What happened
On 20 February 2006, a Finnair scheduled flight from Warsaw to Helsinki experienced a serious incident during landing at Helsinki-Vantaa airport. As the Embraer 170, registration OH-LEE, was performing its landing roll, two of the four tyres on the main landing gear burst. The aircraft decelerated more aggressively than normal and came to a stop at the intersection of a runway and a taxiway. There were no injuries to passengers or crew, and no damage to the aircraft was reported beyond the burst tyres.
The investigation
The investigation established that as the aircraft approached Helsinki, the pilots inadvertently operated the emergency/parking brake lever instead of the speed brake lever. Although the pilots released the lever, a technical malfunction caused brake pressure to remain trapped in one of the two parking brake circuits. This residual pressure led to the failure of the outermost tyres during the landing roll.
Investigators also found that the aircraft's warning system was insufficient, as it did not provide clear information regarding the system's status while airborne. Furthermore, the investigation revealed that the abnormal behavior of the emergency brake system had been noted in the aircraft's technical logbook on two previous occasions; however, these had been recorded as mere remarks rather than formal malfunction reports, which meant they did not trigger immediate troubleshooting by maintenance personnel.