CS ACNS.E.LAD.310 Environmental and crash conditions encountered during accidents

ED Decision 2021/008/R

(a) Environmental conditions that may be encountered during the flight of a non-survivable accident do not adversely affect the transmission of information that is sufficient to achieve the position accuracy of the point of end of flight required for non-survivable accidents.

(b) Conditions that may be encountered when the aircraft collides with terrain or water do not adversely affect the transmission of information that is sufficient to achieve the position accuracy of the point of end of flight required for non-survivable accidents.

(c) The position accuracy of the point of end of flight required for survivable accidents is achieved under environmental conditions that are encountered during survivable accidents where the aircraft is severely damaged.

(d) Requirements applicable to the transmission of a homing signal are met under environmental conditions that are encountered during survivable accidents where the aircraft is severely damaged.

[Issue: CS-ACNS/3]

AMC1 ACNS.E.LAD.310 Environmental and crash conditions encountered during accidents

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS

(a) The system should meet the certification specifications for the transmission of activation signals, while the equipment needed for that function is subject to the environmental test conditions of Tables 1 and 2 of this AMC, except for ELTs that are approved in accordance with European Technical Standard Order (ETSO)-C126c.

(b) If activation signals need to be transmitted by non-deployable equipment after reaching the point of end of flight to meet CS ACNS.E.LAD.410, that equipment (including antennas) should be demonstrated to pass the following tests:

(1) the impact shock test of EUROCAE ED-112A, Section 2-4.2.1;

(2) the penetration resistance test of EUROCAE ED-112A, Section 2-4.2.3;

(3) the static crush test of EUROCAE ED-112A, Section 2-4.2.4; and

(4) the high-temperature fire test of EUROCAE ED-112A, Section 2-4.2.5, except that the duration of the high-temperature fire test does not need to be longer than the time that is sufficient for transmitting the activation signals and complying with CS ACNS.E.LAD.410. Successful transmission of activation signals should be demonstrated at the end of this sequence of tests.

(c) If activation signals need to be transmitted by non-deployable equipment after reaching the point of end of flight to meet CS ACNS.E.LAD.420, that equipment (including antennas) should successfully transmit the activation signals after being subjected to the environmental tests applicable to an ELT(AF) in Tables 4-1 and 4-2 of EUROCAE ED-62B (including Change 1). However, if the duration of the flame test of EUROCAE ED-62B, Section 4.5.13 is not sufficient to ensure that at least a complete data set, such as that specified in CS ACNS.E.LAD.140, is received and that CS ACNS.E.LAD.420 is met, an appropriate duration should be determined and used for the flame test.

(d) If activation signals need to be transmitted by deployable equipment after reaching the point of end of flight to meet CS ACNS.E.LAD.140, that equipment should meet the same environmental standard as specified for an ADFR in European Technical Standard Order (ETSO)‑2C517, and should be installed as specified for an ADFR in CS 25.1457 of the Certification Specifications for Large Aeroplanes (CS-25), except that the recording of data to facilitate accident investigations is not necessary for compliance with CS ACNS.E.LAD.310.

(e) The homing-signal transmitter and antennas that are used by the system for transmitting the homing signal should successfully transmit the 121.5-MHz homing signal when subjected to the environmental tests applicable to an ELT(AF) in Tables 4-1 and Table 4-2 of EUROCAE ED-62B (including Change 1).

(f) If ELTs are used to meet CS ACNS.E.LAD.310, they should be installed in accordance with EUROCAE ED-62B (including Change 1), Chapter 6.

Table 1 — Minimum environmental qualification level test conditions applicable to the system

Table 2 — Flame test

[Issue: CS-ACNS/3]

AMC2 ACNS.E.LAD.310 Environmental and crash conditions encountered during accidents

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE SPECIFIC TO SOLUTIONS BASED ON AN ADFR

The system should meet the conditions of AMC1 ACNS.E.LAD.310, except that meeting the conditions of AMC2 ACNS.E.LAD.020 satisfies CS ACNS.E.LAD.310 regarding the ADFR and its integrated ELT.

[Issue: CS-ACNS/3]

AMC3 ACNS.E.LAD.310 Environmental and crash conditions encountered during accidents

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.310.

(b) The ELT(DT), its antennas, and other components that are required for the transmission of activation signals should be installed so as to minimise the risk of disconnection during an accident.

(c) When installing an ELT(DT) that uses an integral battery (as defined in EUROCAE ED-62B, including Change 1), mitigation measures should be taken to ensure that the ELT(DT) remains powered after a survivable accident.

[Issue: CS-ACNS/3]

AMC4 ACNS.E.LAD.310 Environmental and crash conditions encountered during accidents

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.310.

(b) The installation of the components that are necessary to transmit activation signals should minimise the probability that failures resulting from environmental conditions that may be encountered before reaching the point of end of flight hinder the performance of the system.

[Issue: CS-ACNS/3]

GM1 ACNS.E.LAD.310 Environmental and crash conditions encountered during accidents

ED Decision 2021/008/R

COMMON GUIDANCE FOR ALL SOLUTIONS

The accident conditions to be considered for compliance with CS ACNS.E.LAD.310 do not include the case of sudden in-flight destruction of the aircraft.

[Issue: CS-ACNS/3]

CS ACNS.E.LAD.320 Flight dynamics and locating the aircraft

ED Decision 2021/008/R

(a) Based on detailed assumptions about the minimum performance of the communication infrastructure, it is demonstrated that:

(1) if the system transmits activation signals before or without deploying any equipment:

(i) the activation signals and the deactivation signals are transmitted in such a manner that the communication infrastructure detects these signals at all possible values of aircraft pitch attitude, aircraft roll attitude, aircraft altitude, and aircraft speed, as well as at all possible rates of change of these parameters within the normal flight envelope;

(ii) the following is not adversely affected on accident flight trajectories with parameter values within the ranges of Table 1 of this CS:

(A) performance of the automatic activation of the system;

(B) performance of the transmission of the activation signals by the system;

(C) detection of the activation signals by the communication infrastructure; and

(D) position accuracy of the point of end of flight that is required for non‑survivable accidents; and

(iii) the position accuracy of the point of end of flight that is required for survivable accidents is achieved on typical flight trajectories of survivable accidents;

(2) if the system transmits activation signals from deployable equipment:

(i) the deployable equipment has at least the same performance as an ADFR with regard to deployment, activation, and crashworthiness of the transmitter;

(ii) unless the system transmits before deployment activation signals that are sufficient to achieve the position accuracy for non-survivable accidents, the crash testing specifications of the transmitter in the deployable equipment and the deceleration properties of the deployable equipment are such that the transmission of activation signals is not adversely affected by impact shock forces that are representative of deployment during a non-survivable aircraft collision with terrain;

(iii) the communication infrastructure detects the activation signals of the deployable equipment when that equipment is deployed and not moving; and

(iv) the communication infrastructure detects the activation signals and deactivation signals when the aircraft stands on its landing gears and no equipment is deployed; and

(3) the performance specified in (1) or (2), as applicable, is achieved at any location.

(b) Documentation is prepared, which demonstrates the minimum performance of a communication infrastructure that is required for complying with (a).

Table 1 — Parameter ranges for typical accident flight trajectories

AMC1 ACNS.E.LAD.320 Flight dynamics and locating the aircraft

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS

The following detailed assumptions about the minimum performance of the communication infrastructure should be provided regarding:

(a) the distribution of sensors, repeaters, and stations over time and in space, and the resulting coverage of the communication infrastructure; and

(b) the minimum availability and integrity of the communication infrastructure that is needed to ensure that the communication infrastructure is very likely to detect and transmit without errors activation signals from an aircraft; ‘availability’ should be understood as the probability that the communication infrastructure can process the information that is contained in activation signals into data and transmit this data as intended.

[Issue: CS-ACNS/3]

AMC2 ACNS.E.LAD.320 Flight dynamics and locating the aircraft

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE SPECIFIC TO SOLUTIONS BASED ON AN ADFR

(a) The system should meet the conditions of AMC1 ACNS.E.LAD.320.

(b) Assuming that:

(1) when it is released, the deployable package of the ADFR has an initial ground speed (in the local horizontal plane) of 300 knots or the design diving speed, whichever is lower;

(2) there is no wind; and

(3) Vi is the highest impact velocity at which the ELT in the deployable package of the ADFR is demonstrated to successfully transmit a 406-MHz signal after an impact shock test as specified in EUROCAE ED-112A, Section 3-3.2,

the horizontal distance needed for the deployable package of the ADFR to be decelerated solely by aerodynamic forces to a ground speed equal to Vi should not exceed 70 metres.

(c) Unless the aircraft is equipped with an ELT(AF) or (AP), the ADFR should be installed to achieve a 95-% probability that at least one satellite of the international COSPAS-SARSAT programme receives the 406-MHz signal transmitted by the ELT that is integrated into the deployable package of the ADFR when the aircraft stands on its landing gears and that package is not deployed.

[Issue: CS-ACNS/3]

AMC3 ACNS.E.LAD.320 Flight dynamics and locating the aircraft

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO SOLUTIONS BASED ON AN ELT(DT) AND TO SOLUTIONS BASED ON HRT

(a) The system should meet the conditions of AMC1 ACNS.E.LAD.320.

(b) If the system transmits activation signals before or without deploying equipment, the performance that is defined as successful regarding:

—      automatic activation (refer to CS ACNS.E.LAD.240);

—      transmission of the activation signals (refer to CS ACNS.E.LAD.110 and CS ACNS.E.LAD.120);

—      detection of the activation signals by the communication infrastructure; and

—      position accuracy of the point of end of flight (refer to CS ACNS.E.LAD.410),

should be demonstrated on typical accident flight trajectories with parameter values within the ranges of Table 1 of CS ACNS.E.LAD.320. In addition, the position accuracy of the point of end of flight for survivable accidents (refer to CS ACNS.E.LAD.420) should be demonstrated on typical flight trajectories of survivable accidents. The demonstrations should be made in the most unfavourable conditions of time and location, or a sensitivity analysis should be conducted to demonstrate that the variation in time or location does not significantly affect the result. The threshold values for automatic activation should be contained within a range where successful transmission is demonstrated.

Verification may rely on computer-based simulations and ground tests. In the case of a subsonic aeroplane, a verification method may be to:

(1) demonstrate that the system was successfully automatically activated and transmitted the activation signals, and that the communication infrastructure detected the activation signals (including assessment of the link budget) based on the flight data sets on accidents and incidents that are referred to in EUROCAE ED-237, Appendix 1;

(2) demonstrate that the example flight trajectory of Subpart 3, Section E, Appendix A meets the position accuracy requirement of CS ACNS.E.LAD.410 (‘Position accuracy for non‑survivable accidents’); and

(3) demonstrate that the position accuracy requirement of CS ACNS.E.LAD.420 (‘Position accuracy for survivable accidents’) is met, assuming that during the last 20 seconds before reaching the point of end of flight:

(i) valid position data is available from the position source of the system; and

(ii) the aircraft makes a stabilised turn at a ground speed of 180 knots and a bank angle of 45°.

(c) The antennas that are used by the system, including position source antennas, should be installed so that position determination and transmission of the activation signals are successful at all aircraft attitude angles and aircraft speeds that correspond to normal operation.

(d) The antennas that are used by the system, including position source antennas, should be installed so that position determination and transmission of the activation signals are likely to be successful at aircraft pitch attitudes, aircraft roll attitudes, aircraft speeds, and rates of change of these parameters that might be experienced between the time of activation of the system and reaching the point of end of flight.

[Issue: CS-ACNS/3]

GM1 ACNS.E.LAD.320 Flight dynamics and locating the aircraft

ED Decision 2021/008/R

COMMON GUIDANCE FOR ALL SOLUTIONS

(a) With regard to assumptions about the coverage of the communication infrastructure, it is recommended to consider the coverage that is provided for at least 95 % of the time, to assess compliance with paragraph (a) of CS ACNS.E.LAD.320.

(b) With regard to the availability and integrity of the communication infrastructure, COSPAS‑SARSAT document C/S R.012 (‘COSPAS-SARSAT 406-MHz MEOSAR implementation plan’) includes the following minimum performance requirements:

(1) availability: ‘The system should be available 99.5 % of the time over a period of one year.’; and

(2) processing anomalies: ‘The system should not produce more than one processing anomaly for every 10,000 alert messages. A processing anomaly is an alert message produced by the system, which should not have been generated, or which provided incorrect information.’.

[Issue: CS-ACNS/3]

CS ACNS.E.LAD.340 Activation and transmission over water and over land

ED Decision 2021/008/R

Automatic activation of the system and transmission of the activation signals are successful whether the point of end of flight is located over water or over land.

[Issue: CS-ACNS/3]

AMC1 ACNS.E.LAD.340 Activation and transmission over water and over land

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS

(a) If the system relies on non-deployable equipment that transmits activation signals after reaching the point of end of flight to comply with CS ACNS.E.LAD.410 or CS ACNS.E.LAD.420, those activation signals should be transmitted within 15 seconds after reaching that point.

(b) If the system relies on activation signals that are transmitted by deployable equipment to locate the point of end of flight, that equipment should be floatable and capable of transmitting after being deployed over or in water.

[Issue: CS-ACNS/3]

CS ACNS.E.LAD.350 Means and procedures to prevent undesirable activation

ED Decision 2021/008/R

(a) No means, except for circuit protective devices that are specified by applicable requirements, are provided in the cockpit or cabin to disarm or disable the system during flight.

(b) Instructions are provided to the flight crew to address manual activation of the system and handling of undesirable activation.

(c) The instructions for continued airworthiness include procedures to avoid that activation signals are inadvertently transmitted during maintenance of the system.

[Issue: CS-ACNS/3]

AMC1 ACNS.E.LAD.350 Means and procedures to prevent undesirable activation

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS

The instructions provided to the flight crew should be included in the aircraft flight manual (AFM). Those instructions should address as a minimum the following:

(a) conditions that justify manual activation of the system and conditions that do not justify manual activation;

(b) recommended flight crew action after manual activation or manual deactivation of the system; and

(c) recommended flight crew action in case of undesirable activation (automatic or manual); these recommendations should address as a minimum the following:

(1) using in a timely manner available communication means to inform the relevant ATS unit and the operator of the undesirable activation; and

(2) action, if any, to stop the undesirable activation.

[Issue: CS-ACNS/3]

GM1 ACNS.E.LAD.350 Means and procedures to prevent undesirable activation

ED Decision 2021/008/R

COMMON GUIDANCE FOR ALL SOLUTIONS

To reduce cases of undesirable activation, CS ACNS.E.LAD.350 permits to include specific means to disarm or disable the system during maintenance activities or before specific design flights or production flights.

[Issue: CS-ACNS/3]

CS ACNS.E.LAD.360 Shared airborne resources and transmission means

ED Decision 2021/008/R

The use of shared airborne resources or transmission means does not adversely affect the performance of the system.

[Issue: CS-ACNS/3]

GM1 ACNS.E.LAD.360 Shared airborne resources and transmission means

ED Decision 2021/008/R

COMMON GUIDANCE FOR ALL SOLUTIONS

In CS ACNS.E.LAD.360:

(a) ‘airborne resources’ means any object (processor, memory, software, data, etc.) or component that is used by a processor, an integrated modular avionics platform, core software or an application. An airborne resource may be shared by multiple applications or may be dedicated to a specific application. An airborne resource may be physical (a hardware device) or logical (a piece of information).

(b) ‘transmission means’ include transmitters and antennas.

[Issue: CS-ACNS/3]