Lecture 9 Flashcards
High wing benefits
Better lift/drag ratio
Better lateral (roll) stability
Shorter ldg distances
Low wing benefits
Easier to build strong landing gear support
Better roll maneuverability
Shorter takeoff distance
Which wing configuration is the most susceptible to ground effect?
The one with the wings closest to the ground.
Tee Tail Horizontal Stabilizer
TEE tail allows flow over the rudder at high AOA. Typically the horizontal stabilizer blocks the air flow= no rudder= no yaw control. This keeps the horizontal stabilizer and rudder out of the main wing downwash
Disadvantages of tee tail horizontal stabilizer
vertical stabilizer must be larger and heavier
What does the Tee Tail decrease?
Interference drag by eliminating number of acute angles
Pressure drag and skin friction drag by eliminating one of the horizontal flight controls
What happens when you press the left pedal on a tee tail?
deflects the left-hand ruddervator down and left and the right-
hand ruddervator up and left
How to produce up pitch with tee tail?
moving the control column or stick back which deflects the left-hand ruddervator up and right and the right-hand ruddervator up and left
Why do fighters have 2 tails?
to be able to stabilize in the event of damage and reduce the height needed for full control
Biplanes have short wings and short wing spans because…
Short wings= fast rolls
Short span wings = thinner than monoplane wings and still strong
Flying wires
Transmit the lift back to the fuselage
Landing wires
Transmit the downward impact of landing, or negative G loads, on the wings back to the fuselage
Interplane struts
Transmit the lift loads and landing loads between the top and bottom wings
Cabane struts
Support the top section of wing above the fuselage and transmits the lift loads
Center Section
an airfoil shaped section above the fuselage to which the upper wings attach
Interplane Interference
Airfoils flying in proximity reduce the pressure differential differential
What is the “gap”
the distance between the chord of the top wing and the chord of the bottom wing (interference becomes a problem when the gap is less than one chord length apart)
What is Decalage
the angle of difference between the upper wing and lower wings of a biplane
one of the wings is set to a higher angle of incidence than the other wing
Main advantages of ruddervators
Lighter, less wetted surface, less drag
Increase stealth- canted surfaces reflect the radar away from source
Reduce infrared signature
Improve safety and reduce cabin noise
Main disadvantages of ruddervators
Require a more complex rudder system
Required to be more structurally robust
Control forces required for operating the ruddervators are higher
Tandem wing
Both wings lift up and no horizontal stabilizer pulls down- limited CG range
Who made and what is a canard wing?
Wright brothers, special type of tandem wing
Negative of canard wing and solution
Less pitch stability. The canard wing stalls before the main wing
Do most airplanes worry about CG movements left and right?
No
If we took away the tail, how would the airplane fly?
Use split control at wingtips- split rudders
Move ailerons inboard and combine with elevators- Elevons
