Let’s talk a bit about "that which shall not be named"….engine failures.
Most people know that when an airplanes engine fails the pilot can glide and try to land on a highway or something similar, the pilot may take out part of the wing on a street light post but could fare better if there is more clearance. But what about helicopters? What happens when the engine fails?
As a small aside, there is a great YouTube video entitled Strapped Into A Falling Helicopter from a channel called “Smarter Every Day” where the host, not knowing much about rotorcraft, learns specifically about this procedure. Given the obvious importance of this scenario it will come as no real surprise that practice autorotations constitute a fairly sizable portion of the helicopter flight lessons in our flight school.
Starting out I want to take a minute to allay some fear that a reader may have regarding this subject. Here is some data from ushst.org:
- Over the last 10 years helicopter accidents have declined by 40%
- Most aviation accidents are not caused by the powerplant/engine failure. This data shows that statistically speaking a pilot (or passenger) is actually safer in a helicopter than behind the wheel of a car, walking across the street, swimming at the lake, etc.
During an autorotation there is a lot going on, a lot to keep track of, and not a lot of time until the maneuver is completed. As with anything, practice is required to increase familiarity, and therefore everything gets slower and slower so you can react better in the moment. The pilot must make gentle control inputs to maintain the aircraft's attitude, maintain rotor rpm in a safe range, modulate the collective as necessary given the helicopter's descent rate, and, after the basics are learned, fly to an open spot to actually land.
My first autorotation felt like an amusement park ride: a sudden free fall, my head spinning (not actually spinning), not knowing where to look or what to look at as we glided to the ground, I found myself looking up at the sky at one point as my instructor pointed the nose at the clouds and then we were sliding slowly to a stop on the runway! All in about 11 to 14 seconds! From that first experience to learning more about the maneuver and being able to see it all happen and have control over the how and when of it was a very empowering feeling.
The autorotation control input basics form the skeleton, but I now consider autos to be quite ‘organic’ as the timing and severity of my inputs depend on the helicopter's location, altitude, air temperature, wind direction and velocity, aircraft weight, and CG location, so many variables at play. The state of autorotation in a helicopter is a very stable flight profile, when I demonstrated autos to my students for the first time, they, like me, were a bit overwhelmed but after a few seconds in the Glide Phase they all commented on how stable they felt. Autos are really not the end of the world as some may be prone to think. In a stage check when I was as student, a senior helicopter CFI showed me the map pilots use (called a sectional chart) and made the point that an airplane can really only land at an airport but a helicopter can land almost anywhere, which to me was a fairly comforting thought.