Incident Details
On 17 October 2014, the crew of a Boeing 737-800 was conducting a flight from GMAD to EPWA at flight level FL380. After establishing radio contact with the 'JR' sector of air traffic control, the pilot received information about the expected standard arrival procedure (STAR) LOGDA 4U for landing at EPWA.
Shortly thereafter, the air traffic controller observed on the radar display a deviation from the assigned flight level for the Boeing 737-800. When asked about their intentions, the crew stated that they had assumed the assignment of the standard arrival procedure also constituted clearance to descend.
Findings
The investigation was conducted by the Polish State Commission on Aircraft Accident Investigation (PKBWL). The aircraft was a Boeing 737-800, but its registration was not specified in the report. No injuries, damage, or fatalities were documented. The incident occurred in the Warsaw Flight Information Region (FIR EPWW) during daytime, though the exact time was not provided. No safety recommendations were issued by the PKBWL.
Cause
The probable cause, as determined by the PKBWL, was non-compliance by the B738 crew with air traffic regulations.