SIFT Army Aviation Exam Practice Questions and Answers |100% Pass

SIFT Army Aviation Exam Practice Questions and Answers |100% Pass Airfoil - Answer-Blade that cuts through air so that air passes above and below it Top of an airfoil is ________ - Answer-Cambered Why is the top of an airfoil cambered? - Answer-To allow air to quickly get past the airfoil and create low pressure What happens to the air below the airfoil? - Answer-Has a shorter distance to travel and is slower, creating high pressure Lift - Answer-Upward force created by the difference in air pressure above and below the airfoil angle of incidence (pitch angle) - Answer-Angle between the cord line and the direction of the rotors spin Angle of Attack (AOA) - Answer-Angle between the chord line and the direction of incoming air To create lift you need a ________ AOA - Answer-Positive How do you create a positive AOA - Answer-Front of the blade needs to be raised above the back, relative to the wind What type of airfoil can generate lift with zero or negative AOA - Answer-Cambered or nonsymmetrical EMILLYCHARLOTTE 2024/2025 ACADEMIC YAER ©2024 EMILLYCHARLOTTE. ALL RIGHTS RESERVED FIRST PUBLISH SEPTEMBER 2024 Page 2/12 Weight is an important factor in flight because: - Answer-You need to generate enough force to move the weight off the ground, thus requiring more lift What 3 factors can cause a change in weight mid-flight? - Answer-Strong winds, adverse weather conditions, banking What is the most frequent factor that causes a change in weight mid-flight? - Answer-Banking the helicopter As the angle of a bank increases, what also needs to increase? - Answer-The angle of the airfoil which will produce more lift Load factor (G load) - Answer-Added strain created by banking and increasing the angle of the airfoil G load equation - Answer-G = L1 / L0 G - Answer-Load factor L1 - Answer-Actual load on the rotor blades L0 - Answer-Resting or normal load of the helicopter Thrust - Answer-Force that moves the helicopter horizontally How do you create thrust? - Answer-Converting lift via alterations of the pitch angle and the AOA Drag - Answer-Opposing force to thrust What are the 3 subcategories of drag? - Answer-Profile, parasitic, and induced Parasitic drag - Answer-Increases with airspeed and is the dominate type of drag at high airspeeds EMILLYCHARLOTTE 2024/2025 ACADEMIC YAER ©2024 EMILLYCHARLOTTE. ALL RIGHTS RESERVED FIRST PUBLISH SEPTEMBER 2024 Page 3/12 Profile drag - Answer-Similar to parasitic, except it only concerns the drag created by the frictional resistance of spinning airfoils. Profile drag remains the same throughout flight neither dominating or negligible. Induced drag - Answer-Byproduct of the lift created by the rotor. Only type of drag that typically decreases as airspeed increases. Induced drag is the primary drag at low speeds but becomes barely meaningful at high speeds. Maximum lift/drag ratio - Answer-Airspeed that will allow the helicopter to fly the furthest. When induced drag has decreased significantly but parasitic drag has not yet taken over. Basic Empty Weight - Answer-Weight of the helicopter once everything directly unattached is removed. Solely includes the weight of the helicopter itself, any optional equipment, and all the fluids contained. Basic rule: if the helicopter could still function without something it isn't included in the basic empty weight. Maximum Gross Weight - Answer-Weight that the helicopter can bear safely. 2 types of maximum gross weight? - Answer-Internal and external Internal Maximum Gross Weight - Answer-Maximum weight within the interior of the helicopter: includes pilot, passengers, and any gear or baggage External Maximum Gross Weight - Answer-weight that can be supported externally by the helicopter, including external winches Center of gravity - Answer-Point at which the entire weight of the helicopter, including both internal and external attachments is averaged EMILLYCHARLOTTE 2024/2025 ACADEMIC YAER ©2024 EMILLYCHARLOTTE. ALL RIGHTS RESERVED FIRST PUBLISH SEPTEMBER 2024 Page 4/12 Front loaded center of gravity - Answer-Identified by the fuselage tipping forward, with the nose pointing towards the ground. How do you solve a front loaded center of gravity? - Answer-Add weight to the back of the helicopter. Aft loaded center of gravity - Answer-Identified by the fuselage tipping backwards, with the nose pointing towards the sky. How do you solve an aft loaded center of gravity? - Answer-Remove weight from the back and add it to the front. What are the 4 flight controls? - Answer-Collective pitch control, throttle, cyclic pitch control, and the anti-torque pedals. Collective pitch control - Answer-Used to create lift and control vertical movement. Can be raised or lowered to increase or decrease lift. Location of the collective pitch control - Answer-Left of the pilots seat How does the collective pitch control achieve lift? - Answer-Altering the pitch of the rotor blades simultaneously. What happens when you increase the pitch of the rotor blades? - Answer-Angle of incidence increases and more lift is generated What happens when you decrease the pitch of the rotor blades? - Answer-Angle of incidence is decreased and less lift is generated EMILLYCHARLOTTE 2024/2025 ACADEMIC YAER ©2024 EMILLYCHARLOTTE. ALL RIGHTS RESERVED FIRST PUBLISH SEPTEMBER 2024 Page 5/12 Throttle - Answer-Controls the power of the engine When do you use the throttle? - Answer-When the rotor RPM rises or falls beyond a specific value A clockwise turn of the throttle _________ power - Answer-Decreases A counterclockwise turn _________ power - Answer-Increases Correlator - Answer-A mechanical tool that links the collective to the throttle, automatically increasing and decreasing the throttle as the collective is used. Doesn't account for any other factor so some manual control is still required. Governor - Answer-Electronic sensor that tracks RPM and adjust the throttle as needed. Cyclic pitch control - Answer-Primarily used to generate thrust and control horizontal movement Location of the cyclic pitch control - Answer-Between the pilots legs