SIFT - Army Aviation Exam – 56
Questions and answers-100% Correct
Three types of Rotor Systems - -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 - -Normal: 7-12 @300-500 AGL
Steep: 13-15
Shallow: 3-5
-Manufacturer's Empty Weight (MEW) - -Total weight of the aircraft as it was
built. this includes the system operating components but does not include
unusable fuel. before fluids, fuel or oil is inserted.
-Operating Empty Weight (OEW) - -MEW plus the weight of the crew, fluids,
unusable fuel, and the equipment required for flight.
-All-Up Weight (AUW) or Aircraft Gross Weight (AGW) - -Is the aircraft
weight at any given moment during flight. the AUW / AGW can decrease at
any point during flight.
-Maximum Landing Weight (MLW) - -Aircraft's weight limit for landing
-Maximum Zero Fuel Weight (MZFW) - -Permissible weight of aircraft with
its contents and unusable fuel, no usable fuel or fluids
-Maximum Takeoff Weight - -The maximum allowable weight for takeoff.
-Maximum Ramp Weight (MRW) - -The weight limit for an aircraft to taxi or
be towed on the ground.
-Parasitic Drag - -Created by the non-lifting portions of the helicopter, such
as the fuselage, engine cowlings, hub, mast, landing gear, and external
loads.
Lowest drag at low speeds, increases to Highest drag at high speeds.
-Profile Drag - -The drag created by the frictional resistance is the spinning
airfoils.
, Middle drag at low speeds, only increases slightly as speed increases.
-Induced Drag - -Generated by the airflow circulation around the wing as it
creates lift.
Highest drag at lower speeds, decreases to lowest at higher speeds.
-4 forces of hovering - -Weight, lift, thrust, drag in balance
-Magnus effect - -the upward force of the fast moving, high pressure air
pushing up on the rotor blades. 1852 German Physicist Gustav Magnus
official discovery
-What forces must be overcome by lift? - -Weight
Drag
-Gyroscopic Precession - -The attribute of rotating bodies to manifest
movement ninety degrees in the direction of rotation from the point where a
force is applied to the spinning body
-Transverse Flow Effect - -Transverse Flow is the difference of Lift, Drag and
Induced Flow that exists between the Forward Half and the Rear Half of the
rotor disc between 10 and 20 knots.
-Translational Lift - -The additional lift obtained when entering forward
flight, due to the increased efficiency of the rotor system.
-Dissymmetry of Lift - -The unequal lift across the rotor disc that occurs in
forward flight due to the difference in airflow over the advancing and
retreating blades.
-Relative Wind - -the flow of air which moves opposite the flight path of an
airplane
-Autorotation - -a maneuver used by helicopter pilots to make an
emergency landing when he or she has lost engine power during flight
-4 primary controls of Helicopter - -Cyclic control system, collective control,
anti-torque pedals, throttle control
-Cyclic Control System - -mounted on the flight deck floor and centered
between the pilots legs, us utilized to adjust the aircrafts pitch and roll axes.
cyclic controls allow the pilot to manipulate the lift vector up to 360 degrees
around the aircraft, allowing it to hover in one location
Questions and answers-100% Correct
Three types of Rotor Systems - -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 - -Normal: 7-12 @300-500 AGL
Steep: 13-15
Shallow: 3-5
-Manufacturer's Empty Weight (MEW) - -Total weight of the aircraft as it was
built. this includes the system operating components but does not include
unusable fuel. before fluids, fuel or oil is inserted.
-Operating Empty Weight (OEW) - -MEW plus the weight of the crew, fluids,
unusable fuel, and the equipment required for flight.
-All-Up Weight (AUW) or Aircraft Gross Weight (AGW) - -Is the aircraft
weight at any given moment during flight. the AUW / AGW can decrease at
any point during flight.
-Maximum Landing Weight (MLW) - -Aircraft's weight limit for landing
-Maximum Zero Fuel Weight (MZFW) - -Permissible weight of aircraft with
its contents and unusable fuel, no usable fuel or fluids
-Maximum Takeoff Weight - -The maximum allowable weight for takeoff.
-Maximum Ramp Weight (MRW) - -The weight limit for an aircraft to taxi or
be towed on the ground.
-Parasitic Drag - -Created by the non-lifting portions of the helicopter, such
as the fuselage, engine cowlings, hub, mast, landing gear, and external
loads.
Lowest drag at low speeds, increases to Highest drag at high speeds.
-Profile Drag - -The drag created by the frictional resistance is the spinning
airfoils.
, Middle drag at low speeds, only increases slightly as speed increases.
-Induced Drag - -Generated by the airflow circulation around the wing as it
creates lift.
Highest drag at lower speeds, decreases to lowest at higher speeds.
-4 forces of hovering - -Weight, lift, thrust, drag in balance
-Magnus effect - -the upward force of the fast moving, high pressure air
pushing up on the rotor blades. 1852 German Physicist Gustav Magnus
official discovery
-What forces must be overcome by lift? - -Weight
Drag
-Gyroscopic Precession - -The attribute of rotating bodies to manifest
movement ninety degrees in the direction of rotation from the point where a
force is applied to the spinning body
-Transverse Flow Effect - -Transverse Flow is the difference of Lift, Drag and
Induced Flow that exists between the Forward Half and the Rear Half of the
rotor disc between 10 and 20 knots.
-Translational Lift - -The additional lift obtained when entering forward
flight, due to the increased efficiency of the rotor system.
-Dissymmetry of Lift - -The unequal lift across the rotor disc that occurs in
forward flight due to the difference in airflow over the advancing and
retreating blades.
-Relative Wind - -the flow of air which moves opposite the flight path of an
airplane
-Autorotation - -a maneuver used by helicopter pilots to make an
emergency landing when he or she has lost engine power during flight
-4 primary controls of Helicopter - -Cyclic control system, collective control,
anti-torque pedals, throttle control
-Cyclic Control System - -mounted on the flight deck floor and centered
between the pilots legs, us utilized to adjust the aircrafts pitch and roll axes.
cyclic controls allow the pilot to manipulate the lift vector up to 360 degrees
around the aircraft, allowing it to hover in one location
