“An airplane whose engine fails is a glider. A helicopter whose engine fails is a brick.”
So wrote Neil deGrasse Tyson back in 2015 in a tweet that saw the famous astrophysicist and general science guy roundly and comprehensively corrected. In a viral video debunking the quip, YouTuber Destin Sandlin from the channel SmarterEveryDay enlisted some helicopter pros to demonstrate the concept of autorotation – in other words, he got in a helicopter and switched the engine off mid-flight to see what would happen.
As dangerous as that sounds, Sandlin isn’t the only person willing to put his faith in physics like this. The good folks at Interesting Engineering have discovered a clip of another helicopter pilot showing how autorotation can save the day in the face of a mid-air engine failure – and this time, it happens when the chopper is high up in the mountains of British Columbia.
Luckily for everyone involved, this was a planned event – the video description reads "This is only a simulation and was done under careful supervision but it demonstrates exactly what would happen."
“This is looking really nice,” we hear the pilot say as the helicopter comes in to land – but then, “mayday mayday mayday!”, the engine has failed. What do they do?!
Well, we’ll let you watch the video, but spoiler alert: they’re fine. After gliding for a while at 80 knots – about 150 kilometers per hour or 92 miles per hour – the pilot reduces the speed enough to use autorotation to land the chopper.
So what is autorotation? As Tim McAdams from the Aircraft Owners and Pilots Association (AOPA) explains, it’s actually “one of the most critical maneuvers” that budding helicopter pilots have to learn. Essentially, it refers to a helicopter flying without engine power (but with the rotors still going – otherwise you’re in big trouble.)
To a non-pilot, it can sound quite intimidating. It requires quick reflexes and precise control – if you react too slowly, or the main rotor slows down too much, you can lose control of the vehicle and drop out of the sky like Neil deGrasse Tyson’s brick. On the other hand, letting the rotor spin too fast can damage the blades, which is probably bad news when you’re hundreds of feet in the air without a working engine. But to trained helicopter pilots, it’s apparently not such a big deal: most of the problems learners have stem from nerves, and many say other maneuvers such as hovering are much harder.
Listening to Pilot Yellow, it’s easy to believe autorotation is a walk in the park – he never loses his cool. Explaining how landing on the mountain rocks would be dangerous, he scouts a flat sandy place to land on the River Stave, and gently brings the helicopter down to Earth.
So if you’ve ever thought about going for a helicopter ride, but were scared of what might happen if the engine failed, rest assured: the pilot knows what to do.