Control, Flaps, Straight and Level Flashcards
more stability means
poor controllability
When pushing the control column aft, the elevator goes up, and the aerodynamic force acting on the stabilizer is:
downward aerodynamic force. It is being pushed down therefore increainsg the nose
The horizontal stabilizer and rudder are what kind of wing
symmetrical
The strength of the tailplane-elevator depends on:
the force applied
the length of the arm from the CG
relative size and shape
Stabilator or All-flying tail
The normal tailplane-elevator consists of a tailplane and an elevator which moves up an down. The all-flying tail completely moves.
Adverse yaw
When rolling, a different drag is created in each wings. (The wing going up - more lift - more drag)
Making the aircraft yaw to the other side
Differential ailerons
Help in reducing adverse yaw by creating a parasite drag on the lower wing
Frise-type aileron
Increase the drag of the descending wing. The aileron lower part lowers even more creating a increased parasite drag
Coupled ailerons and rudder
Causees the rudder to move automatically to reduce adverse yaw
Crosswind Sideslipping approach
Yawing the aircraft to the centerline above the ground. Unless touching down soon, the aircraft will drift to the direcion of the wind, therefore you should lower the into-wind wing
Servo tab / balance tab
A small portion of the end of the control surface is tilted the other way
Anti balance tab
Used in all-flying tail, since change to elevatar are more harsh, these anti balance tabs here to reduce the aerodynamic force and give the pilot a “feel”
Side effect of roll
Yaw
Side effect of yaw
Roll
The effectiveness of controls is enhanced at: low speed or high speed
High speed
Mass balance
Altering the CG of the hinged control to avoid fluttering controls
Effects of flap
Increased lift at lower airspeeds
Balloon effect
When lowering flaps, that airplane tendenacy is to lift itself. It should be opposed with down control force
Why does the nose changes pitch when lowering flaps
Because the weight-lift couple are changed, the CP moves aft
Balloon vs pitch when lowering flaps
The weight-lift couple change will pitch the nose up,
the balloon will only make the airplane climb for a short time
What happens to L/D ratio with flaps extended
Since lift is increased, the ratio is decreased.
The aircraft will not glide as far as it would
Lower flap levels vs higher flaps level
Each flap level will increase drag, but lower flap drag will be smaller compared to higher levels
“Lift flaps” def.
When the lifting capability of the wing is increased significantly for little cost in drag
Drag flap def.
When the lifting capability of the wing is increased (smaller tho) but higher cost of drag
Extending the flaps without changing power settings will make the airspeed (due to drag)
Decrease
How to balance the increased drag when lowering flaps
Either more thrust or a steeper descent
What happens to the stalling AoA when extending flaps
Being lowered. More flaps, the stall AoA is smaller
What happens to stall speed with increasing flaps
Lowered. We can fly lower air speeds
Vfe
Maximum flap extension speed
4 types of flaps
Simple, split, slotted, fowler
Simpe flaps
A flap at the trailing edge being lowered
Split flap
A flap at the trailing edge that is lowered, but a small surface area above it remains the same as the wing was before
Slotted flap
Air can flow in a slot between the leading edge of the flap and the wing, delaying the stall
Fowler flap
Moves backwards and down
Slats
A leading edge type of flap which allows air to flow through a slot between it and the wing, delaying the turbulent airflow caused at the upper surface due to high AoA
Flaps set at takeoff level will
Shorten the ground run and make the climb SHALLOWER
Lift-weight couple and thrust-drag couple canceling each other but not completely (one makes the aircraft nose up, the other noe down) what else also provides aerodynamic force?
The tailplane/eleavtor
To maintain a level flight in low airspeeds we need
to increase the cLift, that means to increase the AoA
When weight is reduced gradullay during flight, the lift force is stronger than the weight force. What can we do. Remember the foruma: L = cLift * 1/2rho*squared-V * S
Reduce speed or reduce cLift (angle of attack)
Reducing speed is preferable to maintain efficient L/D ratio
