CS 23.2500 General requirements on systems and equipment function
ED Decision 2017/013/R
(a) Requirements CS 23.2500, CS 23.2505 and CS 23.2510 are general requirements applicable to systems and equipment installed in the aeroplane, and should not be used to supersede any other specific CS-23 requirement.
(b) Equipment and systems required to comply with type certification requirements, airspace requirements or operating rules, or whose improper functioning would lead to a hazard, must be designed and installed so that they perform their intended function throughout the operating and environmental limits for which the aeroplane is certified.
AMC1 23.2500 General requirements on systems and equipment function
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.1 Systems and Equipment Function Requirements
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3231/F3231M-21 Standard Specification for Electrical Systems for Aircraft with Combustion Engine Electrical Power Generation
F3235-17a Standard Specification for Aircraft Storage Batteries
F3232/F3232M-20 Standard Specification for Flight Controls in Small Aircraft
F3233/F3233M-21 Standard Specification for Flight and Navigation Instrumentation in Aircraft
F3229/F3229M-17 Standard Practice for Static Pressure System Tests in Small Aircraft
F3064/F3064M-21 Standard Specification for Aircraft Powerplant Control, Operation, and Indication
F3066/F3066M-18 Standard Specification for Aircraft Powerplant Installation Hazard Mitigation
F3117-20 Standard Specification for Crew Interface in Aircraft
F3120/F3120M-20 Standard Specification for Ice Protection for General Aviation Aircraft
F3408/F3408M-21 Standard Specification for Aircraft Emergency Parachute Recovery Systems
ASTM F44 published standards for showing compliance for electrical systems that are installed on aeroplanes with electric or hybrid-electric propulsion systems. EASA has not yet accepted F3316-19; however, EASA would take into consideration applications from applicants that use this standard as the basis for the development of their means of compliance subject to agreement with EASA.
EASA does not consider that F3235-17a alone provides a complete means of compliance for electrical storage batteries in small aircraft (e.g. paragraph 4.2.1). Therefore, additional and complementary means of compliance should be developed and agreed with EASA for the specific application.
AMC2 23.2500 General requirements on systems and equipment function
ED Decision 2019/020/R
CS-23 Amdt 4
23.1301 Function and installation
23.1303 Flight and navigation instruments
23.1305 Powerplant instruments
23.1309(a) Equipment, systems, and installations
23.1311 Electronic display instrument systems
23.1321 Arrangement and visibility
23.1323 Airspeed indicating system
23.1325 Static pressure system
23.1327 Magnetic direction indicator
23.1329 Automatic pilot system
23.1335 Flight director systems
23.1351(b), (e), (f), (g) Electrical Systems - General
23.1357 Circuit protective devices
23.1361 Master switch arrangement
23.1367 Switches
23.1381(c) Instrument lights
23.1416 Pneumatic de-icer boot system
23.729(d) Landing gear extension and retraction system
23.843(b) Pressurization tests
23.1141(b), (c), (d) Powerplant controls: general
23.1201 Fire extinguishing system materials
23.1203(e) Fire detector system
Remarks
23.1305 must be complemented. F3064-18 § 6.2.1.6 provides this AMC.
AMC3 23.2500 General requirements on systems and equipment function
ED Decision 2019/020/R
CS VLA Amdt 1
VLA.1301 Function and installation
VLA.1303 Flight and navigation instruments
VLA.1305 Powerplant instruments
VLA.1307 Miscellaneous equipment
VLA.1309 Equipment, systems, and installations
VLA.1321 Arrangement and visibility
VLA.1323 Airspeed indicating system
VLA.1325 Static pressure system
VLA.1327 Magnetic direction indicator
VLA.1351 Electrical Systems - General
VLA.1357 Circuit protective devices
VLA.1361 Master switch arrangement
VLA.1367 Switches
VLA.729 Landing gear extension and retraction system
VLA.1141 Powerplant controls and accessories: general
Remarks
VLA.1305 must be complemented. F3064-18 § 6.2.1.6 provides this AMC.
GM 23.2500(b) General requirements on systems and equipment function
ED Decision 2020/006/R
The improper functioning of equipment and systems may be caused by intentional unauthorised electronic interaction (IUEI). An applicant that wishes to certify an aeroplane with certification level 4 should, therefore, also consider cybersecurity threats as possible sources of ‘improper functioning’ of the equipment and systems. In showing compliance with CS 23.2500(b) for equipment and systems whose improper functioning could lead to an unacceptable threat condition, the applicant may consider AMC 20-42. This AMC provides acceptable means, guidance and methods to perform security risk assessment and mitigation for aircraft information systems.
CS 23.2505 General requirements on equipment installation
ED Decision 2017/013/R
(a) Each item of installed equipment is installed according to limitations specified for that equipment.
(b) On multi-engine aeroplanes, engine-driven accessories essential to safe operation must be distributed among multiple engines.
AMC1 23.2505 General requirements on equipment installation
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.2 Equipment Function and Installation Requirements
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3231/F3231M-21 Standard Specification for Electrical Systems for Aircraft with Combustion Engine Electrical Power Generation
F3235-17a Standard Specification for Aircraft Storage Batteries
F3232/F3232M-20 Standard Specification for Flight Controls in Small Aircraft
F3233/F3233M-21 Standard Specification for Flight and Navigation Instrumentation in Aircraft
F3408/F3408M-21 Standard Specification for Aircraft Emergency Parachute Recovery Systems
ASTM F44 published standards for showing compliance for electrical systems that are installed on aeroplanes with electric or hybrid-electric propulsion systems. EASA has not yet accepted F3316-19; however, EASA would take into consideration applications from applicants that use this standard as the basis for the development of their means of compliance subject to agreement with EASA.
EASA does not consider that F3235-17a alone provides a complete means of compliance for electrical storage batteries in small aircraft (e.g. paragraph 4.2.1). Therefore, additional and complementary means of compliance should be developed and agreed with EASA for the specific application.
AMC2 23.2505 General requirements on equipment installation
ED Decision 2017/025/R
CS-23 Amdt 4
23.1301 Function and installation
23.1437 Accessories for twin-engine aeroplanes
AMC3 23.2505 General requirements on equipment installation
ED Decision 2017/025/R
CS VLA Amdt 1
VLA.1301 Function and installation
CS 23.2510 Equipment, systems, and installations
ED Decision 2017/013/R
(a) The equipment and systems identified in CS 23.2500, considered separately and in relation to other systems, must be designed and installed such that:
(1) each catastrophic failure condition is extremely improbable; and
(2) each hazardous failure condition is extremely remote; and
(3) each major failure condition is remote.
(b) The operation of equipment and systems not covered by CS 23.2500 does not cause a hazard to the aeroplane or its occupants throughout the operating and environmental limits for which the aeroplane is certified.
AMC1 23.2510 Equipment, systems, and installations
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.3 Equipment, Systems, and Installation
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3230-20a Standard Practice for Safety Assessment of Systems and Equipment in Small Aircraft
F3233/F3233M-21 Standard Specification for Flight and Navigation Instrumentation in Aircraft
F3227/F3227M-21 Standard Specification for Environmental Systems in Aircraft
F3309/F3309M-21 Standard Practice for Simplified Safety Assessment of Systems and Equipment in Small Aircraft
F3408/F3408M-21 Standard Specification for Aircraft Emergency Parachute Recovery Systems
Remarks
At variance with F3230-20a, paragraph 4.2.4.1, the use of service history data is limited to the fleet of an aeroplane type/aeroplane types for which the applicant is the holder of one or more type certificates (TCs), the owner of the data, or, if accepted by EASA, has concluded with the owner of the data an agreement that permits its use by the applicant for that purpose.
At variance with the note under Table 1 of F3309/F3309M-21, that Table 1 provides the applicable criteria for classification of a failure condition based on the severity of the effects.
At variance with F3309/F3309M-21, paragraph 3.2.4, the term ‘on the order of’ means that, for various reasons, the component failure rate data is not precise enough to allow accurate estimates of the probabilities of failure conditions. This inability to establish accurate estimates of the probabilities of failure conditions results in some degree of uncertainty and the expression ‘on the order of’ is included in the descriptions of the quantitative probability terms that are provided to reflect this uncertainty. When calculating the estimated probability of each failure condition, that uncertainty should be accounted for in a way that does not compromise safety. In this context, ‘on the order of’ does not mean that for instance, the quantitative assessment of a major failure condition can be exceeded by a certain percentage to be ‘on the order of’ 1E-5. It means that there is uncertainty when determining the component failure rate, and that uncertainty should be accounted for in a way that does not compromise safety.
At variance with Example 2 in paragraph 4.5.3.3 of F3309/F3309M-21, the use of service history data is limited to the fleet of an aeroplane type/aeroplane types for which the applicant is the holder of the TC(s), the owner of the data, or, if accepted by EASA, has concluded with the owner of the data an agreement that permits its use by the applicant for that purpose.
AMC2 23.2510 Equipment, systems, and installations
ED Decision 2017/025/R
CS-23 Amdt 4
23.1309 Equipment, systems, and installations
23.1323 Airspeed indicating system
23.1325 Static pressure system
23.1329 Automatic pilot system
23.1331(b), (c) Instruments using a power source
23.1335 Flight director systems
23.1337(b), (c) Powerplant instruments installation
23.1357 Circuit protective devices
23.1431 Electronic equipment
23.1437 Accessories for twin-engine aeroplanes
23.672(c) Stability augmentation and automatic and power-operated systems
23.677(d) Trim systems
23.701 Flap interconnection
23.735(d) Brakes
23.775(g) Windshields and windows
23.831(d) Ventilation
23.841(b)(8), (c), (d)(2), (d)(3) Pressurised cabins
AMC3 23.2510 Equipment, systems, and installations
ED Decision 2017/025/R
CS VLA Amdt 1
VLA.1309 Equipment, systems, and installations
VLA.1323 Airspeed indicating system
VLA.1325 Static pressure system
VLA.1331 Instruments using a power supply
VLA.1337 Powerplant instruments
VLA.1357 Circuit protective devices
VLA.1431 Electronic equipment
VLA.677 Trim systems
VLA.701 Flap interconnection
VLA.735 Brakes
VLA.775 Windshields and windows
VLA.831 Ventilation
CS 23.2515 Electrical and electronic system lightning protection
ED Decision 2023/002/R
For an aeroplane where the exposure to lightning is likely:
(a) each electrical or electronic system that performs a function, the failure of which would prevent the continued safe flight and landing of the aeroplane, must be designed and installed such that:
(1) the function at the aeroplane level is not adversely affected during and after the time the aeroplane is exposed to lightning; and
(2) the system recovers normal operation of that function in a timely manner after the aeroplane is exposed to lightning unless the system’s recovery conflicts with other operational or functional requirements of the system;
(b) each electrical and electronic system that performs a function, the failure of which would reduce the capability of the aeroplane or the ability of the flight crew to respond to an adverse operating condition, must be designed and installed such that the system recovers normal operation of that function in a timely manner after the aeroplane is exposed to lightning.
AMC1 23.2515 Electrical and electronic system lightning protection
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.4 Electrical and Electronic System Lightning Protection
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
Remarks
F3367-21a Standard Practice for Simplified Methods for Addressing High Intensity Radiated Fields (HIRF) and Indirect Effects of Lightning on Aircraft, as referenced in F3061/F3061M-20, paragraph 17.3.4, is not an EASA accepted practice.
At variance with F3061-20:
(a) paragraph 17.3.1 should be replaced with the following:
each electrical or electronic system that performs a function, the failure of which would prevent the continued safe flight and landing of the aeroplane, must be designed and installed such that:
(1) the function at the aeroplane level is not adversely affected during and after the time the aeroplane is exposed to lightning; and
(2) the system recovers normal operation of that function in a timely manner after the aeroplane is exposed to lightning unless the system’s recovery conflicts with other operational or functional requirements of the system;
(b) paragraph 17.3.2 should be replaced with the following:
each electrical and electronic system that performs a function, the failure of which would reduce the capability of the aeroplane or the ability of the flight crew to respond to an adverse operating condition, must be designed and installed such that the system recovers normal operation of that function in a timely manner after the aeroplane is exposed to lightning; and
(c) paragraphs 17.3.3 and 17.3.4 should be removed.
AMC2 23.2515 Electrical and electronic system lightning protection
ED Decision 2017/025/R
CS-23 Amdt 4
23.1306 Electrical and electronic system lightning protection
CS 23.2520 High-intensity radiated fields (HIRF) protection
ED Decision 2017/013/R
(a) Each electrical and electronic system that perform a function, the failure of which would prevent the continued safe flight and landing of the aeroplane, must be designed and installed such that:
(1) the function at the aeroplane level is not adversely affected during and after the time the aeroplane is exposed to the HIRF environment; and
(2) the system recovers normal operation of that function in a timely manner after the aeroplane is exposed to the HIRF environment, unless the system’s recovery conflicts with other operational or functional requirements of the system.
(b) For aeroplanes approved for instrument flight rules (IFR) operations, each electrical and electronic system that performs a function, the failure of which would reduce the capability of the aeroplane or the ability of the flight crew to respond to an adverse operating condition, must be designed and installed such that the system recovers normal operation of that function in a timely manner after the aeroplane is exposed to the HIRF environment.
AMC1 23.2520 High-intensity radiated fields (HIRF) protection
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.5 High-Intensity Radiated Fields (HIRF) Protection
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3236-17 Standard Specification for High Intensity Radiated Field (HIRF) Protection in Small Aircraft
Remarks
F3367-21 Standard Practice for Simplified Methods for Addressing High Intensity Radiated Fields (HIRF) and Indirect Effects of Lightning on Aircraft, as referenced in F3061/F3061M-20, paragraph 18.1, is not an EASA accepted practice.
AMC2 23.2520 High-intensity radiated fields (HIRF) protection
ED Decision 2017/025/R
CS-23 Amdt 4
23.1308 High-Intensity Radiated Fields (HIRF) protection
CS 23.2525 System power generation, storage, and distribution
ED Decision 2017/013/R
The power generation, storage, and distribution for any system must be designed and installed to:
(a) supply the power required for operation of connected loads during all intended operating conditions;
(b) ensure no single failure or malfunction will prevent the system from supplying the essential loads required for continued safe flight and landing; and
(c) have enough capacity, if the primary source fails, to supply essential loads, including non-continuous essential loads for the time needed to complete the function, required for safe flight and landing.
AMC1 23.2525 System power generation, storage, and distribution
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.6 System Power Generation, Storage, and Distribution
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3231/F3231M-21 Standard Specification for Electrical Systems for Aircraft with Combustion Engine Electrical Power Generation
F2490-20 Standard Guide for Aircraft Electrical Load and Power Source Capacity Analysis
F3233/F3233M-21 Standard Specification for Flight and Navigation Instrumentation in Aircraft
F3117-20 Standard Specification for Crew Interface in Aircraft
F3120/F3120M-20 Standard Specification for Ice Protection for General Aviation Aircraft
Remarks
At variance with F3231-21:
(a) paragraph 4.4.2 should be replaced with the following:
4.4.2 A protective device for a circuit essential to flight safety shall not be a fuse and it may not be used to protect any other circuit.
(b) paragraph 4.4.5 should be replaced with the following:
4.4.5 If the ability to reset a circuit protective device is essential to safety in flight, a means shall be provided so that it can be readily reset in flight; refer to Specification F3117/F3117M.
ASTM F44 published standards for showing compliance for electrical systems that are installed on aeroplanes with electric or hybrid-electric propulsion systems. EASA has not yet accepted F3316-19; however, EASA would take into consideration applications from applicants that use this standard as the basis for the development of their means of compliance subject to agreement with EASA.
AMC2 23.2525 System power generation, storage, and distribution
ED Decision 2023/002/R
CS-23 Amdt 4
23.1303 Flight and navigation instruments
23.1331(b), (c) Instruments using a power source
23.1351(a), (b), (c) Electrical Systems – General
23.1353 Storage battery design and installation
23.1357 Circuit protective devices
Remarks
At variance with CS 23.1357(b) and (d), EASA does not accept a protective device for a circuit essential to flight safety in designs applications after the date of entry into force of the AMC & GM to CS-23 Issue 4; automatic fuses or circuit breakers should be used instead.
AMC3 23.2525 System power generation, storage, and distribution
ED Decision 2023/002/R
CS-VLA Amdt 1
VLA 1303 Flight and navigation instruments
VLA 1331 Instruments using a power supply
VLA 1351 Electrical Systems – General
VLA 1353 Storage battery design and installation
VLA 1357 Circuit protective devices
Remarks
At variance with CS-VLA 1357(b) and (d), EASA does not accept a protective device for a circuit essential to flight safety in designs applications after the date of entry into force of the AMC & GM to CS-23 Issue 4; automatic fuses or circuit breakers should be used instead.
CS 23.2530 External and cockpit lighting
ED Decision 2017/013/R
(a) The applicant must design and install all lights to minimise any adverse effects on the performance of flight crew duties.
(b) Any position and anti-collision lights, if required by operational rules, must have the intensities, flash rate, colours, fields of coverage, and other characteristics to provide sufficient time for another aircraft to avoid a collision.
(c) Any position lights, if required by operational rules, must include a red light on the left side of the aeroplane, a green light on the right side of the aeroplane, spaced laterally as far apart as practicable, and a white light facing aft, located on an aft portion of the aeroplane or on the wing tips.
(d) Taxi and landing lights, if required, must be designed and installed so they provide sufficient light for night operations.
(e) For seaplanes or amphibian aeroplanes, riding lights must provide a white light visible in clear atmospheric conditions.
AMC1 23.2530 External and cockpit lighting
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.7 External and Cockpit Lighting
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3233/F3233M-21 Standard Specification for Flight and Navigation Instrumentation in Aircraft
F3234/F3234M-17 Standard Specification for Exterior Lighting in Small Aircraft
F3117-20 Standard Specification for Crew Interface in Aircraft
F3120/F3120M-20 Standard Specification for Ice Protection for General Aviation Aircraft
AMC2 23.2530 External and cockpit lighting
ED Decision 2017/025/R
CS-23 Amdt 4
23.1381 Instrument lights
23.1383(a), (b), (c) Taxi and landing lights
23.1385(a), (b), (c) Position light system installation
23.1387 Position light system dihedral angles
23.1391 Minimum intensities in the horizontal plane of position lights
23.1393 Minimum intensities in any vertical plane of position lights
23.1395 Maximum intensities in overlapping beams of position lights
23.1397 Colour specifications
23.1399 Riding light
23.1401 Anti-collision light system
AMC3 23.2530 External and cockpit lighting
ED Decision 2017/025/R
CS VLA Amdt 1
VLA.1384 External lights
ED Decision 2017/013/R
Safety and survival equipment, required by the operating rules, must be reliable, readily accessible, easily identifiable, and clearly marked to identify its method of operation.
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.8 Safety Equipment
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3083/F3083M-20a Standard Specification for Emergency Conditions, Occupant Safety and Accommodations
F3117/F3117M-20 Standard Specification for Crew Interface in Aircraft
ED Decision 2017/025/R
CS-23 Amdt 4
23.1411 Safety Equipment-General
23.1415 Ditching equipment
ED Decision 2017/025/R
CS VLA Amdt 1
VLA.1411 Safety Equipment-General
CS 23.2540 Flight in icing conditions
ED Decision 2017/013/R
An applicant who requests certification for flight in icing conditions must show the following in the icing conditions for which certification is requested:
(a) the ice protection system provides for safe operation; and
(b) the aeroplane design must provide protection from stalling when the autopilot is operating.
AMC1 23.2540 Flight in icing conditions
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.9 Flight in Icing Conditions
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3233/F3233M-21 Standard Specification for Flight and Navigation Instrumentation in Aircraft
F3120/F3120M-20 Standard Specification for Ice Protection for General Aviation Aircraft
AMC2 23.2540 Flight in icing conditions
ED Decision 2023/002/R
CS-23 Amdt 4
23.1323 Airspeed indicating system
23.1325(b), (g) Static pressure system
23.775(f) Windshields and windows
Remarks
Following the cancellation of FAA AC-1419-2D, applicants should now use the icing conditions that are outlined in AMC1 23.2165.
CS 23.2545 Pressurised systems elements
ED Decision 2017/013/R
Pressurised systems must withstand appropriate proof and burst pressures.
AMC1 23.2545 Pressurised systems elements
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.10 Pressurized System Elements
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3229/F3229M-17 Standard Practice for Static Pressure System Tests in Small Aircraft
AMC2 23.2545 Pressurised systems elements
ED Decision 2017/025/R
CS-23 Amdt 4
23.1438 Pressurization and pneumatic systems
23.1435(a)(4), (b) Hydraulic Systems
23.1453 Protection of oxygen equipment from rupture
CS 23.2555 Installation of recorders (e.g. cockpit voice recorders and flight data recorders)
ED Decision 2017/013/R
If recording is required by the operating rules, the system:
(a) is installed so as to ensure accurate and intelligible recording and safeguarding of the required data, also in conditions encountered during crash, water immersion or fire;
(b) is powered by the most reliable power source and remains powered for as long as possible without jeopardising service to essential or emergency loads and emergency operation of the aeroplane;
(c) includes features to facilitate the localisation of a memory medium after an accident; and
(d) is installed so that it automatically records when the aeroplane is capable of moving under its own power.
AMC1 23.2555 Installation of recorders (e.g. cockpit voice recorders and flight data recorders)
ED Decision 2023/002/R
ASTM F44 F3264-21 Standard Specification for Normal Category Aeroplanes Certification
9.12 Installation of Cockpit recorders & 9.13 Installation of Flight Data Recorders
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3228-17 Standard Specification for Flight Data and Voice Recording in Small Aircraft
9.13 Installation of Flight Data Recorders:
F3061/F3061M-20 Standard Specification for Systems and Equipment in Small Aircraft
F3228-17 Standard Specification for Flight Data and Voice Recording in Small Aircraft
AMC2 23.2555 Installation of recorders (e.g. cockpit voice recorders and flight data recorders)
ED Decision 2017/025/R
CS-23 Amdt 4
23.1457 Cockpit voice recorders
23.1459 Flight recorders
AMC3 23.2555 Installation of recorders (e.g. cockpit voice recorders and flight data recorders)
ED Decision 2017/025/R
None