AU3544600A - Air traffic management system - Google Patents

Description

WO 00/62234 PCT/AUOO/00290 Air Traffic Management System Field of the invention The present invention relates to a method for scheduling the flow of air traffic into a destination airport over a particular time period. 5 Background of the invention The airline industry provides services to its customers which are designed to satisfy air travel requirements, such services include ensuring adequate flow of air traffic at an airport. However, airport capacity varies with the prevailing weather and associated noise abatement requirements. As demand for travel and airline capability has increased and exceeded 10 airport/airspace infrastructure capacity, delays to scheduled aircraft arrivals and departures have occurred. The inability of an airline service provider to meet its scheduling commitments may be the result of many factors, some of which are within the control of the Air Traffic Controller responsible for the flow of traffic at a particular airport, and some are not. These difficulties 15 usually result due to delays to arrivals and departures at the destination and departure airports respectively. The sequencing of air traffic landing at a particular airport is a function of Air Traffic Control (ATC), with controller ensuring that runway movement rates are optimised as aircraft arrive at their destination. Any resultant delay is absorbed by aircraft holding or flying additional track 20 miles, thus incurring unnecessary cost to operations. The ATC typically regulates the flow of traffic at an airport by: - making an assessment of each aircraft's arrival time; 0 determining the landing sequence and estimated landing time of a number of aircraft over a particular time period; and 25 . as appropriate, instructing en-route controllers to delay identified aircraft. Real time advice regarding particular aircraft arrival times is not routinely provided to airline operators.

WO 00/62234 PCT/AUOO/00290 2 There are limits to the capacity of any airport or airway system and there are often peak periods where demand does exceed capacity, particularly for airports which service large cities such as Sydney Airport in Australia. Excess demand at Sydney airport for example, is currently addressed by a Controlled Departure 5 Time Programme. Under this arrangement airline schedules are reviewed by an air traffic controller at Sydney, the evening prior to operation and, when the scheduled demand exceeds the anticipated capacity, a revised departure time is provided to the operating company. Whilst this process has provided some relief from excessive airborne holding, delays still occur and the arrival schedule of flights into Sydney airport has become increasingly difficult to manage 10 delays, which may occur due to: limits on aircraft movement rates at some airports; * limits on hours of operation (eg. curfews); a limited gate and parking facilities at some aerodromes; 0 surges due to weather at both destination and departure ports; 0 noise abatement requirements; 15 o marketing pressures to schedule operations to the most attractive times; and * lack of schedule co-ordination. Once an initial delay has occurred in the planned schedule on a particular day of a destination airport, those flights that are due to arrive at the destination airport may be subjected to a further delay as a result of the initial delay. 20 Any resultant delay is absorbed by aircraft holding or flying additional track miles, thus incurring unnecessary cost to operations. Summary of the invention The object of the invention is to provide an improved method and system for scheduling the flow of air traffic. 25 According to a first aspect of the present invention, there is provided a method for scheduling the flow of air traffic into a destination airport over a particular time period, the method including the steps of: (a) establishing an arrival schedule over the particular time period at said destination airport for a plurality of aircraft; WO 00/62234 PCT/AUOO/00290 3 (b) determining prior to the particular time period, the departure airports from which each of said aircraft departs, so as to define a travel path from a departure airport to the destination airport for each aircraft; (c) dividing the travel path of each aircraft into a plurality of travel 5 sequences; (d) estimating from historical data, an initial time estimate for each travel sequence, said initial time estimate being dependent upon any one or more of the following variables: (i) aircraft type; 10 (ii) time for departing aircraft to taxi from its departure gate, to becoming airborne; (iii) time for a departing aircraft, after becoming airborne, to reach a set course point; (iv) flight time for an aircraft from the set course point 15 to reach a designated route fix; (v) time taken by an arriving aircraft from passing over the designated route fix, to land on the specified landing runway of the destination airport; (vi) time taken for an arriving aircraft to taxi from the 20 specified landing runway to its gate or its parking position; (vii) flight path; (viii) weather conditions; or (ix) any other travel time influencing factor; 25 (e) establishing an initial total estimated travel time for each aircraft by summing the respective travel sequence times for each aircraft; (f) sequencing the departure time of each aircraft in accordance with the initial total estimated travel time, so that the time of aircraft arrival is estimated and an arrival schedule is established.

WO 00/62234 PCT/AUOO/00290 4 The method may also further include the step of: (g) monitoring the variable conditions so as to be appraised of when the total estimated travel time for one or more aircraft is likely to vary from said initial total estimated travel time. 5 The method may also further include the step of: (h) amending the departure times of any of the aircraft for which the total estimated travel time has been varied so that the aircraft arrive in substantial accordance with the arrival schedule. According to a second aspect of the present invention, there is provided a system to scheduling 10 the flow of air traffic into a destination airport over a particular time period including: an aircraft arrival schedule means adapted to establish record an arrival schedule over the particular time period at said destination airport for a plurality of aircraft, said aircraft arrival schedule means capable of determining prior to the particular time period, the departure airports from which each of said aircraft 15 departs, so as to define a travel path from a departure airport to the destination airport for each aircraft and wherein the travel path of each aircraft is divided into a plurality of travel sequences; data base means adapted to estimate from historical data. an initial time estimate for each travel sequence. said initial time estimate being dependent upon any one 20 or more of the following variables: (i) aircraft type; (ii) time for departing aircraft to taxi from its departure gate, to becoming airborne; (iii) time for a departing aircraft, after becoming 25 airborne, to reach a set course point; (iv) flight time for an aircraft from the set course point to reach a designated route fix; (v) time taken by an arriving aircraft from passing over the designated route fix, to land on the specified 30 landing runway of the destination airport; WO 00/62234 PCT/AUOO/00290 5 (vi) time taken for an arriving aircraft to taxi from the specified landing runway to its gate or its parking position; (vii) flight path: 5 (viii) weather conditions; or (ix) any other travel time influencing factor; and wherein the aircraft arrival schedule means is further adapted to establish an initial total estimated travel time for each aircraft by summing the respective travel sequence times for each aircraft, and to sequence the departure time of each aircraft in accordance with the initial total 10 estimated travel time, so that the time of aircraft arrival is estimated and an arrival schedule is established. The aircraft arrival schedule means may monitor the variable conditions so as to be appraised of when the total estimated travel time for one or more aircraft is likely to vary from said initial total estimated travel time. 15 The aircraft arrival schedule means may also allow amendment of the departure times of any of the aircraft for which the total estimated travel time has been varied so that the aircraft arrive in substantial accordance with the arrival schedule. Preferably the variable conditions are monitored in real time. More preferably, the variable conditions may be monitored by a real time computer system. 20 Preferably the method is implemented using a computer software program. Optionally, the historical data may be recorded in a database. The database may be a relational database and further comprise a database management system for the upkeep and management of the historical records. Typically the airport traffic is monitored and controlled by at least one air traffic control person 25 who also sets the landing time at the destination airport. Usually the plurality of aircraft is operated by a plurality of airline operators. The operators of the airlines will usually communicate the times at which they intend to arrive at the destination airport. The communication may be by any number of means such as facsimile. email, or via a direct modem link with the air traffic control person. Alternatively, the communication via WO 00/62234 PCT/AUOO/00290 6 modem may allow an airline operator to monitor the departure times set for their designated aircraft from the departure airports. Preferably the estimated historical data for each travel sequence is taken from measured data from a multiplicity of flights. 5 Preferably the particular period of time is a 24 hour period of time broken into daily time quartiles of 6 hour periods each, allowing for easy management of the system by the air traffic control person and the airline operator. Preferably the estimated arrival schedule for each aircraft is assigned a time period in which the aircraft can land, known as the programmed time of landing. 10 Preferably the variable conditions that are monitored includes delays. Optionally the variable conditions may further include notifications of newly scheduled and re-scheduled flights. amendment of a terminal area management plan (the plan used to manage the flow of taxiing traffic about an airport. Additionally any flight cancellations may also be monitored. Brief description of the drawings 15 Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. I shows schematic illustrations of a method for scheduling the flow of air traffic into a destination airport over a particular time period. 20 Detailed description of the embodiments A first embodiment of the method of the present invention is shown in figure 1, which is a method for scheduling the flow of air traffic into a destination airport over a particular time period. The method includes the step of the first stage 10 in which the arrival schedule is sent from an 25 airline operator to an air craft control person of a destination airport. The aircraft controller determines at stage 10. the available times during a given period in which the planes can actually land at the destination airport so that an arrival schedule is established. The method then involves step 20. in which the travel path of the plurality of flights are determined.

WO 00/62234 PCT/AUOO/00290 7 The travel paths are then broken down into travel sequences at step 30, for each of the flights. At step 30 the travel path of the flight is broken down into separate record components to be recorded as: * the time in which the aircraft leaves from the departure gate to the time the aircraft 5 becomes airborne: * the time for a departing aircraft, after becoming airborne, to reach a set course point; * the time for an aircraft from the set course point to reach a designated route fix; . the time taken by an arriving aircraft from passing over the designated route fix, to land on the specified landing runway of the destination airport; 10 0 the time taken for an arriving aircraft to taxi from the specified landing runway to its gate or its parking position; At step 40, the time for each of these sequences is estimated from stored historical data 50. The historical data 50 is stored times for each of the time periods: (h) the time in which the aircraft leaves from the departure gate to the time 15 the aircraft becomes airborne; (i) the time for a departing aircraft, after becoming airborne, to reach a set course point: (j) the time taken by an arriving aircraft from passing over a designated route fix, to land on the specified landing runway of the destination airport; 20 (k) the time taken for an arriving aircraft to taxi from the specified landing runway to its gate or its parking position; Each of time periods (a) to (d) are dependent upon: WO 00/62234 PCT/AUOO/00290 8 (a) the aircraft type (b) the flight path, and (c) the weather conditions At step 60, in which each of the times determined from the flight times (a) to (d) are added so as to determine the total time for each flight. From this total time, the time at which each flight should depart from its departure airport is determined and the departure time is then set. The estimated flight times for each sequence are then monitored at stage 70 during the progress of the flights for the time period. The time difference between the estimated times at 40 and the actual times which are monitored for each record component at 80 are then assessed at 90. If there is a difference between the estimated and the actual flight times at 90, and other flights have not departed from their departure airports. then the flight departure time is amended at step 100 and a new departure time is set at 60. In this way the delay of an aircraft in flight is reduced and the traffic flow about an airport becomes easier to manage. The reduction delay in this example of the invention and in the embodiment described below, significantly reduces the operating costs of the airline operator, ensures schedule stability, and improves gate utilisation. aircraft utilisation, crew utilisation and passenger connections. Other benefits are that the real time data provides real time information regarding a flight which can assist in conducting scenarios for alternative flight landing times and take off schedules. The Central Traffic Management System Another method and system for scheduling the flow of air traffic into a destination airport over a particular time period, is the "Central Traffic Management System" (CTMS), a software program and management system developed by the inventors of the present invention. Where in the specification the following acronyms are used to describe the CTMS, they have the following meaning: Acronym Meaning ACA Airports Coordination Australia (SLOT Database) ACARS Aircraft Communication Addressing and Reporting System ACID Aircraft Identification (May be FLT NO or REG) ADEP Aerodrome of Departure WO 00/62234 PCT/AUOO/00290 9 ADES Aerodrome of Destination AFTN Aeronautical Fixed Telecommunication Network AMDIS Aircraft Movement and Delay Information System ATL Actual Time of Landing ATS Air Traffic Services Division CDTP Controlled Departure Time Program CISB Corporate Information Services Branch CTMS Central Traffic Management System ETD Estimated Time of Departure (AIP) ETDE Estimated Time of Departure extrapolated from GDTA or TOTA ETDF Estimated Time of Departure based on Flight Plan ETDP Estimated Time of Departure based on PTL ETDS Estimated Time of Departure based on Schedule ETF Estimated Time to Fix ETL Estimated Time of Landing (AIP) ETLE Estimated Time of landing extrapolated from actual flight event ETLF Estimated time of Landing based on Flight Plan ETLS Estimated Time of Landing based on Schedule FDP Flight Data Processor/Processing FIX En-route fix, which identifies inbound route FLT NO Flight Number (Includes Airline Operator eg., QFA123, AAA9) FTL Flow Time of Landing (known as Estimated Landing Time {ELT} in the current Sydney Flow Management System and as the Proposed Time of Landing (PLT} in other local usage).

WO 00/62234 PCT/AUOO/00290 10 GAT Gate Arrival Time (Generic or general usage) GATA Actual Gate Arrival Time GATE Gate Arrival Time extrapolated from an actual flight event GATF Gate Arrival Time based on Flight Plan GATP Gate Arrival Time based on PTL GATS Gate Arrival Time based on Airline Schedules GDT Gate Departure Time (Generic or general usage) GDTA Actual Gate Departure Time GDTF Gate Departure Time based on Flight Plan GDTP Gate Departure Time based on PTL GDTS Gate Departure Time based on Airline Schedules GNDMI Ground Manoeuvring Interval KSA Kingsford Smith International Airport. Sydney PTL Programmed Time of Landing SLOTA Arrivals SLOT (Sydney Only) SLOTD Departures SLOT (Sydney Only) TAAATS The Australian Advanced Air Traffic System TAMP Terminal Area Management Plan TARDAS The Advanced Runway Decision Advisory System TMAMI Terminal Control Area Manoeuvring Interval TOF Time Over Fix (general or generic usage) TOFA Actual Time Over Fix TOFE Time Over Fix extrapolated from actual flight event TOFF Time Over Fix based on Flight Plan TOFP Time Over Fix based on PTL WO 00/62234 PCT/AUOO/00290 TOFS Time Over Fix based on Airline Schedules TOT Take Off Time (general or generic usage) )TOTA Actual Take Off Time TOTE Take Off Time extrapolated from GDTA TOTF Take Off Time based on Flight Plan )TOTP Take Off Time based on PTL TOTS Take Off Time based on Airline Schedules AIP Aeronautical Information Publication )DEP Departure )RWY Aerodrome Runway ATA Actual Time of Arrival EET Estimated Elapsed Time )TMA Terminal Area (physical 3 dimensional space around nominated aerodrome) ATD Actual Time of Departure 4)ETA Estimated Time of Departure TWR Control Tower CNL Cancel FPL Flight Plan The CTMS is closely coupled to the live ATC system. The CTMS assists in the smooth operation of the ATC system by recalculating the departure times of scheduled flights inbound to CTMS aerodromes so as to minimise or eliminate the need for flow control and the inherent airborne delays. CTMS uses data items (see "Data Items " described below) to recalculate the departure time of scheduled flights as follows: WO 00/62234 PCT/AUOO/00290 12 1 When the TAMPs for all CTMS airports are registered, CTMS estimates an arrival schedule for each flight of an airline over a particular time period by calculating the Programmed Times of landing (PTL) available within each half hour period of the particular time period, for each CTMS airport. 2 Once the Airline Schedules are loaded into CTMS, CTMS calculates the estimated landing time for each flight based on the scheduled gate departure time. This is achieved by estimating from historical data, an initial time estimate for each stage of the flight path. The data is determined from historical data measured for the following stages of flight: (a) the aircraft type; (b) the time for the departing aircraft to taxi from its departure gate, to becoming airborne; (c) the time for a departing aircraft, after becoming airborne, to reach a set course point of the flight, the time being dependent on the aircraft type; (d) the time taken by an arriving aircraft from passing over a designated route fix, to land on the specified landing runway of the destination airport, the time being dependent on the aircraft type; (e) time taken for the arriving aircraft to taxi from the specified landing runway to its gate or its parking position; (f) the flight path, being dependent on the aircraft type Any one of the above historical data may (in other embodiments of the invention), be also dependent on the weather conditions: 3 From the estimated landing times, CTMS allocates a programmed time of landing to each flight and calculates all of the programmed flight event times based on the PTL. 4 CTMS notifies the airline operators, of the PTLs allocated for their particular flights and the Gate Departure Times (revised as necessary) required to achieve these PTLs. 5 CTMS repeats the above processes (steps 1 to 4) so as to amend the departure times for individual notifications of newly scheduled and re-scheduled flights.

WO 00/62234 PCT/AUOO/00290 13 6 CTMS also repeats these processes (steps 1 to 4), for all affected flights at routine TAMP re-issue times and when an individual TAMP is amended so as to amend the departure times. 7 CTMS checks and when necessary modifies flight schedules based on FPL, CHG messages received via the AFTN. FPL messages for unscheduled flights are also decoded and added to the lists of flights. CTMS follows the progress of all flights recording, where known, the actual times at which significant events occur for each flight (ie. Gate departure, take off, landing and gate arrival). Data Types The CTMS uses various data types, these are: * SLOT Allocation data * Aircraft Movement data * Airline Schedule data * AFTN data * TAAATS data * Reference data * Terminal Area Reference data . Estimated Time to Fix (ETF) data . Terminal Area Management Plan (TAMP) data Airline Schedule Data This data is supplied by the major airlines for the scheduled movements of their aircraft and possibly for other aircraft for which they have a responsibility. It is provided on a daily basis for the following two days of operations, giving a daily update of the next day's operations. AFTN Data Data is received as individual messages relating to specific flights. The AFTN message types that CTMS processes are shown in the following table: WO 00/62234 PCT/AUOO/00290 14 AFTN Description Message ADFN These messages are filed by the pilot or aircraft operator to give FPL notice of an intended flight. DEP These messages notify the actual time of departure of a flight. CHG These messages inform of a change to previously notified flight plan details. TAAATS data CTMS receives data from the TAAATS system. The following data is required Information Details Departure Departures for each relevant flight using TAAATS parameters to define departure: a ACID * ATD 0 ADEP 0 ADES Flight Details Flight Plan information including changes created within TAAATS. Estimated Landing Time ETL as calculated for each relevant arriving flight when STAR is allocated and any subsequent change to that time Actual Airborne Landing Actual landing and or airborne time for each Time relevant flight Other Aircraft Movement Data Other aircraft movement data is as follows: * Individually scheduled flights input directly by ATS WO 00/62234 PCT/AUOO/00290 15 Actual aircraft movement data * GDTA . TOTA (ACARS equipped aircraft only) * ATL (ACARS equipped aircraft only) * GATA Terminal Area Reference Data Terminal area reference data has a number of elements as shown in the following table: Terminal Area Description Reference Data Departure Airport This time interval is the estimated time for a Ground departing aircraft to taxi from its departure gate to Manoeuvring becoming airborne. Interval (ADEP GNDMI) For each CTMS airport an ADEP GNDMI is stored in three broad categories of aircraft from each relevant terminal to each departure runway. Departure Airport This time interval is the estimated time for a Terminal departing aircraft, after becoming airborne, to reach Manoeuvring Area the set course point. Interval (ADEP TMAMI) For each CTMS airport an ADEP TMAMI is stored in three broad categories of aircraft from each departure runway to the set course point for each route. Destination Airport This time interval is the estimated time taken by an Terminal arriving aircraft from passing over the designated Manoeuvring Area route fix, to land on the specified landing runway of WO 00/62234 PCT/AUOO/00290 16 Terminal Area Description Reference Data Interval the destination airport. (ADES TMAMI) For each CTMS airport an ADES TMAMI is stored in three broad categories of aircraft, each varying by the type of approach to be flown, from the arrival fix for each route to each arrival runway. Destination Airport This time interval is the estimated time taken for an Ground arriving aircraft to taxi from the specified landing Manoeuvring runway to its gate or its parking position. Interval (ADES GNDMI) For each CTMS airport an ADES GNDMI is stored in three broad categories of aircraft from each arrival runway to each terminal. Estimated Time to Fix Data These are time intervals for aircraft to fly from the set course point at an ADEP to the inbound Fix for the ADES. The ETF interval is stored in five broad categories for each route. Other Reference Data Other reference data which may be included in CTMS are: * Aircraft Types 0 Airports . Outbound Routes for each CTMS airport . Inbound fixes used on approach to each CTMS airport . Airline Operators WO 00/62234 PCT/AU00/00290 17 TAMP Data TAMP Data for each CTMS Aerodrome is as shown in the following table: TAMP Data Description Period of Effect The 15 minute period to which the following data relates. Airport This identifies the runways that will be used for arrival Configuration and departure. Arrival This identifies the number of arrivals that ATS Acceptance rate determines that an airport can accept within a one hour period. Departure rate This identified the number of departures that an airport can handle within a one hour period Approach Type This identifies the type of approach to be flown based on the forecast meteorological conditions: e VMC - Visual approach e IMC - Instrument approach * ILS - Precision Instrument approach Loading Airline Schedules Airline schedule data covering a 48 period is be transferred at approximately 5.00 PM to the ATC of each CTMS airport by the airlines who have flights due to land within the 48 hour period. Data Fields Extracted from Airline Schedules When this data is fully loaded, CTMS extracts and stores the following data for each flight for the 48 hour period: * Aircraft Identification (this may be the FLT NO or the REG) . Aircraft Type (if given) WO 00/62234 PCT/AUOO/00290 18 - Departure Airport * Scheduled Gate Departure Time * Destination Airport a Scheduled Gate Arrival Time * REG if notified but not used as ACID Determining the Aircraft Category Where the flight details in the airline schedules include an aircraft type, the aircraft type category is obtained by searching the Aircraft Category Table for the entry matching the aircraft Type. Entries in the Aircraft Category Table appears as shown in the following table of examples: Aircraft Type Aircraft Category B767 Jet DH8 Turbo-Prop PA31 Other Obtaining the Inbound Fix CTMS uses the ADES, ADEP and Category fields to access the fix reference table to obtain the default route and inbound fix applicable to this ADEP, ADES and aircraft Category. Where the aircraft category is not known, a default route and fix based on ADEP and ADES only will be used and an aircraft category will be assumed. Entries in the fix table will appear as shown in the following table of examples: ADEP ADES Category Outbound Inbound Inbound Fix Route Route YSCB YSSY Jet RIVET YSCB YSSY Jet BIK YSCB YSSY Turbo-Prop ODA YSCB YSSY Turbo-Prop

ODA

WO 00/62234 PCT/AUOO/00290 19 ADEP ADES Category Outbound Inbound Inbound Fix Route Route YSSY YSCB Other WOL Programming of Flights When the above processes are complete the Flight Programming Function is initiated automatically and the estimates of the time for each flight is recorded within CTMS. Loading TAMP Data TAMP data is normally input daily at a set time by the responsible Air Traffic Controller at each CTMS airport. TAMP data comprises four quartiles each covering a 6 hour period. Each quartile comprises 12 'lines' containing the RWY configuration, hourly acceptance rate and approach type for a 15 minute period. Each quartile and line will commence at a specific time that may be offset from the hour and half hour by up to 15 minutes. Draft Quartiles A number of draft quartiles may be created for each period. The controller may evaluate the delay that will result from the combination of different active and draft quartiles using the delay forecast function. When the controller has selected the most appropriate quartile for a period it will be designated as active and the previously active quartile will become superseded. CTMS will register the four active quartiles, if present, as the TAMP for the location. Delay Forecast Function The delay forecast function allows access to the airline schedules for the period covered by the nominated quartiles and calculates the delay (if any) that would be generated at the location for each half hour period. Active and draft quartiles may be in the calculation. The forecast delay for each 30 minute period is displayed to the controller for evaluation.

WO 00/62234 PCT/AUOO/00290 20 Amending Active TAMP data Once quartiles have been made active and registered within CTMS they cannot be amended directly. The only way to change an active quartile is to create a new draft quartile for the relevant period and nominate it as the active one. The previously registered quartile(s) will become superseded. TAMP data cannot be changed retrospectively, ie. quartiles and lines currently in use or not yet in use may be amended provided they are draft, but those whose period of validity has expired may not. Calculating PTLs from Active TAMP data When a new active quartile is registered the CTMS calculates the PTLs available for each 15 minute period from the airport acceptance rate, as shown in the following table of examples: Arrival Acceptance PTL Interval PTLs Rate per hour 0600 -0630 20 60 minutes divided by 0600, 0603, 0606, 20 arrivals = 3 minutes 0609, 0612 etc. 35 60 minutes divided by 0600, 0602, 0603, 35 arrivals = 1.7 0605, 0607, 0608 etc minutes 60 60 divided by 60 = 1 0600, 0601, 0602, 0603 minute etc. Receipt of AFTN and TAATS Messages Flight Plan and modification messages are processed in CTMS as follows: . Flight details are correlated with the airline schedule where possible . The outbound and inbound route segments for the flight are checked * For 'untouchable' flights (that is flights which have departed an airport which does not have the CTMS) the flight planned ETA will be checked against the GATS WO 00/62234 PCT/AUOO/00290 21 Correlating Flight Details The processes for correlating flight details in an FPL or CHG message with scheduled flight details is shown in the following table: WO 00/62234 PCT/AUOO/00290 22 If match found for Then Otherwise ACID between In scheduled flights - Go to ADEP and ADES at Change the flight status "Messages for approximate ETD from scheduled to planned. unidentifiable flights" below * Store the new REG if different to the scheduled REG * Store the new TYP if different to the scheduled TYP and re-determine the aircraft category. If different then go to "Aircraft Category Changed" In reserved PTLs list - Confirm the reserved PTL - Set the flight status to planned * Store the new REG if different to the reserved REG * Store the new TYP if different to the reserved TYP and re-determine the aircraft category. If different then go to "Aircraft Category Changed" WO 00/62234 PCT/AUOO/00290 23 Aircraft Category Changed If the new aircraft TYP notified in the flight plan results in a change to the Aircraft category, CTMS recalculates the ETDS, TOFS and ETLS. Checking the Outbound and Inbound Route Segments The outbound and inbound route segments from the flight plan are correlated with the assumed route obtained for this flight from the airline schedule and the fix reference table. . If these are the same then no further action is required . If these are different then CTMS will identify new set course point and inbound fix and recalculate the ETDS, TOFS, ETLS and GATS event times for the flight * CTMS will then recheck the ETLS against the PTL. See "Rechecking the ETLS" below. Entries in the fix table will appear as shown in the following table of examples: ADEP ADES Category Outbound Inbound Inbound Fix Route Route YSCB YSSY Jet RIVET YSCB YSSY Jet BIK YSCB YSSY Turbo-Prop ODA YSCB YSSY Turbo-Prop ODA YSSY YSCB Other WOL Comparing ETA and GATS for Excepted or 'Untouchable' Flights If the flight has a time greater than 3 hours or has an approved special flight status, then CTMS compares the flight planned ETA with the GATS. * If the difference between these times is less than a pre-defined compatibility margin, then no action is required . If their difference is greater than this margin then the GATS will be set to the ETA and the TOFS and ETLS event times will be recalculated.

WO 00/62234 PCT/AUOO/00290 24 - The new ETLS will become the PTL for the flight because it is, by definition, an 'excepted' or 'untouchable' flight. Checking Departure Time If a Flight Plan Modification message includes an amended departure time, that is different to the ETDS by more than a pre-defined compatibility margin, as defined by a VSP. CTMS will store the new ETD as the GDTS and recalculate all flight event times based on this new GDTS, as shown in the following table: Event Recalculation TOTS New GDTS plus ADEP GNDMI ETDS New TOTS plus ADEP TMAMI TOFS New ETDS plus ETF ETLS New TOFS plus ADES TMAMI GATS New ETLS plus ADES GNDMI New PTLs not Allocated A new PTL will not be allocated to a scheduled flight for which: . a revised ETD is notified by modification message . a different aircraft type that result in a change in aircraft category is notified in the FPL message unless a new PTL has been reserved for the flight using the Examine Flight Options Function. Messages for Unidentifiable Flights When the flight details correlation detailed above fails to find a match in the airline schedules then the CTMS process as follows . For a Flight Plan message * Originate advice of an unknown flight to CTMS Administration . If an airline but not a specific flight was identifiable then also originate advice of a non-compatible flight plan to the airline WO 00/62234 PCT/AUOO/00290 25 . Add this flight to the schedule and run the Flight Programming Function for this flight alone. For a modification advise . Originate advice of an unknown flight to CTMS Administration . If an airline but not a specific flight was identifiable then also originate an advice for a non-compatible flight to the airline Flight Change Notification Any change to the GDTS for a scheduled flight that results from the above processes shall originate an advice to the airline and CTMS Administration. Receipt of AFTN DLA Message AFTN DLA messages the CTMS airport. As the format for this type of message does not include a new ETD, CTMS will not take any action on receipt of a DLA message. Receipt of AFTN CNL Message Delete the flight plan record for the flight, this will not cancel the schedule information if the schedule has been notified separately from flight plan. Receipt of AFTN & TAAATS aircraft actual movement advice Aircraft actual movement advice sourced from the AFTN and or from within the TAAATS system is detailed within the chapter titled "Flight Progress Monitoring". Flight Programming When the airline schedules and the TAMPs for all CTMS airports are loaded, CTMS commences the flight programming function. Calculating Scheduled Flight Event Times The flight programming function involves using the various data fields loaded in the schedules and TAMPs to access the appropriate reference tables and from these to calculate a series of intervals and event times for each flight based on the scheduled gate departure time, as follows . Take Off Time (TOTS) . Departure or set course time (ETDS) . Time Over Inbound Fix (TOFS) WO 00/62234 PCT/AUOO/00290 26 * Time of Landing (ETLS) The flight schedule is then sorted into an arrival sequence by GATS at each CTMS airport. Allocating PTLs to Flights Each Flight is allocated a Programmed time of Landing (PTL), 'untouchable' flights are allocated first to ensure that the appropriate PTL is available for allocation. When a PTL has been allocated, the remaining programmed times for each flight are calculated as follows: * Gate Departure time (GDTP) . Take Off Time (TOTP) * Time Over Fix (TOFP) * Gate Arrival Time (GATP) The above event times are the same as the scheduled times unless the allocated PTL is later than the ETL by more than a pre-defined compatibility margin. Allowing Bulk Changes The CTMS systems allows airline operators to make decisions relating to changing and swapping PTL's within their own system. CTMS shall accommodate this by allowing: . Bulk changes . Swaps between operators * Booking vacant PTL's whilst these changes are underway. Notifying the Airlines Operators When the above process is complete, the airline operators are notified of the allocated PTL and revised gate departure and arrival times for each of their flights. Calculating the TOTS To calculate the TOTS, CTMS will be required to perform a number of steps as shown in the following step action table: WO 00/62234 PCT/AUOO/00290 27 Step Action 1 Determine the ADES passenger terminal 2 Determine the ADES 3 Calculate the TOTS Determining the ADEP Terminal The ADEP passenger terminal is obtained by searching the passenger terminal table for entries matching the airline operator for the flight. The airline operator is determined from the leading 2 or 3 non-numeric characters in the FLT NO. If the airline cannot be determined from the FLT NO, then the default terminal for the airport will be allocated. Entries in the Passenger Terminals Table will appear as shown in the following table of examples: Airport Airline Terminal YSCB QFA YSCB-DOM < ADEP Terminal YSSY AAA YSSY-AAAD YSSY QFA YSSY-QFAD Determining the ADEP GNDMI The ADEP GNDMI is obtained by searching the ground manoeuvring table for an entry matching the ADEP passenger terminal. the ADEP departure runway (as defined in the TAMP for the schedule departure time) and the aircraft category for the flight. Entries in the ground manoeuvring table will appear as shown in the following table of examples: WO 00/62234 PCT/AUOO/00290 28 TERMINAL ADEP RWY CATEGORY ADEP GNDMI YSSY-QFAD 16 Turbo-Prop YSSY-QFAD 16 Jet YSSY-AAAD 16 Turbo-Prop YSSY-AAAD 16 Jet YSSY-INTL 16 Jet YSSY-OTHER 16 Other YSCB-DOM 35 Turbo-Prop YSCB-DOM 35 Jet YSCB-RAAF 35 Jet YSCB-RAAF 35 Turbo-Prop The TOTS for each flight is the Scheduled Departure Time plus the ADEP GNDMI. Flights from non-CTMS airports The process is similar for a non-CTMS airport except that default values are used for ADEP GNDMI. These values are not specific to any terminal or departure RWY. Default values for ADEP GNDMI at CTMS airports Default values for ADEP GNDMI are used for CTMS airports when there is no active TAMP quartile registered for the period in which the departure is to occur. Calculating the ETDS To calculate the ETDS, CTMS performs a number of steps as shown in the following step action table: Step Action 1 Determine the ADEP TMAMI 2 Calculate the ETDS WO 00/62234 PCT/AUOO/00290 29 Determining the ADEP TMAMI The ADEP TMAMI is obtained by searching the terminal area manoeuvring table for an entry matching the ADEP, the ADEP departure runway (as defined in the TAMP for the schedule departure time), the ADES and the aircraft category for the flight. Entries in the terminal area manoeuvring table appear as shown in the following table of examples: ADEP ADEP Outbound Aircraft ADEP RWY Route Category TMAMI YSCB 35 Y91 Turbo-Prop YSCB 35 A232 Jet YSCB 30 A232 Other The ETDS for each flight is the TOTS plus the ADEP TMAMI. Flights from non-CTMS airports The process is similar for a non-CTMS airport except that default values are used for ADES TMAMI. These values are not specific to any departure RWY or route. Default values for ADEP TMAMI at CTMS airports Default values for ADEP TMAMI will be used for CTMS airports when if there is no active TAMP quartile registered for the period in which the departure is to occur. Calculating the TOFS To calculate the TOFS, CTMS performs a number of steps as shown in the following step action table: Step Action 1 Determine the ETF 2 Calculate the TOFS WO 00/62234 PCT/AUOO/00290 30 Determining the ETF The ETF is obtained by searching the ETF table for an entry matching the ADEP, the route fix and the aircraft category for the flight. Entries in the ETF will appear as shown in the following table of examples: ADEP FIX Aircraft Category ETF YSCB ODA Fast Turbo-Prop YSCB RIVET Slow Jet YSSY WOL Other The TOFS for each flight is the ETDS plus the ETF. Calculating the ETLS To calculate the ETLS, CTMS performs a number of steps as shown in the following step action table: Step Action 1 Determine the ADES TMAMI 2 Calculate the ETLS Determining the ADES TMAMI The ADES TMAMI is obtained by searching the ADES TMAMI table for an entry matching the inbound fix, the ADES runway and approach type (from the ADES TAMP), and the aircraft category for the flight. Entries in the ADES TMAMI appear as shown in the following table of examples: FIX ADES Aircraft Type of ADES Runway CATEGORY APPROACH TMAMI ODA 16 Turbo-Prop VMC ODA 16 Turbo-Prop IMC RIVET 16 Jet IMC WO 00/62234 PCT/AUOO/00290 31 FIX ADES Aircraft Type of ADES Runway CATEGORY APPROACH TMAMI RIVET 16 Jet ILS ODA 16 Other VMC CAA 16 Other VMC CAA 16 Turbo-Prop VMC CAA 16 Turbo-Prop IMC JRY 16 Jet IMC JRY 16 Jet ILS The ETLS for each flight is the TOFS plus the ADES TMAMI. Calculating Event Times for Unnotified Flights When a valid flight plan is received for a flight into a CTMS airport which has not previously been notified, CTMS must calculate event times for it. The process for calculating these event times involves a number of steps as shown in the following table: Step Action 1 Extract the required flight details from the flight plan 2 Determine the aircraft Category, terminals and ADEP GNDMI and TMAMI 3 Calculate the GDTF and TOTF 4 Determine the ADES TMAMI and GNDMI 5 Calculate the TOFF and GATF 6 Allocate a PTL.

WO 00/62234 PCT/AUOO/00290 32 Extracting the Flight Details The flight plan will be decoded and the following details extracted and stored for the flight: * ACID - ADES * ADEP - TYP * ETDF * Inbound Fix * ETLF * REG Determining the Aircraft Category The aircraft category is obtained by searching the Aircraft Category table for the entry matching the aircraft TYP. Determining the Terminals The default terminals in the passenger terminal table for the ADEP and ADES will be used for unnotified flights. Determining the ADEP GNDMI and TMAMI The ADEP GNDMI and TMAMI are obtained by referencing the ADEP TAMP (or using default values) and searching the ground and TMA manoeuvring interval tables for entries matching the flight details. Determining the ADES GNDMI and TMAMI The ADES GNDMI and TMAMI are obtained by referencing the ADES TAMP (or using default values) and searching the ground and TMA manoeuvring interval tables for entries matching the flight details. Calculating Event Times for Unnotified Flights The standard ICAO usage of ETD as referring to the set course time is applied to all unnotified flights. Event times for unnotified flights will be calculated as follows : WO 00/62234 PCT/AUOO/00290 33 - The ETDF is the ETD from the flight plan * The GDTF is the ETDF minus the ADEP TMAMI and GNDMI - The TOTF is the ETD minus the ADEP TMAMI 0 The ETLF is the ETA from the flight plan . The TOFF is the ETLF minus the ADES TMAMI - The GATF is the ETLF plus the ADES GNDMI Allocating a PTL to an Unnotified Flight PTLs are allocated to unnotified flights only to prevent those PTLs being allocated to scheduled flights via the Examine Flight Options Function. Unnotified Flights from CTMS to non-CTMS airports For unnotified flights departing from CTMS airports for non-CTMS airports. CTMS will calculate only the ADEP GDTF and ADEP TOTF. These flights are not monitored after take off. Allocating PTLs to Flights The allocation of PTLs to flights is performed when the scheduled event time calculations for all flights have been completed. The Flight Programming function involves a number of steps as shown in the following table: Step Action I Sort the aircraft schedule 2 Determine if the flight is an 'exempt' or *untouchable' flight. 3 For all 'excepted' or 'untouchable' flights allocate the PTL equal to or next after the ETLS. 4 When PTLs have been allocated to all untouchable flights then allocate PTLs to all other flights, see "Allocating the PTL" WO 00/62234 PCT/AUOO/00290 34 Merging and Sorting the Schedules The schedules submitted by the various airlines are merged and sorted in ascending order by GATS for each CTMS airport. Exempt or Untouchable Flights Exempt or untouchable flights are those: * departing from overseas * between city pairs that have a nominal flight time stored in the reference data that is greater than 3 hours * having approved special flight status (eg. VIP PM, VIP GG or MEDICAL) Allocating the PTL The latest possible landing time is the gate arrival time from the airline schedule minus the ADES GNDMI. The earliest possible landing time is the ETLS calculated from the scheduled gate departure time. Allocate the next available PTL equal to or after the ETLS to the flight. Because of excessive allowances in the scheduled gate arrival times for some flights and variations in the departure and arrival runways used, basing the PTL allocation on the ETLS instead of the GATS minus the ADES GNDMI can produce a negative time penalty (ie. a time saving) for the airline. Calculate Programmed Event Times Calculate the programmed flight event times based on the allocated PTL. Because the PTL relates to the ADES the following table shows this process in reverse order: Step Action I Calculate the ADES programmed gate arrival time 2 Calculate the ADES programmed time over fix 3 Calculate the ADEP programmed ETD 4 Calculate the ADEP programmed take off time WO 00/62234 PCT/AUOO/00290 35 Step Action 5 Calculate the ADEP programmed gate departure time Calculating the GATP To calculate the GATP, CTMS performs a number of steps as shown in the following step action table: Step Action 1 Determine the ADES Passenger Terminal 2 Determine the ADES GNDMI 3 Calculate the GATP Determining the ADES Terminal The ADES passenger terminal is obtained by searching the passenger terminal table for entries matching the airline operator for the flight, weather the Domestic or International terminal is to be used. If the airline operator is not directly associated with a particular terminal building, then the database will be checked to see if the operator is represented by or hosted by another airline (at that ADES). If so, the other airlines details will be used. If not, then the default terminal for the airport will be assumed. Entries in the Passenger Terminals Table will appear as shown in the following table of examples: WO 00/62234 PCT/AUOO/00290 36 Airport Airline Terminal YSCB QFA YSCB-DOM YSSY AAA YSSY-AAAD YSSY QFA YSSY-QFAD < ADES Ternunal YSSY YSSY-GA1 Determining the ADES GNDMI The ADES GNDMI is obtained by searching the ground manoeuvring table for an entry matching the ADES, the ADES RWY (from the ADES TAMP), the ADES passenger terminal and the aircraft category for the flight. Entries in the ground manoeuvring table will appear as shown in the following table of examples: ADES ADES RWY TERMINAL CATEGORY ADES GNDMI YSSY 16 DOM2 Turbo-Prop YSSY 16 DOMl Jet YSSY 16 DOM2 Turbo-Prop YSSY 16 DOMI Jet Calculating the GATP The GATP for each flight is the allocated PTL plus the ADES GNDMI. Calculating the TOFP The TOFP for each flight is the allocated PTL minus the ADES TMAMI. Calculating the ETDP The ETDP for each flight is the TOFP minus the ETF.

WO 00/62234 PCT/AUOO/00290 37 Calculating the TOTP The TOTP for each flight is the ETDP minus the ADEP TMAMI. Calculating the GATP The GATP for each flight is the TOTP minus the ADEP GNDMI. Default data in Programmed Time Calculations When the event times are recalculated for a flight from a non-CTMS airport, or for a CTMS airport for which no TAMP has been loaded, the process will be similar to that described above except that default data (not obtained from an active TAMP) will be used. TAMP Amendments Whenever a new active TAMP quartile for a CTMS airport that involves a change to the airport configuration for arrivals and/or departures, a change in the arrival acceptance rate and/or type of approach is registered, CTMS: * Re-calculates the PTLs for the CTMS airport(s) affected * Re-performs the allocation of PTLs as detailed above in this map * Recalculates event times for all flights based on the new PTL's. However movements scheduled within 2 hours of the time that the change is made will be unaffected reflecting the reaction time required by the airlines. Addition of new Flights The addition of new flights will not disrupt PTLs allocated via the bulk programming already performed. New flights will be fitted into the arrival sequence for each CTMS airport as the availability of PTLs permits. Examine Flight Options Function The examine flight options function permits users to evaluate the feasibility of conducting an unscheduled or newly scheduled flight to a CTMS airport. The Examine Flight Options Function also permits interactive users to enter details of a proposed flight or to revise details for an existing flight. When the flight details are entered. the CTMS will run the flight programming function to calculate the ETL for that flight and WO 00/62234 PCT/AUOO/00290 38 determine the nearest available PTL which is on or after the ETL. This PTL is displayed to the user together with other PTLs which are available for allocation to the flight. The user then has the ability to reserve a PTL for the proposed flight, by FLT NO, for a period determined by agreement within the CCB. Registration of Itinerant Flight Function The registration of itinerant flight function permit ATS users to register a new scheduled flight. Register Flight Itinerant Function The operation of the register itinerant flight function is similar to the examine flight options function. Newly registered flights are simply added to the bulk schedule and the Flight Programming Function run for this flight only. Itinerant flights advised prior to bulk programming will be included in the 'bulk programming'. Itinerant flights advised after bulk programming will be allocated a PTL without disrupting existing allocations. Flight Progress Monitoring The Flight Progress Monitoring Function is provided to assist airlines to get an improved view of what is happening to the progress of their flights. The elements of flight progress monitoring allows: * The receipt and processing of actual aircraft movement messages - Monitoring of designated fixes and airports Aircraft movement messages that permit CTMS to monitor the progress of flights are as follows: * Gate departure messages - Take off messages * Departure or ATD messages - Landing messages * Gate arrival messages 0 TAAATS system messages WO 00/62234 PCT/AUOO/00290 39 Flight Progress Monitoring Function Flight following commences when CTMS receives advice of an aircraft push back from its departure gate at a CTMS aerodrome or setting course from a non-CTMS aerodrome. Accurate Arrival Information TAAATS data is provided to update ETL and GAT. Monitoring of Designated Fixes The designated fix display function permits users to sort and display snapshot lists of flights over designated fixes and airports in chronological order. It also permits counts of flights over designated fixes and airports together with the ability to make projections. It will also allow airlines to view current and projected TAMPs for CTMS airports. Receipt of Gate Departure Time Upon receipt of a gate departure time from a suitably equipped aircraft or airport operator the CTMS shall change the flight status from planned to Active, store this time in the Actual Gate Departure Time (GDTA) field and extrapolate the: * TOTE * ETDE . TOFE * ETLE * GATE Receipt of a Take-Off Time Upon receipt of a take off advice from a suitably equipped aircraft or airport operator, the CTMS shall store this time in the actual take off time (TOFA) field and re-extrapolate the: * ETDE * TOFE 0 ETLE 0 GATE WO 00/62234 PCT/AUOO/00290 40 Receipt of a DEP Message or Actual Time of Departure Upon receipt of a DEP or other departure advice from a suitable equipped aircraft or airport operator, the CTMS shall store this time in the ATD field and re-extrapolate the: * TOFE * ETLE * GATE Receipt of a Landing Time Upon receipt of a landing time from a suitably equipped aircraft or airport operator, the CTMS shall store this time in the ATL field and re-extrapolate the Gate Arrival Time (GATE). Receipt of an Actual Gate Arrival Time Upon receipt of a Gate Arrival Time from a suitably equipped aircraft or airport operator, the CTMS shall store this time in the Actual Gate Arrival Time (GATA) field and change the flight status from Active to Complete. Receipt of TAAATS System Messages When a TAAATS STAR is generated for a flight inbound to a CTMS airport, the system shall update the ETL and extrapolate a new GAT from that ETL and the taxi time for the nominated runway. Other Reporting Functions CTMS can also provide the capability to produce additional reports for users in real time. These reports represent a snapshot at the time of generation and automatic update will not be supported. Reports for ATC ATC shall be able to generate reports for ATC users. These reports will include: e Sort and display flights over designated fixes and airports. - "What if' scenarios involving different airport arrival acceptance rates. * The approval program including PTL's not allocated. * Possible airborne and surrounding delay reports.

WO 00/62234 PCT/AUOO/00290 41 Reports for Industry Major airlines can be provided with a total view of the database excluding details of flights not under their direct operational control, or an affiliated airline. Minor airlines and ad hoc operations will be permitted to view the following reports over a secure Internet site: * Their approved program including PTL not allocated, and the functionality to amend these programs * Airport TAMPs The foregoing describes embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto, without departing from the scope of the present invention.

Claims (21)

1. 2. A method according to claim 1, further including the step of: (g) monitoring the variable conditions so as to be appraised of when the total estimated travel time for one or more aircraft is likely to vary from said initial total estimated travel time.
2. 3. A method according to claim 2, further including the step of: (h) amending the departure times of any of the aircraft for which the total estimated travel time has been varied so that the aircraft arrive in substantial accordance with the arrival schedule.
3. 4. A method according to any one of the preceding claims, wherein the variable conditions are monitored in real time.
4. 5. A method according to any one of the preceding claims, wherein the historical data is calculated from empirical data and retrieved from a database.
5. 6. A method according to any one of the preceding claims, wherein the plurality of aircraft are operated by a plurality of airline operators.
6. 7. A method according to any one of the preceding claims, wherein the particular time period is a 24 hour period of time.
7. 8. A method according to any one of the preceding claims, wherein the time period is broken into daily time quartiles of 6 hour periods each.
8. 9. A method according to any one of the preceding claims, wherein a programmed time of landing is calculated from the estimated arrival schedule for each aircraft.
9. 10. A method according to any one of claims 2 to 9, wherein the variable conditions further include any one or more of the following variables: (a) delays of a flight; (b) notifications of newly scheduled and re-scheduled flights; (c) amendment of a terminal area management plan; or WO 00/62234 PCT/AUOO/00290 44 (d) flight cancellations.
10. 11. A system to schedule the flow of air traffic into a destination airport over a particular time period including: an aircraft arrival schedule means adapted to establish record an arrival schedule over the particular time period at said destination airport for a plurality of aircraft, said aircraft arrival schedule means capable of determining prior to the particular time period, the departure airports from which each of said aircraft departs, so as to define a travel path from a departure airport to the destination airport for each aircraft and wherein the travel path of each aircraft is divided into a plurality of travel sequences; data base means adapted to estimate from historical data, an initial time estimate for each travel sequence. said initial time estimate being dependent upon any one or more of the following variables: (i) aircraft type; (ii) time for departing aircraft to taxi from its departure gate, to becoming airborne; (iii) time for a departing aircraft, after becoming airborne, to reach a set course point; (iv) flight time for an aircraft from the set course point to reach a designated route fix; (v) time taken by an arriving aircraft from passing over the designated route fix, to land on the specified landing runway of the destination airport; (vi) time taken for an arriving aircraft to taxi from the specified landing runway to its gate or its parking position; (vii) flight path; (viii) weather conditions; or (ix) any other travel time influencing factor; and WO 00/62234 PCT/AUOO/00290 45 wherein the aircraft arrival schedule means is further adapted to establish an initial total estimated travel time for each aircraft by summing the respective travel sequence times for each aircraft, and to sequence the departure time of each aircraft in accordance with the initial total estimated travel time, so that the time of aircraft arrival is estimated and an arrival schedule is established.
11. 12. A system according to claim 11, wherein the aircraft arrival schedule means monitors the variable conditions so as to be appraised of when the total estimated travel time for one or more aircraft is likely to vary from said initial total estimated travel time.
12. 13. A system according to claim 12, wherein the aircraft arrival schedule means allows amendment of the departure times of any of the aircraft for which the total estimated travel time has been varied so that the aircraft arrive in substantial accordance with the arrival schedule.
13. 14. A system according to any one of claims 11 to 13, wherein the variable conditions are monitored in real time.
14. 15. A system according to any one claims 11 to 14, wherein the historical data recorded in the data base means is calculated from empirical data and retrieved from a database.
15. 16. A system according to any one claims 11 to 15, wherein the plurality of aircraft are operated by a plurality of airline operators.
16. 17. A system according to any one of claims 11 to 16, wherein the particular time period is a 24 hour period of time.
17. 18. A system according to any one of claims 11 to 17, wherein the time period is broken into daily time quartiles of 6 hour periods each.
18. 19. A system according to any one of claims 11 to 18, wherein a programmed time of landing is calculated from the estimated arrival schedule for each aircraft.
19. 20. A system according to any one of claims 12 to 19, wherein the variable conditions further include any one or more of the following variables: (a) delays of a flight; (b) notifications of newly scheduled and re-scheduled flights; (c) amendment of a terminal area management plan; or flight cancellations. WO 00/62234 PCTAUOO/00290 46
20. 21. A method for scheduling the flow of air traffic into a destination airport over a particular time period, substantially as hereinbefore described with reference to the examples disclosed herein.
21. 22. A system to scheduling the flow of air traffic into a destination airport over a particular time period, substantially as hereinbefore described with reference to the examples disclosed herein.