Learning to Hover

A big selling point of helicopters is that you can land in your backyard. Where then would be the best place to learn to hover? An airport with a 12,000' runway and a 7,500' crosswind runway. You want a lot of open space where you're guaranteed not to hit anything. You want somewhere that neighbors won't complain about the noise. You want somewhere with long sight lines to the horizon so that you won't concentrate your gaze in too close. You want somewhere that you can get fuel when you run out. All roads lead to the big airport! Generally the tower and ground controllers will give you permission to practice hovering on whichever runway isn't be used that day and/or over a seldom-used taxiway.

Most instructors will start by giving you one control at a time. You take the antitorque pedals and they handle the cyclic and collective pitch. You practice pedal turns. Then you take the collective while the instructor controls the cyclic and pedals. You go up, you go down. Maybe you land. Then you take the cyclic and the instructor takes the other controls and ... 1 second later the helicopter is oscillating like crazy and you hear "I have the controls" in your headset. Any good instructor will alert you to the fact that you need to be very light on the controls: "you fly with pressures, not movements." The instructor will also tell you that there is a bit of lag between the time that you put in a control input and the time that the helicopter reacts. What most instructors won't tell you is how to deal with these facts.

Here are a few tips for handling the cyclic, which controls forward/back and left/right movement of the helicopter:

1. Focus your gaze at least 1/2 mile in the distance if the sightlines in your practice area are long enough.
2. As soon as the helicopter is handed to you it will start to drift to the right. The tail rotor is counterbalancing engine torque but at the same time is pushing the machine to the right. Expect to hold a little bit of left pressure on the cyclic to avoid this translational drift.
3. Don't put in and hold a control input pressure. Suppose the helicopter is moving forward a bit. You press back on the cyclic and hold that pressure. One second later the helicopter has responded to the initial pressure by arresting its forward creep. One second after that the helicopter has responded to two seconds of continuous pressure by rushing backwards at a frightening clip. If the helo is moving forward, press backwards for a split-second then try to return the cyclic to a neutral position. See if the helicopter stops creeping. If so, great. If not, try another little stab of back pressure. Although every second or two you are doing something with the cyclic, in any given instant you need not be putting in any cyclic input. Nudge the cyclic and then return to center. Nudge and then return.
4. After an hour or two the instructor might be doing more harm than good in handling the other two controls. Everything is cross-coupled so if he is messing with the collective or the pedals it will require you to take action with the cyclic. It is actually easier to handle all three controls because at least the machine isn't doing completely unpredictable things from your point of view.
5. Take a break every 20 minutes by practicing takeoffs, trips around the pattern, and approaches to landings.

Why Flying a Helicopter is Hard

Why do people have trouble flying a helicopter? Some don't! I taught a U.S. Navy airplane pilot to fly and hover a helicopter in about twenty minutes. At no time did he lose control of the machine, even hover taxiing back to the parking spot. Why did this guy have such an easy time? As an experienced jet and instrument pilot, he was very sensitive to changes in aircraft attitude. If the nose yawed very slightly to the left, he put in a slight right pedal pressure. If the nose dropped very slightly, he noticed the horizon moving and pulled back on the cyclic slightly.

What do folks who've never flown an aircraft before do? Sit there fat and happy while the attitude drifts a bit. Eventually the drift gets to the point that the helicopter is pointing 180 degrees from where it started or 45 degrees nose-up or 45 degrees nose-down and heading straight for the trees. At this point even a brand new pilot senses that something is amiss and it is time for a flight control input. A big one. The 45-degree nose-down attitude then turns into a 45-degree nose-up attitude.

The key in flying successfully and smoothly is to watch for small attitude changes and compensate with small control inputs. This is easier said than done, of course, and the instrument-rated airplane pilots have a big edge.

First Lesson: Air

Before you get into the air you'll probably spend about half an hour on a preflight inspection of the helicopter. With most airplanes most of the critical pieces are hidden underneath bodywork and not accessible except to a mechanic during an oil change or 100-hour inspection. With the Robinson R22 the engine is mostly flapping in the breeze and what is hidden can easily be accessed via a flip-up door.

If the weather is nice you'll probably remove the doors. This ensures that you'll be nice and cool inside the machine. In theory you could look straight down while in flight and scare yourself but in practice your attention will be focussed on looking out the front and trying to hold the machine in a fixed attitude relative to the horizon. So don't hesitate to fly your very first lesson with the doors off. When the doors are off, it is good practice to take everything out of your pockets and put them in the baggage compartment underneath the seats. You don't want loose items getting sucked out of the helicopter and contacting the tail rotor, the fastest-rotating and most fragile part of the whole machine.

Sadly, a big part of your first lesson will be practicing the most difficult helicopter maneuver: hovering. Hardly anyone is able to become proficient at hovering in less than 5 or 6 hours of flight training. Every one of those hours is exhausting. Much of the time is frustrating.

First Lesson: Ground

Because so many students have crashed R22s there are a bunch of special legal requirements associated with the aircraft. You aren't allowed to get into the machine at all until you've received and logged ground instruction.

The ground lesson is partly about energy management in the event of an engine failure and partly about not getting the helicopter into unusual attitudes.

As with airplanes, much of the key to safety in a helicopter is energy management. In an airplane you have potential energy (altitude) and kinetic energy (forward speed) that can be traded off against each other to bring the airplane down gently in the event of an engine failure or ordinary landing. The helicopter has three kinds of energy: potential (altitude), kinetic (forward speed), and angular momentum (blade speed).

In an airplane you can make decisions about trading forms of energy very late in the day. For example, if you pull the stick all the way back at 6000' above the ground you will gradually slow down and eventually stall and perhaps enter a spin. With many airplanes you could spin nearly all the way to the ground before applying forward stick and opposite rudder to get back to a normal flight condition. All without an engine.

In a helicopter, by contrast, if the blades spin down more than 10-15% from their normal velocity, there is no way to convert potential or kinetic energy into spinning such that the helicopter will start to fly again. If you can't restart your engine, therefore, your helicopter can very quickly become a rock.

In a turbine-powered helicopter like a Bell 206 JetRangers the blades are heavy and the blades won't slow down for several seconds after an engine failure. In the flyweight Robinson, however, after an engine failure you have no more than 1.2 seconds to take exactly the right actions or the helicopter cannot be recovered.

What if you do take all the right actions? Suppose that you're up at 4000' and the engine quits. You lower the collective pitch (lever on your left) immediately to flatten the blades and allow them to be driven by the wind through which the helicopter is now falling at 2000 feet-per-minute. You adjust the cyclic (stick in front of you) for about 65 knots of forward speed. You aim for a landing zone. The good news is that you don't need a very large one but the bad news is that the glide ratio is between 2:1 and 4:1 instead of an airplane's 10:1 and therefore you don't have as large an area from which to choose. As you get within about 50' from the ground you pull back the cyclic to flare the helicopter and shed most of the forward speed. Just as in an airplane this flare also arrests most of the vertical speed. At the second to last moment you stop flaring and return the helicopter to being parallel to the ground. Ideally at this point you are hovering 5' or so above a soccer field and the blades are still spinning. Finally you raise the collective as the helicopter falls, using the stored energy in the blades against the force of gravity. You land gently on the skids. (In practice the cyclic flare is more important than the "hovering autorotation" at the end; a lot of people walk away from helicopter engine failures if they get the cyclic flare right but can't manage to pull the collective smoothly at the last moment.)

This all sounds good until you look at the "deadman's curve". The marketing literature for helicopters says "if the engine fails, you can autorotate down to a smooth landing." The owner's manual, however, contains a little chart of flight conditions from which it is impossible to landing without at least bending the helicopter. Unfortunately these conditions are the very ones in which nearly all helicopters seem to operate. If you're above 500', for example, you're pretty safe. But TV station helicopters are often lower than that when filming. Flying along at 65 knots at any altitude is safe, but if the camera needs the pilot to hover the helicopter slows to a crawl and may get under the "height-velocity diagram", as the FAA calls the deadman's curve.

Choosing a Flight School and Instructor

There are four ways to lose a flight: weather is unfavorably cloudy or windy, instructor is not available, helicopter is down for maintenance, helicopter has been scheduled by another student. If you are training at a school with only one helicopter and one instructor, the risk of being unable to fly is very high.

Helicopter

Look for a school with at least three training helicopters and two instructors.
Given that you don't know how to fly, how do you evaluate an instructor? The best instructors are relaxed and comfortable even as the student makes a lot of mistakes. The best instructors are able to talk a student through a maneuver rather than putting their hands on the controls and "demonstrating". Once you've learned how to hold a hover and fly straight-and-level, take at least one lesson with each instructor at your school and then pick the one whose style suits you best. You'll probably learn at least 50 percent faster with a really good instructor compared to an average instructor.

As a lower-time instructor myself, it pains me to say this, but I think that most of the really good instructors with whom I have flown had at least 800 hours [I wrote that sentence some years ago; now I have my 800 hours]. The low-time guys were often nervous and took the controls too readily. I have flown with one or two really high time instructors who were not so great; they could do amazing things with the helicopter but they weren't good at explaining to another person how to do those amazing things.

One strategy that you might pursue is to find a lower-time instructor who is a good explainer for the lower-risk maneuvers and then do the more challenging maneuvers with a high-time instructor. Maneuvers that demand a higher level of skill from the instructor include 180-degree autorotations, slope operations, throttle chops, and hover autorotations over anything other than a smooth paved surface.