WattFlyer RC Electric Flight Forums - Discuss radio control eflight - View Single Post - Everything You Wanted To Know About Electric Powered Flight
Old 02-24-2008, 05:20 PM
  #24  
AEAJR
Community Moderator
 
Join Date: Aug 2005
Location: NY, USA
Posts: 5,827
Cool The Mythical Best First Plane

As many electric flyers are new flyers, I was asked to add a section on selecting your first plane. The next article is about what makes a good first plane and some of the issues to consider.

Note that I am only looking at electric planes or gliders. I have not taken other forms of power into consideration.

Your feedback and questions would be appreciated.

Ed Anderson
===========================


The Mythical Best First Plane
by Ed Anderson
aeajr on the forums

If you run a search on any of the RC forums you will find many posts that ask
for advice on the best first plane for them to get. The purpose of this
discussion is to show that there is no perfect first plane. But there are
things that can be taken into account to help someone pick an appropriate
plane.

Be advised that this discussion will be based on my personal experiences, my
bias, my prejudice, my research , what I have observed, and what I have been
told. That is exactly the basis that every one uses when they give you their
advice. So take this and mix it in with other advice you trust, as no one
person has the answer, only opinions based on our knowledge set.

Go and read, so you can build on what you read here. Then make an informed
decision and go with it. And when you are greeted by the first all knowing
guy who tells you that you made a mistake, you will be able to explain your
reasons, the considerations and the goals upon which you purchased that plane.
And if he doesn't agree? That's OK, we are all entitled to our opinions.

First Consideration - How are you going to learn?

An Instructor - The best, but not the only path to success

If you plan to learn to fly under the close guidance of an instructor, then do
NOT go and buy a plane. Go to your instructor and ask what they suggest.
Learning under an instructor is the best way to learn to fly. That
knowledgeable guide is going to take you through planned steps that will
impart skill and knowledge. So the best first plane is the one that allows
that instructor to do that. Your best first plane is the one s/he is most
comfortable using.

No one else's opinion matters as you have placed yourself in their hands and
should follow their lead. Otherwise why are you working with an instructor?
This opinion comes from a guy who has never worked under the close guidance of
a flight instructor but received much coaching from helpful and willing members
of the club I joined. But any journey of learning is best started with a
knowledgeable guide, and when you engage a guide, you follow them. Nuff said
about that!

A Coach - Much better than going it alone

A coach is an experience friend or club member who is willing to give you some
time, provide some assistance and point you in the right direction from time
to time. However they are not going to take on the close training
responsibility of an instructor. They will help, but you will be doing a lot
of the learning on your own. This is how I learned.

If you have not purchased a plane yet, be sure to ask your coach(es) for some
input as to the plane, or at least the design of the plane.

To be a coach, I feel the person has to spend some time with you on the field.
Perhaps they preflight your plane. Maybe they take it up for the first flight
to make sure it is OK. They may or may not use a buddy box. But the key is
that they will give you some help. Having a coach is a wonderful thing.
Things that are a mystery to you can be made clear in a moment by that helpful
coach.

The key is that you take on a lot of responsibility as you will be on your own
much of the time and there is probably no formal program that is being
followed. If you can't find an instructor, try to find a coach.

An Advisor

I and many of the people who post on these forums are trying to take on the
role of advisor. We can't be there with you but we can explain a few things,
and point you to good sources. We can tell you what has worked for us. A
coach is much better but you can have coaches and advisors and you can benefit
from the multiple sources of information. If you have an instructor, you can
ask for clarification from advisors but you should always take your lead from
your instructor. Whether a paid or not, they have made a commitment to you.
You have to do the same.


On Your Own

Here I mean that you bought something, read the instructions and tried to fly
it. Can you be successful? Sure! But the chance of success goes up as you
add levels of help. Find advisors, seek coaches and get an instructor if you
can. You are more likely to progress faster and your planes are more likely
to survive your progress. Flying is not a simple or obvious thing. It took
intelligent people thousands of years to learn how to do it. There is no
disgrace in you taking advantage of some of that previous experience and
knowledge. Get some help if you can.

If you have not purchased a plane yet, ask your advisors for some suggestions. ALWAYS
ask why they feel this particluar plane or feature is important. Sometimes their goals differ
from yours and you should factor this into your discussion.


WING DESIGNS

High, Mid or Low

Broadly speaking, airplanes have one of three wing locations. They are
either high wing, mid wing or low wing. This does not include things
like flying wings or delta wings. These don't have a fuselage in a
conventional sense. And, while there are people who learn to fly on
these designs, I don't consider them the first choice for
beginner/trainer planes.

Most people will agree that the better choice for beginner/trainer
planes are high wing designs. The reason is simple, with the wing high
and the fuselage hanging below, the plane tends to be more stable and
self righting. This can help keep a new pilot out of trouble.

Mid wing and low wing planes are typically less stable as the weight of
the fuselage is mounted around or above the wing. These planes are
typically more agile and aerobatic than the high wing planes. That P51
Mustang you saw at the hobby store is a good example. It may be a cool
looking plane but it isn't really the best choice for a first plane.
That is why the fighter pilots who flew it in combat started on
something else when they were learning to fly. It might be a good idea
if you did the same. They make good second or third planes once you have
mastered the basics of flight.

Dihedral

You will notice that some planes have wings that are basically straight.
That is, they come straight out from the fuselage. Others have an
upward angle where the end of the wing is higher than the root, the part
that attaches to the plane. This is called dihedral. On some planes
the upward sweep goes through two or three upward angles. In this case
we say the wing is polyhedral, or having many dihedral angles.

Wings with some dihedral tend be more stable and self righting than flat
wings. Wings with flat designs tend to be more responsive and will tend
to go where you put them, but also tend to stay there. This means that
if you bank the plane to make a turn, you better remember to bank it
back to level or it will stay that way. A banked wing will tend to lose
altitude if not managed properly. A plane with dihedral in the wing will
tend to return to level flight if you release the sticks.

In fact, when I am helping new flyers, if their plane has a fair amount
of dihedral, I will often advise them to release or center the stick if
they get into trouble. While not always the right thing to do, most of
the time the plane will right itself if it has enough altitude and
enough dihedral in the wing. It sounds funny but sometimes the planes
know better than we do when it comes to flying. We have to teach people
to let the plane fly.

Whether you are flying glow, gas, glider or electric, having some
dihedral in the wing of your trainer will help it to stay stable and
level during your early flights. To some extent dihedral will tend to
"fight" roll based aerobatics like inverted flight knife edges and the
like. However, when you are trying to master take-off, landing and
straight level fight, this is less of a concern.


ENGINE LOCATIONS

Many people expect the motor and propeller to be on the front of the
plane. However there are many places where the propeller can be
located. It can be a pull or push design. It can be in front or in
back. And while pure sailplanes don't have motors, e-gliders use a
motor as a launching system to get into position to look for lift.

There is much to be said for a pusher design on a first plane. On
take-off and during flight, the engine location may not matter on that
first plane. However when you come in for a landing, having the engine
and propeller high and out of the way can be very helpful. You are less
likely to hit the prop and, if you do come in hard on the nose, your
repairs are more likely to be restricted to fixing fuselage damage and
less likely to involve fixing or replacing the motor and/or propeller.

I don't have a problem with front motor designs as they are clearly the
most common. However I think that the pusher design has some advantages
for new flyers.


POWER SOURCE

Today RC aircraft are powered in a variety of ways, each having its
advantage. While there are good first/trainer planes in each category it
is worth a moment to explore the different ways to power your RC plane.


Gliders

Pure gliders or sailplanes have no motors. They achieve flight through
some sort of launching system. Once in the air they may simply glide
down or they may be designed for the pilot to look for natural sources
of lift such as thermals or slope lift. Clearly you have no fuel cost
and your battery needs are extremely modest. So the cost of fuel,
chargers, motor packs and the like just don't show up.

If this is a thermal glider, you will typically need some kind of
launcher. It might be a good arm toss for a hand launched/discus
launched glider or it might be a hi-start, an elastic system that
typically costs under $100 an lasts for years. If this is a slope
glider, then your fuel comes from natural air flow, but you have to find
the right location.

First gliders tend to be in the 1.5 to 2 meter, 60 inch to 80 inch range and
weight between 8 and 38 ounces. They typically fly fairly slowly.
This slow flight gives the pilot the advantage of having more time to
think and react to the plane.

The one down side of gliders is that they don't have the instant power
nature of powered planes. But their silent flight and low operating
costs can make them very attractive to new flyers.


Electrics

For electric powered aircraft, including e-gliders, you use a
combination of an electric motor and battery system to get your plane
into the air. Electric power has become very popular as battery and
motor technology has advanced. Today's sophisticated electric planes
can rival the performance of traditional fuel powered planes.

Electrics are quiet, clean and very dependable. On the other hand you have the
up front cost of battery packs, and battery chargers. If you allocate the cost
of these items over their useful life, electric flight is quite economical.

Electric power also lends itself to small planes and indoor use. Today you can
buy kits, ARFs or RTF electric planes that weigh 1 ounce or less. The broader
"parkflyer" weighs from 8 ounces to about 32 ounce and can be flown in areas
the size of baseball, football or soccer fields. Others require more room.

Some electrics can fly very slowly which allows them to be flown
indoors. Many of these "slow flyers" make excellent first or trainer
planes, even outdoors if you wait for calm weather.

Since you don't have the vibration inherent in internal combustion power
system, electric planes tend to be build lighter, however once you add
the battery system back in, an electric plane tends to be similar in weight to
comparable fuel planes, especially if they have modern brushless motors and
lithium batteries.

It should also be noted that over the duration of the flight, the available
power will start to drop off as the battery pack runs down. So maneuvers that
can be done
in the beginning of the flight might be difficult near the end of the flight.
This drop off will probably always exist but today's battery technology is
making this less and less of an issue as flight times extend from the 5 minute
flights of a couple of years ago to the more common 10-20 minute flights of
today.

One last point on electric power. Because it is clean and quite,
electric planes can sometimes be flown in locations where fuel powered
planes might be denied. This factor alone has probably been a key
contributor to the rise of electric power for RC airplanes.



CONSTRUCTION

Today you can select kits, ARFs and RTFs made from a variety of
materials. Which you choose is a matter of personal taste and your
desire to work with that material during a kit build or repairing crash
damage.

Balsa wood and light plywood construction is the tried and true material
for traditional kits. You can make very light strong structures that
fly extremely well. Add heat shrink polyester film covering materials,
silk or other covering materials you can construct almost anything using
simple tools and techniques.

First plane/trainers constructed in this way are fairly resilient, but
hard hits can result in breaks that will need to be taken to the work
bench to repair. A hard crash can produce serious structural failures.

A variety of foams have become popular. EPS, expanded polystyrene is
used in cups and packing materials. Major structures are often molded
from solid foam. It is light and fairly rigid. It can take a pretty
good hit and when it does break it tends to break in large pieces. A
little 5 minute epoxy can effect repairs in the field and get the flyer
back in the air fairly quickly.

However repeated impacts can cause permanent dents and damage that must
be fixed. Accumulated impacts that might not bother a balsa plane can
start to degrade the integrity of the foam causing a loss of shape.
Again repairs can be usually effected with pieces of foam and epoxy.

There are a wide variety of kits, ARFs and RTF planes based on EPS foam.
Because most of the structures can be molded to shape, the planes can be
built very inexpensively.

Elapor is a branded product of Multiplex. EPO, expanded Polyolefin and Z foam
are similar in character. These are more damage resistant than EPS, but not as
rigid so it sometimes requires more bracing than EPS. These foams will more
likely tear than shatter as EPS does. Using the right glue, each can be fixed
quickly so that the pilot will get back into the air quickly. In balance some
feel these are a better choice for models, so this group is growing in
popularity. Each has its own special character, but all seem to be a good
compromise between rigidity, weight and damage resistance. .

EPP, expanded polypropylene is another popular foam that has been around for a
while. It moves further from EPS in that it is less rigid than the rest of the
foams. In fact EPP is quite rubbery and tends to be heavier than the other
foams. As such it needs more bracing in order to maintain a solid wing or
fuselage shape. However for damage resistance EPP is the king. I have bounced
EPP planes off of hard surfaces and sustained no damage at all.

Planes made of molded solid EPS parts tend to be heavier than balsa or
EPS structures. EPP is so resilient that it has
spawned a new class of full contact combat flying. Popular with slope
glider flyers, EPP equipped pilots will intentionally crash into each
other to try to knock each other out of the sky. Since little or no
damage will result from the crash, the pilot can just relaunch for the
next round.

Molded Polystyrene and Polyethylene are also popular. Polystyrene is the
plastic typically used in plastic model kits. And Polyethylene is the kind of
plastic used in plastic milk bottles. Like the foams, these are inexpensive to
manufacture and can be quite resistant to damage. More commonly seen in small
electric RTF planes, these are growing in popularity.

Other forms of foam and plastic are also being used in first/trainer planes.
However the ones mentioned above cover the vast majority of models out there.
Their advantage over wood is resistance to damage and ease of repair. However
wood remains popular for the light and strong structures it can produce. The
foams and plastics just open up more options for new pilots.

Which you choose is up to you. If you like the idea of building with
wood, you will find a wealth of wood kit based first/beginner planes.

If you want to minimize the build, or minimize the chance of extensive
repairs, the foams may be more to your liking. And the plastics are
most typically seen in ARF or RTF packages rather than kits.

If we look at the electric plane market we see a much higher percentage
of foam and plastic planes as compared to the glow or thermal
gliders. This is especially true in the RTF part of the market.

While I have no statistics, I would guess that the sale of non-wood
first/beginner planes probably outnumber wood starters in the electric
market. That doesn't mean that the wood planes are going away just that
the market is expanding very rapidly and most of the expansion seems to
be in non-wood construction.

So, the good news is that you can have whatever you want to meet
whatever goals you set for yourself.


Channels of control - How many should you have?

Let's knock down some myths about channels and what can and can not be flown
and what can and can not be used to learn to fly. Today you can buy RC
airplanes with one channel of control and 12 or more channels of control.
They can all be flown and anyone who says they can't is wrong. Is that strong
enough?

Understand that each channel is used in some way to control the plane or some
function on the plane. From a flying point of view we will be focused on
attitude control. That is pitch, roll, yaw and speed. Broadly you can think
of them as up/down, left right and fast/slow.. This isn't correct,
but for the moment it will do. You can learn the true meaning of
pitch/roll/yaw and speed later.

The more channels of control you have, the more control you have over the
plane. Dah! However the more channels of control you have the more
responsibility you have in applying those controls. A 10 channel plane has
been designed with the assumption that the pilot knows how to use those
controls and has a sophisticated radio system to help them manage those
channels. Maybe it would be easier to learn if we had a plane that didn't
need our full understanding of 10 channels of control or a $500-$1,500 radio
system to fly it.

So how many is enough?

One - Probably Not

Two - Yes and Maybe

Two Channel Gliders Gliders - Yes!

Many gliders are two channel. Based on their design you can have very
effective control. You can even fly wild aerobatics at speeds in excess of
100 mph. Two channel gliders can be very exciting and wonderfully enjoyable.

Typically the channels will control pitch and roll. This can be done with
elevator/rudder or elevator/aileron. With these two axis of control we can
have excellent command of the plane. Of course the plane needs to be designed
properly for the controls it has, but that will be a given here. We are not
trying to design planes.

There are hundreds of successful and effective glider designs made for slope
soaring, thermal duration soaring, hand launch, discus launch and other forms
of flying. Zagi slope wings, Gentle Lady thermal gliders, Gambler discus
launched gliders and others are examples of this kind of plane. They can be
exciting to fly and can really teach you about flying. So, when someone tells
you that you can't control a plane with only two channels, they are very
wrong! Go to the glider field or slope soaring field and you will see all
the evidence you need.

It is for this reason that many people feel the best plane to use to learn to
fly is a glider. They are typically simpler in design, lower in cost, easier
to understand and do not suffer from complicated, expensive and troublesome
power systems. You could fly for the next 20 years, have a fleet of planes
and never need more than a two channel radio. You can even enter national
competitions and win championships with a simple, low cost two channel radio
and a two channel plane.

So, two channel gliders are excellent planes to use to learn to fly. I often
recommend them.

Oh, you never thought of gliders? Maybe you should.


Two channel - Rudder/throttle control or differential thrust - maybe

If one channel is used to control the electric motor, then we can control speed
and duration of the flight. Usually these planes have been designed to climb on
power and glide down on reduced power. Rudder is used to control direction.
Planes, like the Firebird series are of this type. By placing the motor at the
right angle, the application of power will cause the plane to pitch up and
climb. What this kind of plane can not control is negative pitch. That is, you
can't push the nose down to go into a directly controlled descent or dive. This
limits your control in windy situations or where you need a more rapid descent
than gravity and glide path provide.

My personal experience with these planes are that they fly well and are easy but
they can not be safely flown in much wind by a new pilot. Since you can't dive
into the wind they are easily blown away with the pilot having little ability to
fly the plane back up-wind. If you have one, fly it in calm conditions.

An alternate design is the differential thrust models that have two motors.
These planes have no flight control surfaces. Like the example above, when you
apply full power they tend to climb and when you reduce throttle they glide
down, but you can't direct the nose down to fight the wind. These planes steer
left and right by changing the speed of the motors.

My personal experience with these is that they are even less wind worthy than
the Rudder/Throttle planes. In dead calm conditions they can be fun but
control is so limited that I can't recommend them as trainers. But they can be
a lot of laughs.

Thousands of new pilots have had their first taste of flying on these
throttle/rudder pr differential thrust planes. And you can do some pretty cool
things with them.
However, without the ability to control downward pitch, to dive into the wind,
these planes can be very easy to lose in any sort of wind, especially for the
inexperienced pilot.


Three Channel - Electric Power - Yes

We already achieved a yes for gliders with two channels. For unpowered silent
flight, two is enough. In my opinion, when we have three channels to work
with we have enough control for the new power pilot to have a good command of
a plane with a motor. They can control pitch, roll and speed. The plane can be
managed
but the controls are still quite simple. A plane designed around this channel
count, can be a great learning platform and can carry the pilot long into the
future.

In my opinion, the most important asset we gain is the ability to push the
nose down so that we can penetrate into the wind. If you have ever seen a
glider pilot fly you know that even though he does not have a motor, he has
the able to fly down wind and to come back against the wind. This is done
through a controlled dive where the plane picks up speed so that its air speed
exceeds that of the oncoming wind and progress can be made over the ground.

Whether it is throttle/elevator/rudder or throttle/elevator/ailerons, this
plane can be controlled and therefore gives the new pilot the authority to
command the plane as he wishes. In fact very exciting planes can be made with
three channel control. They can be highly aerobatic or they can be slow
flyers that can fly indoors.

So, in my opinion with three channels we have reached the minimum channel count
for controlled powered flight. We have enough control, yet we can use very
simple and inexpensive equipment to fly the plane. A single stick radio with a
slide, lever or switch can provide all we need. I prefer proportional control
of the motor, but even with only on/off motor control you still have enough
control. However I always recommend proportional control for the motor.

For some, this will be all the control they will ever need. They can have
slow flyers, high speed aerobats, beautiful scale ships and never lack
positive control of the plane. This is where I started my flight training and
it has taken me quickly into all kinds of wonderful flying experiences.


Four or more channels. - Yes Yes

So, if three is enough, why do we need more? The answer is more channels give
us more control. While we have positive control of a three channel power
plane, we can have more positive control with four or more. Now we can have
throttle, pitch, roll and yaw control and apply them all at the same time or
any time of our choosing. This normally translates into throttle, rudder,
elevator and ailerons. This can provide more controlled landings, or make 3D
flight possible. Aerobatics can be much more sophisticated.

While 2 channel beginner gliders are very common and three channel beginner
electrics are common, glow powered starter planes are much more likely to have
four channels. Part of this is a matter of tradition and part has to do with
the nature of the plane. Glow powered starter planes are typically larger,
faster and more powerful than the typical starter electric. While the gliders
might be larger they are normally much lighter and travel at much slower
speeds.

A typical glow powered starter plane might be 5 pounds and capable of 50 mph.
It represents a lot more energy than a 3 channel 1 pound electric that is
moving along at 25 mph or a 30 ounce glider floating along at 10 mph. When you
tell that bigger faster plane to turn, you want to make sure you have as much
control
as possible.

For this reason, while I do not fly glow powered planes, when speaking with
potential new glow pilots, I normally recommend they equip themselves for a
minimum of four channels. There is no question that you can fly a glow
powered plane on throttle/rudder/elevator but you won't find many around on
the shelves of your local hobby store. Where you will see three channel glow
planes it is more likely to be in the flying wings and pylon racer designs.
However these are not your customary first/trainer planes in the glow world.


Five Plus - what are they for?

Let's just finish up with a brief overview of why you would ever have more
than 4 channels:

Retractable landing gear - 1 channel
Flaps - one channel
Spoilers/airbrakes - 1 channel
tow release - 1 channel
Scale features -
Bomb doors
Powered canopy
and on and on
Show features
Smoke
Glitter
just imagine

And some functions can benefit from using more than one channel.

It is very common to put a servo on each aileron and assign them to individual
channels. Now you can trim them from the radio and you can set up different
up throws from down throws to tune the plane for less drag. Using this setup
you can also double duty the ailerons as flaps or spoilers.

Flaps are likewise often split between two channels for more flexible
control.

Less common is the split elevator that has two servos on two channels that can
be made to follow the ailerons to make the plane roll faster or perform other
stunts more effectively.

It goes on and on. It takes expensive and sophisticated radio gear to handle
some of these functions, but that cost is going down and the ease of set-up is
going up. Many beginners are now entering the hobby with computer radios as
their first radio, or their first upgrade from an initial 2, 3 or 4 channel
standard radio.


SPACE

How much space do you have for flying? If you have totally clear space of at least 600'X600', about 9 square acres, approx 4-6 squarefootball/soccer fields, then most parkflyer class planes should be fine. These are planes that are typically two pounds or less that typically fly at about 40 mph or less. These planes are commonly powered by Speed 400 or 480 brushed motors. They also fly well at partial throttle so that you can fly at less than full power and have more time to think and less rush to turn.

If your space is more like 200X200, one square acre or one football/soccer field, then a different plane is in order. Now you want something more akin to a slow flyer. These planes do ver well under 20 mph and some can fly so slowly that you can almost jog with them. Their main challenge is their light wing loading and wign designs make them challenging to fly in more than about 5 mph winds. However, for a new flyer with limited space, they make wonderful first planes.

These are my own designations and are based on my subjective
ranking of the space a new flyer should have when learning on
his own. An experienced fyer can fly faster planes in smaller spaces,
but a new flyer wants to have more space so you are not in a constant
state of panic trying to turn.

Of course you can get above the edges of the field and expand your space,
but if you lose control, you drop in woods, on top of kids or smash
someone's windshield. If that windshield is in a car is traveling
down a road when you hit the windshield, you could cause an
accident or worse.

So much for space. You get the idea.


Summary

So, if you made it this far, you should get an award! By now you should have
seen that there is no ideal best first plane. It is a myth. Many planes can be
excellent first planes.

What we have discussed are the characteristics of planes that would be better
suited for new pilots.

So, here is my mythical best first plane:

High Wing
Significant dihedral
2 or 3 channel glider
3 or 4 channel electric
Foam construction - EPP, Elapor, EPO, Zfoam or EPS foam
I love gliders and feel they make great first planes/trainers
If it is power, I think the pushers are outstanding

I hope you found some of this useful, helpful and perhaps interesting. If not,
how did you get this far?

The AMA

The AMA, the Academy of Model Aeronautics, is an outstanding resource to the
new and experienced flyer. I encourage you to become a member. Here is an
outstanding series of articles published by the AMA that will be really useful
to new pilots. It is called, "From the Ground Up" by Bob Aberle. I highly
recommend
it.
http://www.modelaircraft.org/mag/FTGU/Part1/index.html

RC Clubs in the United States:
http://www.modelaircraft.org/clubsearch.aspx

International RC Clubs
http://www.fai.org/fai_members/addresses.asp


Good luck new pilot and welcome to RC flying!

Last edited by AEAJR; 02-24-2008 at 06:43 PM.
AEAJR is offline  
 
Page generated in 0.03198 seconds with 7 queries