Performance and Limitations Flashcards
What is the CG shift formula?
a. What is the weight addition/removal formula?
Weight shifted / total weight = Change in CG / Distance weight is shifted
a. Weight added or removed / new total weight = Change of CG / Distance between location where weight is added / removed and old CG
Define the following weights.
a. Standard empty weight
b. Optional or extra equipment
c. Basic empty weight
d. Useful load (disposable load)
e. Payload
f. Operational empty weight
g. Max gross weight
h. Zero fuel weight
a. Weight of the airframe and engine with all standard equipment installed. Also includes unusable fuel and oil
b. Additional instruments, radios equipment, etc, installed but not considered standard. Also includes fixed ballast, fuel engine coolant, hydraulic and deicing fluid
c. Weight with all optional equipment included. Full oil is usually included.
d. Difference between gross takeoff weight and basic empty weight. AKA all load that is removable. Includes usable fuel, the pilot, crew, passengers, baggage, freight, etc.
e. Load available after the pilot, crew and usable fuel have been deducted
f. Basic empty weight plus the pilot. Excludes payload and usable fuel.
g. Max permissible weight of the airplane
h. Weight of the airplane exclusive of of usable fuel
What are the following types of altitude?
a. Indicated
b. True
c. Absolute
d. Pressure
e. Density
a. Indicated - read directly from the altimeter
b. True - height above sea level
c. Absolute - height above the terrain
d. Pressure - height above the standard datum plane (what altimeter reads if set to 29.92)
e. Density - pressure altitude corrected for nonstandard temperature
Define the following airspeeds.
a. Indicated
b. Calibrated
c. True
a. Indicated (IAS) - read directly from ASI
b. Calibrated (CAS) - IAS corrected for installation and instrument error
c. True (TAS) - actual speed through the air
Power increase/decrease affect on Vmc?
a. Performance?
Power increase = higher Vmc (more yaw)
Power decrease = lower Vmc
a. Power increase = higher performance (more power)
Power decrease = lower performance
Temperature increase affect on Vmc and performance?
a. Pressure decrease?
b. Humidity increase?
Higher temp = lower Vmc (less dense air = less power), lower performance
a. Lower pressure = lower Vmc (less dense air = less power), lower performance
b. Higher humidity = lower Vmc (less dense air = less power), lower performance
Bank angle affect on Vmc and performance
a. 0 degree bank
b. 2-3 degree bank
c. 5 degree bank
Assuming no turn is occurring
a. 0 bank = higher Vmc (sideslip & low rudder AoA = more rudder needed), lower performance (more drag due to sideslip)
b. 2-3 bank = lower Vmc (zero sideslip & moderate rudder AoA = moderate rudder available), best performance (zero sideslip - least drag)
c. 5 bank = lowest Vmc (sideslip & highest rudder AoA = least rudder needed), lower performance (sideslip - higher drag)
Windmilling prop affect on Vmc and performance?
a. Feathered prop?
Windmilling prop = higher Vmc (higher drag = more yaw), lower performance (higher drag)
a. Feathered prop = lower Vmc (less drag = less yaw), higher performance (less drag)
Aft CG affect on Vmc and performance?
Aft CG = higher Vmc (shorter arm btw CG and rudder = less rudder effectiveness), higher performance (less tail down force = less drag)
Heavy aircraft weight affect on Vmc and performance?
Heavy weight = lower Vmc (higher horizontal lift available = less yaw), lower performance (higher AoA = more lift required = more power required)
Flaps extended affect on Vmc and performance?
Flaps extended = lower Vmc (higher induced drag on operating engine side = less yaw towards inop engine), lower performance (more drag from flaps and ailerons to counter adverse yaw)
Gear extended affect on Vmc and performance?
Gear down = must know more about position of gear relative to CG and direction of gear travel (direction of gear travel = direction of CG movement) HOWEVER, gear down provides a keel effect = lower Vmc, lower performance (higher parasite drag)
Critical engine failure affect on Vmc and performance?
Critical engine fails = higher Vmc (more yaw), lower performance (more control inputs = higher drag)
Ground effect affect on Vmc and performance?
Ground effect = higher Vmc (less drag = more power available = more yaw), higher performance (less drag)
Under what conditions must Vmc be determined?
SMACFUM
Standard day sea level conditions (max power available)
Most unfavorable weight
Aft CG (most unfavorable)
Critical engine prop windmilling
Flaps takeoff position, gear up, trimmed for takeoff
Up to 5 degree bank towards operating engine
Maximum takeoff power on operating engine
