Page 378 - UK Air Operations Regulations 201121

Part CAT - ANNEX IV - Commercial Air Transport Operations
CAT.IDE.A.195 AMC1
20th November 2021
(1) data link communication messages related to ATS communications to and from the
aeroplane, including messages applying to the following applications:
(i) data link initiation;
(ii) controller-pilot communication;
(iii) addressed surveillance;
(iv) flight information;
(v) as far as is practicable, given the architecture of the system, aircraft
broadcast surveillance;
(vi) as far as is practicable, given the architecture of the system, aircraft
operational control data; and
(vii) as far as is practicable, given the architecture of the system, graphics;
(2) information that enables correlation to any associated records related to data link
communications and stored separately from the aeroplane; and
(3) information on the time and priority of data link communications messages, taking
into account the system’s architecture.
(b) The recorder shall use a digital method of recording and storing data and information and a
method for retrieving that data. The recording method shall allow the data to match the
data recorded on the ground.
(c) The recorder shall be capable of retaining data recorded for at least the same duration as
set out for CVRs in CAT.IDE.A.185.
(d) If the recorder is not deployable, it shall have a device to assist in locating it under water.
By 16 June 2018 at the latest, this device shall have a minimum underwater transmission
time of 90 days. If the recorder is deployable, it shall have an automatic emergency locator
transmitter.
(e) The requirements applicable to the start and stop logic of the recorder are the same as the
requirements applicable to the start and stop logic of the CVR contained in
CAT.IDE.A.185(d) and (e).
Data link recording
GENERAL
(a) As a means of compliance with CAT.IDE.A.195, the recorder on which the data link
messages is recorded may be:
(1) the CVR;
(2) the FDR;
(3) a combination recorder when CAT.IDE.A.200 is applicable; or
(4) a dedicated flight recorder. In that case, the operational performance requirements
for this recorder should be those laid down in EUROCAE Document ED-112
(Minimum Operational Performance Specification for Crash Protected Airborne
Recorder Systems) dated March 2003, including amendments No 1 and No 2, or any
later equivalent standard produced by EUROCAE.
(b) As a means of compliance with CAT.IDE.A.195(a)(2), the operator should enable
correlation by providing information that allows an accident investigator to understand what
data was provided to the aeroplane and, when the provider identification is contained in the
message, by which provider.
(c) The timing information associated with the data link communications messages required
to be recorded by CAT.IDE.A.195(a)(3) should be capable of being determined from the
airborne-based recordings. This timing information should include at least the following:
(1) the time each message was generated;
(2) the time any message was available to be displayed by the crew;
(3) the time each message was actually displayed or recalled from a queue; and
(4) the time of each status change.
(d) The message priority should be recorded when it is defined by the protocol of the data link
communication message being recorded.
(e) The expression ‘taking into account the system architecture’, in CAT.IDE.A.195(a)(3),
means that the recording of the specified information may be omitted if the existing source
systems involved would require a major upgrade. The following should be considered:
(1) the extent of the modification required;
(2) the down-time period; and
(3) equipment software development.
The intention is that new designs of source systems should include this functionality
and support the full recording of the required information.
(f) Data link communications messages that support the applications in Table 1 below should
be recorded.
(g) Further details on the recording requirements can be found in the recording requirement
matrix in Appendix D.2 of EUROCAE Document ED-93 (Minimum Aviation System
Performance Specification for CNS/ATM Recorder Systems, dated November 1998).
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