Occurrence
On 30 January 2015, a Bombardier DHC-8-400 operated by Eurolot SA was conducting an approach to land in the Warsaw Terminal Manoeuvring Area (TMA EPWA). During the approach, the aircraft deviated from the altitude cleared by air traffic control by more than 300 feet.
The crew received clearance to descend to 3000 feet. After turning to intercept the ILS for Runway 11, the aircraft descended to 2500 feet. Controllers then instructed the crew to climb back to 3000 feet. The remainder of the approach was completed normally using the ILS system.
Probable Cause
The cause of the incident was the crew's failure to press the ALT SEL button, which prevented the autopilot from capturing the previously set altitude of 3000 feet.
Preventive Measures
No preventive measures were applied by the operator.
Safety Recommendations
The investigation commission did not issue any safety recommendations.