Plane passengers were horrified when the flight crew on their plane waiting to take off in south-central Russia told them it was 'perfectly normal' that the aircraft was filling with smoke.
Some concerned passengers filmed the smoke making its way through the Angara Airlines cabin before taking off from Irkutsk, a city in Russia's Irkutsk Oblast region.
Flight attendants initially told passengers there was nothing to worry about, but the plane was later replaced, resulting in a three-hour delay to the flight's destination of Ust-Kut, also in Irkutsk Oblast.
Some people reportedly started screaming, 'We are on fire! We are on fire!' at the sight of the smoke.
The smoke was first noticed by passengers sitting at the rear of the aircraft - an Antonov An-24.
The video, taken by one of the passengers and posted online, shows two passengers talking to the flight attendant about the smoke.
Instead of evacuating the plane and investigating the cause of the fumes, a female flight attendant said: 'Do not worry, it will all pass in a moment. This is the jets starting, this is normal. There is no smell.'
The airline eventually agreed to replace the plane, after passengers continued to complain.
A passenger on the Angara Airlines flight uses his phone to start filming the smoke filling the cabin, pictured
Smoke starts filling the cabin on the Angara Airlines flight, pictured. Passengers were told that it was 'perfectly normal'
Some passengers complained that they had been left traumatised by the incident.
The Antonov An-24 is a 44-seat passenger aircraft which was first flown in 1959 - more than 100 are still in airline service.
A fatal accident in 2011 led to calls for the An-24 to be banned from scheduled flights inside Russia.
Angara Airlines is the leading airline flying out of Irkutsk and is a major player on the domestic Siberian market