Night noise

Day noise and night noise
Many people are not bothered at all by the noise from planes during the day, because they are at work or see it as part of everyday life. But they can be very bothered by it at night.

Heathrow Airport is allowed to operate a limited service at night. There are Government restrictions on the level of night time noise that is allowed and the number of planes that can fly at night.

On average, Heathrow has about 16 to 18 planes a night.

The rules for night time

Night flight restrictions
There has never been a ban on night flights. However, in 1962, in response to increasing community concern about noise, the Government introduced restrictions and since then there have been a number of different types of restrictions. The Government allows night flights because it sees them as being important for the well-being of the airline and travel industries, and for the UK economy as a whole. However, in order to balance the needs of the local communities it places restrictions on the type and number of aircraft at night. The restrictions apply from 11pm to 7am and apply per season -summer and winter. Every year the end of one season and the beginning of the next coincide with the changes from and to British Summer Time. The period between 11pm-7am is known as the Night period. Tighter restrictions apply between 11.30pm and 6am. This is known as the Night Quota period. The periods between the Night Quota period and the Night Period ie 11pm to 11.30pm and 6am to 7am are known as the ‘Shoulder’ periods.

Over the whole of the Night period (ie 11pm to 7am) the noiest types of aircraft cannot be scheduled to operate.

In the Night Quota period (ie from 11.30pm to 6am) there are two limits. The first restricts flights to a maximum number. The second is the Quota Count points system. Each aircraft which wishes to operate at night has to be assessed by the Civil Aviation Authority and allocated a Quota Count (QC) number. The more noise it makes, the higher the QC number. The very quietest aircraft are exempt.

The noisier types of aircraft (ie those with the highest QC numbers) cannot be scheduled to operate in the Night Quota period. Those with the smaller QC numbers (ie the quieter ones) can be scheduled to operate but each time they fly in or fly out in this time period the amount of QC points they have been allocated must be subtracted from an overall limit on points which may be used in a season. So for example an aircraft which is QC1 when arriving will use up 1 point from the overall limit. Aircraft may have different QC numbers for when they are arriving and when they are departing, depending on the amount of noise they make for each.
Both limits apply over the whole season and not per day or week so the number of flights may vary from day to day. However BAA strictly manages and monitors night flights to ensure that neither limit is exceeded by the end of the season.

This system encourages airlines who want to fly at night to use the quietest aircraft. However, there is also the limit on the maximum number of flights which cannot be exceeded. Once this limit is reached, no more flights may operate even if there are QC points remaining. The reverse also applies, ie if the QC limit is reached but the maximum number of flights has not been reached, again no more flights may operate.

Review of night-flights
The Government reviews the restrictions every few years which includes a full public consultation. The results of the latest review took effect from winter season 2006/07 and will last until 2012. The consultation documents giving full details of the review and the Government’s decisions are available on the Department for Transport’s website www.dft.gov.uk. A copy of the BAA response is available on the BAA Website www.baa.com.