IEC PAS 62396-6:2014

IEC PAS 62396-6 ®
Edition 1.0 2014-12
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
colour
inside
Process management for avionics – Atmospheric radiation effects –
Part 6: Extreme space weather and potential impact on the avionics environment
and electronics
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IEC PAS 62396-6 ®
Edition 1.0 2014-12
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
colour
inside
Process management for avionics – Atmospheric radiation effects –

Part 6: Extreme space weather and potential impact on the avionics environment

and electronics
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XB
ICS 03.100.50; 31.020; 49.060 ISBN 978-2-8322-1943-0

– 2 – IEC PAS 62396-6:2014 © IEC 2014

CONTENTS
FOREWORD . 3

1 Scope . 5

2 Normative references . 5

3 Terms, definitions and abbreviations . 5

3.1 Terms and definitions . 5

3.2 Abbreviations and acronyms . 5

4 Technical recommendations . 6
4.1 General . 6
4.2 ESW environment . 6
4.2.1 Mechanisms responsible for ESW . 6
4.2.2 Changes in avionics environment due to ESW . 6
4.3 Impact of ESW on aircraft passengers and crew . 6
4.3.1 Impact on passengers and crew. 6
4.3.2 In flight radiation environment monitoring . 6
4.4 Impact of ESW on aircraft electronic systems. 7
4.4.1 Effect on electronics, equipment and systems. 7
4.4.2 ESW simulation testing of electronics equipment and systems and
analysis methods . 7
4.5 Considerations of ESW design margins. 7
Annex A (informative) Extreme Space Weather: impacts on engineered systems and
infrastructure from the Royal Academy of Engineering . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
PROCESS MANAGEMENT FOR AVIONICS –

ATMOSPHERIC RADIATION EFFECTS –

Part 6: Extreme space weather and potential impact

on the avionics environment and electronics

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

A PAS is a technical specification not fulfilling the requirements for a standard, but made
available to the public.
The document “Extreme Space Weather: impacts on engineered systems and infrastructure”
from the Royal Academy of Engineering (United Kingdom, London) has served as a basis for
the development of this publicity available specification.
The permission from the Royal Academy of Engineering (United Kingdom, London) to include
the report within this PAS is gratefully acknowledged by the IEC.
IEC PAS 62396-6 has been processed by IEC technical committee 107: Process management
for avionics.
– 4 – IEC PAS 62396-6:2014 © IEC 2014

The text of this PAS is based on the This PAS was approved for

following document: publication by the P-members of the

committee concerned as indicated in
the following document
Draft PAS Report on voting
107/244/PAS 107/250/RVD
Following publication of this PAS, the technical committee or subcommittee concerned may

transform it into an International Standard.

This PAS shall remain valid for an initial maximum period of 3 years starting from the

publication date. The validity may be extended for a single period up to a maximum of
3 years, at the end of which it shall be published as another type of normative document, or
shall be withdrawn.
A bilingual version of this publication may be issued at a later date.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
PROCESS MANAGEMENT FOR AVIONICS –

ATMOSPHERIC RADIATION EFFECTS –

Part 6: Extreme space weather and potential impact

on the avionics environment and electronics

1 Scope
This PAS details the mechanisms and conditions that produce “extreme space weather”
(ESW) and the changes within the avionics environment under such conditions. Consideration
is given to the impact and risks of ESW on passengers and crew travelling on aircraft in flight
and the option for in flight monitoring of the environment. Avionics electronics and systems
operating during flight can be affected under such conditions and these are reviewed. By
testing of complete equipment for extreme space weather tolerance, the degree of robustness
to ESW can be assessed. In the PAS, flight related infrastructure (not the aircraft itself) that
can be affected or disabled by an extreme space weather event is identified; such
infrastructure can be in the local “space” environment or on the ground.
This PAS is identical to the “Extreme Space Weather: impacts on engineered systems and
infrastructure” document from the Royal Academy of Engineering (United Kingdom, London)
which is included in Annex A.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this PAS and are
indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 62396-1:2012, Process management for avionics – Atmospheric radiation effects – Part
1: Accommodation of atmospheric radiation effects via single event effects within avionics
electronic equipment
3 Terms, definitions and abbreviations
For the purposes of this PAS, the following terms, definitions and abbreviations apply.

3.1 Terms and definitions
For the purposes of this PAS the terms and definitions given in IEC 62396-1:2012 apply.
3.2 Abbreviations and acronyms
For the purposes of this PAS the abbreviations and acronyms given in IEC 62396-1:2012 and
in Clause 15 of Annex A, as well as the following, apply.
CAA Civil Aviation Authority
CME Coronal mass ejections
EASA European Aviation Safety Agency
EMC Electromagnetic compatibility
ESD Electrostatic discharge
– 6 – IEC PAS 62396-6:2014 © IEC 2014

ESW Extreme space weather
FAA Federal Aviation Administration

GEO Geostationary orbit
GMD Geomagnetic disturbance
GNSS Global navigation satellite systems

GPS Global positioning system
HF High frequency
ICAO International Civil Aviation Organisation

ICRP International Commission on Radiological Protection
IEEE Institution of Electrical and Electronic Engineers
LEO Low earth orbit
MEO Medium earth orbit
MTTR Mean time to repair
NOAA National Oceanic and Atmospheric Administration
NRA National risk assessment
SAE Society of Automotive Engineers
SEIEG Space Environment Impact Expert Group
UHF Ultra high frequency
VHF Very high frequency
4 Technical recommendations
4.1 General
Annex A describes the effects of the extreme space weather (ESW) improving the
understanding, evaluates the impacts and provides recommendations on suitable mitigation
strategies.
4.2 ESW environment
4.2.1 Mechanisms responsible for ESW
An understanding of how an ESW event occurs, its impact and duration is given in Clauses 3
and 4 of Annex A.
4.2.2 Changes in avionics environment due to ESW
Consideration is given to the radiation environment at aircraft altitudes and the recommended
potential radiation levels.
4.3 Impact of ESW on aircraft passengers and crew
4.3.1 Impact on passengers and crew
During an ESW event, the radiation levels during a flight at altitudes and latitudes at risk may
be above those normally considered acceptable for the general public; a clear understanding
of the risks and mitigations will enable the industry to manage these events effectively. This is
discussed in more detail in Clause 8 of Annex A.
4.3.2 In flight radiation environment monitoring
In flight radiation monitoring is recommended because it has a number of benefits providing:

a) Reliable method for determining the onset of ESW.

b) Ability to disseminate the onset information before there is major infrastructure impact and

provides warning.
c) Clear measurement of the radiation exposure of passengers and crew.

d) Identification of the radiation levels at which there is impact or weaknesses in the

electronic flight systems.
4.4 Impact of ESW on aircraft electronic systems

4.4.1 Effect on electronics, equipment and systems

The effects of atmospheric radiation on avionics electronics have been understood for a
number of years and in 2006, IEC TS 62396-1 was published by the IEC technical committee
107 to provide guidance to the avionics industry. When this technical specification was issued
it documented that a very large space weather event occurred in February 1956 and
enhancements of 300 times on the radiation flux were experienced in certain locations at flight
altitudes. Clause 9 of Annex A expands on the effects and mitigations for avionics electronics.
NOTE The Technical Specification IEC TS 62396-1:2006 has been cancelled and replaced by a newer edition
IEC 62396-1:2012 published in the form of an International Standard.
4.4.2 ESW simulation testing of electronics equipment and systems and analysis
methods
During ESW events which may result in more than a 2-decade increase in radiation flux, the
flight critical equipment will be expected to continue safely in operation.
One way to validate the equipment capability in ESW is to perform complete equipment
system testing in a radiation simulator at enhanced flux levels. There are a small number of
facilities world wide that can be used to test complete avionics systems and determine their
robustness to this type of event. On the other hand, there are qualitative and quantitative
methods for demonstrating that the electronic component, the electronic equipment and the
system exhibit enough design/architecture margins to mitigate the radiation effects taking into
account probabilities of increased radiation effects due to ESW in the safety analysis.
4.5 Considerations of ESW design margins
As more information becomes available from past and future large solar events, it should be
possible to recommend an acceptable margin for radiation tolerance of such enhancements in
atmospheric radiation.
– 8 – IEC PAS 62396-6:2014 © IEC 2014

Annex A
(informative)
Extreme Space Weather: impacts on engineered systems and

infrastructure from the Royal Academy of Engineering

This Annex describes the effects of the extreme space weather (ESW) improving the

understanding, evaluates the impacts and provides recommendations on suitable mitigation

strategies.
Contents
Forewo rd 3 8 Ionising radiation impacts on
aircraft passengers and crew 38

1 Executive summary 4 8.1 Introduction 38

8.2 Consequences of an extreme event 39

2 Introduction 8 8.3 Mitigation 40

2.1 Background 8 8.4 Passenger and crew safety –

2.2 Scope 8 summary and recommendations 41

3 Space weather 9 9 Ionising radiation impacts on avionics and
3.1 Introduction 9 ground systems 42
3.2 Causes of space weather 9 9.1 Introduction 42
3.3 The geomagnetic environment 11 9.2 Engineering consequences on avionics of
3.4 The satellite environment 12 an extreme event 42
3.5 Atmospheric radiation environment 13 9.3 Engineering consequences of an
3.6 Ionospheric environment 13  extreme event on ground systems 42
3.7 Space weather monitoring and forecasting 13 9.4 Mitigation 43
3.8 Space weather forecasting -  9.5 Avionics and ground systems –
summary and recommendations 15 summary and recommendations 44
4 Solar superstorms 16 10 Impacts on GPS, Galileo and other GNSS positioning,
4.1 Outline description 16 navigation and timing (PNT) systems 45
4.2 The history of large solar storms and their impact 17 10.1 Introduction 45
4.3 Quantifying the geophysical impact 18 10.2 GNSS for navigation 45
4.4 The environmental chronology of a superstorm 18 10.3 GNSS for time and timing 46
4.5 Probability of a superstorm 19 10.4 GNSS - summary and recommendations 47
4.6 Solar Superstorm environment –
summary and recommendations 20 11 Impacts on radio communication systems 48
11.1 Introduction 48
5 Impacts on the electrical power grid 22 11.2 Terrestrial mobile communication networks 48
5.1 Introduction 22 11.3 HF communications and international broadcasting 50
5.2 Consequences of an extreme event on the UK grid 23 11.4 Mobile satellite communications 51
5.3 Mitigation 24 11.5 Satellite broadcasting 51
5.4 National electricity grid –  11.6 Terrestrial broadcasting 51
summary and recommendations 27 11.7 Communications – summary and recommendations 52
 2WKHUJHRPDJQHWLFDOO\LQGXFHGFXUUHQWHĆHFWV  12 Conclusion 53
6.1 Pipelines and railway networks 29
6.2 Trans-oceanic communications cables 29 13 Bibliography 55

6.3 Recommendations 29
14 Glossary 61
7 Radiation impacts on satellites 30
7.1 Introduction 30 15 Abbreviations and acronyms 62
  (OHFWURQHĆHFWV 
  6RODUHQHUJHWLFSDUWLFOHHĆHFWV  Appendix: Authors 65
7.4 Satellite failures and outages 31
7.5 Engineering consequences of an extreme
event on satellites 32
7.6 Mitigation 35
7.7 Satellites – summary and recommendations 36
2 Royal Academy of Engineering

– 10 – IEC PAS 62396-6:2014 © IEC 2014
FoForreewwoorrdd
Foreword
An eAn extrxtreme spaceme space we weaeather ether evvenent, or solar superstt, or solar superstorm, is one oorm, is one of f
a number oa number of pof pottenentially high impact, but lotially high impact, but low prw probability naobability naturtural al

hazarhazards. In rds. In response tesponse to a gro a groowing awing awwarareness in goeness in govvernmenernment, t,

eextrxtreme spaceme space we weaeather nother now fw feaeaturtures as an elemenes as an element ot of the UK f the UK

NaNational Risk Assessmentional Risk Assessment.t.

,QLGHQ,QLGHQWLI\LQJWKLVKD]DUWLI\LQJWKLVKD]DUGWKH8.JRGWKH8.JRYYHUQPHQHUQPHQWEHQHWEHQHooWWWWHGIUHGIURPWKRPWKHH

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\
VVZZRUOGFODVVVFLHQRUOGFODVVVFLHQWLoFHWLoFH[SHUWLVHDQGIU[SHUWLVHDQGIURPDQXPEHURRPDQXPEHURII
earlier studies cearlier studies conductonducted in the US. Hoed in the US. Howweevverer, the c, the conseonsequenquential tial
impact on the UK’impact on the UK’s ens engineering ingineering infrfrastructurastructure - which includes e - which includes
the electricity grid, sathe electricity grid, sattellitellite te technology and air passenger safechnology and air passenger safeetty – y –
has nohas not prt preeviouslviously been critically assessed. This ry been critically assessed. This report addreport addresses esses
WKDWKDWWRPLVVLRQERPLVVLRQE\EULQJLQJW\EULQJLQJWRRJHJHWKHUDQXPEHURWKHUDQXPEHURIIVFLHQVFLHQWLoFDQGWLoFDQG
engineering domain eengineering domain experts txperts to ideno identitify and analyse those impacts. fy and analyse those impacts.
I belieI believve thae that this studyt this study, with its str, with its strong engineering fong engineering focus, is the ocus, is the
most emost extxtensivensive oe of its type tf its type to dao datte. e.
It is mIt is my hope thay hope that bt by acting on the ry acting on the rececommendaommendations in this rtions in this report, eport,
stakstakeholders will preholders will progrogreessivssively mitigaely mitigatte the impact oe the impact of the inef the inevitable vitable
solar superstsolar superstorm. orm.
PrProoffessor Pessor Paul Cannon FREnaul Cannon FREngg
Chair oChair of the study wf the study working grorking grooupup

ExtrExtreme spaceme space we weaeather:ther: impacts on en impacts on engineergineered sed systystems and inems and infrfrastructurastructuree 33

1. Executive summary
Rarely oc curring solar superstorms generate X-rays and solar space situational awareness, an ability to undertake post-event
radio bursts, accelerate solar particles to relativistic velocities and analysis, and the infrastructure to improve our understanding of

cause major perturbations to the solar wind. These environmental this environment.

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satellites, avionics, air passengers, signals from satellite navigation 7KHUHSRUWH[SORUHVDQXPEHURIWHFKQRORJLHVDQGZHoQGWKDW

systems, mobile telephones and more. They have consequently WKH8.LVLQGHHGYXOQHUDEOHWRDVRODUVXSHUVWRUPEXWZHDOVRoQG

EHHQLGHQWLoHGDVDULVNWRWKHZRUOGHFRQRP\DQGVRFLHW\7KH that a number of industries have already mitigated the impact of

purpose of this report is to assess their impact on a variety of such events. In a ’perfect storm’ a number of technologies will be
engineered systems and to identify ways to prepare for these VLPXOWDQHRXVO\DĆHFWHGZKLFKZLOOVXEVWDQWLDOO\H[DFHUEDWHWKH
low-probability but randomly occurring events. The report has an risk. Mitigating and maintaining an awareness of the individual and
emphasis on the UK, but many of the conclusions also apply to linked risks over the long term is a challenge for government, for
other countries. asset owners and for managers.
Explosive eruptions of energy from the Sun that cause minor Space weather: impacts on engineered systems – a summary is a
solar storms on Earth are relatively common events. In contrast, shortened version of this report suitable for policy makers and the
extremely large events (superstorms) occur very occasionally – media – see www.raeng.org.uk/spaceweathersummary.
perhaps once every century or two. Most superstorms miss the
Earth, travelling harmlessly into space. Of those that do travel
towards the Earth, only half interact with the Earth’s environment
Key points:
and cause damage.
Solar superstorm environment
Since the start of the space age, there has been no true solar The recurrence statistics of an event with similar magnitude and
superstorm and consequently our understanding is limited. impact to a Carrington event are poor, but improving. Various
There have, however, been a number of near misses and these studies indicate that a recurrence period of 1-in-100 to 200 years is
have caused major technological damage, for example the 1989 reasonable and this report makes assessments of the engineering
collapse of part of the Canadian electricity grid. A superstorm which impact based on an event of this magnitude and return time. If
occurred in 1859, now referred to as the ‘Carrington event’ is the further studies provide demonstrable proof that larger events do
largest for which we have measurements; and even in this case the occur – perhaps on longer timescales - then a radical reassessment
measurements are limited to perturbations of the geomagnetic RIWKHHQJLQHHULQJLPSDFWZLOOEHQHHGHG7KHKHDGOLQHoJXUHRI
oHOG$QHYHQWLQLVWKHKLJKHVWUHFRUGHGIRUDWPRVSKHULF 100 years should not be a reason to ignore such risks.
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highest recorded radiation events measured on spacecraft. Electricity grid
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How often superstorms occur and whether the above are on the national electricity grid. Modelling indicates around six super
representative of the long term risk is not known and is the subject grid transformers in England and Wales and a further seven grid
of important current research. The general consensus is that a transformers in Scotland could be damaged through geomagnetic
solar superstorm is inevitable, a matter not of ‘if’ but ‘when?’. One disturbances and taken out of service. The time to repair would be
contemporary view is that a Carrington-level event will occur within between weeks and months. In addition, current estimates indicate

DSHULRGRI\HDUVZLWKDFRQoGHQFHRIaDQGZLWKLQD a potential for some local electricity interruptions of a few hours.
SHULRGRI\HDUVZLWKDFRQoGHQFHRIaEXWWKHVHoJXUHV Because most nodes have more than one transformer available,
should be interpreted with considerable care. not all these failures would lead to a disconnection event. However,
National Grid’s analysis is that around two nodes in Great Britain
Mitigation of solar superstorms necessitates a number of could experience disconnection.
WHFKQRORJ\VSHFLoFDSSURDFKHVZKLFKERLOGRZQWRHQJLQHHULQJ
out as much risk as is reasonably possible, and then adopting Satellites
operational strategies to deal with the residual risk. In order to Some satellites may be exposed to environments in excess of
achieve the latter, space and terrestrial sensors are required to W\SLFDOVSHFLoFDWLRQOHYHOVVRLQFUHDVLQJPLFURHOHFWURQLFXSVHW
monitor the storm progress from its early stages as enhanced rates and creating electrostatic charging hazards. Because of the
activity on the Sun through to its impact on Earth. Forecasting multiplicity of satellite designs in use today there is considerable
a solar storm is a challenge, and contemporary techniques are XQFHUWDLQW\LQWKHRYHUDOOEHKDYLRXURIWKHpHHWEXWH[SHULHQFH
XQOLNHO\WRGHOLYHUDFWLRQDEOHDGYLFHEXWWKHUHDUHJURZLQJHĆRUWV from more modest storms indicates that a degree of disruption to
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metrics. Irrespective of forecasting ability, space and terrestrial nature of spacecraft designs and their diversity is expected to limit
sensors of the Sun and the near space environment provide critical the scale of the problem. Our best engineering judgement, based
4 Royal Academy of Engineering

– 12 – IEC PAS 62396-6:2014 © IEC 2014
11. Ex. Executivecutive summarye summary

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eevvenent, but it is unlikt, but it is unlikely thaely that these outages will be sprt these outages will be spread eead evvenly enly rreduction in GNSS serviceduction in GNSS services wes would be likould be likely tely to cause opero cause operaational tional

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wwould ineould inevitably prvitably proovve more more vulnere vulnerable than oable than others. In addition, thers. In addition, nanavigavigation stion systystem is mostlem is mostly backy backed up bed up by ty terrerrestrial naestrial navigavigation aids; tion aids;

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but with higher risk therbut with higher risk thereafteafteer frr from incidencom incidence oe of further (morf further (more e This study has cThis study has concluded thaoncluded that the UK’t the UK’s cs commerommercial ccial cellular ellular
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sasattellitellite oe owners and operwners and operaattors will need tors will need to caro careefully efully evvaluaaluatte the e the HHĆĆHFWVRHFWVRIIDVRODUVXSHUVWDVRODUVXSHUVWRUPWKDQWKRVHGHSORRUPWKDQWKRVHGHSOR\\HGLQDQXPEHUHGLQDQXPEHU
need fneed for ror replaceplacemenement sat sattellitellites tes to be launched earlier than planned o be launched earlier than planned oof of other cther counountries (including the US) sinctries (including the US) since they are they are noe not rt relianeliant t
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PPassenassengers and crgers and creew airborne aw airborne at the time ot the time of an ef an extrxtreme eeme evvenent t mitigamitigattion strion strateategies, which alrgies, which already appear teady appear to be in placo be in place, are, are e
wwould be eould be exposed txposed to an additional dose oo an additional dose of rf radiaadiation estimation estimatted ted to o necnecessaryessary. .
EHXSWEHXSWRRP6P6YYZKLFKLVVLJQLoFDQZKLFKLVVLJQLoFDQWO\LQHWO\LQH[[FFHHVVRVVRIIWKHP6WKHP6YYDDQQQQXDOXDO
llimit fimit for members oor members of the public frf the public from a planned eom a planned exposurxposure and about e and about High frHigh freequency (HF) cquency (HF) communicaommunicationtionss
thrthree times as hiee times as high as the dose rgh as the dose receceiveived fred from a CT scan oom a CT scan of the f the HF cHF communicaommunications is liktions is likely tely to be ro be renderendered inopered inoperable able ffor seor sevvereral al
chest. Such lechest. Such levvels implels imply an incry an increased canceased cancer risk oer risk of 1 in 1,000 f 1 in 1,000 dadays during a solar superstys during a solar superstorm. HF corm. HF communicaommunications is used much tions is used much
ffor each person eor each person exposed, although this must be cxposed, although this must be consideronsidered ed less than it used tless than it used to be; hoo be; howweevverer, it does pr, it does proovide the primary long vide the primary long
LLQWKHFQWKHFRRQQWHWH[[WRWRIIWKHOLIWKHOLIHHWWLPHULVNRLPHULVNRIIFDQFFDQFHUHUZKLFKLVDERXWZKLFKLVDERXW distancdistance ce communicaommunications beartions bearer fer for long distancor long distance aire aircrcraft (noaft (not all t all
NNo pro practical meactical method othod of ff fororecast is likecast is likely in the short tely in the short term sincerm since e airaircrcraft haaft havve sae sattellitellite ce communicaommunications and this ttions and this technology maechnology may y
the hithe high energh energy particles ogy particles of grf greaeattest cest conconcern arrivern arrive ae at close tt close to the o the also falso fail during an eail during an extrxtreme eeme evvenent). Ft). For those airor those aircrcraft in the air aaft in the air at t
sspeed opeed of lighf lightt. Mitiga. Mitigation and post etion and post evvenent analysis is needed thrt analysis is needed through ough WKHVWDUWRWKHVWDUWRIIWKHHWKHHYYHQHQWWKHUWWKHUHDUHDUHDOUHDOUHDG\ZHDG\ZHOOGHHOOGHoQHGSUoQHGSURFRFHGXUHGXUHHVV
bebetttter onboarer onboard aird aircrcraft monitaft monitoring. An eoring. An evvenent ot of this type wf this type would ould tto fo folloollow in the ew in the evvenent ot of a loss of a loss of cf communicaommunications. Hotions. Howweevverer, in the , in the
ggenereneraatte ce consideronsiderable public cable public conconcern.ern. eevvenent ot of a persistf a persistenent loss ot loss of cf communicaommunications otions ovver a wide arer a wide area, it ea, it
PDPD\EHQHF\EHQHFHVVDU\WHVVDU\WRRSUSUHHYYHQHQWpLJKWpLJKWWVIUVIURPWDNLQJRRPWDNLQJRĆĆ,QWKLVH,QWKLVH[WU[WUHPHHPH
GrGround and aound and avionic devionic devicvice te technologyechnology FDVHWKHUFDVHWKHUHGRHVQRHGRHVQRWWDSSHDUWDSSHDUWRREHDGHEHDGHooQHGPHFKDQLVPIQHGPHFKDQLVPIRRUFORVLQJUFORVLQJ
Solar enerSolar energegetic particles indirtic particles indirectly generectly generaatte chare charge in ge in or ror reopening airspaceopening airspace once once ce communicaommunications hations havve re rececoovverered.ed.
semicsemiconductonductor maor matterials, causing electrerials, causing electronic equipmenonic equipment tt to o
malfunction. Vmalfunction. Very little documenery little documentary etary evidencvidence ce could be obould be obtained tained Mobile saMobile satetellitllitee c coommunicammunicattionsions
rreegargarding the impact oding the impact of solar enerf solar energegetic particles on grtic particles on ground ound 'XULQJDQH'XULQJDQH[WU[WUHHPHVSDFPHVSDFHZHZHDHDWWKHUHKHUHYYHHQQW/EDQGa*+]VDW/EDQGa*+]VDWWHHOOLOOLWHWH
LQLQIUIUDVWUXFWXUDVWUXFWXUHDQGLWLVFHDQGLWLVFRQVHTXHQRQVHTXHQWO\GLćFXOWWWO\GLćFXOWWRRHH[WU[WUDSRODDSRODWWHWHWRRDD ccommunicaommunications mightions might be unat be unavvailable, or prailable, or proovide a poor quality vide a poor quality
solar superstsolar superstorm. Mororm. More documene documentary etary evidencvidence oe of normal and stf normal and storm orm oof servicf service, fe, for beor betwtween one and threen one and three daee days oys owing twing to scino scintillatillation. tion.
time impacts is atime impacts is avvailable in railable in respect tespect to ao avionics - no doubvionics - no doubt because t because The oThe ovvererall vulnerall vulnerability oability of L-band saf L-band sattellitellite ce communicaommunications ttions to o

WKHRSHUWKHRSHUDDWLQJHQWLQJHQYLUYLURQPHQRQPHQWKDVDKLJKHUpX[RWKDVDKLJKHUpX[RIIKLJKHQHUKLJKHQHUJ\J\ VXSHUVWVXSHUVWRUPVFLQRUPVFLQWWLOODLOODWWLRQZLOOEHVSHFLoFWLRQZLOOEHVSHFLoFWRRWKHVDWKHVDWWHHOOLWOOLWHHVV\\VWVWHPHP))RRUU
particles. Our estimaparticles. Our estimatte is thae is that during a solar superstt during a solar superstorm the aorm the avionic vionic aaviaviation users the opertion users the operaational impact on sational impact on sattellitellite ce communicaommunications tions
ULVNZLOOEHaWLPHVKLJKHUWKDQWKHTXLHVFULVNZLOOEHaWLPHVKLJKHUWKDQWKHTXLHVFHQHQWEDFNWEDFNJJUURXQGRXQG will be similar twill be similar too HF HF.
risk lerisk levvel and this cel and this could incrould increase piloease pilot wt workload. Workload. We noe notte thae that t
aavionics arvionics are designed te designed to mitigao mitigatete functional f functional failurailure oe of cf componenomponents, ts, TTerrerrestrial brestrial broadcastinoadcastingg
equipmenequipment and st and systystems and cems and consequenonsequently they artly they are also partially e also partially 77HUUHUUHVWULDOEUHVWULDOEURDGFDVWLQJZRDGFDVWLQJZRXOGEHYXOQHURXOGEHYXOQHUDEOHWDEOHWRRVHFVHFRQGDURQGDU\H\HĆĆHFWHFWVV
rrobust tobust to solar enero solar energegetic particles.tic particles. such as loss osuch as loss of pof powwer and GNSS timing.er and GNSS timing.
Global naGlobal navigavigation sation sattellitellite se systystems (GNSems (GNSS)S)
OUR ESOUR EESTIMATIMATE IS THATE IS THATT DURING A SOLAR DURING A SOLAR
Assuming thaAssuming that the sat the sattellitellites – or enough oes – or enough of them – survivf them – survived ed
the impact othe impact of high enerf high energy particles, wgy particles, we ane anticipaticipatte thae that a t a
SUPERSSUPERSTTTTOORM THE ARM THE AVIONIC RISK WILL VIONIC RISK WILL
solar superstsolar superstorm miorm mighght rt render GNSS partially or cender GNSS partially or compleomplettely ely
BBEE ~1,200 T ~1,200 TIIMMEEESS HHIIGGHER THAN THHER THAN THEE
inoperinoperable able ffor beor betwtween one and threen one and three daee days. The outage period ys. The outage period
QUIESCENT BQUIEEESCENT BAACKCKGRGROUND RISK LEVEL AND OUND RISK LEVEL AND
will be dependenwill be dependent on the servict on the service re requirequiremenements. Fts. For critical timing or critical timing
ininffrrastructurastructure it is importane it is important that that holdot holdovver oscillaer oscillattors be deploors be deployyed ed
THIS CTHIS CCCOOULD INCREAULD INCREASSE PILE PILOOT WTT WOORKLRKLOOOOAADD.
capable ocapable of mainf maintaining the rtaining the requisitequisite pere perfformancormance fe for these periods. or these periods.
ExtrExtreme spaceme space we weaeather:ther: impacts on en impacts on engineergineered sed systystems and inems and infrfrastructurastructuree 55

Recommenda tions
A number of detailed recommendations are included in each Aircraft passenger and crew safety

chapter. Some of the most important are set out below. It is vital 6. Consideration should be given to classifying solar

WKDWDOHDGJRYHUQPHQWGHSDUWPHQWRUERG\LVLGHQWLoHGIRUHDFKRI superstorms as radiation emergencies in the context of air

these recommendations. SDVVHQJHUVDQGFUHZ,IVXFKDFODVVLoFDWLRQLVFRQVLGHUHG

appropriate an emergency plan should be put in place

Policy to cover such events. While the opportunities for dose
The report makes two key policy recommendations. These are that: reduction may be limited, appropriate reference levels should
be considered and set, if appropriate.
1. A UK Space Weather Board should be initiated within
government to provide overall leadership of UK space Ground and avionic device technology
ZHDWKHUDFWLYLWLHVń7KLVERDUGPXVWKDYHWKHFDSDFLW\WR 7. Ground-and space-derived radiation alerts should be provided
maintain an overview of space weather strategy across all to aviation authorities and operators. The responsible aviation
departments. authorities and the aviation industry should work together to
2. The Engineering and Physical Sciences Research Council GHWHUPLQHLIRQERDUGPRQLWRULQJFRXOGEHFRQVLGHUHGDEHQHoW
(EPSRC) should ensure that its own programmes recognise LQpLJKW5HODWHGFRQFHSWVRIRSHUDWLRQVKRXOGEHGHYHORSHGWR
the importance of extreme space weather mitigation and GHoQHVXEVHTXHQWDFWLRQVWKLVFRXOGHYHQLQFOXGHUHGXFWLRQVLQ
EPSRC should be fully integrated into any research council DOWLWXGHLIGHHPHGEHQHoFLDODQGFRVWHĆHFWLYH
strategy.
Global navigation satellite systems (GNSS)
Solar superstorm environment 8. All critical infrastructure and safety critical systems that require
3. The UK should work with its international partners to further DFFXUDWH*166GHULYHGWLPHDQGRUWLPLQJVKRXOGEHVSHFLoHG
UHoQHWKHHQYLURQPHQWDOVSHFLoFDWLRQRIH[WUHPHVRODU to operate with holdover technology for up to three days.
events and where possible should extend such studies to
provide progressively better estimates of a reasonable worst Terrestrial mobile communication networks
FDVHVXSHUVWRUPLQWLPHVFDOHVRIORQJHUWKDQa\HDUV 9. All terrestrial mobile communication networks with critical
resiliency requirements should also be able to operate
Electricity grid without GNSS timing for periods up to three days. This
4. The current National Grid mitigation strategy should be should particularly include upgrades to the network including
continued. This strategy combines appropriate forecasting, those associated with the new 4G licenses where these are
engineering and operational procedures. It should include used for critical purposes and upgrades to the emergency
increasing the reserves of both active and reactive power services communications networks.
to reduce loading on individual transformers and to
compensate for the increased reactive power consumption High frequency (HF) communications
...