Fundamentals of Flight .203

Question 1

Relative Wind
Induced Flow
Resultant Relative Wind
Angle of Attack
Angle of Incidence

Answer 1

Relative Wind - air in motion equal to and opposite flight path velocity of airfoil in motion
Induced Flow - downward flow of air
Resultant Relative Wind - relative wind modified by induced flow
Angle of Attack - angle measured from resultant relative wind and chord line
Angle of Incidence - angle between chord line and rotational relative wind
Aerodynamic center - point on chord line where all lift takes places

Question 2

Feathering
Collective Feathering
Cyclic Feathering
Flapping
Lead and Lag
Gyroscopic Precession

Answer 2

Collective Feathering - changes angle of incidence equally on all blades same time. Affects overall lift
Cyclic Feathering - change angle of incidence differentially around the rotor system. Controls blowback and dissymetry of lift. Causes attitude to change not lift
Flapping - up/down movement of blades because of changing velocities (primary means of combatting dissymetry of lift)
Lead and Lag - CG move inward/outward to alleviate pressure from flapping up/down
Gyroscopic Precession - manifestation of applied force 90 degrees after application in direction of rotation

Question 3

Mushing

Answer 3

Rearward cyclic during fast foward airspeeds causing upward flow to lose a/c altitude

Question 4

Empty Weight
Basic Weight
Operating Weight
Gross weight
Useful load

Answer 4

Empty Weight - A/C structure weight
Basic Weight - with hyd/oil/unusable fuel full
Operating Weight - baggage, pax, gear (no fuel/ammo)
Zero fuel weight - everything except fuel
Gross weight - total weight of an A/C
Useful load -