Summary
On May 22, 2016, a SprintAir SAAB-340A operating a flight from Warsaw Chopin Airport (EPWA) to Gdańsk Lech Wałęsa Airport (EPGD) experienced a crack in the left cockpit window at approximately 20:05 UTC while cruising at flight level 200. The crack affected only the outer heating layer of the window, and no decompression occurred. The flight crew decided to return to the departure airport, where the landing was completed without further issues. There were no injuries among the three occupants.
Event Details
The incident took place en route between EPWA and EPGD. The aircraft, a SAAB-340A, was being operated by SprintAir SA. At the time of the event, the outer heating layer of the left cockpit window fractured. The inner layers remained intact, preventing any loss of cabin pressure. The crew promptly initiated a return to Warsaw and landed safely.
Findings
An investigation conducted by the operator revealed that in the 12 months preceding this incident, there had been three other window failures on the same aircraft type: one delamination, one crack, and one heating malfunction. These events necessitated window replacements. The investigation focused on the condition of the window heating system.
Probable Cause
The most likely cause of the incident was operational wear of the window heating system.
Preventive Actions
Following the incident, the operator analyzed the frequency of cockpit window failures over the preceding 12 months. Additionally, a safety information bulletin (SMS 31/07/2017) was issued to flight crew to raise awareness of the issue.