Smartwings, Loss of Cabin Pressure

A Smartwings Boeing 737-800 on behalf of Israir, registration OK-TSF performing flight 6H-734 from Warsaw (Poland) to Tel Aviv (Israel), was enroute at FL390 about 120nm northeast of Kosice (Slovakia) when the crew initiated an emergency descent due to the loss of cabin pressure, the passenger oxygen masks were deployed. The aircraft levelled off at FL100 and diverted to Kosice for a safe landing on runway 01 about 45 minutes after leaving FL390. A replacement Boeing 737-800 registration OK-TVO positioned to Kosice and is estimated to reach Tel Aviv with a delay of about 6 hours. On Jul 20th 2017 Czechia's UZPLN reported the cabin pressure experienced sudden changes multiple times prompting the crew to perform an emergency descent to FL100, the passenger oxygen masks were released. Maintenance determined that the pitot tubes were blocked by a mixture of dust and flowers and supplied from the vertical stabilizer. The pitot tubes were replaced and the system blown clean.

Source: http://www.avherald.com/h?article=4a9a3951&opt=0