Chapter 4 Performance and Limitations Flashcards
Vno
Normal operating speed
Moment
Product o the weight of an item multiplied by an arm. Expressed in lb/in
Basic equations to find center of gravity
WeightxArm = Moment Moment/Arm = Weight Arm(CG) = Total Moment/Total Weight
Vfe
Max flap extension speed
Increase in density effect takeoff and landing
A. Increased takeoff distance (greater TAS)
B. Reduced rate of climb(decreased thrust and reduced acceleration)
C.increased true airspeed on approach and landing
D. Increased landing roll distance
Pressure alt
Alt. Indicated when altimeter setting window is adjusted to 29.92. Alt above the standard datum plane
Air density affect aircraft performance
A. Lift produced by the wings
B. Power output of the engine
C. Propeller efficiency
D. Drag forces
Center of Gravity
The point about which an aircraft would balance if it were possible to suspend it at that point. Expressed in inches from datura
What factors affect air density
Alt.—>the higher the less dense the air
Temp.—> the warmer the air, the less dense
Humidity —> more humid air is less dense
Vy
Best rate of climb speed
Vx
Best angle of climb speed
Arm
Horizontal distance in inches from the reference datum line to the center of gravity of the item
Gross Weight
Max allowable weight of both the plane and it contents
When are spins most likely to occur
A) engine failure on takeoff during climb out-
B)crossed-control turn from base to final(slipping or skidding turn)
C)engine failure on approach to landing
D)Go-around with full nose trim-up
E)Go-around with improper flap retraction
Vsi
Stall speed clean or in specified config
Empty Weight
Weight of the airframe, engines, all permanently installed equipment, and unusually fuel. Depending on the FARs under which was certified, undrainable oil or full reservoir of oil is included
Weight affect takeoff and landing
A. Higher liftoff speed
B. Greater mass to accelerate(slow acceleration)
C. Increased retarding force(drag and ground friction)
D. Longer takeoff distance
Datum
An imaginary vertical plane or line form which all measurements of arm are taken. Established by manufacture
Vne
Never exceed speed
Vle
Max landing gear extension speed
Recover From Spin
Power-reduce to idle
Ailerons-position to neutral
Rudder-apply full opposite against rotation
Elevator-apply positive, forwarded of neutral, movement to break stall
Load Factor
Ratio of the total load supported by the airplane wing to the actual weight of the airplane and its contents. Actual load supported by the wings divided by the total weight of plane. Ex: weight of plane is equal to 1G and if load of 3x the actual weight of plane imposed upon the wing the load factor is equal to 3G
Forward center of Gravity
Higher stall speed
Slower cruise speed
More stable
Greater back elevator pressure required
2 reasons load factor is important
A) dangerous overload
B) increase load factor increases the stalling speed and makes stalls possible at seemingly safe flight speeds
Adverse Yaw
When turning the opposite wing that is raised causes more drag and lift attempting to pull the nose towards the lifted wing, the undesired direction.
Centrifugal force
The equal and opposite reaction of the airplane to the change in direction, and it acts equal and opposite the horizontal component lift
Useful load
Weight of pilot, and anyone else on board, useable fuel and drainable oil
What factors affect performance during takeoff and landings
A. Air density B. Surface wind C. Runway surface D. Upslope or downslope of runway E. Weight
Spin
Is controlled or uncontrolled maneurver in which the airplane descends in a helical path while flying at an AOA greater than the critical AOA. Caused by exceeding critical AOA while applying excessive or insufficient rudder and lesser extent, aileron
Vso
Stall speed in landing config
Va
Maneurving speed
Maneurering Speed
Max speed at which the limit can be imposed without causing structural damage. Allows to stall before an increase in load factor that would exceed the limit load.
Increases with increase in weight and decrease with decrease in weight
May result in load factors reaching the max or being exceeded
- level turns—>load increases significantly after the bank has reached 45* or 50*. Load factor on 60 deg. Is 2G
- turbulence—> severe vertical gusts cause a sudden increase of AOA results in large loads which are resisted by inertia of plane
- speed—> load depends on the speed. Speeds below manuerving speed plane will stall before the load factor can become excessive. Above maneuvering speed, limit load factor can be exceeded by excessive application of the controls
Vlo
Max Landing gear operating speed
Rearward Center of gravity
Lower stall speed
Higher cruise speed
Less stable
Ground Effect
Improved performance the plane experiences when its operating near the ground. Airflow around the wing is restricted by the surface.
Performance characteristics affected when overloaded
A. Higher takeoff speed B. Longer takeoff roll C. Reduced rate and angle of climb D. lower max alt E. Shorter range F. Reduced cruising speed G. Reduced maneurverabililty H. Higher stalling speed I. Higher landing speed J. Longer landing roll K. Excessive weight on the nosewheel
Density alt
Pressure alt. Corrected for nonstandard temp. Under standard atmospheric condition, air at each level in the atmosphere has a specific density, and under standard conditions, pressure altitude and density altitude identify the same level. Density alt. Is vertical distance above sea level
