This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.bbc.co.uk/news/blogs-magazine-monitor-30235844

The article has changed 3 times. There is an RSS feed of changes available.

Version 0 Version 1
Who, what, why: How easy is it to push a plane? Who, what, why: How easy is it to push a plane?
(about 16 hours later)
The story of passengers pushing a frozen Siberian plane soon went viral. But was it really possible, asks Tom de Castella.The story of passengers pushing a frozen Siberian plane soon went viral. But was it really possible, asks Tom de Castella.
"Siberians are so tough that for them pushing a frozen plane along a runway is a piece of cake," the Russian daily newspaper Komsomolskaya Pravda reported. The 30 tonne UTair Tupolev 134 refused to move, reportedly because the wrong grease had been applied, leaving the brake pads frozen in the minus 52C temperature."Siberians are so tough that for them pushing a frozen plane along a runway is a piece of cake," the Russian daily newspaper Komsomolskaya Pravda reported. The 30 tonne UTair Tupolev 134 refused to move, reportedly because the wrong grease had been applied, leaving the brake pads frozen in the minus 52C temperature.
Some of the passengers sprang into action, allegedly pushing the plane backwards until its wheels were able to turn and a tow truck could take over. A video of the incident appears to confirm their version.Some of the passengers sprang into action, allegedly pushing the plane backwards until its wheels were able to turn and a tow truck could take over. A video of the incident appears to confirm their version.
A passenger was quoted as saying that they had been asked to help, and had pushed it "about 5m, maybe more." But the local authorities have cast doubt on the story.A passenger was quoted as saying that they had been asked to help, and had pushed it "about 5m, maybe more." But the local authorities have cast doubt on the story.
"Naturally, the plane was moved by the truck, because people physically could not do it," the West Siberian transport prosecutor's aide Oksana Gorbunova said. "It looks like a joke.""Naturally, the plane was moved by the truck, because people physically could not do it," the West Siberian transport prosecutor's aide Oksana Gorbunova said. "It looks like a joke."
In general it's not very hard to push a plane, says Dr John Andrews, visiting fellow in physics at the University of Bristol. A one-tonne car can be pushed by three people. The same principle applies to a 30-tonne plane. You would need about 90 people or, as in this case, about 50 strong men. "You are just trying to overcome the rolling resistance of the tyres," says Andrews.In general it's not very hard to push a plane, says Dr John Andrews, visiting fellow in physics at the University of Bristol. A one-tonne car can be pushed by three people. The same principle applies to a 30-tonne plane. You would need about 90 people or, as in this case, about 50 strong men. "You are just trying to overcome the rolling resistance of the tyres," says Andrews.
But in the case of the Siberian plane, it appears the main problem was the wheels being locked by frozen grease. Here you have to overcome not only the rolling resistance but the frictional resistance of the ball bearings due to the fact the grease had solidified. That is true if the wheels turn. But the problem with the Siberian plane was unlocking wheels stuck with frozen grease. Here you have to overcome not only the rolling resistance but the frictional resistance of the ball bearings due to the fact the grease had solidified, Andrews says.
The physics relates to something called moments (force x perpendicular distance). It turns out that the passengers - whether they knew it or not - did just the right thing by pushing the wings. Because there was a large distance between the wings and the wheels it gave the people pushing greater leverage. "It's the principle of the spanner - the longer the spanner the less force you have to apply in order to shift the nut," Andrews says. So the passengers' version is feasible, he says. But the same probably wouldn't work with a bigger plane. The wings of a Boeing 747 or Airbus would be higher and probably out of reach, he says. The physics relates to something called moments (force x perpendicular distance). It turns out that the passengers - whether they knew it or not - did just the right thing by pushing the wings. Because there was a large distance between the wings and the wheels it gave the people pushing greater leverage. "It's the principle of the spanner - the longer the spanner the less force you have to apply in order to shift the nut," Andrews says. Once the wheels unlocked, the friction would have melted the grease. Then the tow truck took over. So the passengers' version is feasible, he says. But the same probably wouldn't work with a bigger plane. The wings of a Boeing 747 or Airbus would be higher and probably out of reach, he says.
There's always pulling. A plane pull for charity takes place every year at Bournemouth Airport where teams of 20 pull a 35-tonne Boeing 737 a distance of 50m as fast as they can. And then there are the fitness fanatics - in 1990 a Malaysian man pulled a 737 with his ponytail. However, they were not dealing with locked wheels in Siberian temperatures.There's always pulling. A plane pull for charity takes place every year at Bournemouth Airport where teams of 20 pull a 35-tonne Boeing 737 a distance of 50m as fast as they can. And then there are the fitness fanatics - in 1990 a Malaysian man pulled a 737 with his ponytail. However, they were not dealing with locked wheels in Siberian temperatures.
Subscribe to the BBC News Magazine's email newsletter to get articles sent to your inbox.Subscribe to the BBC News Magazine's email newsletter to get articles sent to your inbox.