Flight Controls And Stability Flashcards
Define directional stability
Stability around the verticle axis.
Pivots around the center of gravity
Outline longitudinal stability
Stability of pitching of the aircraft around the lateral axis
Outline lateral stability
Stability of roll around the longitudinal axis
What is dihedral and how does it effect the aircraft
Dihedral is the design of the wing where they are in an upward angle. Thus helps with lateral stability, and will make the aircraft return to a static balanced state when disturbed.
Advantage if high wing aircraft
Pendulum stability.
Due to the Center of gravity being below the wing this brings the craft back to a stable condition when disturbed.
When is anhedral wings used
When an aircraft is too stable (c-17) typically large transport high wing aircraft.
Reduce Dutch roll
For manourvability in high speed military aircraft
Outline keel surface in relation to aircraft
A force the tail fin and rudder experience during sideslip due to the airflow. This force is above the CoG so tends to right the aircraft
Swept back wing advantage in relation to stability
During sideslip to the new relative airflow the lower wing produces more lift than the higher wing. This is due to the shorter chord but larger camber generating more lift than a long chord and little camber. (High wing)
Outline primary flight control requirements
Instinctive Ease of operation Feel Smooth in action Safe and reliable
3 means to control flight control motive power
Mechanical
Electric
Hydrualic
Name 5 secondary flight controls
Flaps Slats Spoilers Speedbrakes Trim
In relation to spoilers what’s the difference between ground and flight
In flight spoilers are used to loose altitude without speeding up aircraft. Or they are used to help roll the aircraft. Assisting ailerons or functioning by themselves.
On ground they are used to destroy lift, create turbulence and drag to slow aircraft down after landing
Speed brakes purpose
To destroy lift by disrupting airflow to slow down the aircraft
Where are trim tabs located
On primary flight control surfaces
4 types of trim
Fixed
controlled
Variable incidence tail plane
Center of gravity
