A widespread software vulnerability triggered the grounding of approximately 6,000 Airbus A320 aircraft over the weekend, impacting global air travel. The issue, stemming from a disruption caused by solar radiation, prompted Airbus to mandate a software update for airlines worldwide. The incident, initially flagged after an unexpected descent of a JetBlue flight in late October, highlights the potential for previously unforeseen risks within modern aircraft systems and the challenges of safeguarding against space weather events. As of today, december 5th, nearly all affected planes have been cleared for flight following the software patch.
Approximately 6,000 Airbus A320 aircraft were grounded over the weekend due to a software vulnerability sensitive to solar radiation. Airbus mandated that airlines implement an update before resuming flights. Here’s a breakdown of what happened.
On October 30, an Airbus A320 operated by JetBlue experienced an unexpected descent during cruise, with no input from the pilots. The uncontrolled drop lasted between four and five seconds before the autopilot re-engaged and corrected the aircraft’s trajectory. An investigation revealed the 80-meter descent was triggered by software disrupted by intense solar radiation. The incident underscores the potential for unexpected vulnerabilities in complex aircraft systems.
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DECODED. Airbus: A JetBlue A320 suddenly went into a dive, what’s happening in Airbus cockpits?
Solar and cosmic radiation consists of high-energy particles that collide with the Earth’s atmosphere, generating a cascade of secondary particles, including neutrons, protons, ions, and electrons. While most of these particles are deflected by the Earth’s magnetic field, some penetrate to the surface and reach aircraft in flight.
The Neutron Hunt is On
Aircraft avionics – encompassing all electronic, electrical, and computer systems that assist in piloting – are particularly susceptible to neutrons. Aircraft manufacturers and aerospace equipment suppliers are aware of this risk and protect their systems accordingly. When a neutron strikes a digital component, it can cause “bit inversions,” leading to malfunctions in onboard computers. This is what occurred on the JetBlue A320.
Neutrons impacted a memory chip within the flight control computer, inverting “0”s to “1”s – these bit inversions. The ELAC2 software was affected because it offered less protection against solar radiation. This computer, manufactured by Thales and responsible for controlling the aircraft’s horizontal stabilizer, mistakenly interpreted the erroneous “1” as a command to dive, causing an unintended movement and subsequent descent.
To resolve the issue, airlines were required to update the software by installing an older version (ELAC1), which, paradoxically, is better protected against solar radiation. This earlier software incorporates safety mechanisms that detect the erroneous “1” as a malfunction and ignore it.
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Why have Airbus’s problems impacted so many aircraft?
The fix was implemented within hours for 98% of the 6,000 affected aircraft. Approximately 100 planes remain grounded, requiring a more recent hardware version to eliminate any risk.
