11.1 Aerodynamics Flashcards
What are the three main aircraft axes?
. Lateral
. Longitudinal
. Vertical
Regarding the 3 aircraft axes what motion acts around them?
. Lateral = pitch
. Longitudinal = roll
. Vertical = yaw
What are the three primary flight controls?
. Ailerons
. Elevators
. Rudder
What are the 4 secondary flight controls?
. Slats
. Flaps
. Flight spoilers
. Trim systems
What may be added to increase the efficient of aileron flying control surfaces?
Roll spoilers
What is used for roll control around the longitudinal axis?
2 ailerons
When one aileron deflects upwards….?
The aileron on the other wing deflects downward
When are both the inboard and outboard ailerons used for roll control?
During low speed flight to improve turn efficieny
During high speed flight, only the ……. Aileron is used
Inboard
What is used for pitch control around the lateral axis?
Elevators
Do elevators move at the same time or are they differential?
They operate at the same time in same direction
Up deflected elevators create what effect?
Nose up attitude
Why is the stabiliser sometimes referred to as an all moving tail?
Because it has a fully movable aircraft horizontal stabiliser
What aircraft are stabilators normally found on?
High speed military aircraft
What is the purpose of a stabilator?
To enhanced manoeuvrability and eliminate Mach tuck caused by shock waves
What happens if the pilot pulls the yoke rearward ( towards them)?
Nose will go up, elevators deflected up
Where is a canard located?
Fuselage mounted, horizontal surface, fwd of wing.
What does a canard provide?
Longitudinal stability and control
What are the two main designs of a canard?
. Lifting canard
. Control canard
What is the rudder used for?
Used for yaw control around the vertical axis
What is the purpose of the rudder limiter system?
It limits the amount the rudder can move at high speeds
What is the degree of full rudder travel of travel up to 150 knots?
30 degrees
What is the difference between speed brakes and spoilers?
Speed brakes are purely to cause drag
Whereas, spoilers increase drag and reduce lift
How much does a plain flap increase lift by?
55%
How much does a fowler flap increase lift by?
95%
Describe a slat
A movable leading edge of the wing, when retracted, forms a slot
What are the two main drag devices?
. Air brakes
. Spoilers
Where are spoilers located and what is the purpose of them?
Located on upper surface of wing close to trailing edge.
Function is too increase drag and decrease lift
What is the purpose of a vortex generator?
Improves boundary layer control
How does a vortex generator work?
Takes relatively high energy air from outside of boundary layer and mixes it with low energy air in the boundary layer, thus reducing span wise flow
What do stall wedges (strips) ensure?
That the root stalls before the tip
What does the trim system compensate for?
Compensates for any imbalances of the aircraft for a steady flight
What are the three things control collum systems can be divided into?
. Control input
. Control transmission
. Control surface output
What does the side stick control?
. Pitch ( elevators) - up and down
. Ailerons - left and right and roll spoilers for roll control
How is rudder control done?
By rudder pedals
Where are the control inputs for secondary flight controls normalled placed?
On the pedestal
Control inputs can be done by three different ways, what are they?
. Hydraulically
. Electrically
. Mechanically
Where are control surfaces normally placed and why?
At the trailing edge of the profile, so it can change the camber size to facilitate for increase or decrease of lift
A basic control surface is an aerodynamic horn, where is it placed and why?
Located just forward of the hinge line
Moves into the wind during deflection aiding movement
What is the purpose of the balance tab?
Changes the camber of control surface and accelerated air flow at trailing edge which assists the deflection of control surface of pilot
What control surface requires a mixer unit?
Ruddervators
What is the purpose of the anti balance tab?
The anti balance tab deflects in the same direction as the control surface which increases the efficiency of the control surface but makes the deflection effort harder for the pilot
How does the control tab work?
The pilot operates the tab and the lift produced by the tab operates the control surface. The pilot can feel the air load on tab and not the control surface
What is the tim tab used for?
To correct any imbalances in the aircraft
How is the trim tab operated?
From the cockpit via a cable system, a screw jack and a trim rod
How do ailerons respond if the pilot rolls the aircraft to the left?
The aileron on the left wing moves up and the aileron on the right wing moves down
What is the effect of pulling the control column rearwards?
Elevators deflect upward, nose up
