Operation Manual

Sp_ecialist-terms
ref,erri ng
tci
fixed-wing
aircraft
Spoilers:
A'vague
term used
for any
part
of
the control system
which
primarily produces
drag
(and
sometimes aftects
wing
lift). For example: airbrakes,
rotating trailing
edge
brakes
or
camber-changing
flaps
which
can
be de-
tlected
more than 30 degrees
negative
or
positive.
Dividing the
flaperon into two
makes it
possible
to set
up
the functions
ol aileron and camber-changing
tlap
more efficiently
in aerodynamic
terms,
particularly
on
long-span
wings
(better
lift distribution and
improved
aileron
response).
In the
interests of
good
aileron
response,
the aileron
movement
of the outboard
control surface
should be
greater
than that of the
inboard surface;
on the other
hand, the llap
movement oJ the
inboard control surface
should
be
greater
than that of the
outboard surface,
to
ensure docile
stall behaviour.
camber-changing
flaps
(or
simply
flaps)
Fis 65
Control
surfaces
at the trailing
edge of the
wing, used to
vary the camber
of the
wing section, and thus
also the
characteristics
of the
wing, to suit
particular
Jlight
requirements.
Positive def lections
(flaps
down)
produce
an
increase
in the wing's
lift
coeflicient
(slow
flight), with
a slight
increase in drag. Small
negative deflec-
tions,
around
2
-
3 degrees,
reduce drag
for high-speed
llight.
lf flaps
are deflected
more than about
+30 degrees,
drag
rises considerably.
Flaps
make
a
usetul
landing
aid
(spoilers,
crow system).
Flaperons:
Fuli-span
control surtaces
at the
wing trailing edge,
which
double as
ailerons and
camber-changing
flaps.
Aibron Carn!,or
-
charu|.ng
naB
crow system
(aileron
brakes)
Fis 68
An
extension
of
the
"Quadro"
mixed function, utilising
the mixed control
surlaces as
"spoilers".
The inboard
control surfaces
are set to a
positive
braking
position
(flap
down),
the outboard surfaces
to a negative
braking
position
(flap
up). Used on
high-performance
gliders
(F3B
class)
which are
not Jitted with
proper
airbrakes or
sooilers.
Oandr€r
-
a*Lnging
lt
p
spolbr
Fig.69
camber-changing
flaps.
Snap-flaps:
Mixed
function: elevator
-
Cambr-
cha.qang nap
Often used
on aerobatic
models
to reinforce
the effect
of the
elevator.
lf up-elevator
is applied,
the camber-
changing
flaps are deflected
down; the
result is an
increase
in the wing's
lift coefficient.
Down-elevator
is
accompanied
by up{lap,
and the
wing's
litt
coefficient
is
reduced.
The overall effect
is that the aircraft
is capable
of
very tight
looping manoeuvres
-
ideal for the
"square"
figures.
Fig. 70
V-tail
(or
"
buttertly
tail')
Combined elevator
and
rudder in the
form of a
"V".
When elevator
is applied,
both control
surfaces
move in
the same
direction.
When rudder
is applied, they
move
in opposite
directions.
Fig.66
Delta
("elevons"):
Full-length
control
surfaces at
the wing trailing
edge, on
models
without a tailplane
(delta,
flying wing).
The
elevons
double
as ailerons
and elevators.
euadro:
Fis 6/
Full-length
control
surfaces
(flaperons)
divided
into two
separate
flaps
per
wing.
Each control surface
doubles
as aileron
and
camber-changing
tlap.
Carnber
-
cttarying
lbB
Apoibr
TC