SIFT Army Aviation Study guides, Class notes & Summaries

[SIFT] ARMY AVIATION INFORMATIONA helicopter is: A. A type of gyrocraft. B. A type of rotorcraft. C. A category of rotary-wing airplanes. D. A sub-group of gyrocopters. - correct answer b Helicopter turbine engines produce ___ thrust per pound than piston engines: A. less B. the same C. more D. the same, but only after factoring in the effect of density altitude - correct answer c The main forces acting on a helicopter are: A. Induced lift, mass, thrust, and form drag. B. Lift, ...

2021 Army SIFT testThe four aerodynamics forces. - correct answer Thrust, Drag, Weight and Lift Thrust - correct answer The forward force produced by the power plant/propeller or rotor. It opposes or overcomes the force of drag. As a general rule, it acts parallel to the longitudinal axis. Drag - correct answer A rearward, retarding force caused by disruption of airflow by the wing rotor, fuselage, and other protruding objects. Drag opposes thrust and acts rearward parallel to the relative...

army aviation information test SIFT 2the three axes around which flight movement occurs are? - correct answer lateral, longitudinal, and vertical one way to state Bernoulli's principle is? - correct answer the faster a fluid is traveling, the less its pressure on the supporting surface the amount of airfoil's curvature is called its? - correct answer camber the earths atmosphere is composed of what? - correct answer 78% nitrogen, 21% oxygen, and 1% other gases in a stabilized hover...

army aviationthe lift and thrust must exceed the weight and drag. increasing main rotor blades' AOA while maintaining their rotational speed creates extra lift and the aircraft ascends. Decreasing the pitch results in a descent. - correct answer vertical flight the increased efficiency of the rotor disk caused by interference of the airfloe when near the ground - correct answer in ground effect also known as dual rotor; has 2 large horizontal rotor assemblies instead of one main assembl...

army aviationthe lift and thrust must exceed the weight and drag. increasing main rotor blades' AOA while maintaining their rotational speed creates extra lift and the aircraft ascends. Decreasing the pitch results in a descent. - correct answer vertical flight the increased efficiency of the rotor disk caused by interference of the airfloe when near the ground - correct answer in ground effect also known as dual rotor; has 2 large horizontal rotor assemblies instead of one main assembl...

ARMY SIFT AVIATION INFORMATION Newton's first law of motion - correct answer States that an object at rest will stay at rest, and an object in motion will remain in motion at a constant velocity unless acted upon by an unbalanced force. The unbalanced force may be any force, such as gravity or friction. For example, a ball sitting on the floor will remain still unless a force is exerted upon it--a kick from a foot, a push from a hand, or a strong wind moving it. Newton's Second Law of Moti...

SIFT - Army AviationThree types of Rotor Systems - correct answer 1. Semirigid - composed of two blades that are rigidly mounted to the main rotor hub 2. Rigid - the blade roots are rigidly attached to the rotor hub 3. Fully articulated - allow each blade to lead/lag (move back and forth in plane), flap (move up and down about an invoiard mounted hinge), independent of the otherblades, and feather (rotate about the pitch axis to change lift) 3 Types of Approach - correct answer Normal: 7-12...

SIFT - Army AviationTypes of drag - correct answer Parasitic Profile Induced Parasitic drag - correct answer caused by the non-lifting portions of the helicopter (fuselage, engine, cowlings, hub, mast, landing gear, external loads) increases with airspeed, dominant type of drag at high airspeeds Profile drag - correct answer caused by frictional resistance of the lift-producing surfaces (rotor blades) passing through the air remains constant throughout speeds Induced drag - corr...

SIFT (Army Aviation Information) Practice TestThe typical structure of a helicopter is a ______ (fill in the blank) with a ____ (fill in the blank) protruding upward out of it. - correct answer Fuselage (the body of the craft), Mast. The engine of the craft drives power upward through the ____ (fill in the blank) to the rotor blades, which are controlled by the pilot. - correct answer Mast This main rotor is used to generate ____ (fill in the blank). - correct answer Thrust. ____ (fill ...

SIFT (Army Aviation)Profile drag - correct answer Caused by the blades frictional resistance Induced drag - correct answer Downwash Parasite drag - correct answer Components attached to a helicopter that dont contribute to lift Total drag - correct answer Sum of profile, induced, and parasite drag. Bernoullis principle - correct answer As flow increases, pressure decreases Phases of flight - correct answer Takeoff, climb, cruise, descent, landing. Flat and curved side pressure ...