require a gyroscopic pitch-bank, direction and rate of turn indicator, plus a slip-skid indicator, adjustable altimeter, and a clock. Flight into instrument meteorological conditions (IMC) require radio navigation instruments for precise takeoffs and landings.
The basic principles of air navigation are identical to general navigation, which includes the process of planning, recording, and controlling the movement of a craft from one place to another.
In aviation, visual meteorological conditions (VMC) is an aviation flight category in which visual flight rules (VFR) 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 instrument meteorological conditions (IMC). The boundary criteria between IMC and VMC are known as the VMC minima and are defined by: visibility, cloud ceilings, and cloud clearances.
Instrument rating refers to the qualifications that a pilot must have in order to fly under instrument flight rules (IFR). It requires specific training and instruction beyond what is required for a private pilot certificate or commercial pilot certificate, including rules and procedures specific to instrument flying, additional instruction in meteorology, and more intensive training in flight solely by reference to instruments.
In aviation, instrument meteorological conditions (IMC) is a flight category that describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under instrument flight rules (IFR), rather than by outside visual references under visual flight rules (VFR). Typically, this means flying in cloudy or bad weather. Pilots sometimes train to fly in these conditions with the aid of products like Foggles, which are specialized glasses that restrict outside vision, forcing the student to rely on instrument indications only.
Pilot licensing or certification refers to permits for operating aircraft. They are issued by the Civil Aviation Authority (CAA) in each country, establishing that the holder has met a specific set of knowledge and experience requirements. This includes taking a flying test. The certified pilot can then exercise a specific set of privileges in that nation's airspace. Despite attempts to harmonize the requirements between nations, the differences in certification practices and standards from place to place serve to limit full international validity of the national qualifications. In addition, U.S. pilots are certified, not licensed, although the word license is still commonly used informally. Legally, pilot certificates can be revoked by administrative action, whereas licensing requires intervention by the judiciary system.
Pilot certification in the United States is typically required for an individual to act as a pilot-in-command of an aircraft. It is regulated by the Federal Aviation Administration (FAA), a branch of the U.S. Department of Transportation (USDOT). A pilot may be certified under 14 Code of Federal Regulations (CFR) Part 61 or 14 CFR Part 141. Pilots may also be certified under 14 CFR Part 107 for commercial drone operations.
Pilot licensing in Canada is administered by Transport Canada under the Aeronautics Act and the Canadian Aviation Regulations (CARs).
Pilot licensing in the United Kingdom is regulated by the Civil Aviation Authority (CAA).
An instrument rating is required for a pilot to fly under instrument flight rules (IFR). In the United States, the rating is issued by the Federal Aviation Administration.
Special visual flight rules are a set of aviation regulations under which a pilot may operate an aircraft. It is a special case of operating under visual flight rules (VFR).
VFR over-the-top (OTT) refers to flying over top of clouds in visual flight, rather than with reference to instruments. This is usually done for brief amount of time to avoid weather or turbulence.
A safety pilot is a rated pilot who helps maintain visual separation from other aircraft, clouds, and terrain while another pilot is wearing view limiting devices for the purposes of simulating instrument conditions.
The low-frequency radio range, also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main navigation system used by aircraft for instrument flying in the 1930s and 1940s, until the advent of the VHF omnidirectional range (VOR), beginning in the late 1940s. It was used for en route navigation as well as instrument approaches and holds.
A visual approach is an approach to a runway at an airport conducted under instrument flight rules (IFR) but where the pilot proceeds by visual reference and clear of clouds to the airport. The pilot must at all times have either the airport or the preceding aircraft in sight. This approach must be authorized and under the control of the appropriate air traffic control (ATC) facility. The International Civil Aviation Organization (ICAO) definition adds that the visual approach can commence when "either part or all of an instrument approach is not completed", varying only slightly from the Federal Aviation Administration regulation and is essentially identical.
Continental Charters Flight 44-2, a domestic non scheduled passenger flight from Miami, Florida to Buffalo, New York, crashed on December 29, 1951 near Napoli, New York. The twin engine C-46 Commando, registration N3944C, crashed approximately 10:25 pm in adverse weather conditions. Of the four crew and 36 passengers on board, three crew members and 23 passengers perished. The flight crew's poor judgment in attempting a flight by visual reference during instrument weather conditions was the cause of the accident.
On March 5, 1963, American country music performers Patsy Cline, Cowboy Copas, and Hawkshaw Hawkins were killed in an airplane crash near Camden, Tennessee, United States, along with the pilot Randy Hughes. The accident occurred as the three artists were returning home to Nashville, Tennessee, after performing in Kansas City, Kansas.
Continued VFR into IMC is when an aircraft operating under visual flight rules intentionally or unintentionally enters into instrument meteorological conditions. Flying an aircraft without visual reference to the ground can lead to a phenomenon known as spatial disorientation, which can cause the pilot to misperceive the angle, altitude, and speed they are traveling. This is considered a very serious safety hazard in general aviation. According to AOPA’s Nall Report, approximately 4% of general aviation accidents are weather related, yet these accidents account for more than 25% of all fatalities.