On June 5, 2025, a SriLankan Airlines Airbus A320-200 (registration 4R-ABM) operating flight UL306 from Colombo to Singapore encountered multiple flight instrument failures, prompting an emergency landing in Medan, Indonesia. The aircraft, carrying 136 passengers, departed Colombo at 20:25 for the four-hour flight. While climbing through 34,000ft over the Indian Ocean, the crew received warnings of a failed first officer's anti-ice system and a 'Pitot Standby' message, indicating issues with the pitot tubes that provide airspeed data. These tubes are heated to prevent icing, which can lead to incorrect speed readings and potential stalls.

The crew followed procedures, consulted flight dispatch, and continued the flight, relying on the captain's pitot tube data. After passing the ETOPS exit point, the aircraft entered 'Alternate Law,' disengaging autopilot and auto-thrust due to conflicting airspeed data. Navigation computers also failed to determine accurate speed, further complicating the situation. The crew declared a "PAN PAN," requested a descent to a safer altitude block (30,000–35,000ft), and maintained 33,000ft at reduced speed. However, an overspeed warning followed by a stall warning triggered a "MAYDAY" declaration. The crew executed stall recovery procedures and diverted to Medan's Kualanamu International Airport, landing safely on runway 23 at 23:35 local time.

Sri Lanka's Civil Aviation Authority noted the aircraft was dispatched with an inoperative first officer's pitot heater under Minimum Equipment List requirements. The incident, deemed serious, is under investigation. The 14.2-year-old aircraft, leased from Aircastle since 2011, remained in Medan for three days before returning to Colombo on June 8. The A320 is configured with 16 business and 120 economy seats.