1. This contingency plan provides guidance for operational NAT Air Traffic Services (ATS) units to prepare for risks and potential outages caused by the Y2K events. Despite efforts to achieve Y2K-compliance status, a potential risk of disruption and/or outages remains. This plan recognises that Air Traffic Control (ATC) will implement whatever measures are necessary to ensure the safety of air traffic operations.

   Event dates

    

2. Combinations of day, month and year may create problems to software functions. Examples of these combinations are:

    

• 21 August 1999 (Saturday)

 

1. ATS Unit Contingency plans should take into account the impact of the following date event related general characteristics:

    

    

2. Potential for several systems failing at the same time or within short durations of each other.

    

    

3. Potential for main, standby and redundant sytems to fail simultaneously.

    

    

4. Data corruption passing between systems not being detected as errors therefore leading to anomalous behaviour.

    

    

5. Problems arising prior to or after the cross over dates due to either time horizons, (applications working with future or past dates), or periodic functions running at set intervals, for example hourly, daily, weekly, monthly etc.

    

1. Scope

   Outages

 

1. In day-to-day operations, outages of single technical systems are normally covered by rules and procedures. In the case of the Y2K-related events, a combination or accumulation of problems (e.g. outages of voice/data communications and lack of Flight Data Processing Systems (FDPS)) may occur.

    

    

2. Internal unit-specific handling of Y2K mitigation should be contained in the local procedures. Generic operational and technical linkages should be contained in the Y2K Contingency Plan(s).

    

   System Recovery

    

3. System recovery requires close co-ordination between ATS units. The scope and duration of software failures may take longer to detect and correct in Y2K-related events.

    

1. Impact on Air Traffic Management (ATM) systems

   General

 

1. ATM relies on the functionality of its many systems and sub systems. Those that have been identified as being at potential risk on the event dates are listed elsewhere in this section.

    

   Time Events

    

2. ATS related systems work with Universal Co-ordinated Time (UTC) values and events based on UTC; this may cause Y2K problems at times other than those related to local time. The impact of UTC change-over for ATS systems vis-à-vis change-over at local time should be considered. Supplier services or infrastructure failures may result from time variations.

    

    

3. The differences in local time, when ATS units are situated on the border of two time-zones, e.g.: the United Kingdom compared to mainland Europe, should be considered.

    

    

4. Software functions may be corrupted well before the midnight hours of the event dates and problems may last longer than just a few hours. The early filing of flight plans to take place on 1 January 2000 may be one source of concern. Likewise, the time after midnight may be seen as critical in respect of accumulating effects.

    

   System, sub- system and element failures

    

5. Failures of any of the following systems/sub-systems may have an adverse effect on ATM operations within the NAT and their domestic interfaces:

    

   RADAR DATA PROCESSING

   FLIGHT DATA PROCESSING

   FLIGHT INFORMATION SYSTEMS

   COMMUNICATIONS

   Radio/Telephony (R/T) Systems

   Data Link & On-Line Data Interchange (OLDI) Connections

   Voice & Data Communications

   Aeronautical Fixed Telecommunication Network (AFTN) Connections

   Connections to Military Stations

   Aircraft Communications Addressing and Reporting System (ACARS)

   High Frequency (HF) VOLMET

   FLOW MANAGEMENT UNITS

   Air Traffic Control System Command Centre (ATCSCC)

   Eurocontrol Central Flow Management Unit (CFMU)

   RECORDING

   Voice

   Data

   Radar

   WEATHER INFORMATION

   Display of Information

   Sources for FDPS

   EMERGENCIES/Search and Rescue (SAR)

   AIR DEFENCE INTERFACES AND DATA CONNECTIVITY

   SECTOR CONFIGURATIONS

   MANUAL ATC

   Data Processing Systems

   TIME SOURCES

    

6. Failures of any of the following elements may also have an adverse effect on ATM operations within the NAT and their domestic interfaces:

    

DEPENDENCIES (UTILITIES)

AIRCRAFT OPERATIONS

Dispatch

Flight Operations

Airborne Systems

OFF LINE PROCESSING SYSTEMS

STATISTICAL DATA

NAVIGATIONAL AND LANDING AIDS

 

1. Impact on ATM procedures

 

1. ATM procedures are based on normal system operation and locally established procedures are in place to mitigate the loss of system functionality. Y2K related failures may present new challenges in order to maintain system integrity and safety of operations. Procedures to mitigate the impact of Y2K events are contained in section 5 below.

    

1. Action plans

 

1. The action plans outline the strategies to be implemented by ATS Units to mitigate the impact of the Y2K problems in NAT airspace during the time events described in section 1 above. It is envisaged that contingency measures will be considered from 12 hours before the time events for a 36 hour period (time event + 24hrs.) and until such time as confidence in safety is assured. It is recognised that not all scenarios can be addressed within the terms of this plan, therefore operational circumstances may necessitate real-time adjustments.

    

   Critical Action Teams

    

2. In addition to each Provider State’s critical management organisation, each NAT unit/Provider State shall establish a critical action team to monitor Y2K related events and to exchange information with other units.

    

   ACTION PLAN FOR 31 December 1999 /1 January 2000

    

3. It is envisaged that measures relating to the use of composite type spacing and increased longitudinal spacing would be terminated when confidence in airborne and ground systems has been achieved. It is anticipated that these assurances will be achieved during the Eastbound flow. Inter Centre co-ordination will take place prior to resumption of "normal" operations. The ATS Units will have the ability to tactically adjust operations in the light of actual events.

    

 

1. OTS Track design and loading for Eastbound 31 December 1999 and Westbound 1 January 2000, to permit composite type spacing (i.e. 60 NM lateral and 1000ft vertical);

    

    

2. the OTS shall be designed/published in advance;

    

    

3. optimum altitudes, routings and climbs may not be available;

    

    

4. random routes will be reduced whenever possible; and

    

    

5. the number of tracks published will be determined and agreed by Operations Managers of the North Atlantic ATC units.

    

 

1. ATS Units will apply vertical separation minima to ensure the integrity of the system.

    

    

2. 5 minutes added to current longitudinal minima.

    

 

1. Air Traffic Flow Management (ATFM) measures may be applied as circumstances dictate.

    

 

1. Plans and resources shall be in place for reversion to manual operations

    

 

1. procedures shall be in place to address Y2K issues.

    

    

2. procedures affecting external/adjacent facilities shall be established.

    

 

1. military activities should be minimised to the extent possible.

    

    

2. civil/military co-ordination is required.

    

 

1. co-ordination between all affected ATM facilities should be developed to ensure a smooth transition through all time events.

    

    

2. contingency co-ordination procedures shall be agreed between the units.

    

 

1. personnel shall be adequately briefed on Y2K issues and their impact on ATM operations.

    

    

2. necessary training shall be provided.

    

 

1. ATM providers shall ensure appropriate staff are available during time events.

    

 

1. A Notice to Airmen (NOTAM), Aeronautical Information Circular (AIC) or equivalent shall be issued on a timely basis.

    

    

2. Advisory information should be published in the note portion of the OTS message.

    

 

1. Back-up systems, including utilities, should be tested and available.

    

    

2. Back-up procedures should be validated and refresher training for operational and technical staff shall be provided.

    

    

3. Consumable supplies, such as paper flight strips, strip holders, etc. should be adequate for a prolonged outage.

    

 

1. Operational units should review flight planning and flight data handling procedures to ensure continuity of service.

    

 

1. Staff should be aware of the potential for multiple Y2K related in-flight contingencies.

    

    

2. Flights equipped with Traffic Alert and Collision Avoidance System (TCAS)/Airborne Collision Avoidance System (ACAS) should utilise the system throughout the NAT.

    

    

3. ATC should be notified immediately if flight critical system degradation is observed.

    

 

1. Operational units shall compile a check list of all essential operational and technical requirements and ensure that they are in place prior to critical time events.

    

    

2. Operational units should share checklists in order to ensure a comprehensive exchange of information.

    

    

3. A sample checklist is provided in Section 6.

    

 

1. Information should be exchanged between operational units regarding Y2K related experiences.

    

 

1. This could affect aircraft navigation systems if they do not re-set properly. GPS is not widely used as a time source and the risk to ATC ground stations is judged to be relatively low. Compliance with Federal Aviation Administration (FAA) Technical Service Order (TSO) C129(a) is a requirement for those aircraft operating within Minimum Navigation Performance Specifications (MNPS) airspace using GPS as a primary means. It must be recognised that there may be aircraft that are not compliant with TSO C129(a) operating in the NAT region outside of MNPS airspace. The following action shall be taken:

    

    

2. Provider and operator awareness to be raised;

    

    

3. An agreed NOTAM to be issued (plus note on the OTS Message referring to NOTAM(s)); and

    

    

4. The United Kingdom, on behalf of all NAT Provider States, will promulgate the NOTAM two AIRAC cycles before the roll-over date and valid for at least one AIRAC cycle after the roll-over date.

    

 

1. The following action shall be taken:

    

    

2. Provider and operator awareness to be raised, appropriate staff to be in place (e.g. to take care of manual data handling); and

    

    

3. An agreed NOTAM to be issued (plus a note on the OTS Message referring to NOTAM(s)).

    

 

1. Systems may not correctly recognise the Leap Year, either the transition 28-29th February or March 1 the impact on the total number of days in the year 2000. Therefore the following actions shall be taken:

    

    

2. Provider and operator awareness to be raised and appropriate staff to be in place (e.g. to take care of manual data handling); and

    

    

3. An agreed NOTAM to be issued (plus a note on the OTS Message referring to NOTAM(s)).