2104 - MIDTERMS Flashcards
performs the same function as
an airplane’s wings, providing lift as the blades rotate.
Main Rotor Blade
Also known as the rotor shaft, the mast connects the transmission to
the rotor assembly
Rotor Mast
transmits power from the engine to the main and tail rotors.
Transmission
generates power for the helicopter.
Engine
The main body of the helicopter is known as
Fuselage
some helicopters have wheels, but most have skids, which are hollow tubes with no wheels or brakes
Landing Skids
extends out from the rear of the fuselage and holds the
tail rotor assemblies.
Tail Boom
Basic Parts of Helicopters
Rotor Blade
Rotor mast
Jesus nut
Blade Grip
Control rod
Upper swash plate
Ball Bearings
Lower Swash plate
from the upper swash plate have a connection point on
the blades, making it possible to transfer movements of the upper swash plate to the blades.
Control Rod
lie between the upper and lower swash plates, allowing
the upper plate to spin freely on top of the lower plate.
Ball Bearings
fixed and doesn’t rotate.
Lower swash plate
is a slang term for the main rotor retaining nut or mast nut, which holds the main rotor to the mast.
Jesus nut
connect the blades to a hub.
Blade Grips
is mechanically simple, but structurally complex because operating loads must be absorbed in bending rather than
through hinges. In this system, the blade roots
are rigidly attached to the rotor hub.
Rigid rotor system
is usually composed of two blades that are rigidly mounted to the main rotor hub. The main rotor hub is free to tilt with respect to the main rotor shaft on what is known as a teetering or flapping hinge. The semirigid rotor is also capable of feathering, which means that the pitch angle of the blade changes.
SEMIRIGID ROTOR SYSTEM
allow each blade to lead/lag (move back and forth in plane), flap (move up and down about an inboard mounted hinge) independent of the other blades, and feather (rotate about the pitch axis to change lift)
FULLY ARTICULATED ROTOR SYSTEM
provides power on the ground for self contained engine startups and for energizing the systems with the engine shut down.
Battery
driven by the engine and is the normal power source in flight. It powers the helicopter system and charges the battery
Generator
can be used instead of the battery on
the ground for engine starting and for running the electrical tests.
External Power Unit/ Ground Power Unit-
is the difference in lift that exists between the advancing half of the rotor disk and the retreating half. It is caused by the fact that in directional flight the aircraft relative wind is added to the rotational relative wind on the advancing blade, and subtracted on the retreating blade. The blade passing the tail and advancing around the right side of the helicopter has an increasing airspeed which reaches maximum at the 3 o’clock position. As the blade continues, the airspeed reduces to essentially rotational airspeed over the nose of the helicopter. Leaving the nose, the blade airspeed progressively decreases and reaches minimum airspeed at the 9 o’clock position. The blade airspeed then increases progressively and again reaches rotational airspeed as it passes over the tail
DISSYMMETRY OF LIFT
provides power on the ground for self contained engine startups and for energizing the systems with the engine shut down
Battery
driven by the engine and is the normal power source in flight. It powers the helicopter system and charges the battery.
Generator
can be used instead of the battery on
the ground for engine starting and for running the electrical tests.
Ground Power Unit/External Power Unit
