CAT.GEN.MPA.205 Aircraft tracking system — Aeroplanes

EQUIPMENT, PERFORMANCE AND PROCEDURES WHEN AIRCRAFT TRACKING IS REQUIRED

(a)Automatic tracking of aeroplane position The aircraft tracking system should rely on equipment capable of automatically detecting and transmitting a position report to the aircraft operator, except if (d)(2) applies.

(b)Position reporting period The tracking of an individual flight should provide a position report at time intervals which do not exceed 15 minutes.

(c)Content of position reports Each position report should contain at least the latitude, the longitude and the time of position determination and whenever available, an indication of the aeroplane altitude, except that for each flight:

(1)One of the position reports may contain only time-stamped data indicating that the aeroplane has left the gate;

(2)One of the position reports may contain only time-stamped data indicating that the aeroplane has become airborne;

(3)One of the position reports may contain only time-stamped data indicating that the aeroplane has landed; and

(4)One of the position reports may contain only time-stamped data indicating that the aeroplane has reached the gate.

(d)Source of position data The data contained in a position report may come from:

(1)ATC surveillance systems, if the ATC surveillance data source is capable of providing this data with a delay equal to or less than 10 minutes;

(2)the flight crew, if the planned flight duration is less than two position reporting periods;

(3)aeroplane systems. In that case:

(i)the source of time, latitude and longitude data should be the navigation system of the aeroplane or an approved GNSS receiver;

(ii)the source of altitude data should be:

(A)the same source as for time, latitude and longitude data, or

(B)an approved source of pressure altitude; and

(iii)the delivery time of position reports from the aeroplane to the operational control over the flight should, to the extent possible, not exceed 10 minutes; or

(4)any data source when the position report is of a type designated by (c)(1), (c)(2), (c)(3) or (c)(4). In that case, the delivery time of position reports from the data source to the operational control over the flight should, to the extent possible, not exceed 10 minutes.

(e)Temporary lack of aircraft tracking data Aircraft tracking data may be incomplete due to a temporary or unexpected issue prior to or during the flight. However, the operator should:

(1)identify any loss of aircraft tracking data which is not due to a temporary issue, and

(2)address any systematic lack of aircraft tracking data affecting a given aeroplane or a given route in a timely manner.

(f)Operational control over the flights When abnormal flight behaviour is suspected, this should be checked and acted upon without delay.

(g)Recording of aircraft tracking data during normal operation When the tracking of a flight is required, all related aircraft tracking data should be recorded on the ground, including position data from ATC surveillance systems when they are used. The aircraft tracking data of a given flight should be retained until confirmation that the flight is completed and no accident or serious incident occurred.

(h)Preserving aircraft tracking data after an accident or a serious incident Following an accident or a serious incident, the operator should retain the aircraft tracking data of the involved flight for at least 30 days. In addition, the operator should be capable of providing a copy of this data without delay and in an electronic format that is human-readable using a common text file editor.

(i)Procedures The operator should establish procedures describing its aircraft tracking system, including the identification of abnormal flight behaviour and the notification of the competent ATS unit (ATS unit responsible for providing the alerting service in the airspace where the aircraft is believed to be), when appropriate. These procedures should be integrated with the emergency response plan of the operator.

ROUTES INCLUDED IN AIRSPACE COVERED BY ATS SURVEILLANCE

(a)Trajectory points located at a distance of less than 50 NM from the departure airfield and trajectory points located at a distance of less than 50 NM from the destination airfield may be considered as not part of the ‘planned route’.

(b)Trajectory points located at a distance of less than 50 NM from any diversion airfield may be considered as not part of the ‘planned diversion routes’.

(c)An ATS surveillance service may be considered ‘supported by ATC surveillance systems locating the aircraft at time intervals with adequate duration’ if those ATC surveillance systems are capable of locating aircraft at time intervals not exceeding 15 minutes when operated normally.

(d)When applicable, the operator should check that the conditions required for using the exception defined by CAT.GEN.MPA.205(b) are fulfilled before operating into new airspace blocks.

(e)When applicable, the operator should check at time intervals not exceeding 180 calendar days that the conditions required for using the exception defined by CAT.GEN.MPA.205(b) are maintained.

EXPLANATION OF TERMS For the understanding of the terms used in CAT.GEN.MPA.205:

(a)’capability to provide a position additional to the secondary surveillance radar transponder’ means airborne equipment other than the SSR transponder, which is operative and which can be used to automatically transmit time-stamped position data without change to the approved airborne systems; and

(b)‘abnormal flight behaviour’: see GM1 to Annex I (Definitions).

DETERMINING WHETHER A FLIGHT NEEDS TO BE TRACKED Table 1 provides a summary of the cases applicable to an aeroplane which is within the scope of CAT.GEN.MPA.205(a).

Table 1: Cases applicable to the flight of an aeroplane subject to the aircraft tracking requirement

METHOD FOR ASSESSING WHETHER A FLIGHT NEEDS TO BE TRACKED The following gives an example of a method to assess whether flights performed along a given route need to be tracked.

(a)Determine the planned route and the planned diversion routes and consider only points of these routes located at a distance of greater than or equal to 50 NM from the departure airfield, the destination airfield and the diversion airfields. If there is no such point, then the flight does not need to be tracked, otherwise go to (b).

(b)Identify all airspace blocks crossed by the result of (a) and go to (c).

(c)If every airspace block meets all of the following conditions, then the flight does not need to be tracked:

(1)ATS surveillance service is provided in the airspace block;

(2)This ATS surveillance service relies on ATC surveillance systems which are normally capable of detecting aircraft in the airspace block at time intervals not exceeding 15 minutes; and

(3)The air navigation service provider competent for the airspace block has information sufficient to contact the on-duty staff at the operator;

POSSIBLE SOURCES AND MINIMUM CONTENT OF A POSITION REPORT Table 1 presents a summary of the possible sources and the minimum content of a position report according to AMC1 CAT.GEN.MPA.205.

Table 1: Possible sources and minimum content of a position report

AIRCRAFT TRACKING — CHOICE OF THE POSITION REPORTING PERIOD

(a)Unless the aircraft tracking system includes functionalities enhancing the detection of deviations from normal operation (e.g. airborne systems capable of automatically transmitting more information under some conditions, possibility for the operational control to adjust the position reporting period of an ongoing flight, etc.), the choice of the position reporting period has a significant influence on the effectiveness of the aircraft tracking system.

(1)Indeed, assuming that an operator has set itself the objective of detecting, within a given time T, deviations from normal operation, and that the operator relies for this purpose only on position reports, then the position reporting period needs to be less than T.

(2)Furthermore, when no other information than position reports is available to locate a missing aircraft, then the search zone is a circle with a radius corresponding to the distance likely to have been covered since the last detection. The corresponding search area grows as the square of the time, until the position of the aircraft is detected again or the fuel on board is exhausted. Taking the example of an aeroplane cruising at Mach 0.8 (i.e. covering a distance of about 8 NM per minute), after 15 minutes the search area is 155 000 square kilometres.

(3)In the publication of the Australian Transportation Safety Bureau titled ‘The Operational Search for MH370’ (dated October 2017), it is recommended that ‘Aircraft operators, aircraft manufacturers, and aircraft equipment manufacturers investigate ways to provide high-rate and/or automatically triggered global position tracking in existing and future fleets’.

(b)It is advised to take the above into account when setting up the aircraft tracking system.

PROVIDING CONTACT INFORMATION TO COMPETENT AIR NAVIGATION SERVICE PROVIDERS A solution for the operator to make the necessary contact information available to all competent air navigation service providers (ANSPs) could be to register to the global OPS Control Directory of ICAO. Another possible way is to provide in the ATS flight plan (item 18 ‘Other information’) information sufficient to contact the on-duty staff of the aircraft operator.

GUIDANCE Additional guidance for the establishment of an aircraft tracking system is found in ICAO Circular 347 – Aircraft Tracking Implementation Guidelines, dated 2017.