Executive summary. This report covers January to June 2015.

Transcription

1 LHR Flight Performance Q2 Report 215

2 Contents Executive Summary 3 KPI 4 1ft requirements/infringements 5 Departure Noise Limits 7 Day Noise/Night Noise Infringements 8 Track Keeping 9 CDA 13 Joining Point 15 Go Arounds 19 Night noise/qc Usage 2 Arrival and Departure information 23 Engine Ground Running 24 Additional Information 26 Glossary of Terms 27 Page 2 Heathrow Airport Flight Performance Q2 Report 215

3 Executive summary This report covers January to June 215. January to June 215 has seen an overall East/West split of 74.1% Westerly and 25.9% Easterly. 1ft infringements are down on the same period for 214 from 243 to 119. Of these 119 infringements to the 1ft requirement, 23 were below 9ft. Fluctuations to the 1ft requirement are based mainly around temperature with hotter days leading to more infringements. Night Noise infringements are down from 18 for Q2 in 214 to 12 for of these infringements occurred in the shoulder, and 6 departed after 23:3 when restrictions are at their tightest. There have been 2 Day Noise infringements for Jan-Jun 15. Flight Performance continues to provide noise data to British Airways Aircraft Performance Team for their A38 departures. Track Keeping All Runways has seen a small increase on the same period for last year from 94.68% to 94.77%. CDA Averages remain up for Day and Core Night periods. Night and the 6 Hour are marginally down. The 24 Hour CDA Average is also down from 89.44% to 87.79%. Joining Point for Lates and Lows for both Night and Day show improvement. Late joiners are typically under tactical instructions from ATC, vectoring aircraft for operational reasons on the day. The Summer 215 Night Quota continues well. All charts and graphs are shown on the pages that follow are for reference purposes only. Heathrow Airport Flight Performance Q1 Report 215 Page 3

4 KPI chart to end of June 215 KPI Comparable 214 data 215 Comparison RAG January to June 214 January to June 215 1ft GREEN Noise Infringements Night GREEN Noise Infringements Day 2 Track Keeping Average 27R 98.9% 97.37% GREEN Track Keeping Average 27L 97.64% 96.93% GREEN Track Keeping Average 9R 87.9% 88.92% GREEN Track Keeping Average 9L**** 77.3% 8.9% GREEN Track Keeping All Runways 94.68% 94.77% GREEN CDA Day Average 86.98% 87.25% GREEN CDA Night Average 93.45% 93.44% GREEN CDA Core Night Average 95.21% 96.1% GREEN CDA 6: Hour Average 93.8% 92.74% GREEN 24 Hour CDA Average* 89.44% 87.79% GREEN Joining Point Day LATES Average 1.2%.57% GREEN Joining Point Day LOWS Average 1.61% 1.21% GREEN Joining Point Night LATES Average* 1.77% 1.55% GREEN Joining Point Night LOWS Average* 2.79% 2.66% GREEN Night Quota Pro Rata for Quota Count** 62.5% 56.7% Night Quota Pro Rata for Movements** 82.3% 84.3% * Service levels in NATS contract ** Excess usage pro-rata indicates increased risk of aircraft being refused permission to arrive or depart during 23:3-6:hrs local *** Significant increase in contacts or callers relative to enquiries can indicate a rise in demand on the FEU **** Low numbers of departures off 9L due to the Cranford agreement can result in a wide fluctuation in performance when compared to the other three runways. Caller = person Contact = number of times Enquiries = number of issues Each element of this report is preceded where applicable by the relevant Aeronautical Information Publication (AIP) reference and summary text detailing the purpose of the requirement. Data is then presented on current performance. It should be noted that Heathrow is 83ft above sea level and the ANOMS NTK system measures height relative to Heathrow elevation and not sea level. References in the AIP are usually above sea level (quoted as Heathrow QNH) and therefore need to be reduced by 83ft to be comparable with heights as measured by ANOMS. No account is taken of the variability of heights as measured by the radar which, depending on the distance from the radar head can be +/- 2ft from that indicated. This is obviously allowed for by NATS when managing operations. FOR THE PURPOSES OF THIS REPORT ANY REFERENCE TO HEIGHT SHOULD BE READ AS ABOVE AIRFIELD ELEVATION UNLESS OTHERWISE STATED. ALL DATA CONTAINED WITHIN THIS REPORT SHOULD BE CONSIDERED IN LIGHT OF THE PRECEDING TEXT AND COMMENT BOX THAT FOLLOWS. Page 4 Heathrow Airport Flight Performance Q2 Report 215

5 1ft requirement AIP REFERENCE AD 2-EGLL-1-14 After take-off the aircraft shall be operated in such a way that it is at a height of not less than 1 ft aal at 6.5km from start of roll as measured along the departure track of that aircraft. Period From 1/1/215 to 3/6/215 Height Infringement Reports 1ft Infringements by Month with Temperature No of Aircraft failing to reach 1ft at 6.5 km Jan 15 No of Aircraft failing to reach 1ft at 6.5km against Temp Feb 15 Mar 15 Apr 15 May 15 Jun Average Monthly Temperature Month <1ft Average Temp <9ft Heathrow Airport Flight Performance Q1 Report 215 Page 5

6 1ft infringements by airline London Heathrow Period From 1/1/215 to 3/6/215 Airline < 1 ft < 9 ft ALK SRILANKAN AIRLINES 5 2 BAW BRITISH AIRWAYS 42 3 ETD ETIHAD AIRWAYS 1 MAS MALAYSIA AIRLINES 4 MAU AIR MAURITIUS 9 4 PAL PHILIPPINE AIRLINES Inc 15 7 QAF UNKNOWN 1 QTR QATAR AIRWAYS 1 1 SAA SOUTH AFRICAN AIRWAYS 7 5 UAE EMIRATES 1 UAL UNITED AIRLINES 3 VIR VIRGIN ATLANTIC 7 1 Total of all Infringements: 119 Page 6 Heathrow Airport Flight Performance Q2 Report 215

7 Departure Noise Limits AIP REFERENCE AD 2-EGLL-1-15 Subject to sub-paragraphs (5) and (6) below, any aircraft shall, after take-off, be operated in such a way that it will not cause more than 94 dba Lmax by day (from 7 hours to 23 hours local time) as measured by any noise monitoring terminal at any of the sites referred to in subparagraph (2*) above. Subject to sub-paragraphs (5) and (6) below, any aircraft shall, after take-off, be operated in such a way that it will not cause more than 89 dba Lmax by night (from 23 hours to 7 hours local time) and, that it will not cause more than 87 dba Lmax during the night quota period (from 233 to 6 house local time) as measured by any noise monitoring terminal at any of the sites referred to in subparagraph (2*) above. (5) The limits specified in sub-paragraphs (3*) and (4*) above shall be adjusted in accordance with the following table in respect of any noise monitoring terminal at any of the sites referred to in the table in sub-paragraph (2*) to take into account of the location of that terminal and it s ground elevation relative to the aerodrome elevation. (6) For the purposes of determining an infringement of the limits specified in sub paragraphs (3*) and (4*) above, if the aircraft was requested to take-off with a tailwind, an amount of up to 2dB of the noise recorded at the noise monitor should be disregarded. The amount to be disregarded shall be:.4 db for a tailwind of up to 1 knot..8 db for a tailwind exceeding 1 knot but not exceeding 2 knots 1.2 db for a tailwind exceeding 2 knots but not exceeding 3 knots 1.6 db for a tailwind exceeding 3 knots but not exceeding 4 knots 2. db for a tailwind exceeding 4 knots For this purpose, tailwind is to be calculated from the wind data measured in the on-air field anemometers and wind vanes according to the formula: (windspeed x cosine (runway heading minus wind direction))x-1 * AIP see glossary on page 3 Heathrow Airport Flight Performance Q1 Report 215 Page 7

8 Day Noise Infringements Day Noise Infringements Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Night Noise Infringements Night Noise Infringements Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Page 8 Heathrow Airport Flight Performance Q2 Report 215

9 Departure Track Keeping AIP REFERENCE AD 2-EGLL-1-17 For monitoring purposes, a departure will be deemed to have complied with the Noise Preferential Routeing (NPR) if, in the portion of flight below the appropriate vectoring altitude (see note 9 right), it is properly recorded by the airport s noise and trackkeeping (NTK) system as having flown wholly within the Lateral Swathe (LS). The LS is defined from the centre-line of the relevant route coded in the NTK system, based upon a map accredited for this purpose by the Department for Transport, by the closer to the centre-line depicted on the map of (a) a pair of lines either side, each diverging at an angle of 1 from a point on the runway centre-line 2m from startof-roll; and (b) a pair of parallel lines representing a distance of 1.5 km either side of the route centreline. For avoidance of doubt, the depicted route and LS may include curved sections representing turns. Note 9. Aircraft which have attained an altitude of 4 ft ( Heathrow QNH ) may be directed by air traffic controllers onto a different heading and commanders complying with any such direction will not by reason of so complying be deemed to have departed from the NPR. Track deviations by runway Period From 1/1/215 to 3/6/215 Runway Total Departures 215 Total Deviations 215 % Compliance R 42,3 1, L 41,26 1, R 33,379 3, L Totals 116,868 6, Heathrow Airport Flight Performance Q1 Report 215 Page 9

10 % of On Track Departures by Flow and Route Current and Previous Year for 1/1/215 to 3/6/215 Easterly Month 9LBPK 9LBUZ 9LCPT 9LDET 9LDVR 9LMID1P 9LMID1P 9LMID1Q 9LSAM Jan Feb Mar Apr May-14 Jun Jan Feb Mar Apr May Jun Easterly Month 9RBPK 9RBUZ 9RCPT 9RDET 9RDVR 9RGAS 9RMID 9RMID1M 9RMID1N 9RSAM Jan Feb Mar Apr May Jun Jan Feb Mar Apr May Jun * The percentage of all 9L routes will vary greatly due to the small number of departures off that runway due to the Cranford agreement. Page 1 Heathrow Airport Flight Performance Q2 Report 215

11 % of On Track Departures by Flow and Route Current and Previous Year for 1/1/215 to 3/6/215 Westerly Month 27LBPK 27LCPT 27LDET 27LDOK1C 27LDOK1D 27LDVR 27LGOG 27LMID 27LSAM 27LWOB Jan Feb Mar Apr May Jun Jan Feb Mar Apr May Jun Westerly Month 27RBPK 27RCPT 27RDET 27RDOK1A 27RDOK1B 27RDVR 27RGOG 27RMID 27RSAM 27RWOB Jan Feb Mar Apr May Jun Jan Feb Mar Apr May Jun Heathrow Airport Flight Performance Q1 Report 215 Page 11

12 Track Keeping Key Performance Indicator Period from 1/1/215 to 3/6/ Jun-97 Jan-15 Feb-15 Mar-15 Percentage on track Apr-15 May-15 Jun-15 West% East%-9RCPT Total%-9RCPT East% Total % Page 12 Heathrow Airport Flight Performance Q2 Report 215

13 Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Continuous Descent Approach (CDA) AIP REFERENCE AD 2-EGLL-1-17 ( Note 7 ) For monitoring purposes, a descent will be deemed to have been continuous provided that no segment of level flight longer than 2.5 nautical miles (nm) occurs below 6ft QNH and level flight is interpreted as any segment of flight having a height change of not more than 5ft over a track distance of 2 nm or more, as recorded in the airport Noise and Trackkeeping system. * The CDA data is broken down into four time periods, Day (7hrs 23hrs), Night (23hrs 7hrs), Core night (233hrs 6hrs ) and the 6:hr (6hrs 7hrs) CDA Use during the day 7-23 CDA over 24 months. Three month Rolling Average line CDA% Heathrow Airport Flight Performance Q1 Report 215 Page 13

14 CDA Use in Night 23-7 CDA 24 Months Rolling Average CDA% Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 CDA Use in Core Night CDA 24 Months Rolling Average CDA% Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Page 14 Heathrow Airport Flight Performance Q2 Report 215

15 CDA Use during 6-7 CDA 24 Months Rolling Average CDA% Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Joining Point AIP REFERENCE AD 2-EGLL-1-16 ( Note 1 ) Between 6 and 233 hours (local time) where the aircraft is approaching runway 27 (L or R) and is using the ILS in IMC or VMC it shall not descend on the glidepath below an altitude of 25 ft (Heathrow QNH) before being established on the localizer, nor thereafter fly below the glidepath. An aircraft approaching without assistance from the ILS shall follow a descent path which will not result in its being at any time lower than the approach path that would be followed by an aircraft using the ILS glidepath, and shall follow a track to intercept the extended runway centre-line at or above 25 ft (Heathrow QNH). Between 233 and 6 hours (local time) where the aircraft is approaching runway 27 (L or R) and is using the ILS in IMC or VMC it shall not descend on the glidepath below an altitude of 3 ft (Heathrow QNH) before being established on the localizer at not less than 1nm from touchdown, nor thereafter fly below the glidepath. An aircraft approaching without assistance from the ILS shall follow a descent path which will not result in its being at any time lower than the approach path that would be followed by an aircraft using the ILS glidepath, and shall follow a track to intercept the extended runway centre-line at or above 3 ft (Heathrow QNH). Heathrow Airport Flight Performance Q1 Report 215 Page 15

16 Between 7 and 23 hours (local time) where the aircraft is approaching runway 9 (L or R) and is using the ILS in IMC or VMC it shall not descend on the glidepath below an altitude of 25 ft (Heathrow QNH) before being established on the localizer, nor thereafter fly below the glidepath. An aircraft approaching without assistance from the ILS shall follow a descent path which will not result in its being at any time lower than the approach path that would be followed by an aircraft using the ILS glidepath, and shall follow a track to intercept the extended runway centre-line at or above 25 ft (Heathrow QNH). Between 23 and 7 hours (local time) where the aircraft is approaching runway 27 (L or R) and is using the ILS in IMC or VMC it shall not descend on the glidepath below an altitude of 3 ft (Heathrow QNH) before being established on the localizer, at not less than 1nm from touchdown, nor thereafter fly below the glidepath. An aircraft approaching without assistance from the ILS shall follow a descent path which will not result in its being at any time lower than the approach path that would be followed by an aircraft using the ILS glidepath, and shall follow a track to intercept the extended runway centre-line at or above 3 ft (Heathrow QNH). The NTK system is unable to take into account multiple fluctuations in pressure within an hour. This can lead to an increase in the reported number of LOWS in the summer months. Page 16 Heathrow Airport Flight Performance Q2 Report 215

17 Rolling 2 years Joining Point Period from Jul 13 to Jun Percentage on Joining Point Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Month DayLates DayLows NightLates NightLows Day Joining Point Lates* Period from Jul 13 to Jun Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Percentages on Day Lates Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Month * Lates and Lows see glossary on page 3 Heathrow Airport Flight Performance Q1 Report 215 Page 17

18 Day Joining Point Lows* Period from Jul 13 to Jun Percentage on Day Lows Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Month Night Joining Point Lates* Period from Jul 13 to Jun Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Percentages on Night Lates Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Month * Lates and Lows see glossary on page 3 Page 18 Heathrow Airport Flight Performance Q2 Report 215

19 Night Joining Point Lows* Period from Jul 13 to Jun Percentage on Night Lows Jul 13 Aug 13 Sep 13 Oct 13 Nov 13 Dec 13 Jan 14 Feb 14 Mar 14 Apr 14 May 14 Jun 14 Jul 14 Aug 14 Sep 14 Oct 14 Nov 14 Dec 14 Jan 15 Feb 15 Mar 15 Apr 15 May 15 Jun 15 Month Go Around* Data Period from Jan 15 to Jun Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Go Arounds * Lates and Lows see glossary on page 3 * Go Around see glossary on page 3 Heathrow Airport Flight Performance Q1 Report 215 Page 19

20 Night Noise Winter 28 Summer 215 Season Movement Limit Quota Points Winter (including carry over* from previous season) Summer Winter (including carry over* from previous season) Summer Winter (including carry over* from previous season) Summer Winter (including carry over* from previous season) Summer Winter (including carry over* from previous season) Summer Winter (including carry over * from previous season) Summer Winter (including carry over * from previous season) Summer Limits are set by the DfT The regime applies to a night period (23 7 hours) during which the noisiest types of aircraft (QC8 and QC16) may not be scheduled to land or take off. In addition QC4 types may not be scheduled to land or takeoff in the night quota period (233 6).In addition, between hours (the night quota period) there are further restrictions the number of aircraft movements are restricted by a movements limit and additionally there is a limit of noise quota points. These limits are set for each summer and winter season. Neither of these limits may be exceeded, ie if the movements limit were to be reached, no further movements would be able to take place even if quota points were still available, and vice versa Summary of allocation usage Winter 26 Summer 215 Season Seasons Seasons QC points Movements Total Total Total Movements Exempt Not Not Not Quota movements carried carried QC points movements QC against counted counted counted Points limit over over allowed allowed value limit Delays DfT Emergency Limit Winter Summer Winter Summer Winter Summer Winter Summer Winter Summer Winter Summer Winter Summer Winter Summer Winter Summer * Carry over see glossary on page 3 Page 2 Heathrow Airport Flight Performance Q2 Report 215

21 Summer Usage of QC Points (including carry over) Period from Summer 97 to Summer QC Points S97 S98 S99 S S1 S2 S3 S4 S5 S6 S7 S8 S9 S1 S11 S12 S13 S14 S15 Season Quote Count Limits Actual Use Summer Usage of Movements (including carry over) Period from Summer 97 to Summer S97 S98 S99 S S1 S2 Movements S3 S4 S5 S6 S7 S8 S9 S1 S11 S12 S13 S14 S15 Season Movement Limits Actual Use Heathrow Airport Flight Performance Q1 Report 215 Page 21

22 Summer Season Weekly Pro Rata Usage Comparison (MV) 12 Percentage Pro rata Week number Target Summer 26 Summer 27 Summer 28 Summer 29 Summer 21 Summer 211 Summer 212 Summer 213 Summer 214 Summer 215 Summer Season Weekly Pro Rata Usage Comparison (QC) Percentage Pro rata Week number Target Summer 26 Summer 27 Summer 28 Summer 29 Summer 21 Summer 211 Summer 212 Summer 213 Summer 214 Summer 215 Page 22 Heathrow Airport Flight Performance Q2 Report 215

23 Arrival and Departure information Runway Alteration Adherence Arrivals 96.% 95.% 94.% 93.% 92.% 91.% 9.% 89.% 88.% 87.% Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 215 TEAM after 7L Pure West Days only Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 215 Departures off landing Runway Jan-Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 215 Heathrow Airport Flight Performance Q1 Report 215 Page 23

24 Engine Ground Running The maximum total ground running exposure time over the night period from 23 to 7 hours must not exceed 15 minutes. Within the total 15 minutes, the maximum amount of ground running at high power must not exceed 6 minutes in any one night or exceed a rolling 3 day average of 2 minutes. Number of tests in each month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ground Idle Runs 26 Ground Idle Runs 27 Ground Idle Runs 28 Ground Idle Runs 29 Ground Idle Runs 21 Ground Idle Runs 211 Ground Idle Runs 212 Ground Idle Runs 213 Ground Idle Runs 214 Ground Idle Runs 215 Page 24 Heathrow Airport Flight Performance Q2 Report 215

25 Total running time in the month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Run Time 26 Total Run Time 27 Total Run Time 28 Total Run Time 29 Total Run Time 21 Total Run Time 211 Total Run Time 212 Total Run Time 213 Total Run Time 214 Total Run Time 215 Average number of tests per night Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Heathrow Airport Flight Performance Q1 Report 215 Page 25

26 Additional information Information on noise is also available on the BAA Heathrow website. This part of the website was updated in May 27. It includes a flight tracking system called WebTrak which enables local residents to log on and view flight tracks for aircraft arriving at and departing from Heathrow. As well as being able to track flights, WebTrak also gives details of the aircraft s height and position. Noise complaints and enquiries may now be made from the website. These facilities have been introduced to complement the long-standing facilities so complaints/enquiries may still be made by telephone or (see right). Updated statistical information on complaints and enquiries is now included in BAA Heathrow s Corporate Responsibility Report which is available in full on our website ( A summary is available from Heathrow Public Affairs, telephone Making noise complaints or enquiries On the Website By telephone Public Affairs Noise Complaints Freephone By noise_complaints@baa.com Useful websites for information on government policies in relation to Heathrow aircraft movements, ie night flights; changes to night-time use of Heathrow s runways, etc. Information on Noise Insulation and Noise and Blight Schemes is available in the BAA Heathrow Corporate Responsibility Report (see above). Page 26 Heathrow Airport Flight Performance Q2 Report 215

27 Glossary of Terms AIP ANOMS Carry over CDA dba FEU FLOPC Go Around IMC ILS KPI Lates and Lows LHR LS nm NATS NPR NTK QC QNH TEAM VMC Aeronautical Information Publication Noise, track keeping and complaints system Night restrictions are set on a seasonal basis. Up to 1% of a season's unused quota can be carried forward (known as "carry over") to the next season and up to 1% of a following season's quota can be anticipated Continuous Descent Approach A-weighted decibels Flight Evaluation Unit Flight Operations Performance Committee A go around is an aborted landing of an aircraft which is on approach to the runway Instrument Meteorological Conditions Instrument Landing System Key performance indicators During the daytime the aircraft are required to be "established" on the ILS at 7.5nm from touchdown. This equates to approximately 25ft aal. At night the distance is extended to 1nm which equates to approximately 3ft aal. London Heathrow Lateral swathes Nautical Miles National Air Traffic Services Noise Preferential Routes Noise and Track Keeping monitoring system Quota Count The barometric pressure at sea level (QFE is the barometric pressure at the aerodrome) Tactically Enhanced Arrivals Mode. In order to help alleviate delay in the stacks, ATC may change from the published alternation schedule. In order to maintain minimum separation distances between inbound aircraft, maintain usual high safety standards and keep air traffic flowing, ATC may use both runways for arrivals for a short period. Visual Meteorological Conditions Heathrow Airport Flight Performance Q1 Report 215 Page 27

28 Produced by Heathrow Flight Performance team, Second Floor Meridian, The Compass Centre, Nelson Road, London Heathrow Airport, Hounslow TW6 2GW. Further information If you would like further information, please contact the Flight Performance team: By telephone: By noise_complaints@baa.com By post: Flight Performance team Second Floor Meridian The Compass Centre Nelson Road London Heathrow Airport Hounslow TW6 2GW Website: Make an enquiry on our website: Please note that the freephone telephone number is an answerphone. Please leave your name, contact details and brief details of your enquiry. A member of the FEU will contact you as soon as possible. Page 28 Heathrow Airport Flight Performance Q2 Report 215