Iberia Flight 610

Iberia Flight 610 was a scheduled domestic passenger flight from Madrid to Bilbao, Basque Country, Spain. On 19 February 1985, a Boeing 727-200 operating the flight crashed into a ravine after one of its wings sliced a television antenna on the summit of Mount Oiz in Biscay during an approach to Bilbao Airport. All 141 passengers and 7 crew on board died. The crash is the deadliest aviation disaster in both the Basque Country and Iberia history.

Spanish officials concluded that the crash had been caused by pilot error. During the approach to Bilbao, the autopilot's altitude select system failed to engage due to undetermined reasons, enabling the aircraft to descend past its target altitude. The altitude alarm had sounded to inform the crew that they had reached the intended altitude. However, both crew members misinterpreted it and caused the aircraft to fly even lower. The left wing eventually struck a television antenna, shearing it off and causing the aircraft to crash.

As of 2026, Iberia Flight 610 remains the third-deadliest aviation accident in mainland Spain, behind Spanair Flight 5022 in 2008 and Avianca Flight 011 in 1983, and the deadliest crash on mainland Spanish territory without any survivors.

Flight

Flight 610 was a scheduled domestic passenger flight from Spanish capital of Madrid to Bilbao, the largest city in Basque Country. Piloted by Captain Patiño and First Officer López, the aircraft was supposed to take off from Madrid–Barajas Airport in the morning. The flight was a short one as the aircraft was expected to arrive approximately 45 minutes later.

On February 19, Flight 610 departed Madrid at 08:47 CET with 141 passengers and 7 crew members. It was scheduled to land at Bilbao Airport at 09:35. First Officer López was the pilot flying, while Captain Patiño was the pilot monitoring. According to the weather report, the area around Bilbao, particularly in the mountains, would be covered with fog. The flight was uneventful until the approach.

Crash

Approximately 900 feet from the target altitude of 5,000 ft, the first tonal alarm sounded. The aircraft reached 5000 ft at 09:25 and the second tonal alarm informed the crew that the aircraft had reached the intended altitude. The target altitude was lowered again, this time to 4,300 ft. The crew then commanded the autopilot to increase the rate of descent to 1,500 ft in order to quickly reach the intended altitude. The altitude alert went off and the crew continued the descent as the second tonal alarm had not sounded. The crew began to initiate the loop back towards the airport by making a tight turn to the left. During the turn, they would bypass Mount Oiz.

The rate of descent was eventually decreased to 750 feet per minute. The pilots then fed the autopilot with the intended input and began to configure the flaps. The aircraft continued to descend. The weather conditions at that time were cloudy with fog, with 4 km of visibility.

At 08:27, after 57 seconds from the moment of descent to a safe altitude, flying 177 ft above Mount Oiz (elevation 3,356 ft) in a landing configuration, and at a speed of 239 mph, the aircraft's left wing collided with an antenna of the Euskal Telebistarues (EITB) television tower at 3,356 ft. The tower struck right between the airframe and the wing, completely shearing the wing off from the airframe. Losing all possible lift from the left side, the aircraft immediately rolled to the left and dived towards the woods. It hit dozens of pine trees in the process, leaving swathes of cut trees for 930 meters before it crashed into a ravine in inverted condition. The wreckage slid for another 230 meters, ending in a tremendous explosion and instantly killing all 148 passengers and crew on board.