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flight training for helicopters

Helicopters are expensive.
Helicopters are slow. Helicopters can't carry very much. Helicopters run
out of fuel before they have flown very far. Compared to an airplane you
sacrifice a tremendous amount of utility in exchange for the following:
the ability to land
anywhere
the ability to fly very
low and slow (albeit not safely as we'll see below)
Helicopters are also fun
and challenging.
Helicopters suffer from 8
accidents per 100,000 hours flown and about 10 percent of accidents are
fatal (other data suggest that the fatal rate is closer to 1.4 per 100,000
hours). This is a similar safety record to general aviation airplanes. As
an inexperienced pilot of a cheap light helicopter, however, your risk is
at least 5 times higher than that of a Vietnam vet flying a fancy
turbine-powered helicopter. The accident rate for personal helicopter
flights, almost all of which are in cheap light machines, was 44 per
100,000 hours and 16 of those would be fatal. For practical purposes,
therefore, it seems that you're at least 10 times more likely to kill
yourself in a helicopter as you are in a fixed wing trainer such as the
Cessna 172, Diamond DA20/DA40, or Piper Warrior.
The good news about
helicopter safety is that it is largely under your control as the pilot.
If you want to cruise along for 25 miles skimming the ground 100' above
obstacles and then land in your friend's backyard, which is surrounded by
powerlines and trees, you are asking for trouble. If you take off and land
at public airports and fly 500' above the terrain your risk is probably
not that different from doing the same trip in a small airplane. As with
other kinds of flying safety depends to a large extent on the ratio
between a pilot's level of confidence and level of skill.
Consider starting with an
airplane
On average, you are
required to accumulate least 45 hours of helicopter time before you will
get a Private certificate. In practice most students take much longer. New
pilots have to learn all the rules and regulations, how to read charts and
understand airspace, how to talk on the radio, how to navigate when on a
cross-country flight, and how to fly a helicopter.
If you are already a
certificated airplane pilot you already have all of the required skills
except knowing how to fly a helicopter. Most authorities relax
the flight time requirement to about 30 hours and in practice many
students are able to pass their check ride after 30 hours.
Unless you're completely
fearless the prospect of hurtling towards the ground at a lethal rate of
speed in an unfamiliar machine is frightening. Yet this is a required
manoeuvre when landing any aircraft. Fear makes it harder to learn. Better
to conquer your fear and get comfortable in the air in a much cheaper
rented fixed wing airplane than in an expensive helicopter.
Your trainer

You'll almost surely
start training in a Robinson R22, designed by former Bell engineer Frank
Robinson for folks who want to commute from their country homes in the
woods to their car dealerships, hospitals, or law offices in the city. The
R22 cruises fast and everything in the machine is designed to be as
simple, lightweight, and maintenance-free as possible. It is truly the
perfect helicopter except for one small problem: the market Robinson
designed it for does not exist. It turned out that the haute
bourgeoisie preferred to sit in traffic and melt the pavement
underneath their SUVs rather than take responsibility for learning to
operate a helicopter safely.
Flight schools, however,
were quick to notice that the R22 was the world's cheapest helicopter to
operate and began snapping them up. This proved to be a problem because
Frank Robinson never designed the R22 for training and probably would have
relaxed the high cruise speed requirement and put in a higher inertia
rotor system to allow more time to react to an engine failure.
Fully fuelled, the R22 is
barely capable of hovering with 400 lbs. of pilot and instructor on board.
If you're a tad overweight, now is the time to start your diet. If you're
too fat, you'll have to learn in a turbine-powered Bell JetRanger, which
costs a fortune per hour because of its costly maintenance requirements
and thirst for fuel.
Old school helicopter
pilots will scoff at the Robinsons for a variety of reasons, including the
low inertia rotor system, but basically there are no alternatives.
Schweizer, for example, which bought the old Hughes design, only
manufactures a handful of piston-engine helicopters each year.
Choosing a Flight School
and Instructor
There are four ways to
lose a flight: weather is unfavourably 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.
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 manoeuvre 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.
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 2:1 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 is also good but if the camera
needs the pilot to hover the helicopter slows to a crawl.
First Lesson: Air
Before you get into the
air you'll probably spend about half an hour on a pre-flight 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 manoeuvre:
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.
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 neighbours 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 anti-torque 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:
Focus your gaze at least
1/2 mile in the distance if the sightlines in your practice area are long
enough.
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.
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 centre. Nudge and then return.
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.
Take a break every 20
minutes by practicing takeoffs, trips around the pattern, and approaches
to landings.
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