A Rossiya Airbus A320-200, registration VQ-BDQ performing flight FV-811 from Saint Petersburg (Russia) to Baku (Azerbaijan), was enroute at 10100 meters (FL331) about 55nm north of Moscow's Sheremetyevo Airport when the crew initated a diversion to Sheremetyevo Airport due to a medical emergency on board. The aircraft landed overweight but safely at Sheremetyevo's runway 25R about 20 minutes later. The passenger was taken to a local hospital.

Passengers reported a fellow male passenger suddenly got seriously ill, lost consciousness and deteriorated rapidly. A doctor on board provided first aid raising the suspicion of a drug overdose and recommended an immediate landing stating the patient would die otherwise.

A replacement Airbus A319-100 registration VQ-BAS continued the flight about 7 hours after landing.

The airline said the incident aircraft could not continue the flight because of procedures as result of the overweight emergency landing.

The incident aircraft is still on the ground in Moscow.