Notes to editors:
The sixth Fly Quiet table rated the top 50 airlines operating at Heathrow (by number of flights per quarter) according to six noise related criteria. The airlines received a red/amber/green rating for each criterion, as well as an overall score that allows them to understand how they are performing in relation to other airlines.
As some elements of the Fly Quiet league, for example CDA, are influenced by seasonal variables, comparisons between the same quarterly periods of year to year are particularly useful.
Further details about the Fly Quiet programme:
The six noise metrics
Airlines were consulted on which metrics would be used to compile the Fly Quiet league table. Each metric will be assigned a “RAG” (Red, Amber, Green) status based on the performance bands set for that indicator. As a result operators towards the top of the table will typically have more ‘green scores’ than those towards the bottom. Because scores fluctuate within a band it is possible for an airline with all green scores to sit further down the table, than those with amber or red scores. Individual metric scores will not be published. The ratings are corrected for the number of flights flown by each airline so airlines with more flights are not penalised.
The metrics below make up the Fly Quiet League Table:
1. Noise quota count/seat/movement. This is a relative noise “efficiency” metric which scores the noise efficiency of an operator’s fleet, recognising that whilst larger aircraft tend to be noisier they also carry more passengers. It is calculated by dividing the sum of QC for arrivals and departures by the aggregate seat capacity and total movements by airline of those flights. This provides a balance between a QC/seat or QC/movement metric which will tend to overly bias long haul or short haul carriers respectively.
A ‘red’ score is awarded if the QC/seat/movement indicator exceeds 0.000022. An ‘amber’ score is awarded if the score is better than the minimum performance targets above but greater than 0.00001.
2. Noise Certification – each aircraft is required to have a noise certificate which can be used to determine its relative performance against ICAO noise performance targets (Chapter 3 and Chapter 4). This allows us to recognise “best in class” and compare performance across different types. An average ‘per movement’ Chapter number value is calculated for each airline, which favours the airlines operating best-in-class, modern, quieter aircraft more frequently.
The minimum performance target in these metrics for the purpose of the Fly Quiet programme is Chapter 4. If the average score of an airline’s fleet operated to and from Heathrow is less than the Chapter 4 equivalent a ‘red score is awarded. A ‘green’ score is awarded if the average noise certification score of an airline is better than the equivalent of Chapter 4 base charging category (see our Conditions of Use www.heathrowairport.com).
3. Arrival Operations: Continuous Descent Approach (CDA violations). CDA involves aircraft maintaining a steady angle of approach when landing at the airport, as opposed to stepped approaches which involve prolonged periods of level flight. This reduces noise because it requires less engine thrust and keeps the aircraft higher for longer. By following a CDA on arrival, the noise on the ground can be reduced by up to 5dBA in areas away from the final approach paths. The purpose of the indicator is to capture the non-CDA arrivals and so potentially reduce the disturbance caused.
The minimum performance target for the CDA compliance is set for 55% for the Fly Quiet programme. An airline achieving this but not exceeding 75% gets an ‘amber’ score; CDA compliance of 75% and more means a ‘green’ score is awarded.
4. Departure Operations: Track deviations on departure (TK violations). Aircraft are required to stay within ‘noise preferential routes’ (NPRs) – 3km wide tracks in the sky, designated by the Government to route aircraft away from more densely populated areas as far as possible - until they reach 4000ft. The track deviations indicator is expressed as the proportion of departures that flew outside the NPRs below 4000ft. The purpose of the indicator is to capture the aircraft which operate outside of these boundaries and so potentially cause unexpected noise disturbance. Instances where this occurs for reasons outside of the airline’s control are excluded for the calculation.
The minimum performance target for the track keeping compliance is set for 85% for the Fly Quiet programme. An airline achieving this standard but not exceeding 90% gets an ‘amber’ score; CDA compliance of 90% and more means a ‘green’ score is awarded.
5. Night time Operations 1: arrivals prior to 0430. There is a voluntary arrangement that aircraft scheduled to land between 0430 and 0600 will not land prior to 0430. This is a very sensitive time and issue for local community groups. The purpose of this indicator is to measure adherence to the operator schedules. It is measured as the number of flights arriving before 0430 as a proportion of the total number of arrivals for the airline.
Green: no infringements, Red: one or more infringements
6. Night time Operations 2: unscheduled arrivals prior to 0600. Arrivals scheduled to land after 0600 should not land before then unless there are dispensing circumstances (e.g. Low visibility conditions). This is also a very sensitive time and issue for local community groups. The purpose of this indicator is to measure adherence to the operator schedules. It is measured as the number of unscheduled flights arriving between 0430 and 0600 as a proportion of the total number of arrivals for the airline.
Green: no infringements, Red: one or more infringements
7. As metrics 5 & 6 are limited in terms of the airlines they could affect but are nonetheless important issues for community stakeholders these have been weighted lower than the remaining 4 so as to not result in dramatic fluctuations in an airlines ranking. Instances where metrics 5 & 6 occur for reasons outside of the airline’s control are excluded for the calculation.
The set of indicators is designed to address the aims of the programme whilst giving the operators the opportunity to improve their ranking by short-term (i.e. operational/tactical) or long-term (e.g. fleet planning) measures.
- The overall ranking of operators in the league table is determined on the basis of the cumulative score resulting from six individual metrics; a lower overall score means higher ranking.
- The top 50 operators by number of movements in the given quarter are included in the league table – this aims to eliminate skewing results by including operators with infrequent operations while covering >90% of movements. The individual metrics are normalised before they are converted into the final partial score for the given operator and respective indicator.
- Operators are split into long-haul and short-haul by percentage of long-haul movements. Movements are defined on the basis of aircraft types deployed on the routes operated by the airline to/from Heathrow. A ‘long-haul aircraft’ for the purposes of the Fly Quiet programme is an aircraft which has a maximum take-off weight (MTOW) of 180 tonnes or more.
- An operator is categorised as long-haul if long-haul movements represent more than 80% of the operator’s movements, and is categorised as short-haul if the long-haul movements represent <20% of the operator’s movements. Any operator with 20-80% long-haul movements is split and measured separately on its long-haul and short-haul traffic, i.e. two separate entries for the same airline can appear in the league table.
- The league tables will be published on a quarterly basis with an annual review and recognition of changes in performance.
- The indicators and calculation mechanisms are also proposed in a way that enables even the lower-ranked operators to show some ‘green’ scores rather than to award these operators ‘red’ scores only.