Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Aerodynamics,FF-1/01,Aero Foundations,Translating Tendency,Ground Effect,Translational Lift,Transverse Flow,Dissymmetry of Lift,Drag,Total Aerodynamic Force,Aero in Autorotations,Aerodynamic Difficulties,Engine Failure in a Left Turn,Negative/Low G,Vortex Ring State,Loss of,Tailrotor,Effectiveness,Marginal Power Ops,Retreating Blade Stall,Huey Hovering,Nose High,5 Mast tilt,CG Forward / Aft,Left Skid Low,Translating Tendency,Antitorque (Tail Rotor),Pushes Tail to the Right (Nose - Left),Thrust also pushes fuselage right, below the CG,Compensated for by left cyclic,Thus, left skid lower than right skid,Translating Tendency,Ground Effect,Practically speaking, experienced up to one rotor disk above the ground.,In ground effect hover power up to 30% less than out of ground effect. Why?,Primary: Reduction in downward velocity of induced flow caused by proximity of the ground,Secondary: Disruption in size and number of wing tip vortices (downward and outward flow of air discourages vortex formation),The Transition to Directional Flight,Because hovering is fun, but it isnt getting us anywhere.,Translational Lift,Additional lift because of horizontal movement with respect to the air,Airflow transitions from vertical at a hover to more horizontal in forward flight,Modifies induced flow changing the resultant RW and increasing the AOA,Translational Lift,Airflow at a Hover,Airflow in Forward Flight,Effective Translational Lift,(ETL),Definition,The point at which the aircraft outruns its own downwash,Results:,Lift increases with no collective change,Roll - right; Nose - up,Pitch up and Roll Caused by:,Transverse Flow,Dissymmetry of Lift,Transverse Flow Effect,Definition,A condition of increased drag and decreased lift in the aft portion of the rotor disk caused by the air having a greater induced velocity and reduced angle of attack in the aft portion of the disk.,Transverse Flow Effect,Rotor Disk -Rear,Rotor Disk -Front,Transverse,Flow Effect,More lift in front half of rotor disk,Less lift in rear half,Phase lag effect,felt 90 later,Result:,Right Roll,Dissymmetry of Lift,The difference in lift between the advancing half and the retreating half of the rotor disk,Dissymmetry of Lift,L =,1/2, V,2,S C,L,Dissymmetry of Lift,Result,Nose pitches up,Referred to as “Blowback,Compensate by,Flapping,Cyclic Feathering,Types of Drag,Induced,Profile,Skin Friction,Form,Parasite,Skin Friction,Form,Interference,Wave,Drag,PPC,Total Aerodynamic Force,Lift is perpendicular to Resultant Relative Wind,Drag is parallel to Resultant Relative Wind,Lift is modified by Total Drag,Autorotations,Blade Regions,Descent Rates/Rotor RPM,-10 Pg 9-11,HV Diagram,-10 Pg 9-13,FM 1-203 Pg 6-50,Flight Characteristics,Engine Failure during left turn,-10 Pg 9-2,Negative Gs / Low Gs,-10 Pg 8-10,Right Roll,Mast Bumping Video,AERODYNAMIC PROBLEMS,The main reason why pilots need to know aero,