The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 English feet, or 1,760 yards. The statute mile was standardised between the British Commonwealth and the United States by an international agreement in 1959, when it was formally redefined with respect to SI units as exactly 1,609.344 metres.
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute of latitude. Today the international nautical mile is defined as exactly 1,852 metres. The derived unit of speed is the knot, one nautical mile per hour.
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.
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer.
A nautical chart or hydrographic chart is a graphic representation of a sea region or water body and adjacent coasts or banks. Depending on the scale of the chart, it may show depths of water (bathymetry) and heights of land (topography), natural features of the seabed, details of the coastline, navigational hazards, locations of natural and human-made aids to navigation, information on tides and currents, local details of the Earth's magnetic field, and human-made structures such as harbours, buildings, and bridges. Nautical charts are essential tools for marine navigation; many countries require vessels, especially commercial ships, to carry them. Nautical charting may take the form of charts printed on paper or computerized electronic navigational charts. Recent technologies have made available paper charts which are printed "on demand" with cartographic data that has been downloaded to the commercial printing company as recently as the night before printing. With each daily download, critical data such as Local Notices to Mariners are added to the on-demand chart files so that these charts are up to date at the time of printing.
The airspeed indicator (ASI) or airspeed gauge is a flight instrument indicating the airspeed of an aircraft in kilometers per hour (km/h), knots (kn), miles per hour (MPH) and/or meters per second (m/s). The recommendation by ICAO is to use km/h, however knots is currently the most used unit. The ASI measures the pressure differential between static pressure from the static port, and total pressure from the pitot tube. This difference in pressure is registered with the ASI pointer on the face of the instrument.
In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are:
The true airspeed of an aircraft is the speed of the aircraft relative to the air mass through which it is flying. The true airspeed is important information for accurate navigation of an aircraft. Traditionally it is measured using an analogue TAS indicator, but as the Global Positioning System has become available for civilian use, the importance of such air-measuring instruments has decreased. Since indicated, as opposed to true, airspeed is a better indicator of margin above the stall, true airspeed is not used for controlling the aircraft; for these purposes the indicated airspeed – IAS or KIAS – is used. However, since indicated airspeed only shows true speed through the air at standard sea level pressure and temperature, a TAS meter is necessary for navigation purposes at cruising altitude in less dense air. The IAS meter reads very nearly the TAS at lower altitude and at lower speed. On jet airliners the TAS meter is usually hidden at speeds below 200 knots (370 km/h). Neither provides for accurate speed over the ground, since surface winds or winds aloft are not taken into account.
Indicated airspeed (IAS) is the airspeed of an aircraft as measured by its pitot-static system and displayed by the airspeed indicator (ASI). This is the pilots' primary airspeed reference.
Metrication is the process of introducing the International System of Units, also known as SI units or the metric system, to replace a jurisdiction's traditional measuring units. U.S. customary units have been defined in terms of metric units since the 19th century, and the SI has been the "preferred system of weights and measures for United States trade and commerce" since 1975 according to United States law. However, conversion was not mandatory and many industries chose not to convert, and U.S. customary units remain in common use in many industries as well as in governmental use. Unlike other countries, there is no governmental or major social desire to implement further metrication.
Calibrated airspeed (CAS) is indicated airspeed corrected for instrument and position error.
United Airlines Flight 585 was a scheduled passenger flight on March 3, 1991, from Denver to Colorado Springs, Colorado, carrying 20 passengers and 5 crew members on board. The plane experienced a rudder hardover while on final approach to runway 35 at Colorado Springs Municipal Airport, causing the plane to roll over and enter an uncontrolled dive. All 25 people on board were killed.
Aircraft maneuvering is referenced to a standard rate turn, also known as a rate one turn (ROT).
Flight plans are documents filed by a pilot or flight dispatcher with the local Air Navigation Service Provider prior to departure which indicate the plane's planned route or flight path. Flight plan format is specified in ICAO Doc 4444. They generally include basic information such as departure and arrival points, estimated time en route, alternate airports in case of bad weather, type of flight, the pilot's information, number of people on board, and information about the aircraft itself. In most countries, flight plans are required for flights under IFR, but may be optional for flying VFR unless crossing international borders. Flight plans are highly recommended, especially when flying over inhospitable areas such as water, as they provide a way of alerting rescuers if the flight is overdue. In the United States and Canada, when an aircraft is crossing the Air Defense Identification Zone (ADIZ), either an IFR or a special type of VFR flight plan called a DVFR flight plan must be filed. For IFR flights, flight plans are used by air traffic control to initiate tracking and routing services. For VFR flights, their only purpose is to provide needed information should search and rescue operations be required, or for use by air traffic control when flying in a "Special Flight Rules Area."
In aeronautics, the rate of climb (RoC) is an aircraft's vertical speed, that is the positive or negative rate of altitude change with respect to time. In most ICAO member countries, even in otherwise metric countries, this is usually expressed in feet per minute (ft/min); elsewhere, it is commonly expressed in metres per second (m/s). The RoC in an aircraft is indicated with a vertical speed indicator (VSI) or instantaneous vertical speed indicator (IVSI).
Flight planning is the process of producing a flight plan to describe a proposed aircraft flight. It involves two safety-critical aspects: fuel calculation, to ensure that the aircraft can safely reach the destination, and compliance with air traffic control requirements, to minimise the risk of midair collision. In addition, flight planners normally wish to minimise flight cost through the appropriate choice of route, height, and speed, and by loading the minimum necessary fuel on board. Air Traffic Services (ATS) use the completed flight plan for separation of aircraft in air traffic management services, including tracking and finding lost aircraft, during search and rescue (SAR) missions.
A World Aeronautical Chart (WAC) is a type of aeronautical chart used for navigation by pilots of moderate speed aircraft and aircraft at high altitudes. They are at a scale of 1:1,000,000.
A Machmeter is an aircraft pitot-static system flight instrument that shows the ratio of the true airspeed to the speed of sound, a dimensionless quantity called Mach number. This is shown on a Machmeter as a decimal fraction. An aircraft flying at the speed of sound is flying at a Mach number of one, expressed as Mach 1.
The kilometre per hour is a unit of speed, expressing the number of kilometres travelled in one hour.
