FREE SIFT Army Aviation Information Questions and Answers
During takeoff, blade flapping is utilized to:
Explanation:
The statement "Blade flapping is used during takeoff to counter dissymmetry of lift" is accurate.
Blade flapping is a movement of the rotor blades in a helicopter, where the blades change their angle of incidence as they move up and down during rotation. This movement is necessary to compensate for the dissymmetry of lift that is created by the rotor blades during flight.
An mechanical angle called an angle of incidence exists between
Explanation:
The angle of incidence is the angle between the chord line of an airfoil (such as a helicopter rotor blade) and the plane of rotation. It is the angle at which the blade is set or tilted relative to the airflow or the direction of motion. The angle of incidence affects the amount of lift and drag produced by the blade.
Another name for settling with power is
Explanation:
Settling with power is also known as vortex ring state or power settling. It is a dangerous condition that can occur in helicopters when the rotor system descends into its own downwash, causing a rapid loss of lift and a high rate of descent. This phenomenon occurs when the helicopter is descending too quickly and the rotor system is unable to generate enough lift to support the aircraft. As a result, the helicopter can enter into a vortex ring state, where the rotor downwash becomes trapped within its own wake, leading to a rapid descent that can be difficult to recover from. Settling with power is a serious problem that requires quick action from the pilot to avoid a crash.
A thrust is produced by
Explanation:
Thrust is created by the engine(s) of a helicopter. The engine provides power to the rotor system, which generates lift and produces thrust to propel the helicopter forward, backward, and sideways. The direction of thrust in a helicopter can be controlled by changing the pitch of the rotor blades using the cyclic and collective controls. The tail rotor also provides thrust to counteract the torque produced by the main rotor and to control the helicopter's yaw.
A pilot can ______ by moving a cyclic.
Explanation:
In a helicopter, cyclic control is used to tilt the main rotor disc in a particular direction, which causes the helicopter to move in that direction. The cyclic control also changes the pitch of the rotor blades so that the lift they produce is greater in one part of the rotor disc than in another. This tilts the disc and causes the helicopter to move in the desired direction. By altering the pitch of the rotor blades with cyclic control, the pilot can control the direction and speed of the helicopter's movement.
Which of the following does not refer to a typical helicopter control?
Explanation:
"Dual" is not a common helicopter control. The primary helicopter controls are collective, cyclic, and anti-torque pedals.
Collective control is used to adjust the angle of attack of the main rotor blades and to increase or decrease the helicopter's altitude.
The cyclic control is used to tilt the rotor blades in a particular direction, which causes the helicopter to move forward, backward, left, or right.
The anti-torque pedals control the tail rotor, which is used to counteract the torque produced by the main rotor and to control the helicopter's yaw.
Some helicopters also have additional controls such as the throttle, mixture control, and trim controls, which are used to adjust the engine power, fuel-air mixture, and the helicopter's stability, respectively.
Which of the subsequent is not a typical helicopter taxi maneuver?
Explanation:
"Rotor taxi" is not a commonly used helicopter taxi maneuver. The most common helicopter taxi maneuver is called "hover taxi." In a hover taxi, the helicopter hovers above the ground while moving forward, backward, or sideways, using cyclic control to move in the desired direction. The pilot uses collective control to adjust the helicopter's altitude and the anti-torque pedals to control the yaw.
"Rotor taxi" is not a commonly used term, it may refer to a situation where the helicopter is moving forward at a low altitude, close to the ground, with the rotor blades providing lift and forward motion. This technique is used in some military operations and special operations scenarios but is not a standard taxi maneuver.