EGN 1007 -Introduction to
Aeronautical Engineering
Part II - Aircraft Controls
The 3 axes of movement
Unlike a car,
which moves in
2 dimensions
(left or right), a
airplane can
move in 3
dimensions
• Lateral Axis (the “pitch”)
• Longitudinal Axis ( the “roll”)
• Vertical axis (the “yaw”)
Ailerons and the “ROLL”
A yoke or control wheel
is a device used for
piloting in most fixed-wing
aircraft, analogous to a
steering wheel in an
automobile.
Moving B left or right
controls the roll by
moving A up and
down
Elevators and the “PITCH”
By moving B (yoke
or control stick)
backwards or
forwards a pilot can
move part C, the
ELEVATORS, up or
down.
Rudders and the “YAW”
Foot pressure on the left
rudder pedal moves the
rudder to the left, causing
the nose of the airplane to
move to the left. The
opposite is true when using
the right rudder pedal.
Using BOTH the rudder and ailerons :
“SLIP/SKID”
A slip is an aerodynamic state
where an aircraft is moving
sideways as well as forward
relative to the oncoming
airflow. Flying in a slip is
aerodynamically inefficient
and can also cause motion
sickness in passengers.
however there are common
situations where a pilot may
enter a slip deliberately by
using opposite rudder and
aileron inputs, most
commonly in a landing
approach at low power.
Basic Aircraft Instruments
Six basic instruments in a light twin-engine
airplane arranged in the basic-T.
From top left: airspeed indicator, attitude
indicator, altimeter, turn coordinator, heading
indicator, and vertical speed indicator
Airspeed indicator
Shows the aircraft's speed
(usually in knots) relative to
the surrounding air. It works
by measuring the ram-air
pressure in the aircraft's
pitot tube (slide 14). The
indicated airspeed must be
corrected for air density
(which varies with altitude,
temperature and humidity)
in order to obtain the true
airspeed, and for wind
conditions in order to obtain
the speed over the ground.
Attitude indicator
Shows the aircraft's attitude
relative to the horizon. From
this the pilot can tell whether
the wings are level and if the
aircraft nose is pointing
above or below the horizon.
This is a primary instrument
for instrument flight ( slide
13) and is also useful in
conditions of poor visibility.
Pilots are trained to use
other instruments in
combination should this
instrument or its power fail.
Altimeter
Gives the aircraft's height
(usually in feet or meters)
above some reference
level (usually sea-level) by
measuring the local air
pressure. It is adjustable
for local barometric
pressure (referenced to
sea level) which must be
set correctly to obtain
accurate altitude readings.
Turn coordinator
The turn coordinator is
an aircraft instrument
which displays to a
pilot information about
the rate of turn, rate
of roll, and the
'quality' or
'coordination' of the
turn.
The quality of turn is indicated by an
inclinometer. This is a glass tube
mounted on the face of the instrument,
below the symbolic airplane.
Heading indicator
The heading indicator
(Directional Gyro or DG) is an
instrument used in an aircraft
to inform the pilot of his
heading. The primary means
of establishing heading in most
small aircraft is the magnetic
compass, but that suffers from
errors created by the 'dip' or
downward slope of the earth's
magnetic field. To remedy this,
the pilot will typically maneuver
the airplane with reference to
the heading indicator, as the
gyroscopic heading indicator is
unaffected by dip and
acceleration errors.
Vertical speed indicator
Also sometimes called a
variometer. Senses
changing air pressure
and displays that
information to the pilot
as a rate of climb or
descent, usually in feet
per minute or meters
per second.
Instrument (IFR) vs. Visual (VFR)
Instrument flight rules (IFR) are a set of
regulations and procedures for flying aircraft
whereby navigation and obstacle clearance is
maintained with reference to aircraft
instruments only.
IFR is an alternative to visual flight rules (VFR),
where the pilot is ultimately responsible for
navigation, obstacle clearance and traffic
separation using the see-and-avoid concept.
Pitot tube
A Pitot tube is a
pressure measuring
instrument used to
measure fluid flow
velocity, and more
specifically, used to
determine the
airspeed of an
aircraft.
Takeoff
There are several types of
takeoffs:
• Regular Field – Using the
normal runway length
• Short Field – Using very
little runway in the case
there may be a possible
obstacle
• Soft Field – When there
is a chance you may get
stuck (mud)
Landings (Crab, De-Crab, Side Slip)
De-Crab
The objective of this technique is to maintain wings
level and the aircraft position near the runway
centerline during approach. The nose points into the
wind so that the aircraft approaches the runway
slightly skewed with respect to the runway centerline
(crabbing).
Landings (Crab, De-Crab, Side Slip)
Crab
This is similar to the De-Crab technique. The principal
difference is the aircraft touches down whilst still
crabbing. The position on the runway is corrected
after touch down. This applies significant slip angle to
the tires, and increases the lateral loads on the
undercarriage, so this technique is bounded by speed
restrictions and is not generally recommended.
Landings (Crab, De-Crab, Side Slip)
Landings (Crab, De-Crab, Side Slip)
This requires a higher
level of skill. The
purpose of this
technique is to
maintain heading
aligned with the
centerline
The initial phase of the approach is flown using the Crab
technique to correct for drift. With a slight residual bank angle, a
touchdown is typically accomplished, for the cross wind
direction shown, with the right main wheels touching down just
before the left wheels.