On the day of October 30, 2025, JetBlue Flight 1230 experienced a serious incident involving an uncommanded pitch-down event while cruising at 35,000 feet, injuring 15 people and requiring an emergency landing in Tampa. Investigations pointed to a malfunction in the Elevator Aileron Computer (ELAC) potentially triggered by high-energy cosmic rays affecting flight control data.
Lets start with the basics. The aircraft in question was a 20 year old Airbus A320-232, registered as N605JB. By the time of the event, the plane had accumulated approximately 76,785 flight hours and 27,805 flight cycles. Onboard this flight, there were 124 souls. Out of these 124 souls, 22 were injured, which is 18 passengers, and 4 crew members.
In the afternoon of the day of the accident flight, JetBlue Flight 1230 was preparing to fly it’s route. The preflight preparations were uneventful, and the briefing went as normal. The aircraft got pushed back and conducted it’s taxi to the apron as usual. The aircraft began rolling down the runway and it’s initial climb and climb to its cruising flight level was normal. About 45 minutes after the departure, the aircraft suddenly started pitching forward at an alarming rate. The aircraft descended 100 feet in 7 seconds. After this happened, the pilots immediately resumed control, and started a controlled descent. They then proceeded to make an emergency lading in Tampa.
So what really happened? The investigation confirmed that a high-energy subatomic particle, likely from solar activity struck a memory cell in the ELAC 2 (Elevator and Aileron Computer). This caused what engineers call a “bit-flip”—changing a 0 to a 1 in the system’s code. However, the bit-flip was not the real solution. The bit-flip occurred in the section of memory responsible for calculating the Angle of Attack. There was a data corruption in this process. The computer believed that the Angle of Attack was too high, and the plane was about to stall. As a reaction to this, it gave an aggressive pitch down input.
The incidents that occurred in this flight, while not fatal, must have been a terrifying ordeal for all the passengers and crew on board. A Airlines were ordered to remove the L104 software and revert to a “stable, validated” earlier version, specifically L103+, which was not susceptible to the solar-induced “bit flip” error. All in all, this flight landed successfully thanks to the good airmanship of the pilots.