Incident: Ryanair Sun B738 near Bucharest on Sep 8th 2021

A Ryanair Sun Boeing 737-800, registration SP-RKK performing flight RR-5351/FR-5351 from Katowice (Poland) to Antalya (Turkey), was enroute at FL350 just crossing the border between Romania and Bulgaria into Bulgaria about 90nm southwest of Bucharest Otopeni Airport (Romania) when the crew decided to divert to Otopeni Airport requesting ATC to contact their company with the message that their lavatories needed to be blocked as the waste system was no longer working. The aircraft turned around and landed on Otopeni's runway 08R about 21 minutes later.

The aircraft remained on the ground for about 4 hours, then continued the journey to Antalya reaching their destination with a delay of 4:40 hours.