Al Root
Investors understandably get nervous about software on planes, and a hiccup at Airbus has sent shares lower. The current situation with its A320 jet, however, doesn't appear to be a significant issue.
A benefit for investors is that it offers an opportunity to learn about something they probably rarely think about: cosmic rays.
Airbus stock was down 2% in overseas trading on Tuesday, while S&P 500 and Dow Jones Industrial Average futures were up 0.2% and 0.1%, respectively.
Tuesday's drop puts the shares down about 8% since the company recalled some 6,000 jets in the A320 family to correct a potential problem with onboard computers.
On Oct. 30, JetBlue Flight 1230 "experienced an uncommanded and limited pitch down event," read part of an emergency airworthiness directive from the European Union Aviation Safety Agency. It appears that a computer provided incorrect angle-of-attack, speed, or altitude information.
Airbus didn't respond to a request for additional information.
How that happens boils down to how computers work. The smallest unit of data on a computer is a bit, a one or a zero, with a transistor flipping on or off to represent one of those states. Modern microchips have tens of billions of transistors.
They are so small that radiating particles can hit a transistor and flip it on or off, causing an error. Adding to the risk is that there is more radiation in the upper atmosphere, where planes fly.
Radiation has created problems in the past. In October 2008, a Qantas A330 cruising at 37,000 feet lost altitude quickly after one of the aircraft's three air data inertial reference units put out incorrect values on all flight parameters. At least 110 of 303 passengers and nine crew were injured. A likely cause was radiation turning a transistor on or off.
It seems scary, but it's rare. What is more, the industry knows it can happen. That is why there is redundancy in computing and software to check and triple-check inputs. Airbus was able to correct the condition mainly with a software patch, code that can check and correct errors.
Redundancy and error checking are common in aerospace. It was present on A320 family jets before the Oct. 30 incident. It appears that the initial fix was actually to undo a software update, going back to an older version, according to Citi analyst Charles Armitage.
The situation is very different from Boeing's problem with flight-control software, which was partly responsible for the two 737 MAX crashes in 2018 and 2019. That was a poorly designed new system with inadequate redundancy that wasn't adequately disclosed to pilots.
Most of the Airbus planes are back in service. Still, the size of the recall is a reminder of how software controls just about everything in modern life.
Coming into Tuesday trading, Airbus stock was up 24% year to date and 31% over the past 12 months. Investors have been encouraged by rising demand for jets. The challenge for Airbus and Boeing is to boost production.
Airbus is expected to deliver about 820 jets in 2025. It delivered 863 in 2019, and Wall Street expects it will deliver more than 900 next year. Boeing is expected to deliver about 600 jets in 2025. It delivered more than 800 in 2018, and Wall Street expects it will deliver almost 700 next year.
Write to Al Root at allen.root@dowjones.com
This content was created by Barron's, which is operated by Dow Jones & Co. Barron's is published independently from Dow Jones Newswires and The Wall Street Journal.
(END) Dow Jones Newswires
December 02, 2025 09:02 ET (14:02 GMT)
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