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Beginners Guide to I.C. Flight – As Published by the BMFA -PART 2
February 12, 2012
5:02 pm
Forum Posts: 111
Member Since:
February 1, 2012
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Before you take your aircraft to the flying field you must ensure that your transmitter and receiver
batteries are fully charged. Naturally these will be rechargeable cells and not torch batteries!
Your radio gear instruction booklet will give you all the information on connecting up your
batteries for charging and you should follow this advice meticulously. The day before you intend
to use the radio for the first time, give both batteries a full 18 hours on charge. If, as most people,
you only fly at the weekend, give your batteries a full overnight charge (10 to 12 hours) before you
fly. As a fairly broad ‘rule of thumb’, every 20 minutes of ‘switch-on’ time requires 2 hours of
charging time to top up the batteries. So if you have, say, four flights in a day you will need to
charge for at least 8 hours before your next day’s flying.
Even if you do not fly at all, the batteries will still discharge slowly when not in use. The batteries
will require 30 minutes charging time for every day out of use. Therefore, if you do not use your
radio gear for a week, it will need a minimum of 30 minutes x 7 days = 31/2 hours of charging
time to bring them back to full charge provided that they started the week fully charged. If you had
a flying session before the week of non-use, then you should give the equipment a full overnight
charge of 10 to 12 hours.
Ni-cads are very tolerant and will easily withstand a 100% overcharge or more, especially if you
are trickle (or ‘slow’) charging them. Don’t ever be afraid to give an overnight charge if you have
any doubt at all about the state of your batteries.
If, for any reason, you have dry cell torch batteries in your radio gear you should begin each flying
session (say a weekend) with fresh batteries. The main danger with using dry cells is that you
never know how much power is left in them and a power failure in the air can only lead to
disaster. Our earlier advice could bear repeating – buy rechargeable batteries right from the start.

As you already know, on the transmitter the right-hand stick controls the elevator and the ailerons
(rudder in 3 channel mode). Moving the stick towards you will raise the nose of the aircraft in level
flight: moving it away from you will lower the nose. Moving the stick to the left or right will cause
the aircraft to bank in the same direction - and turn - that way.
These controls are spring loaded so that they always return to the neutral position when released.
This particular stick is the equivalent of the control column in a full-size aircraft and is therefore
often referred to as ‘the stick’.
On the left-hand control stick, back and forward movement operates the throttle. This control is
not spring-loaded but operates on a ratchet so that it remains in whatever position it is set.
Side to side movement on this control operates the rudder in the appropriate sense on 4-channel
aircraft. On 3-channel aircraft (elevator, rudder and throttle) it is usually left unused as the rudder
is connected to the ‘aileron’ control on the right-hand stick.
Alongside each of these controls on the transmitter are sliding levers which are the trims for each
control. These effectively alter the neutral position of the related control so that by using them
when the aircraft is in the air you can cancel out any out-of-balance forces which make the
aircraft tend to climb/dive or turn. They work in the same sense as the stick they are associated
with. If you pull the elevator trim towards you the nose of the model will rise and vice versa.
Get very familiar with your transmitter. Hold it as if you were flying and get to know where all the
controls are by touch. When you are actually in the air there simply won’t be time to look at the
transmitter to find out where a particular control is located - and you’ll probably be unable to find
your aircraft when you look up!
Now, having told you all about the controls on your radio, let us see how these relate to the
control surfaces on your aircraft.

The elevator controls the pitching moment, that is to say it raises and lowers the nose of the
The ailerons give lateral control, banking the wings from side to side
The rudder moves the nose of the aircraft to the right or the left
The throttle lever controls the power which the engine delivers - fully forward, with the throttle trim
also fully forward, gives full power: fully back, with the trim fully forward, gives flight idle (the
engine runs at a safe idle speed and will not cut in flight): fully back, with the trim also fully back,
will stop the engine running. You will need to set this all up on the ground and you should ask
your instructor for help with this.

Let’s look at an aircraft in level flight and see how the controls work.
The elevator is used to hold the aircraft level. Backward movement on the stick will cause the
nose to rise and the aircraft to climb, although not for long unless power is increased. Similarly,
forward movement on the stick will cause the nose to go down and the aircraft will dive, building
up a lot of speed unless power is reduced. So you see, the throttle and elevator controls affect
one another to an extent. An increase in power in level flight will cause the aircraft to climb unless
the stick is moved forward to hold the aircraft level, in which case the aircraft will fly faster.
Similarly, if power is reduced the aircraft will descend unless the stick is held back, in which case
the aircraft will fly more slowly.
If you find that to hold the aircraft level you need a constant pull or push on the stick, you need to
use the trim facility. Just move the trim lever in the same direction as the pressure you are using
to hold the aircraft level until the aircraft will fly level with the stick in neutral. After trimming you
will, of course, still have to make the necessary stick movements to ‘fly’ the aircraft or hold it level.
The aileron control is used to keep the wings level when in level flight. The stick is moved to ‘pick
up’ the wing which is down. You will find that if you can keep the wings level the aircraft will fly in
a straight line.
However, if you fly in a straight line for very long the aircraft will soon be out of sight. You must
continually make turns and to do so you use the aileron control - whether it is linked to the
ailerons in a four channel aircraft or to the rudder in a three channel aircraft. Moving the aileron
control to the side will cause the aircraft to bank in that direction. When the aircraft has banked
about 20o use the control to stop the aircraft banking further and to hold that steady angle of
bank. The aircraft will now start to turn, but it will also tend to drop its nose so be ready to apply a
little ‘up’ elevator to keep the nose up. This will also help the aircraft to turn. To straighten out
from the turn, simply bank the aircraft back until the wings are level (relaxing the back pressure
on the elevator) and the aircraft is once again in level flight.
If you have a four channel trainer you will have discovered that you do not need to use the rudder
at all to turn - it is done entirely by use of the ailerons and the elevator. With three channel aircraft
(rudder connected to the ‘aileron’ control) the control is exactly the same. Stick left and the
aircraft will bank and turn left, stick right and the aircraft will turn right.
The reason why these controls are interchangeable is due essentially to the high wing position
and the dihedral angle of the wing. Your instructor will explain the ‘whys and wherefores’ of this to
you. But the big advantage of having separate aileron and rudder controls comes when the
aircraft is on the ground and it can be steered whilst taxying by use of the rudder which is usually
also linked to the nose or tailwheel to give accurate ground manoeuvring. The rudder also has an
important function in the air, mainly in aerobatics though.
As we have already said, the throttle control determines the amount of power the engine is
providing to fly the aircraft. Full throttle is used for take-off, overshooting and many aerobatic
manoeuvres. Low throttle settings give glide, taxying power and, with the trim fully back, ‘engine
stop’ facility. Intermediate throttle positions are used for different conditions of flight and that
power setting which gives a pleasant, relaxed flying speed, neither too fast nor too slow, is known
as ‘cruising power’. The setting for this varies between aircraft, but is normally rather less than
half throttle.

As we said earlier, each club will probably have several members who are BMFA Approved or
Registered instructors and who will willingly teach newcomers to fly, but here we would like to
give you one or two words of advice!
Firstly, your instructor’s word is law when your aircraft is in the air. If he tells you to do something
- do it immediately and without question. By all means discuss it on the ground AFTER the flight if
necessary, but obey implicitly in the air.
Secondly, you must not hold your instructor responsible if the aircraft crashes during a test flight
or at any other time. No responsible instructor will allow your aircraft to crash if he can possibly
avoid it and he will do all he can to prevent the aircraft getting into a situation which could result in
an accident. But he is only human and during your training there will be many occasions when
you are required to fly near the ground when safety margins are very small (take-off and landing
for example) so hard landings and worse are an unavoidable hazard of the sport. Accept these
hazards, trust your instructor and have confidence in the robustness of your aircraft.
Thirdly, try to stay with the same instructor throughout your training. Each instructor has his own
style and if you switch from one to another you may well get confused and it will certainly take you
longer to learn - even though all instructors may be working from this manual.
Some instructors use the ‘Buddy Box’ system, linking two transmitters together so that the
instructor can take over control instantly when necessary. The big advantage of this system is
that early flying can be done at a lower altitude safely so that the aircraft can be seen more
clearly and mistakes more quickly appreciated. During take-off and landing training, too, the
instructor has a greater latitude in taking over when a difficult situation develops. However the
system has some disadvantages in that at later stages of training the student can become too
dependent on the instructor to take control when things go wrong when really the student should
be relying on his own ability to correct errors. In other words, the system can speed up early
training but you should beware of becoming too dependant on it as you progress.
In describing what he wants you (or the aircraft) to do, the instructor will say ‘left’ when he means
YOUR left on the transmitter. For example, if he says ‘turn left’ he will expect you to move the
control to the left and consequently the aircraft will turn to its left - although it may not appear so
to you at times! ‘Up’ and ‘down’ commands require no explanation.

Before you take your aircraft to the flying site there are certain checks which must be carried out.
Make sure that your aircraft balances at the Centre of Gravity point shown on the plan. If you do
not know where this point should be, balance your aircraft so that you can pick it up level with
your fingertips under each wing at a point approximately one-quarter to one-third back from the
leading edge. Check also the lateral balance to ensure that one wing is not heavier than the other
(balance on the spinner or prop nut and the fuselage near the rudder). If it is, make it balance by
adding weight to the ‘light’ wing’s tip.
Ensure that the control surfaces move in the correct direction and that they operate smoothly. At
home, switch on the transmitter, then the receiver, and move the sticks to check the controls:
stick forward - elevator down: stick left - left aileron comes up, right aileron goes down: rudder left
- rudder moves left. If your check is done at the flying field, you must ensure that the frequency
control system is complied with BEFORE switching on.
Push the model along the ground and see that it runs straight, without any wheel binding. If it
veers off right or left, correct this by adjusting the nose or tailwheel.
If you have only ‘bench run’ your engine, now is the time to test it in the aircraft. Start the engine
and check that the transmitter control operates the throttle correctly without any trace of stiffness.
Check that ‘fully forward’ on the throttle control gives full power: ‘fully back’ gives a satisfactory
idle: ‘fully back’ with the throttle trim also fully back stops the engine. If any of these controls are
out of adjustment, re-set them correctly.
You are now ready to get to the flying site for your first flying lesson!

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