Russian Boeing 737 lands safely after turning back with cabin pressure issue, flight data shows

A Russian passenger plane operated by S7 Airlines landed safely on Friday after turning back to Novosibirsk airport in Siberia to check its cabin pressure systems, flight tracking data showed.

S7 had said in a statement earlier on Friday that the plane, which had been flying to the southern Russian resort city of Sochi, had been forced to return to its departure airport "to check the cabin pressure control system."

The flightradar24.com tracking website indicated that the plane, a Boeing 737 with seating capacity for 176 passengers manufactured in 2001, landed safely.

The website had earlier indicated that the plane sent an emergency signal. The site tracked it turning back and then repeatedly circling and flying in large loops to use up its fuel before landing.

The airline said in a statement that a replacement aircraft had been prepared to carry passengers to their original destination of Sochi.

The Western Siberian Transport Prosecutor's office said it had been monitoring the incident.

The incident comes a day after an An-24 passenger plane crashed in Russia's far east as it was preparing to land, killing all 48 people on board in an incident that spotlighted the continued use of old, Soviet-era aircraft.