Quota Count system
Encyclopedia
Quota Count is a system used in the UK
by London's Heathrow
, Gatwick
, and Stansted
airports to limit the amount of noise
generated by aircraft movements at night time (2330 - 0600).
In 1993 a new Quota Count system was introduced based on aircraft noise certification data. Each aircraft type is classified and awarded a quota count (QC) value depending on the amount of noise it generated under controlled certification conditions. The quieter the aircraft the smaller the QC value. Aircraft are classified separately for landing and take-off.
Aircraft were originally divided into six QC bands from 0.5 to 16, but following a review by the Department for Transport
a seventh category - Quota Count 0.25 - was added in March 2007.
The quota count doubles with each increase of 3 dB which corresponds to an approximate doubling of noise power. However, due to the logarithm
ic nature of human aural perception, this 3dB change is perceived as only a small change in the noise level.
Airports operating the system have a fixed quota for each of the summer and winter seasons. As each night-time aircraft movement takes place, an amount of this quota is used depending on the classification of the aircraft. For example, the Boeing 747-400
is classed as QC/2 on landing and QC/4 on takeoff, while the much larger Airbus A380
is rated QC/0.5 on landing and QC/2 on takeoff. The quieter A380 aircraft therefore use up an airport's noise quota between a quarter and half of the rate of the 747, thus providing airlines with an incentive to operate quieter types of aircraft.
Subject to some limited carry-over provisions, when the airport's quota has been fully used up, no more night-time movements are allowed to take place. In practice, the airport spreads the quota so that it is used evenly across the season.
The quotas allocated to each airport operating the system are gradually reduced year-on-year in order to achieve long-term reductions in the impact of night-time aircraft noise. (e.g. http://www.gatwickairport.com/PageFiles/194/NightNoisePDF/NightFlights.pdf)
London Heathrow Airport
prohibits aircraft noisier than QC/2 to operate at night. As this is more stringent than the ICAO
's Chapter 4 limits, QC/2 has become a de facto
aircraft noise standard.
The Quota Count system has been adapted for use in Madrid
and Brussels
.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
by London's Heathrow
London Heathrow Airport
London Heathrow Airport or Heathrow , in the London Borough of Hillingdon, is the busiest airport in the United Kingdom and the third busiest airport in the world in terms of total passenger traffic, handling more international passengers than any other airport around the globe...
, Gatwick
London Gatwick Airport
Gatwick Airport is located 3.1 miles north of the centre of Crawley, West Sussex, and south of Central London. Previously known as London Gatwick,In 2010, the name changed from London Gatwick Airport to Gatwick Airport...
, and Stansted
London Stansted Airport
-Cargo:-Statistics:-Infrastructure:-Terminal and satellite buildings:Stansted is the newest passenger airport of all the main London airports. The terminal is an oblong glass building, and is separated in to three areas: Check-in concourse, arrivals and departures...
airports to limit the amount of noise
Aircraft noise
Aircraft noise is noise pollution produced by any aircraft or its components, during various phases of a flight: on the ground while parked such as auxiliary power units, while taxiing, on run-up from propeller and jet exhaust, during take off, underneath and lateral to departure and arrival paths,...
generated by aircraft movements at night time (2330 - 0600).
Description
From 1962 until 1993, operations at Heathrow were subject to a simple limit on the number of aircraft movements that were allowed to take place during the night period.In 1993 a new Quota Count system was introduced based on aircraft noise certification data. Each aircraft type is classified and awarded a quota count (QC) value depending on the amount of noise it generated under controlled certification conditions. The quieter the aircraft the smaller the QC value. Aircraft are classified separately for landing and take-off.
Aircraft were originally divided into six QC bands from 0.5 to 16, but following a review by the Department for Transport
Department for Transport
In the United Kingdom, the Department for Transport is the government department responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland which are not devolved...
a seventh category - Quota Count 0.25 - was added in March 2007.
| Noise Classification | Quota Count |
|---|---|
| Below 84 EPNdB | Exempt |
| 84 - 86.9 EPNdB | 0.25 |
| 87 - 89.9 EPNdB | 0.5 |
| 90 - 92.9 EPNdB | 1 |
| 93 - 95.9 EPNdB | 2 |
| 96 - 98.9 EPNdB | 4 |
| 99 - 101.9 EPNdB | 8 |
| Greater than 101.9 EPNdB | 16 |
The quota count doubles with each increase of 3 dB which corresponds to an approximate doubling of noise power. However, due to the logarithm
Logarithm
The logarithm of a number is the exponent by which another fixed value, the base, has to be raised to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 1000 is 10 to the power 3: More generally, if x = by, then y is the logarithm of x to base b, and is written...
ic nature of human aural perception, this 3dB change is perceived as only a small change in the noise level.
Airports operating the system have a fixed quota for each of the summer and winter seasons. As each night-time aircraft movement takes place, an amount of this quota is used depending on the classification of the aircraft. For example, the Boeing 747-400
Boeing 747-400
The Boeing 747-400 is a major development and the best-selling model of the Boeing 747 family of jet airliners. While retaining the four-engine wide-body layout of its predecessors, the 747-400 embodies numerous technological and structural changes to produce a more efficient airframe...
is classed as QC/2 on landing and QC/4 on takeoff, while the much larger Airbus A380
Airbus A380
The Airbus A380 is a double-deck, wide-body, four-engine jet airliner manufactured by the European corporation Airbus, a subsidiary of EADS. It is the largest passenger airliner in the world. Due to its size, many airports had to modify and improve facilities to accommodate it...
is rated QC/0.5 on landing and QC/2 on takeoff. The quieter A380 aircraft therefore use up an airport's noise quota between a quarter and half of the rate of the 747, thus providing airlines with an incentive to operate quieter types of aircraft.
Some QC examples
| Aircraft type | QC Departure | QC Arrival |
| Airbus A320 Airbus A320 The Airbus A320 family is a family of short- to medium-range, narrow-body, commercial passenger jet airliners manufactured by Airbus Industrie.Airbus was originally a consortium of European aerospace companies, and is now fully owned by EADS. Airbus's name has been Airbus SAS since 2001... family |
0.5 - 1 | 0.25 - 0.5 |
| Airbus A380 Airbus A380 The Airbus A380 is a double-deck, wide-body, four-engine jet airliner manufactured by the European corporation Airbus, a subsidiary of EADS. It is the largest passenger airliner in the world. Due to its size, many airports had to modify and improve facilities to accommodate it... |
2 | 0.5 |
| Boeing 737 Boeing 737 The Boeing 737 is a short- to medium-range, twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers... Classic |
0.25 - 0.5 | 1 |
| 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... -400 |
4 | 2 |
| 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... -200 |
0.5 | 0.25 |
| Boeing 767 Boeing 767 The Boeing 767 is a mid-size, wide-body twin-engine jet airliner built by Boeing Commercial Airplanes. It was the manufacturer's first wide-body twinjet and its first airliner with a two-crew glass cockpit. The aircraft features two turbofan engines, a supercritical wing, and a conventional tail... -300 |
1 - 2 | 1 |
| 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... -200ER |
2 | 1 |
| Embraer 145 Embraer ERJ 145 family The Embraer ERJ 145 family is a series of regional jets produced by Embraer, a Brazilian aerospace company. Family members include the ERJ 135 , ERJ 140 , and ERJ 145 , as well as the Legacy business jet and the R-99 family of military aircraft. The ERJ 145 is the largest of the group... |
0.25 | 0.25 |
Subject to some limited carry-over provisions, when the airport's quota has been fully used up, no more night-time movements are allowed to take place. In practice, the airport spreads the quota so that it is used evenly across the season.
The quotas allocated to each airport operating the system are gradually reduced year-on-year in order to achieve long-term reductions in the impact of night-time aircraft noise. (e.g. http://www.gatwickairport.com/PageFiles/194/NightNoisePDF/NightFlights.pdf)
London Heathrow Airport
London Heathrow Airport
London Heathrow Airport or Heathrow , in the London Borough of Hillingdon, is the busiest airport in the United Kingdom and the third busiest airport in the world in terms of total passenger traffic, handling more international passengers than any other airport around the globe...
prohibits aircraft noisier than QC/2 to operate at night. As this is more stringent than the ICAO
International Civil Aviation Organization
The International Civil Aviation Organization , pronounced , , is a specialized agency of the United Nations. It codifies the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth...
's Chapter 4 limits, QC/2 has become a de facto
De facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...
aircraft noise standard.
The Quota Count system has been adapted for use in Madrid
Madrid
Madrid is the capital and largest city of Spain. The population of the city is roughly 3.3 million and the entire population of the Madrid metropolitan area is calculated to be 6.271 million. It is the third largest city in the European Union, after London and Berlin, and its metropolitan...
and Brussels
Brussels
Brussels , officially the Brussels Region or Brussels-Capital Region , is the capital of Belgium and the de facto capital of the European Union...
.