Determining Performance and Lmitations Flashcards
What are the four dynamic forces that act on an airplane during all maneuvers?
Lift, Gravity, Thrust, and Drag
What flight condition will result in the sum of the opposing forces being equal
During unaccelerated flight
What is an airfoil? Examples.
Airfoil is a device which gets a useful reaction from air moving over its surface, namely LIFT
Wings, horizontal tail surfaces, vertical tail surfaces, props
Angle of incidence?
The angle of incidence is the angle formed by the longitudinal axis of the airplane and the chord of the wing.
Relative wind?
The relative wind is the direction of the airflow with respect to the wing.
What is angle of attack?
The angle of attack is the angle between the wing chord line and the direction of the relative wind
What is Bernoulli’s Principle
The pressure of a fluid decreases at points where the speed of the fluid increases.
In the case of airflow, high speped flow is associated with low pressure and low speed flow with high pressure.
What are several factors which will affect both lift and drag?
Wing area, shape of the airfoil, angle of attack, velocity of the air, air density
What is Torque Effect?
Torque effect involved Newton’s Third Law of Physics, for ever action there is an equal and opposite reaction. Applied tot he airplane, this means that the internal engine parts and the propeller are revolving in one direction, an equal force is tyring to rotate the airplane in the opposite direction.
What effect does torque reaction have on an airplane on the ground and in flight?
In flight -Torque reaction is acting around the longitudinal axis tending to make the airplane roll.
On ground - during the takeoff roll, an additional turning moment around the vertical axis is induced by torque reaction
What are the four factors that contribute to torque effect?
Torque reaction of the engine and prop
Gyroscopic effect of the prop
Corkscrewing effect of the propeller slipstream
Assymmetrical loading of the prop
What is centrifugal force?
Equal and opposite reaction of the airplane to the change in direction and it acts equal and opposite to the horizontal component of lift
What is load factor?
Load factor is the ratio of the total load supported by the airplane’s wing to the actual weight of the airplane and its contents.
It is the actual load supposed by the wings divided by the total weight of the airplane
2 reasons load factor is important to pilots?
Because of the obviously dangerous overlaod that is possible for a pilot to impose on the aircraft structure
Because an increased load factor increases the stalling speed and makes stalls possible at seemingly safe flight speeds
What situations may result in load factors reaching the maximum or being exceeded?
Level turns
Turbulence
Speed
What are the different operational categories for aircraft?
Normal, utility, aerobatic
What effect does increase in load factor have on stalling speed?
As load factor increases, stalling speed increases
Maneuvering speed?
Maneuvering speed s the maximum speed at which abrupt control movement can be applied ora t which the airplane could be flown in turbulence without exceeding design load factor limits
What is the effect of weight upon maneuvering speed?
Maneuvering speed increases with an increase in weight and decreases with a decrease in weight
What causes an airplane to stall?
When the critical angle of attack has been exceeded
What is a spin?
A spin is a manuever in which the airplane descends in a helical path while flying at an angle of attack greater than the critical angle of attack
What causes a spin
The primary cause of an inadventerant spin is exceeding the critical angle of attack while applying excessive or insufficient rudder, and to a lesser extent, aileron
When are spins most likely to occur?
Engine failure on takeoff climb out
cross control turn from base to final
engine failure on approach to landing
go around with full nose up trim
go around with improper flap retractoin
What procedure should be used to recover from an inadvertent spin?
Close the throttle
Neutralize the ailerons
Apply full opposite rudder
Briskly move the elevator control forward to approximately the neutral position
Once the stall is born, the spinning will stop, neutralize the rudder when the spinning stops
When the rudder is neutralized, gradually apply enough aft elevator pressure to return to level flight
What causes adverse yaw?
When the deflected aileron produces more lift than the other wing
Ground Effect?
Condition of improved performance the airplane experiences when operating near the ground
Define Arm
The horizontal distance in inches fromt he reference datum line to the center of gravity of the item
define moment
the product of the weight of an item multiplied by its arm. Expressed in pound-inches
What is the basic weight an balance equation?
Weight X Arm = Moment
What performance characteristics will be adversely affected when an aircraft has been overloaded?
Higher take off speed longer takeoff run reduced rate and angle of climb lower maximum altitude shorter range reduced cruising speed reduced maneuverability higher stalling speed higher landing speed longer landing roll excessive weight on nosewheel
What effect does a forward center of gravity have on an aircraft’s flight characteristics?
Stability - Good
Maneuverability - poor
Stall Characteristics - Good
Performance - Decreased
Effect of rearward COG on an aircraft’s flight characteristics?
Stability - Poor
Maneuverability - Good
Stall Characteristics - poor
Performance - improved
What factors affect the performance of an aircraft during takeoffs and landings?
Air density (density altitude) Surface wind Runway surface Upslope or downslope runway weight
What is the effect of increased weiht on takeoff and landing performance?
higher liftoff speed
Greater mass to accelerate
Increased retarding force
longer takeoff distance
What effect does an increase in dnesity altitude have on takeoff and landing performance?
INcreased takeoff distance
Reduction rate of climb
Increased true airspeed on approach and landing
increased landing roll distance
Define Density altitude?
Density altitude is pressure altitude corrected for nonstandard temeprature
How does air density affect aircraft performance?
Lift produced by wings
power output of engine
prop efficiency
drag forces
What factors affect air density?
Altitude - the higher the altitude, the less dense the air
Temperature - the warmer the air, the less dense it is
Humidity - more humid air is less dense
How does temperature, altitdue, and humidity affect density altitude?
A. Density altitude will increase (low air density) when one or more of the following occurs:
High air temp
high altitude
high humidity
B. Density altitude will decrease when one or more of the following occurs
low air temperature
low altidude
low humidity
What is pressure altitude and why is it important?
The altitude indicated when the altimeter setting window is adjusted to 29.92.
it is important because it is used to compute density altidue,true altitude, true air speed, and other performance data
