This morning, an S7 flight from Tomsk to Moscow was diverted to Omsk after Russian opposition leader Alexey Navalny was taken seriously ill. The plane was only one hour into its flight when it performed an emergency landing. Mr Navalny was unconscious upon arrival in Omsk and was rushed to the hospital immediately. He is currently in a coma but his doctors say he is stable.

Diverted to Omsk

This second incident makes it a rather busy week for S7 Airlines. The airline recently dealt with a bear on the runway and now has managed a major health incident.

The flight in question was flight S7 2614. The Boeing 737-800, registration VP-BQF, left Tomsk Bogashevo airport at 08:06 local time. It was due to land in Moscow's Domodedovo airport, but after just one hour in the air, the plane landed at Omsk airport in Siberia. Passengers were held on the plane before it took off again, landing in Moscow at 10.15 local time, two hours after it was scheduled to land.

Stay informed: Sign up for our daily aviation news digest.

According to tweets from Mr Navalny's press office, he is in a serious condition in hospital and is using a ventilator. It's thought he was poisoned before boarding the plane as he had not consumed anything on the flight. However, he did drink tea at the airport before boarding.

Suspected poisoning

Videos have since surfaced online from inside the aircraft as it was held on the tarmac at Omsk airport. In the videos, a man can be heard groaning. Reports state Navalny went to use the lavatory at the rear of the aircraft and did not return. He then called for help and was moaning. At this point, the cabin crew announced the emergency landing. Further videos online show an unconscious individual on a stretcher being transported into the back of a waiting ambulance.

It's currently thought that he was administered a toxic substance in a cup of tea he drank at the airport. His team has said it was the only thing he had consumed that morning. However, no official results from the hospital can confirm this. If it's true, this is the second time Navalny has been the victim of a suspected poisoning. Just last year, he suffered a similar incident.

Medical emergencies on planes

An emergency landing was necessary for this incidence, but not all medical emergencies resulting in a change of course. We've all seen films where the cabin crew asks if there is a doctor on the plane. But it turns out, it's not uncommon for aircraft to continue despite a medical problem onboard.

When flying became popular in the 1930's most cabin crew were actually registered nurses. Nowadays, cabin crew are trained to perform CPR and have basic first aid training but are not trained to handle a serious emergency. Planes do carry some medical equipment in case of an emergency, such as defibrillators. As a result, the cabin crew will contact medical professionals on the ground.

The decision to perform an emergency landing is down to the captain. Nowadays, captains can contact professionals and listen to expert advice, but there are lots of complicated factors to take into account. For example, an emergency landing to an airport that is not close to appropriate medical facilities might actually take longer for the patient to receive the care they need.

Additionally, depending on the size of the aircraft and the size of the airport, not all planes can land everywhere. The cost of diverting an aircraft mid-flight is also a consideration. If someone can receive adequate care in the air, a pilot may decide to keep flying.

A speedy recovery

While it has not yet been confirmed that Navalny has been poisoned, we wish him a speedy recovery. Luckily the flight was diverted, and passengers were only two hours late arriving in Moscow. We also hope the S7 doesn't have any more emergencies this week!