CS ACNS.E.LAD.110 Transmission of the activation signals
ED Decision 2021/008/R
(a) Following activation of the system, the system transmits the activation signals within a time frame that maximises the likelihood that the communication infrastructure receives at least once the information that is required for activation signals.
(b) The characteristics of the activation signals are such that the communication infrastructure can detect them and process their required information into data.
[Issue: CS-ACNS/3]
AMC1 ACNS.E.LAD.110 Transmission of the activation signals
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS
If activation signals are transmitted by other equipment than an ELT:
(a) a detailed description of the communication infrastructure that will be used by the system should be provided, including evidence that this communication infrastructure can detect and process activation signals; and
(b) the time frame to transmit activation signals following activation of the system should be based on assumptions about the performance of the communication infrastructure.
[Issue: CS-ACNS/3]
AMC2 ACNS.E.LAD.110 Transmission of the activation signals
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE SPECIFIC TO SOLUTIONS BASED ON AN ELT(DT)
(a) The system should meet the conditions of AMC1 ACNS.E.LAD.110.
(b) The transmission of the activation signals should start no later than 5 seconds after detection of an activation condition or after manual activation by the flight crew.
[Issue: CS-ACNS/3]
AMC3 ACNS.E.LAD.110 Transmission of the activation signals
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE SPECIFIC TO SOLUTIONS BASED ON HRT
(a) The system should meet the conditions of AMC1 ACNS.E.LAD.110.
(b) The transmission of the activation signals should start no later than 5 seconds after detection of an activation condition or after manual activation by the flight crew.
[Issue: CS-ACNS/3]
GM1 ACNS.E.LAD.110 Transmission of the activation signals
ED Decision 2021/008/R
COMMON GUIDANCE FOR ALL SOLUTIONS
It is recommended that activation signals are transmitted even when part of the information that is required by CS ACNS.E.LAD.140 is not available to the system (e.g. due to the failure of some data sources).
[Issue: CS-ACNS/3]
CS ACNS.E.LAD.120 Repeated transmission of the activation signals
ED Decision 2021/008/R
Once activated, the system repeatedly transmits activation signals so that they can be detected by the communication infrastructure at time intervals that do not exceed 1 minute. The system continues to transmit those signals at least until it reaches the point of end of flight or until it is deactivated.
[Issue: CS-ACNS/3]
AMC1 ACNS.E.LAD.120 Repeated transmission of the activation signals
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS
If activation signals are transmitted by other equipment than an ELT, the time intervals for transmitting activation signals should be based on assumptions about the performance of the communication infrastructure that will detect those activation signals.
[Issue: CS-ACNS/3]
CS ACNS.E.LAD.130 Transmission of the deactivation signals
ED Decision 2021/008/R
(a) Upon deactivation of the system, the system automatically transmits deactivation signals so that the information that is required for deactivation signals is transmitted within 1 minute of the time of deactivation.
(b) Transmission of deactivation signals is repeated so that the communication infrastructure receives the information that is required for deactivation signals with a 99.9-% probability.
(c) The characteristics of the deactivation signals are such that the communication infrastructure can detect them and process their required information into data.
[Issue: CS-ACNS/3]
AMC1 ACNS.E.LAD.130 Transmission of the deactivation signals
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS
If deactivation signals are transmitted by other equipment than an ELT, a detailed description of the communication infrastructure that is used by the system should be provided, including evidence that this communication infrastructure will detect and process deactivation signals.
[Issue: CS-ACNS/3]
CS ACNS.E.LAD.140 Activation signals — essential information
ED Decision 2021/008/R
The activation signals contain sufficient information to determine:
— that the system is activated;
— the latitude and longitude of the aircraft;
— the times at which the latitude and longitude were valid;
— the identification of the aircraft from which the activation signals are sent; and
— the type of airborne equipment that transmitted the signals.
[Issue: CS-ACNS/3]
AMC1 ACNS.E.LAD.140 Activation signals — essential information
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS
(a) If the activation signals are transmitted in flight, every activation signal containing information that is used to determine the latitude or longitude of the aircraft should be sent no later than 2 seconds after the time at which this information is valid.
(b) The information that is used to determine the latitude and longitude of the aircraft should be included in the activation signals even if this information is inaccurate.
(c) If an activation signal contains latitude or longitude information, this information should be provided in the World Geodetic System 84 (WGS84) (G1150 or later) or in another realisation of the International Terrestrial Reference Frame (IERS) (2000 or later).
(d) The information contained in the activation signals or their characteristics should be sufficient to determine with certainty whether those signals were transmitted by an automatic ELT, an ELT(DT), or another type of equipment.
[Issue: CS-ACNS/3]
GM1 ACNS.E.LAD.140 Activation signals — essential information
ED Decision 2021/008/R
GUIDANCE FOR SOLUTIONS BASED ON AN ELT(DT)
The primary position source for the ELT(DT) does not need to be an internal or integral GNSS receiver. The ELT(DT) can encode the latitude and longitude based on an approved aircraft position source when this source is available. When the aircraft position source is lost, automatically reverting the position source to the internal GNSS receiver of the ELT(DT) is needed to meet CS ACNS.E.LAD.230.
[Issue: CS-ACNS/3]
CS ACNS.E.LAD.150 Activation signals — supplementary
ED Decision 2021/008/R
If any of the following information is readily available to the system and supported by the communication infrastructure to which the system transmits activation signals, then it is part of the information of the activation signals:
— whether the transmitted latitude and longitude were stamped as invalid data;
— the estimated accuracy of the transmitted latitude and longitude;
— whether the system was automatically or manually activated;
— the aircraft altitude;
— the ground speed of the aircraft;
— the aircraft course; or
— the vertical speed of the aircraft.
[Issue: CS-ACNS/3]
GM1 ACNS.E.LAD.150 Activation signals — supplementary
ED Decision 2021/008/R
COMMON GUIDANCE FOR ALL SOLUTIONS
(a) When considering an already approved aircraft type, information ‘readily available to the system’ can be understood as information whose collection only requires changes to the airborne equipment that is part of the system. For new type certificates, the supplementary information to be contained in activation signals should be agreed with EASA.
(b) ‘supported by the communication infrastructure’ can be understood as information that can be processed into data by the communication infrastructure without modifying that infrastructure.
[Issue: CS-ACNS/3]
CS ACNS.E.LAD.160 Deactivation signals — essential information
ED Decision 2021/008/R
The deactivation signals contain sufficient information to determine:
— that the system was deactivated;
— the identification of the aircraft from which the deactivation signals are sent; and
— the type of airborne equipment that transmitted the signals.
[Issue: CS-ACNS/3]
CS ACNS.E.LAD.170 Transmission of a homing signal
ED Decision 2021/008/R
(a) In case of a survivable accident, a 121.5-MHz homing signal is automatically transmitted after reaching the point of end of flight. The characteristics of the 121.5-MHz homing signal are compatible with standard homing direction finders.
(b) The flight crew can manually initiate the transmission of a 121.5-MHz homing signal, at least when the aircraft is not airborne.
(c) The flight crew can manually stop the transmission of the 121.5-MHz homing signal whether this transmission was automatically or manually initiated unless the homing-signal transmitter is detached from the aircraft.
(d) The 121.5-MHz homing signal is transmitted for at least 48 hours or until the aircraft is submersed.
[Issue: CS-ACNS/3]
AMC1 ACNS.E.LAD.170 Transmission of a homing signal
ED Decision 2021/008/R
ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS
(a) The 121.5-MHz homing-signal transmitter should meet the specifications of EUROCAE ED-62B (including Change 1) that are applicable to:
(1) an automatic ELT with capabilities C (crash survivability) and H1 (121.5-MHz homing signal) and of class 0 or 1; or
(2) an ELT(DT) with capability C and H1, and of class 0 or 1,
except for specifications related to the transmission of the 406-MHz signal, to COSPAS-SARSAT requirements, to ELT controls, or the ELT monitoring system.
(b) When the same battery powers both the transmission of the activation signals and of the 121.5‑MHz homing signal, the battery capacity should be sufficient to cover the transmission of the 121.5-MHz homing signal for 48 hours and the transmission of the activation signals for a duration sufficient to meet CS ACNS.E.LAD.420.
(c) The system should detect that the aircraft collided with terrain or water to initiate the transmission of a 121.5-MHz homing signal. The detection may be made by means of an acceleration sensor (‘g-switch’) or through other methods. Refer to EUROCAE ED-62B (including Change 1), Section 2.9.5.1
(d) The installation of the homing-signal transmitter and of its antenna should be such that after a successful ditching or landing, the transmission is possible despite damage to, or immersion of, the lower part of the fuselage and/or the wings.
[Issue: CS-ACNS/3]
GM1 ACNS.E.LAD.170 Transmission of a homing signal
ED Decision 2021/008/R
COMMON GUIDANCE FOR ALL SOLUTIONS
(a) CS ACNS.E.LAD.170 could be met by installing an ELT(AF) or (AP).
(b) It is recommended that the manual activation of the system (see CS ACNS.E.LAD.250) also initiates the transmission of the 121.5-MHz homing signal as soon as, but not before, the aircraft reaches the point of end of flight.
[Issue: CS-ACNS/3]