European Union Aviation Safety Agency

Solar radiation and aircraft electronics: is this a big issue?

David Learmount Uncategorized , , , , , , , , , , , , , , , , , ,

Much of the world’s fleet of about 11,000 Airbus A320 series aircraft – the most popular airliner in the world according to sales – are affected by a current emergency airworthiness directive from the European Union Aviation Safety Agency and the US Federal Aviation Administration requiring that operators modify their aircraft control software to make it more resistant to the effects of solar radiation.

This followed a sudden loss of height in the cruise involving a JetBlue A320 en route from Cancun, Mexico to Newark, USA on 30 October. Solar radiation is believed to have been responsible for corrupting the data in one of the aircraft’s flight control computers causing the sudden height loss – which injured several passengers. Recovery action by the pilots ensured the aircraft diverted safely to Tampa, Florida.

Most younger A320s need only a quick software patch to harden the microchip resistance in their flight control computers against particularly vigorous bursts of solar radiation, but nearly a thousand of the oldest aircraft may need to change the units.

Solar radiation is known to be able to interfere with GPS signals, radio communication, inertial navigation systems, autopilot, and full-authority digital engine controls (FADEC), although incidents are rare. A mysterious sudden pitch-down by a Qantas A330 in the cruise over Western Australia in October 2008 is now reckoned to have been caused by corrupted data from an air data inertial reference unit (ADIRU) that may have been subject to solar radiation damage.

All aircraft are more vulnerable than suface vehicles to solar radiation effects because, at high altitude, there is less atmospheric attenuation of the sun’s electromagnetic energy. Polar flights are particularly vulnerable because the earth’s magnetic field provides less shielding and the troposphere is at a lower altitude there.

A320 series aircraft have three three flight control primary computers (FCPC), two flight control secondary computers (FCSC), and a flight augmentation computer, all of which provide considerable systems redundancy, plus a cross-checking capability to detect and correct anomalous data.

The UK Civil Aviation Authority said today that there had been virtually no disruption to flight schedules because airlines were so quick to apply software fixes.

1 December 2025: a statement from Airbus on this date claimed that only about 100 A320 series aircraft remained to receive the softwear hardening required by EASA an the FAA.

UK aviation: caught in the crossfire

David Learmount Uncategorized , , , , , , , , , , , , , , , , , , , ,

With the destabilizing effects on global aviation of huge fuel price inflation and unprecedented Russian military aggression in Europe, worsened by post-pandemic staffing shortages, it’s amazing that international commercial air transport works at all right now.

International cooperation has never been more crucial. Yet in the UK, an example of how NOT to do aviation – especially right now – has just been highlighted.

UK-based eVTOL developer Vertical Aerospace will be certificated by the UK CAA according to EU rules despite having separated from EASA

The reason international aviation is still working despite global instability is because the world wants it to, and has set up robust systems to enable it. Like commercial shipping, commercial aviation is naturally a global industry.

That’s why both those industries have specific United Nations agencies devoted to overseeing globally agreed standards and operating practices (SARPs). These agencies are the International Maritime Organization and the International Civil Aviation Organization. Total regulatory unity doesn’t prevail worldwide, but a high degree of harmonization does.

The world’s two most influential national/regional aviation authorities responsible for turning ICAO SARPS into national law are the European Union Aviation Safety Organisation (EASA) and the US Federal Aviation Administration (FAA). These two have worked together for decades to improve the harmonization of their regulations, making them identical where possible. They still meet regularly. Most of the world’s national aviation authorities (NAAs) more or less copy the regulations of one or the other into their own NAA rules.

All the EU states have always had their own NAAs – and still do. But since the 1980s they have worked together on harmonizing their aviation regulations to make Europe’s aviation industry work better.

In the early 2000s, EASA was born out of its predecessor the European Joint Aviation Authorities, to unify Europe’s interpretation of all those ICAO SARPs.

Back in the early 1980s, believe it or not, Boeing had to build almost as many variants of its 737 series as there were countries in Europe, because some nations insisted on safety systems than the FAA did not require, and some of these specifications were unique to each country. For example, one of the UK’s additional requirements – then – was for a 737 stick-pusher.

Today the UK Civil Aviation Authority (CAA) is faced with the consequences of returning to the bad old days because of the UK’s departure from the European Union. Although Theresa May, the UK prime minister preceding Boris Johnson’s election, had instructed the CAA to remain an associate member of EASA following “Brexit”, when Johnson came in his government insisted on ideological purity, thus no CAA association with Europe’s multinational agency.

Meanwhile, right now the CAA has to prepare its reaction to the imminent arrival on the world stage of a new form of commercial air transport: eVTOL (electric vertical take-off and landing), also known as Urban Air Mobility. Expected to take the air taxi world by storm and make it sustainable, the UK plans to be involved in all aspects of this new industry, including manufacturing.

At a time like this, when the world has agreed to harmonize rules associated with another massive new aviation development – drone operation – it does not make sense for any nation to declare unilateral independence from the world rule-making processes.

The CAA, fully aware of its dilemma, has released a statement pledging that it will follow exactly the EASA rules on certification for eVTOL.  Of course, it has to duplicate the regulation in UK law, and any UK eVTOL products or services will be subject to scrutiny by EASA to ensure that it does just that. Hence the UK’s promising eVTOL manufacturer Vertical Aerospace is having to undergo identical parallel certification by two agencies: the CAA and EASA. You couldn’t make it up, could you?

Meanwhile the bureaucratic burden placed on the UK agency is evident from this script heading pages on the CAA’s website: “UK-EU Transition, and UK Civil Aviation Regulations: To access current UK civil aviation regulations, including AMC and GM, CAA regulatory documents, please use this link to UK regulation. Please note, if you use information and guidance under the Headings below, the references to EU regulations or EU websites in our guidance will not be an accurate description of your obligations under UK law. These pages are undergoing reviews and updates.”