Appendix 1 to ETSO-C199 A1 – Traffic Awareness Beacon System (TABS) Requirements

A1 Introduction

A1.1 TABS Intent

A1.1.1 The intent of a TABS is to increase safety by encouraging the voluntary equipage of a low-cost, compact, easy-to-install device that will allow other aircraft equipped with collision avoidance systems and traffic advisory systems to track and display the TABS aircraft. TABSs are intended to be used on aircraft that are exempted from carrying a transponder or Automatic Dependent Surveillance — Broadcast (ADS-B) equipment, such as gliders, balloons and aircraft without electrical systems. TABS devices do not meet the transponder requirements defined in Commission Implementing Regulation (EU) No 1207/2011 of 22 November 2011 laying down requirements for the performance and the interoperability of surveillance for the single European sky. A TABS will allow these exempted aircraft to be visible to other aircraft equipped with:

1. a Traffic Advisory System (TAS) as defined in ETSO-C147();

2. a Traffic Alert and Collision Avoidance System I (TCAS I) as defined in ETSO‑C118();

3. a Traffic Alert and Collision Avoidance System II, (TCAS II), as defined in ETSO‑C119d;

4. ADS-B IN capability as defined in ETSO-C166b, and ETSO-C195b; or

5. ADS-B IN capability as defined in ETSO-C154c in airspace where UAT is used.

A1.1.2 A TABS is designed to:

6. reply to ATCRBS Mode C, and Mode S UF=0, 4, 5, 20 and 21 interrogations;

7. not reply to ATCRBS Mode A interrogations;

8. not reply to Mode S UF=11, and 16 interrogations;

9. incorporate ETSO-C88b, Automatic Pressure Altitude Reporting Code-Generating Equipment;

10. transmit ADS-B Messages: Aircraft Identification and Category, Airborne Position, Airborne Velocity, Emergency Priority Status Message, and Aircraft Operational Status;

11. optionally provide Surface Position Messages;

12. optionally use a commercial GNSS source meeting the requirements of this ETSO.

A1.1.3 A TABS can potentially act as a low-cost platform for other aviation applications. Although additional capabilities are beyond the scope of this ETSO, TABSs may include additional functions such as data loggers, search and rescue transmitter, or provide flight information services.

A1.2 Requirements

A1.2.1 TABS requirements are derived from existing Mode S transponder and 1090 MHz Extended Squitter ADS-B requirements. A designer who builds equipment to meet this ETSO may decide to incorporate the full transponder and ADS-B capability by using a device that meets ETSO-C112e and ETSO-C166b. If they elect to implement the full functionality, they must demonstrate that functionality against the unmodified test procedures in EUROCAE ED-102A, including Corrigendum‑1, dated January, 2012, that are required by ETSO-C112e and ETSO-C166b respectively. Designers who wish to take advantage of the reduced transponder requirements afforded to ETSO‑C199 Class A devices must meet the modified requirements outlined in paragraphs A1.2.3 Transponder Function Requirements, A1.2.4 Altitude Source Function Requirements, and A1.2.5 ADS-B OUT Function Requirements in this Appendix in their entirety. Designers wishing to take advantage of the Class B reduced GNSS requirements will need to meet the requirements outlined in paragraphs A1.2.6 GNSS Position Source Function Requirements.

A1.2.2 MOPS text is used here with the permission of the RTCA. Table 1 provides notes in italics and parenthesis explaining how to read the tables that modify the text in the source documents.

Table 1 — (Source document reference) (type of change)

A1.2.3 Transponder Function Requirements Derived From DO-181E (For Class A Devices)

A1.2.3.1 The transponder function must meet the Minimum Performance Standards (MPS) qualification and documentation requirements in RTCA, Inc. document RTCA document DO-181E, Section 2, for a Level 2, Class 2, transponder as modified below.

A1.2.3.1.1 Flight Crew Control Function Changes

A1.2.3.1.2 A cost factor in any device is the control and display functions to interface with the human operator. TABS display and control requirements are a subset of those required for transponders. Some user controls are allowed via an external device prior to flight (e.g., a personal electronic device (PED)). If the system is powered by batteries, display of the available battery life is recommended. Table 2 provides an overview of the flight crew control functions.

Table 2 — Summary of Control and Indication Requirements by Operation Mode

A1.2.3.1.3 RTCA document DO-181E, Section 2.1.7.a, Flight Crew Control Functions, is amended as shown in Table 3.

Table 3 — DO-181E Section 2.1.7.a amendment

A1.2.3.1.4 RTCA document DO-181E, Section 2.1.7.b, Flight Crew Control Functions, is amended as shown in Table 4.

Table 4 — DO-181E Section 2.1.7.b amendment

A1.2.3.1.5 RTCA document DO-181E, Section 2.1.7.c, Flight Crew Control Functions, is amended as shown in Table 5.

Table 5 — DO-181E Section 2.1.7.c amendment

A1.2.3.1.6 RTCA document DO-181E, Section 2.1.7.d, Flight Crew Control Functions, is amended as shown in Table 6.

Table 6 — DO-181E Section 2.1.7.d amendment

A1.2.3.2 Reply Rate Capability Changes

A1.2.3.2.1 This section reduces the minimum reply rate capability of the TABS consistently with the interrogation acceptance based on two assumptions. The following rationale describes how the modified reply rates were chosen.

A1.2.3.2.1.1 Assumption 1. The worst-case Mode C interrogation count in a 100-millisecond interval from 1 ATCRBS radar is approximately 14 interrogations. 4 ATCRBS radar overlapping beam dwells in 1 second is approximately 53 Mode C interrogations. The Mode C interrogation acceptance rate from 10 TCAS I units is approximately 15 interrogations per second. This represents a total demand on the TABS of 68 Mode C replies per second for this example.

A1.2.3.2.1.2 Assumption 2. The worst-case Mode S reply rate is primarily derived from the expected interrogation pattern of a set of 50 nearby TCAS II units all equipped with hybrid surveillance. The radar load from only roll-call interrogations would be small and would require networked sensors, otherwise the Mode S ground interrogation acceptance rate from radar systems would be 0 (zero).

A1.2.3.2.2 Based on assumptions 1 and 2, RTCA document DO-181E Section 2.2.3.4 Reply Rate Capability is changed as follows:

A1.2.3.2.2.1 RTCA document DO-181E, Section 2.2.3.4.1.a, ATCRBS Reply Rate Capability, is amended as shown in Table 7.

Table 7 — DO-181E Section 2.2.3.4.1.a amendment

A1.2.3.2.2.2 RTCA document DO-181E, Section 2.2.3.4.1.c, ATCRBS Reply Rate Capability, is amended as shown in Table 8.

Table 8 — DO-181E Section 2.2.3.4.1.c added

A1.2.3.2.2.3 RTCA document DO-181E, Section 2.2.3.4.2.a, Mode S Reply Rate Capability, is amended as shown in Table 9.

Table 9 — DO-181E Section 2.2.3.4.a amendment

A1.2.3.2.2.4 RTCA document DO-181E, Section 2.2.3.4.2.b, Mode S Reply Rate Capability, is amended as shown in Table 10.

Table 10 — DO-181E Section 2.2.3.4.2.b amendment

A1.2.3.3 Reply Rate Limiting Changes

A1.2.3.3.1 The modifications in this section address reply rate limiting for ATCRBS and Mode S reply rates consistently with the previous section.

A1.2.3.3.2 RTCA document DO-181E, Section 2.2.7.3.1, ATCRBS Reply Rate Limiting, is amended as shown in Table 11.

Table 11 — DO-181E Section 2.2.7.3.1 amendment

A1.2.3.4 RTCA document DO-181E, Section 2.2.13.1.2.c, Variable Direct Data, is amended as shown in Table 12.

Table 12 — DO-181E Section 2.2.13.1.2.c amendment

A1.2.3.5 RTCA document DO-181E, Section 2.2.13.1.2.d, Variable Direct Data, is amended as shown in Table 13.

Table 13 — DO-181E Section 2.2.13.1.2.d amendment

A1.2.3.6 RTCA document DO-181E, Section 2.2.13.1.2.e, Variable Direct Data, is amended as shown in Table 14.

Table 14 — DO-181E Section 2.2.13.1.2.e amendment

A1.2.3.7 Interrogation Acceptance Protocol Changes (All-Call reply capability)

A1.2.3.7.1 The transponder All-Call interrogation reply acceptance requirements are reduced to reply only to ATCRBS Mode C (P1-P3) interrogations. The purpose is to reduce the reply rate of TABS while maintaining TCAS and TAS interoperability. The requirements of this ETSO are identical to RTCA document DO-181E except for the changes shown below.

A1.2.3.7.2 RTCA document DO-181E, Section 2.2.18.2.2.b, Interrogation Acceptance Protocol (Figure 2-12), is amended as shown in Table 15.

Table 15 — DO-181E Section 2.2.18.2.2.b amendment

A1.2.3.7.3 RTCA document DO-181E, Section 2.2.18.2.2.c, Interrogation Acceptance Protocol (Figure 2-12), is amended as shown in Table 16.

Table 16 — DO-181E Section 2.2.18.2.c amendment

A1.2.3.8 RTCA document DO-181E, Section 2.2.18.2.2.g, Interrogation Acceptance Protocol, paragraph g, All-Call Lockout Conditions, is amended as shown in Table 17.

Table 17 — DO-181E Section 2.2.18.2.g amendment

A1.2.3.9 RTCA document DO-181E, Section 2.2.18.2.2.i, Interrogation Acceptance Protocol Stochastic All‑Calls, should not be implemented in Class A TABS.

A1.2.3.10 Two new sections are added here to explicitly define interrogation acceptance criteria for TABS.

A1.2.3.10.1 RTCA document DO-181E, Section 2.2.18.2.2.L, Interrogation Acceptance Protocol (Figure 2-12), is added as shown in Table 18.

Table 18 — DO-181E Section 2.2.18.2.2L addition

A1.2.3.10.2 RTCA document DO-181E, Section 2.2.18.2.2.m, Interrogation Acceptance Protocol (Figure 2-12), is added to as shown in Table 19. This change reduces the range at which addressed Mode S ground interrogations would be replied to. The intent is to reduce the reply rate of the TABS. Sensitivity to TCAS interrogations is not affected.

Table 19 — DO-181E Section 2.2.18.2.2.m addition

A1.2.3.11 RTCA document DO-181E, Section 2.2.18.2.3, Interrogation Reply Coordination, is amended as shown in Table 20.

Table 20 — DO-181E Section 2.2.18.2.3 amendment

A1.2.3.12 RTCA document DO-181E, Section 2.2.18.2.4, Lockout Protocol, should not be implemented in Class A TABS.

A1.2.3.13 RTCA document DO-181E, Section 2.2.18.2.5, Multisite Lockout Protocol, should not be implemented in Class A TABS.

A1.2.3.14 RTCA document DO-181E, Section 2.2.18.2.7, Flight Status and Vertical Status Protocols, is amended as shown in Table 21.

Table 21 — DO-181E Section 2.2.18.2.7 amendment

A1.2.3.15 RTCA document DO-181E, Section 2.2.18.2.9, All-Call Reply Protocol, should not be implemented in Class A TABS.

A1.2.3.16 RTCA document DO-181E, Section 2.2.19.1, Minimum Level 2 Transponder Requirements, is amended as shown in Table 22.

Table 22 — DO-181E Section 2.2.19.1 amendment

A1.2.3.17 RTCA document DO-181E, Section 2.2.19.1.3, Information Transfer, should not be implemented in Class A TABS.

A1.2.3.18 RTCA document DO-181E, Section 2.2.19.1.4, Interrogation-Reply Coordination, is amended per Table 23. Equipment using Minimum Level 2 Transponder Requirements, SHALL follow the text in DO-181E as written.

Table 23 — DO-181E Section 2.2.19.1.4 amendment

A1.2.3.19 The Lockout Protocol described in RTCA document DO-181E, Section 2.2.19.1.5, should not be implemented in Class A TABS.

A1.2.3.20 The UM Protocol described in RTCA document DO-181E, Section 2.2.19.1.9, should not be implemented in Class A TABS.

A1.2.3.21 The Comm-A Protocol described in RTCA document DO-181E, Section 2.2.19.1.10, should not be implemented in Class A TABS.

A1.2.3.22 The Broadcast Protocol described in RTCA document DO-181E, Section 2.2.19.1.11, should not be implemented in Class A TABS.

A1.2.3.23 The Air-Initiated Comm-B Protocol described in RTCA document DO-181E, Section 2.2.19.1.12.4, should not be implemented in Class A TABS.

A1.2.3.24 The Comm-B Broadcast Protocol described in RTCA document DO-181E, Section 2.2.19.1.12.5, should not be implemented in Class A TABS.

A1.2.3.25 The Updating the Data Link Capability Report described in RTCA document DO-181E, Section 2.2.19.1.12.6.3, should not be implemented in Class A TABS.

A1.2.3.26 The Change of Aircraft Identification described in RTCA document DO-181E, Section 2.2.19.1.13.e, should not be implemented in Class A TABS.

A1.2.3.27 Linked Comm-A Coding described in RTCA document DO-181E, Section 2.2.19.1.14, should not be implemented in Class A TABS.

A1.2.3.28 The Comm-U/V Protocol described in RTCA document DO-181E, Section 2.2.19.1.16, should not be implemented in Class A TABS.

A1.2.3.29 The Data Handling Interfaces described in RTCA document DO-181E, Section 2.2.19.1.17, should not be implemented in Class A TABS.

A1.2.3.30 The Multisite Message Protocol described in RTCA document DO-181E, Section 2.2.19.2, should not be implemented in Class A TABS.

A1.2.3.31 Surveillance Identifier (SI) requirements contained in RTCA document DO-181E, Section 2.2.24.2, should not be implemented in Class A TABS.

A1.2.3.32 The Elementary Surveillance (ELS) Compliant Transponder requirements in RTCA document DO-181E, Section 2.2.24, do not apply to TABS equipment. TABS SHALL not claim ELS compliance. Changes made to ELS registers do not need to be indicated via a Comm-B broadcast. If one or more of the ELS registers are supported, then Section 2.2.24 requirements SHALL apply except Sections 2.2.24 b 4, 2.2.24 c, 2.2.24.2, 2.2.24.3.2.5, and 2.2.24.3.4, which do not apply.

A1.2.3.33 The Enhanced Surveillance (EHS) Compliant Transponders requirements in RTCA/DO-181E, Section 2.2.25, do not apply to TABS. TABS equipment SHALL not claim EHS compliance. Changes made to EHS registers do not need to be indicated via a Comm-B broadcast. If one or more of the EHS registers are supported, then Section 2.2.25 requirements SHALL apply except Sections 2.2.25.1.2.4 and 2.2.25.2.3, which do not apply. Also, Section 2.2.25, paragraph 6 ‘Transponder capable of supporting EHS…’, must support ELS per A1.2.3.32 of this ETSO.

A1.2.4 Altitude Source Function Requirements (For Class A Devices)

A1.2.4.1 The altitude source function shall meet the performance requirements of ETSO-C88b, Automatic Pressure Altitude Reporting Code-Generating Equipment, dated 5 August 2016. It is recommended that the altitude source provide 25 ft or better resolution.

A1.2.5 ADS-B OUT Function Requirements Derived From EUROCAE ED-102A, including Corrigendum-1, (For Class A Devices)

A1.2.5.1 The ADS-B OUT function must be 1090 Extended Squitter (ES) OUT, to support TCAS surveillance. The 1090ES OUT function must meet the Minimum Performance Standards (MPS) qualification and documentation requirements in EUROCAE ED-102A, MOPS for 1090 MHz Extended Squitter Automatic Dependent Surveillance – Broadcast (ADS-B) and Traffic Information Services – Broadcast (TIS-B), dated December, 2009, including Corrigendum-1, Section 2, dated January, 2012, for a Class B0 ADS-B OUT transmitter with the following modifications.

A1.2.5.2 EUROCAE ED-102A, including Corrigendum-1, Section 2, dated January, 2012, Paragraph 2.2.2.1.c, Mode S Transponder Based Transmitters, is amended as shown in Table 24.

Table 24 — ED-102A Section 2.2.2.1.c amendment

A1.2.5.3 The output power SHALL be as specified in EUROCAE ED-102A, including Corrigendum-1, dated January, 2012, Section 2.2.2.2.10.1.a., for Class A0 and B0 equipment. The RF Peak Output power SHALL be at least 18.5 dBW (70 watts).

A1.2.5.4 Broadcast of the ADS-B Surface Position Messages defined in EUROCAE ED-102A including Corrigendum-1, Section 2.2.3.2.4, is optional.

A1.2.5.5 EUROCAE ED-102A including Corrigendum-1, Section 2.2.3.2.7.2, Aircraft Operational Status Messages, is amended as shown in Table 25.

Table 25 — Aircraft Operational Status Message

A1.2.5.6 When TABS is installed with a position source meeting the Class B requirements of this ETSO and transmitting a valid position, the transmitted NIC SHALL be set to 6 (0.5 NM), reference EUROCAE ED-102A including Corrigendum-1, dated January 2012, Section 2.2.8.1.16. The transmitted SIL SHALL be set to 1 (1×1E-3/ h), reference EUROCAE ED-102A including Corrigendum-1, dated January 2012, Section 2.2.5.1.40. When TABS is installed with a position source compliant with ETSO-C145, ETSO-C146 or ETSO-C196, NIC and SIL SHALL be set in accordance with EUROCAE ED-102A including Corrigendum-1, dated January, 2012. When the position is not valid, NIC and SIL SHALL be set to 0 (zero).

A1.2.5.7 The System Design Assurance (SDA), SHALL be set to 1, reference EUROCAE ED-102A, including Corrigendum-1, dated January 2012, Section 2.2.5.1.50. The probability of an undetected fault causing transmission of false or misleading information SHALL be less than or equal to 1E-3.

A1.2.5.8 Navigation Accuracy Category for Position, (NACp) SHALL be derived from the Horizontal Figure of Merit (HFOM) in accordance with EUROCAE ED-102A, including Corrigendum-1, dated January 2012, Section A.1.4.9.9; however, TABS Class B position sources may not provide HFOM directly. When HFOM is not available directly, HFOM SHALL be derived from Horizontal Dilution of Precision (HDOP) according to the following formula: HFOM = 2 * HDOP * User Equivalent Range Error (UERE), where the UERE is 6 metres. This UERE is based on typical single frequency (L1) receiver performance and an assumption of mid-latitude atmospheric propagation. Although the real-time UERE may fluctuate, this assumption is sufficient to support the TABS use case. (Ref. Global Positioning System Signals, Measurements and Performance, by Pratap Misra and Per Enge, copyright 2001).

A1.2.5.9 When a TABS is installed with a position source meeting the Class B requirements of this ETSO and transmitting a valid position, the transmitted Navigation Accuracy Category for Velocity, (NACv) SHALL be set to 1 (10 m/s), reference EUROCAE ED-102A including Corrigendum-1, dated January, 2012, Section 2.2.5.1.19. When position is not valid, NACv SHALL be set to 0 (zero).

A1.2.5.10 Geometric Vertical Accuracy (GVA) SHALL be derived from Vertical Figure of Merit, (VFOM) in accordance with EUROCAE ED-102A including Corrigendum-1, dated January, 2012, Section 2.2.3.2.7.2.8. Class B position sources may not provide VFOM directly. When VFOM is not available directly, VFOM SHALL be derived from Vertical Dilution of Precision (VDOP) according to the following formula: VFOM = 2 * VDOP * UERE, where the UERE is 6 metres.

A1.2.5.11 The Type Code 31, Operational Status Message, subfield ‘Airborne Capability Class Code’, SHALL be changed to indicate the device is a TABS.

A1.2.5.11.1 The Operational Status Message SHALL be modified to indicate that it meets the performance standards of this ETSO. ED-102A, including Corrigendum-1, dated January, 2012, paragraph 2.2.18.4.7 and Figure 2-40, is modified by this ETSO. Message bits 53-54, (ME Bits 21‑22), SHALL describe the capabilities of the TABS per Table 26. Set bit 54 to 1 (one) to indicate that either TABS Class A, Class B, or both classes of equipment are installed.

Table 26 — ED-102A Airborne Capability Class Message format

A1.2.6 GNSS Position Source Function Requirements (For Class B Devices)

A1.2.6.1 Manufacturers may use commercial off-the-shelf (COTS) GNSS position sources to meet the performance of this ETSO as long as the sensor meets the requirements in this section. The position source shall be capable of using satellite-based augmentation system (SBAS) corrections and health messages to exclude satellites from the position solution or to correct satellite range errors. In areas where the SBAS is available, the TABS shall use the SBAS corrections and health messages to exclude satellites from the position solution or to correct satellite range errors. In areas where the SBAS is not available or out of service, the TABS may continue to operate. The regional airspace authority will determine what operational impacts this may have on air‑to‑ground usage of TABS equipment. According to the FAA the GPS constellation experiences a significant ramp error approximately once a year. During these events, a chipset which uses the SBAS will, depending on the received SBAS messages, either correct or exclude the faulty satellite. Refer to RTCA document DO-229E, Minimum Operational Performance Standards for Global Positioning System/Satellite-Based Augmentation System Airborne Equipment, when interpreting SBAS-related requirements.

A1.2.6.2 The GNSS position source SHALL provide a GPS-only solution for use by the TABS ADS-B function. The FAA and EASA have not evaluated the performance of other GNSS systems for use in support of aviation-intended functions. This ETSO will be updated once sufficient analysis has been performed to show that other GNSS are appropriate for use by TABS equipment. Note, the GPS-only solution refers to the use of the GPS satellite constellation, it does not exclude augmentation of the GPS solution, such as provided by SBAS or GBAS systems.

A1.2.6.3 The GNSS horizontal position error SHALL not exceed 30 metres, 95th percentile, when the Horizontal Dilution of Precision (HDOP) is 2.5 or less. The GNSS position source SHALL either transmit a Horizontal Figure of Merit (95 %) (HFOM) or an HDOP metric.

Note: The 30-metre horizontal position fixing error requirement assumes a UERE of 6 metres, consistent with Section A1.2.5.8.

A1.2.6.4 Removed.

A1.2.6.5 The GNSS position source SHALL be capable of transmitting horizontal velocity measurements more accurate than 10 m/s, 95th percentile.

A1.2.6.6 The GNSS position source SHALL not transmit false or misleading data in the presence of broadband interference. There is no minimum interference rejection requirement for TABS equipment and loss of position in the presence of interference is acceptable behaviour.

A1.2.6.7 The GNSS position source SHALL not use SBAS corrections when the SBAS satellite is broadcasting message type 0.

A1.2.6.8 The GNSS position source SHALL exclude satellites with UDREI=15 reported in the SBAS fast corrections.

A1.2.6.9 The GNSS position source SHALL apply SBAS fast and long-term corrections when available.

A1.2.6.10 The GNSS position source SHALL be capable of transmitting geometric altitude, Height Above the Ellipsoid (HAE) measurements more accurate than 45 metres, 95th percentile, when the Vertical Dilution of Precision (VDOP) is 3.7 or less. The GNSS position source SHALL either transmit a Vertical Figure of Merit (95 %) (VFOM) or a Vertical Dilution of Precision (VDOP) metric.

Note: The 45-metre vertical position fixing error requirement assumes a UERE of 6 metres, consistent with Section A1.2.5.10.

A1.2.7 Antenna Function Requirements

A1.2.7.1 The requirements for transponder antennas are specified in ETSO-C112e. The requirements for GNSS antennas are specified in ETSO-C190 and ETSO-C144a. The antennas should be designed to meet the performance specified in the applicable ETSO. However, the TABS may benefit significantly in installation costs from implementations where the antennas are integrated in the TABS equipment. Small degradations in antenna performance may be acceptable as a trade-off for installation cost.

A1.2.7.2 Antennas may be installed internally on aircraft that are transparent to radio frequencies. An internal antenna may not be appropriate on aircraft with a metal hull. If an antenna is installed internally, testing will need to be conducted to ensure the TABS is not negatively impacted and installation guidance must accompany the unit to ensure the system is properly fitted to the aircraft.

A1.2.7.3 Because TABS may be installed on a radio frequency (RF) transparent fuselage near a pilot or passenger, or in a cockpit in close proximity to a pilot or passenger, consideration must be given to antenna placement to ensure it does not pose a hazard to humans or combustible materials. Manufacturers must provide installation guidance describing the minimum safe distance the antenna can be to the nearest human body or if applicable, combustible material. Appendix 3 to this ETSO provides a more in-depth discussion of this subject based on FCC and European documents.

A1.2.8 Form factor and power

A1.2.8.1 An ideal implementation of the TABS would be a single integrated unit with minimal connections to the airframe, such as; mechanical mounting, power, and static air source. Where the equipment might be shared between multiple airframes, the mechanical mounting could incorporate an airframe-specific configuration module (containing such items as the ICAO 24-bit aircraft address), and be designed such that no tools are required to remove or install the TABS.

A1.2.8.2 Low-power consumption design is important. Designs specifically intended for long-term battery operation are ideal. If the TABS is battery powered, it should be designed to provide system integrity commensurate with the failure condition category / classification stated in paragraph 3.2.1.

[Amdt. ETSO/13]

[Amdt. ETSO/16]