We appreciate that noise created at night can cause greater disturbance to people. It is generally quieter at night and the majority of people are trying to sleep. Also, night noise may seem worse in the summer when people are more likely to sleep with windows open.
There is no ban on night flights at Heathrow but since the 1960s, the Government has placed restrictions on them. Heathrow has some of the strictest restrictions of any hub airport in Europe in terms of movements permitted between 11:30pm and 6:00am. Heathrow is restricted to 5,800 take-offs and landings a year during these times.
Around 80% of the night flights at Heathrow are between 4:30am and 6:00am, with on average around 16 aircraft scheduled to arrive each day between these hours. Heathrow also has a voluntary ban in place that prevents flights from landing before 4:30am. There is also a night quota limit, which caps the amount of noise the airport can make at night.
Why do we have night flights?
Night flights are an important part of operations at airports around the world. The time differences in an inter-connected global transport system mean that it is difficult to avoid night flights.
The relationship between flight times and clock times means that early morning arrivals at Heathrow are particularly suited to serving flights from much of China, South East and South Asia. The early arrival permits a full day’s business to be undertaken in the UK and maximises the timing opportunities for those making onward flight connections from London. By feeding other flights, these transfer passengers play an important role in maintaining the range and frequency of destinations served by Heathrow, and in maintaining connectivity with key destinations.
Night flight restrictions
Restrictions on night flights have been in place at Heathrow since 1962 and the structure of the current night flying restrictions at Heathrow has been in place since October 2017. The Night Flight restrictions are part of the Government defined noise measures under the Civil Aviation Act 1982.
Overview of restrictions:
- There are two time periods: 11:00pm–7:00am and 11:30pm–6:00am both with restrictions on certain types of aircraft;
- The more restrictive period (11:30pm–6:00am) is known as the Night Quota Period (NQP) and has limits on the number of movements which are set by the DfT. The limits are set on a seasonal basis: summer and winter;
- Heathrow is currently limited to 5,800 night flights a year: 3,250 in the summer season and 2,550 in the winter season;
- Heathrow is also permitted to carry over up to 10% of the ‘left over’ movements from summer to winter, which means the winter season limits vary more than the summer limits. The summer season is defined using British Summer Time. Heathrow is not permitted to accumulate the carry-over from one year to the next.
Government's approach to night flights
It is the Department of Transport (DfT) that sets restrictions on the amount of noise that airports can make at night. The Government consults on their night flight regime for Heathrow every five years. One of the objectives is to limit or reduce the number of people significantly affected by aircraft noise at night, for example by encouraging the use of quieter aircraft, while maintaining the existing benefits of night flights.
How the restrictions work
Aircraft are classified into nine bands according to the amount of noise they make when taking off and landing. The noisier the aircraft, the higher the band it is placed in. These bands are called quota counts (QC). Every aircraft is given a QC number between 0 and 16.
Quota Count (QC)
Under the QC system, each aircraft type, including different versions of the same model, is assigned a QC according to its noise performance, separately for arrival and departure, as determined by the ICAO noise certification process. For example, a Boeing 737-800 is classified as QC/0.5 on arrival and as QC/0.5 or QC/1 on departure (depending on its maximum certificated take-off weight), whereas a much larger and older Boeing 747-200 will vary between QC/2 and QC/8 on arrival, and between QC/4 and QC/16 on departure, depending on engine fit and maximum take-off weight (MTOW). The number of points for each aircraft is added up and must be within the limit for that season.
In July 2017, following public consultation, the Government announced their new five year regime running from October 2017 to 2022. The new regime includes the reduction of the QC limit for Heathrow from 4,080 to 2,415 (winter) and from 5,100 to 2,735 (summer).
Compliance with night noise restrictions
We aim to comply with the night noise restrictions in place, and report regularly to the Government and the Heathrow Community Engagement Board (HCEB).
However, there are occasions when a scheduled departure is unavoidably delayed because of operational or technical problems. If a flight needs to leave after 11:30pm for these reasons, the airline must request permission and explain the reason for the delay.
Where weather conditions – such as a heavy snowfall – cause widespread disruption, the government can give dispensation for additional night flights. These are in exceptional circumstances only, such as emergencies, delays which are likely to lead to serious congestion at the airport or serious hardship or suffering to passengers which result in prolonged disruption of air traffic.
For more information about Heathrow’s operations, you can download the Heathrow Operations Handbook 2018.