What happened
On June 30, 2015, a Bombardier/DHC-8-402Q operated by PLL LOT was performing a takeoff roll at Vilnius Airport (EYVI), Lithuania. During the acceleration phase, the flight crew noticed that the left airspeed indicator was not providing any readings. Recognizing the instrument discrepancy, the crew immediately aborted the takeoff and taxied the aircraft back to the parking stand.
Upon inspection of the aircraft, the crew discovered that the protective cover for the left Pitot tube had not been removed. Following the removal of the cover, the crew performed a visual cleanliness check and conducted Air Data Computer (ADC) tests. These tests yielded no further irregularities, and the remainder of the flight operations proceeded without further incident. The crew reported the event to the PLL LOT Flight Safety Department and filed an Air Safety Report (ASR).
The investigation
The investigation, conducted by the operator, focused on the circumstances leading to the instrument failure. The investigation established that the primary cause was an inadequate pre-flight inspection.
Findings
- The investigation identified that the pre-flight inspection was not performed with sufficient care to detect the obstruction.
- The time of day, being an early morning departure, was noted as a contributing factor.
- The 'REMOVE BEFORE FLIGHT' streamer, which typically serves as a visual warning for covers, was missing from the Pitot tube cover, making the obstruction harder to detect.