πo • π+ • n • p • π- • γ • n • p • µ • p • γ • n • n • p • p • n Atmospheric Neutrons Part of the Atmospheric/Environmental Hazards
FAA Issue Papers • Issue Papers have been applied to all engine programs over the past 8 years • Engine manufacturers have not objected and have been successful in their analysis • Papers are aimed at System Safety Assessment inclusion of this external threat
FAA Research Actions • FAA funded research on Mitigation Techniques and has a report to be used as guidance • FAA funded research at ORNL to scope a project to determine how one would spec a project to develop a new test facility • Goal was to determine the capabilities and rough cost of such a facility
Industry Actions • Aerospace Vehicle Systems Institute (AVSI) Project AFE72 Mitigating Radiation Effects created the documents that are the basis for the aerospace industry understanding of SEE • The series of documents, currently available from IEC, are the reference documents in the IP • FAA has participated in AFE72 for the past 16 years • AFE72 continues to develop additional documents • Thermal Neutrons, System Testing, have been published
Additional Industry Actions • Airbus - ABD 100 document • Boeing - D6 85570 SEE document. • Avionics supply chain is seeing the requirements.
Current Actions by AFE72 • AFE72 in support of S-18/WG63 has also developed AIR6219 that provides an analysis process available to be used with the ‘A’ revision to SAE ARP 4761 being prepared by S-18 and WG-63 • These groups have been working together for the past 6 years • The AIR is aimed at how to include SEE in a System Safety Assessment • The AIR is published
Collaboration with EASA • The FAA and EASA have been collaborating on the development on Atmospheric Neutron / Single Event Effects guidance for some 7 years now. • EASA used our draft IP material as a starting point for their draft CM • CM was developed in conjunction with the development of the AIR document • The CM has been published (January 8, 2018) • The CM has been applied to projects already.
Next for the FAA • Now that the SAE AIR document is published, recognize the process recommended in the AIR as an element of the Aircraft Safety Assessment • This will address the impact of this threat • End goal of this analysis is to ensure that E/E Systems incorporate sufficient mitigation in new designs • These actions would be in harmony with the EASA CM on atmospheric neutrons • Work with the DoE on the expansion of capabilities at Oak Ridge National Labs to further the understanding the risks to semiconductors in Aviation.
Conclusion Cosmic particles colliding with our atmosphere generate high energy neutrons Neutron collisions with IC materials can yield spurious current/voltage pulses resulting in a variety of SEE Due to technology trends - components and systems are becoming more sensitive to radiation resulting in SEEs SEE should be considered as a formal part of airborne system development to ensure all safety requirements are addressed Can’t design out problematic parts or use defensive design techniques if the problem isn’t understood and quantified Every avionics product shipped today needs to take into account radiation effects