Heavy (aviation)
Encyclopedia
When talking to air traffic controller
s, pilot
s will add the term Heavy to the end of the flight call sign
on flights involving very large aircraft
.
For example you might hear this : "United
341, heavy, ready for departure".
This term alerts air-traffic controllers that they need to provide extra spacing between aircraft as these aircraft generate significant wake turbulence
which can disrupt the flight path of the aircraft right behind. The term is typically used around airports as that is where the cause for concern of wake-turbulence is highest.
Some typical aircraft that use this call sign are the Douglas DC-10, Boeing 747
and Boeing 777
.
Of special note here is the Boeing 757
which even though it might not strictly qualify as a 'heavy' from the weight point of view, is still treated as a 'heavy' by air-traffic controllers as it is notorious for its wake-turbulence generating properties due to the specific nature of its wing design, although the stretch 757-300 series is legally considered a heavy since its takeoff weight exceeds 255,000 lbs.
Air traffic controller
Air traffic controllers are the people who expedite and maintain a safe and orderly flow of air traffic in the global air traffic control system. The position of the air traffic controller is one that requires highly specialized skills...
s, 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...
s will add the term Heavy to the end of the flight call sign
Call sign
In broadcasting and radio communications, a call sign is a unique designation for a transmitting station. In North America they are used as names for broadcasting stations...
on flights involving very large 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...
.
For example you might hear this : "United
United Airlines
United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...
341, heavy, ready for departure".
This term alerts air-traffic controllers that they need to provide extra spacing between aircraft as these aircraft generate significant wake turbulence
Wake turbulence
Wake turbulence is turbulence that forms behind an aircraft as it passes through the air. This turbulence includes various components, the most important of which are wing vorticies and jetwash. Jetwash refers simply to the rapidly moving gases expelled from a jet engine; it is extremely turbulent,...
which can disrupt the flight path of the aircraft right behind. The term is typically used around airports as that is where the cause for concern of wake-turbulence is highest.
Some typical aircraft that use this call sign are the Douglas DC-10, Boeing 747
Boeing 747
The Boeing 747 is a wide-body commercial airliner and cargo transport, often referred to by its original nickname, Jumbo Jet, or Queen of the Skies. It is among the world's most recognizable aircraft, and was the first wide-body ever produced...
and Boeing 777
Boeing 777
The Boeing 777 is a long-range, wide-body twin-engine jet airliner manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet and is commonly referred to as the "Triple Seven". The aircraft has seating for over 300 passengers and has a range from , depending on model...
.
Of special note here is the Boeing 757
Boeing 757
The Boeing 757 is a mid-size, narrow-body twin-engine jet airliner manufactured by Boeing Commercial Airplanes. Passenger versions of the twinjet have a capacity of 186 to 289 persons and a maximum range of , depending on variant and cabin configuration...
which even though it might not strictly qualify as a 'heavy' from the weight point of view, is still treated as a 'heavy' by air-traffic controllers as it is notorious for its wake-turbulence generating properties due to the specific nature of its wing design, although the stretch 757-300 series is legally considered a heavy since its takeoff weight exceeds 255,000 lbs.