Atmospheric radiation is a generic term which refers to all types of ionizing radiation, including neutrons,
penetrating or generated within the earth’s atmosphere. The main contributors to atmospheric radiation are
solar and galactic radiation. Solar radiation is emitted from the sun and galactic radiation originates from
outside our solar system. Both types of radiation can be affected (distorted or bent) by the earth’s magnetic
field.
Note: Throughout this Certification Memorandum, any reference to ‘aircraft systems’ also includes electronic
controls of Engines, APUs and Propeller Systems.
The applicant should demonstrate that aircraft systems, whose failure could contribute to a failure condition
classified as hazardous or catastrophic, are adequately mitigated against SEE. Such mitigation can be
achieved through architectural system considerations, equipment design and/or electronic device selection.
This Certification Memorandum provides complementary information and guidance for compliance
demonstration with current standards when considering the effects of SEE on systems and equipment and is
applicable to aircraft, engines, propellers and auxiliary power units certified in accordance with, but not
limited to, CS-23, CS-25, CS-27, CS-29, CS-E, CS-P and CS-APU (and their associated AMCs).
EASA has also issued a Safety Information Bulletin (SIB) No. 2012-10 Single Event Effects (SEE) on Aircraft
Systems caused by Cosmic Rays which informs aircraft operators, aircraft manufacturers, avionic system
designers, electronic equipment and electronic device manufacturers of the fault conditions that could be
caused by SEE.
Appendix B provides background information regarding the effects of atmospheric radiation on aircraft
systems.

The purpose of this Certification Memorandum is to provide specific guidance material on certification
aspects associated with the use of electronic hardware in airborne systems (referred to as airborne electronic
hardware). Airborne electronic hardware includes line replaceable units, circuit board assemblies, application
specific integrated circuits, programmable logic devices, microprocessors, microcontrollers, integrated
circuits, etc.

Note:
Editorial change in section 6 to reflect that the guidance material provided in section 6 is repealed and superseded byEASA CM-AS-004 Issue 01 Revision 00 on Single Event Effects (SEE) Caused by Atmospheric Radiation, dated 08/01/2018

CS-23 (Normal Category Aeroplanes) has been reorganised by its Amendment 5 into objective specifications. This
Decision introduces the first issue of the acceptable means of compliance (AMC) and guidance material (GM) to the new,
reorganised CS-23.
This AMC complements the CS-23 Amendment 5 objective specifications. An AMC is expected to require regular
amendments to take specific safety issues into consideration and introduce new technologies and AMC methods, so this
AMC to CS-23 is managed as a separate document.
This AMC was established from the existing technical details of the original CS-23 Amendment 4 and CS-VLA (Very Light
Aircraft) Amendment 1. In addition to that, a new set of consensus standards from ASTM International is accepted as a
means of compliance (with deviations, where necessary, as specified in the decision). These consensus standards were
created in close cooperation between industry stakeholders and the aviation authorities. The basis for this first set of
accepted consensus standards is the existing CS-23, CS-VLA and the Federal Aviation Administration (FAA) Part-23.