EK Flashcards
(121 cards)
What are the forces acting on an aircraft in flight
Drag Thrust Lift and Weight
What is direct lift control
The elevator, stabilizer provide direct lift control
What are high lift devices
TE Flaps, LE Flaps. Slats
Define the two major types of drag
Profile+Induce drag = Total drag
What are high drag devices
TE flaps, spoilers, LDG, REV, braking parachute
How do you prevent span vise airflow on a wing especially swept wing
Fences, vortex generators
What is the purpose of vortex generators and fences
Reduce spanvise airflow and thereby reduce its effects
What are winglets and how do the work
Winglets are aerodynamically efficent surfaces located at the wing tips
They are designed to reduce INDUCED drag
They DISPENSE the s p a n w i s e airflow from the upper and lower surfaces at different points
How does a forward CG affect the stall speed
A CG forward Center of Pressure will cause a higher stall speed
What advantages does an aircraft gain from a swept wing
High mach cruise speeds
stability in turbulence
Where does a swept wing stall first
A simple swept or tapered wing will stall the the wing tip first
Explain speed stability
It s the beahviour of the speed after a disturbance at a fixed power setting
What is Mach number
Mach number is a true airspeed indication given as percentage relative to the local speed of sound
What is Mach crit
Mcrit is the aircrafts mach speed where the airflow over a wing becomes sonic
What is Mach tuck
It is the nose down pitching moment an aircraft experiences as it passes its critical mach number
What is the purpose of a mach trimmer
A mach trimmer is to compensate automatically for mach tuck above mcrit
What are the effects of compressibility
The effect of air being compressed onto a surface resulting in an increase in density and thus dynamic pressure rises above its expected value
What changes the aircrafts AOA at the stall
The movement of the Center of pressure point at the stall causes a change in the aircrafts angle of attack
What happens to the stall speed at high alt
Mach number compressibility effect on the wing results in a higher EAS actual equivalent airspeed compressibility error on the IAS increases the stall speed
What is a super stall
It is a stall from which the aircraft is unable to recover
What is dutch roll
an oscillatory instability - it is the combination of yawing and rolling motions
What causes a dutch roll
Swept wings
What are the three puposes of spoilers
Roll control, air speed brakes and ground lift dumpers
What are Krueger flaps
Leading edge flaps used to increase the wing chamber