CS ACNS.E.LAD.001 Applicability and scope

ED Decision 2021/008/R

This Section provides standards for the installation of equipment and systems that are intended to help locate an aircraft in distress, in accordance with Regulation (EU) No 965/2012 (‘Air OPS Regulation’), including when such equipment and systems replace an emergency locator transmitter (ELT) or a low-frequency underwater locating device (ULD). Accidents and distress situations within the scope of this Section are those that take place between take-off and landing, or at an airfield, and severely damage the aircraft, irrespective of the number of fatalities and injuries.

[Issue: CS-ACNS/3]

GM1 ACNS.E.LAD.001 Applicability and scope

ED Decision 2021/008/R

COMMON GUIDANCE FOR ALL SOLUTIONS

Point CAT.GEN.MPA.210 of Annex IV (Part-CAT) to the Air OPS Regulation requires robust and automatic means to accurately determine, following an accident during which the aircraft is severely damaged, the location of the point of end of flight. Point CAT.GEN.MPA.210 is applicable to some categories of large aeroplanes, when operated for commercial air transport (CAT).

The objective of point CAT.GEN.MPA.210 is to have a high probability of timely and accurately locating the accident site after an accident during which the aircraft is severely damaged, irrespective of the accident location and survivability. The scope of point CAT.GEN.MPA.210 includes non-survivable accidents. However, this Section does not address unlawful interference.

Means compliant with point CAT.GEN.MPA.210 are expected to:

—      quickly inform the SAR authority concerned that an accident occurred or is about to occur and provide them with information that can easily be used for locating the accident site; and

—      help the safety investigation authority concerned locate the accident site and the aircraft wreckage so that they can collect evidence in a reasonable time frame.

Therefore, if a means compliant with point CAT.GEN.MPA.210 is installed onboard the aircraft, point CAT.IDE.A.280 does not require equipping the aircraft with an automatic ELT, and point CAT.IDE.A.285 does not require equipping the aircraft with a low-frequency ULD.

The approval of the transmission service that processes signals sent by an airborne system to comply with point CAT.GEN.MPA.210 is out of the scope of this Section.

This Section includes:

—      ‘non-specific’ acceptable means of compliance (AMC) and common guidance material (GM) (applicable to all solutions); and

—      ‘specific’ AMC and GM (applicable only to a particular type of solution).

For each certification specification (CS), there may be one or several non-specific AMC, and one or several specific AMC. When selecting one of the three types of solutions that are described below, all non-specific AMC and all AMC specific to the type of solution selected need to be met to demonstrate compliance with the related CS. When selecting a solution that is different from all these types of solutions or is a combination of several types of solutions, the means of compliance need to include all non-specific AMC and additional conditions to be agreed with EASA.

This Section includes three types of solutions:

—      Automatic deployable flight recorder (ADFR)

An ADFR is composed of a recorder in a deployable package, a deployment system, and sensors in the aircraft. The deployable package contains an ELT that facilitates locating it, and a structure having both an aerofoil function and a float function. The sensors detect the deformation of the aircraft structure caused by the accident and the water pressure due to immersion. These detections result in the automatic deployment of the deployable package as well as in the activation of the ELT. Thanks to the deployment characteristics, the deployable package lands clear of the main impact point. It floats on water if the accident site is in water. The ELT transmits 406-MHz signals that are detected by satellites of the international COSPAS-SARSAT programme. This enables locating the point of end of flight within a few minutes. The ELT also transmits a 121.5-MHz homing signal to support the on-site search and rescue (SAR) of potential survivors. The recording function of the ADFR is not necessary to comply with point CAT.GEN.MPA.210.

—      Distress tracking ELT (ELT(DT))

An ELT(DT) is a specific type of ELT that relies on an ‘automatic triggering function’. That function monitors aircraft parameters and automatically triggers the ELT when it detects conditions that are likely to result in an accident during which the aircraft is severely damaged. The flight crew can also manually activate the ELT(DT) in case of a distress situation. Once the ELT is activated, it transmits 406-MHz signals that are detected by satellites of the international COSPAS-SARSAT programme. This enables locating the point of end of flight within a few minutes. If the accident is survivable, a crash-survivable ELT (the ELT(DT) or an automatic ELT) transmits, after the impact, the 406-MHz signals to satellites of the international COSPAS-SARSAT programme and a 121.5-MHz homing signal. These signals enable accurately locating the point of end of flight and support the on-site search and rescue of potential survivors.

—      High-rate tracking (HRT)

HRT relies on an airborne system that frequently transmits signals that enable locating the aircraft in case of an accident. The frequency of the transmission and the accuracy of the transmitted position data are such that the point of end of flight can be located within a few minutes. Adequate position accuracy of the point of end of flight after a survivable accident is achieved either through high frequency of transmission, or transmission after reaching the point of end of flight, or both. A 121.5-MHz homing signal is also transmitted after a survivable accident to support the on-site search and rescue of potential survivors.

This Section’s requirements do not address remote activation or remote deactivation of airborne systems.

[Issue: CS-ACNS/3]

CS ACNS.E.LAD.010 Definitions

ED Decision 2021/008/R

This CS contains definitions of terms that are only applicable to this Section and may differ from definitions of terms in CS ACNS.A.GEN.005 ‘Definitions’:

—      ‘accident during which the aircraft is severely damaged’ is an accident during which the aircraft sustains damage or structural failure that:

—      adversely affects the structural strength, performance or flight characteristics of the aircraft; and

—      would normally require a major repair or replacement of the affected component,

except for an engine failure or damage to the engine, when the damage is limited to a single engine (including its cowlings or accessories), to propellers, wing tips, antennas, probes, vanes, tyres, brakes, wheels, fairings, panels, landing gear doors, windscreens, the aircraft skin (such as small dents or puncture holes), or for minor damage to main rotor blades, tail rotor blades, the landing gear, and minor damage resulting from hail or bird strike (including holes in the radome);

—      ‘activation of the system’ is the transition of the system from another state to the activated state;

—      ‘activation signals’ are signals transmitted by the system to enable determination of the location of the point of end of flight without sending mobile SAR facilities to the area of the transmitter;

—      ‘automatic activation of the system’ is activation of the system that is automatically triggered by airborne equipment;

—      ‘automatic triggering function’ is a function that is performed by airborne equipment, that monitors aircraft parameters, and that automatically activates the system when it detects conditions that are likely to result in an accident during which the aircraft is severely damaged;

—      ‘communication infrastructure’ is the network of sensors, repeaters, and stations that are used to detect activation signals and deactivation signals, to process into data the information contained in these signals, and further distribute this data to the intended recipients; this infrastructure typically includes satellites and ground stations;

—      ‘deactivation of the system’ is the transition of the system from the activated state to another state;

—      ‘deactivation signals’ are signals that are transmitted by the system to indicate its deactivation;

—      ‘distress situation’ is a situation wherein the aircraft and its occupants are threatened by grave and imminent danger or require immediate assistance;

—      ‘erroneous automatic activation’ is undesirable automatic activation that results from an equipment failure or from an error during the development of the equipment;

—      ‘functions of the system’ are the minimum set of functions performed by the system to comply with point CAT.GEN.MPA.210 of Annex IV (Part-CAT) to Regulation (EU) No 965/2012 (‘Air OPS Regulation’); they include: arming and disarming, detection of activation conditions, automatic activation and automatic deactivation, manual activation and manual deactivation, collection of the information to be transmitted, transmission of activation signals and transmission of deactivation signals, indication of activation to the flight crew, transmission of a homing signal, and means to determine the causes of undesirable automatic activation;

—      ‘homing signal’ is a signal that allows mobile SAR facilities in the vicinity of the transmitter to continuously proceed towards the transmitter;

—      ‘manual activation of the system’ is activation of the system that is manually triggered by a crew member;

—      ‘manual deactivation of the system’ is deactivation of the system that is manually triggered by a crew member;

—      ‘point of end of flight’ is, depending on the nature of the accident, the point where the aircraft crashed into land or water, or landed on land or water, or was destroyed;

—      ‘solution based on an ADFR’ is a solution using equipment that meets the requirements applicable to an automatic deployable flight recorder (ADFR), except those related to the recording and retrieval of data for accident investigation purposes;

—      ‘solution based on an ELT(DT)’ is a solution based on an automatic triggering function that is coupled with an emergency locator transmitter of a distress tracking type (ELT(DT));

—      ‘solution based on HRT’ is a solution based on an automatic triggering function that is coupled with airborne equipment other than an ELT and that frequently transmits the aircraft position and the information that an accident during which the aircraft is severely damaged is likely to occur;

—      ‘signals’ are the information that is transmitted by the system;

—      ‘survivable accident’ is an accident such that, if an automatic fixed emergency locator transmitter (ELT(AF)) were correctly installed on board the aircraft, the ELT(AF) would not be exposed to conditions exceeding the environmental test conditions applicable to an ELT(AF), specified in EUROCAE ED-62B (including Change 1), Chapter 4;

—      ‘system’ is the organised set of airborne applications and airborne equipment to comply with point CAT.GEN.MPA.210 of Annex IV (Part-CAT) to Regulation (EU) No 965/2012 (‘Air OPS Regulation’);

—      ‘the system is activated’ means that the system is transmitting activation signals;

—      ‘the system is armed’ means that all the functions of the system are operating or are ready to operate immediately (in particular, the detection of an accident condition and the signal transmission);

—      ‘the system is disarmed’ means that the system cannot be automatically activated but may be manually activated.

[Issue: CS-ACNS/3]

GM1 ACNS.E.LAD.010 Definitions

ED Decision 2021/008/R

COMMON GUIDANCE FOR ALL SOLUTIONS

(a) A survivable accident is usually understood as an accident where some aircraft occupants could survive. However, for the purpose of demonstrating the performance of the system in conditions representatives of a survivable accident, the definition of ‘survivable accident’ in this Section is based on the environmental conditions applicable to an ELT(AF), specified in EUROCAE ED-62B (including Change 1), Chapter 4.

(b) The following terms, as defined in EUROCAE ED-62B (including Change 1), are used for ELTs throughout this Section:

(1) ‘class’: determines a range of operating temperatures;

(2) ‘capability C (crash survivability)’: means meeting minimum crash-resistance specifications;

(3) ‘capability H1 (121.5-MHz homing signal)’: means transmitting a homing signal at a frequency of 121.5 MHz;

(4) ‘capability G (internal/integral GNSS receiver)’: means containing a GNSS receiver and transmitting GNSS coordinates through the 406-MHz signal;

(5) ‘capability T.001 (first generation)’: means meeting the requirements of COSPAS-SARSAT document C/S T.001 ‘Specification for Cospas-Sarsat 406MHz Distress Beacons’; and

(6) ‘capability T.018 (second generation)’: means meeting the requirements of COSPAS‑SARSAT document C/S T.018 ‘Specification for Second Generation Cospas-Sarsat 406MHz Distress Beacons’.

(c) Non-dedicated airborne data sources that are used for the detection of activation conditions are usually not considered part of the system, except for the source of position information that is transmitted through the activation signals.

(d) An automatic triggering function is intended to activate the system before an accident occurs and should not be confused with a crash sensor.

[Issue: CS-ACNS/3]

CS ACNS.E.LAD.020 System approval

ED Decision 2021/008/R

All equipment that the system is composed of is approved.

[Issue: CS-ACNS/3]

AMC1 ACNS.E.LAD.020 System approval

ED Decision 2021/008/R

ACCEPTABLE MEANS OF COMPLIANCE APPLICABLE TO ALL SOLUTIONS

All ELTs that are part of the system should be approved in accordance with European Technical Standard Order (ETSO)-C126c. The conditions for approval of equipment other than ELTs should be agreed with EASA.

[Issue: CS-ACNS/3]

AMC2 ACNS.E.LAD.020 System approval

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.020.

(b) The ADFR and its integrated ELT should meet the specifications of European Technical Standard Order (ETSO)-2C517, except that the recording of data to facilitate accident investigations is not necessary for compliance with CS ACNS.E.LAD.020.

(c) The ADFR should be installed in accordance with CS 25.1457 of the Certification Specifications for Large Aeroplanes (CS-25), except that the recording of data to facilitate accident investigations is not required for compliance with CS ACNS.E.LAD.020.

(d) the ELT that is integrated into the deployable package of the ADFR should be of class 0 unless, during normal aircraft operation, the ELT is exposed to temperature cycles for which class 1 is sufficient.

(e) The ELT that is integrated into the deployable package of the ADFR should have capabilities G (internal/integral GNSS receiver) and H1 (121.5-MHz homing signal) unless an ELT(AF) or (AP) with capabilities C (crash survivability), G, and H1 is installed.

[Issue: CS-ACNS/3]

AMC3 ACNS.E.LAD.020 System approval

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.020

(b) The ELT(DT) should have capability G (internal/integral GNSS receiver).

(c) The ELT(DT) should have capabilities C (crash survivability) and H1 (121.5-MHz homing signal) unless an ELT(AF) or (AP) with capabilities C and H1 is installed.

(d) The ELT(DT) should be installed in accordance with EUROCAE ED-62B (including Change 1), Chapter 6.

[Issue: CS-ACNS/3]