Flight director (aviation)
Encyclopedia
In aviation
, a flight director is a navigational aid that is overlaid on the attitude indicator
that shows the pilot
of an aircraft
the attitude required to follow a certain trajectory.
A simple example: the aircraft is in level flight on a heading of 045 degrees and at an altitude of 15000 feet maintaining a speed of 260 kts, the FD bars are thus centered. Then the flight director is set to a new heading of 090 degrees and a new altitude of 20000 feet. The aircraft must thus turn to the right and climb.
This is done by rolling to the right and pulling up. The roll bar will deflect to the right and the pitch bar will deflect upwards. The pilot will then pull back on the control column while rolling the aircraft to the right. Once he reaches the proper pitch and bank angle the FD bars will again center and remain centered until it is time to roll back to wings level (when the heading starts to approach 090).
When the aircraft approaches 20000 feet the pitch bar will deflect downwards thus commanding the pilot to reduce pitch in order to level off at the new altitude.
The FD is generally used in direct connection with the Autopilot, where the FD commands the AP to put the aircraft in the attitude necessary to follow a trajectory. The FD/AP combination is typically used in autopilot coupled
low instrument
approaches, (below 200 feet agl
) or CAT II and CAT III ILS
instrument approach
es.
The exact form of the flight director's display varies with the instrument type either crosshair
or command bars.
Aviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...
, a flight director is a navigational aid that is overlaid on the attitude indicator
Attitude indicator
An attitude indicator , also known as gyro horizon or artificial horizon, is an instrument used in an aircraft to inform the pilot of the orientation of the aircraft relative to earth. It indicates pitch and bank or roll and is a primary instrument for flight in instrument meteorological conditions...
that shows the pilot
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...
of 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...
the attitude required to follow a certain trajectory.
Description
The flight director computes and displays the proper pitch and bank angles required in order for the aircraft to follow a selected path.A simple example: the aircraft is in level flight on a heading of 045 degrees and at an altitude of 15000 feet maintaining a speed of 260 kts, the FD bars are thus centered. Then the flight director is set to a new heading of 090 degrees and a new altitude of 20000 feet. The aircraft must thus turn to the right and climb.
This is done by rolling to the right and pulling up. The roll bar will deflect to the right and the pitch bar will deflect upwards. The pilot will then pull back on the control column while rolling the aircraft to the right. Once he reaches the proper pitch and bank angle the FD bars will again center and remain centered until it is time to roll back to wings level (when the heading starts to approach 090).
When the aircraft approaches 20000 feet the pitch bar will deflect downwards thus commanding the pilot to reduce pitch in order to level off at the new altitude.
The FD is generally used in direct connection with the Autopilot, where the FD commands the AP to put the aircraft in the attitude necessary to follow a trajectory. The FD/AP combination is typically used in autopilot coupled
Autoland
In aviation, autoland describes a system that fully automates the landing phase of an aircraft's flight, with the human crew merely supervising the process.-Description:...
low instrument
Autoland
In aviation, autoland describes a system that fully automates the landing phase of an aircraft's flight, with the human crew merely supervising the process.-Description:...
approaches, (below 200 feet agl
Above ground level
In aviation and atmospheric sciences, an altitude is said to be above ground level when it is measured with respect to the underlying ground surface. This is as opposed to above mean sea level , or in broadcast engineering, height above average terrain...
) or CAT II and CAT III ILS
Instrument Landing System
An instrument landing system is a ground-based instrument approach system that provides precision guidance to an aircraft approaching and landing on a runway, using a combination of radio signals and, in many cases, high-intensity lighting arrays to enable a safe landing during instrument...
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.
The exact form of the flight director's display varies with the instrument type either crosshair
Crosshair
A reticle is a net of fine lines or fibers in the eyepiece of a sighting device, such as a telescope, a telescopic sight, a microscope, or the screen of an oscilloscope. The word reticle comes from the Latin "reticulum," meaning "net." Today, engraved lines or embedded fibers may be replaced by a...
or command bars.
See also
- Acronyms and abbreviations in avionicsAcronyms and abbreviations in avionics-A:*ACARS: Aircraft Communications Addressing and Reporting System.*ACAS: Airborne Collision Avoidance System.*ACP: Audio Control Panel.*ACS: Audio Control System.*ADAHRS: Air Data and Attitude Heading Reference System.*ADC: Air Data Computer....
- HUDHead-Up DisplayA head-up display or heads-up display is any transparent display that presents data without requiring users to look away from their usual viewpoints...
- Attitude indicatorAttitude indicatorAn attitude indicator , also known as gyro horizon or artificial horizon, is an instrument used in an aircraft to inform the pilot of the orientation of the aircraft relative to earth. It indicates pitch and bank or roll and is a primary instrument for flight in instrument meteorological conditions...
- Flight instrumentsFlight instrumentsFlight instruments are the instruments in the cockpit of an aircraft that provide the pilot with information about the flight situation of that aircraft, such as height, speed and altitude...