Helicopter Vocab

Front 1

Magnus Effect

Back 1

A lifting force produced when a rotating cylinder produces a pressure differential (same effect that makes a baseball curve)

Front 2

Load Factor (or G Load)

Back 2

The ratio of the load supported by the main rotor system to the actual weight of the helicopter and its contents

Front 3

Moment

Back 3

Weight x Arm
It is the force that results from an object's weight acting at a distance...the further an object is from a pivotal point, the greater its force

Front 4

Arm or Station

Back 4

Horizontal distance from the datum to any component of the helicopter or to any object.
-If rear of the datum a positive number
-If forward of the datum a negative number

Front 5

Solidity Ratio

Back 5

A means to measure potential thrust.

The ratio of the total rotor blade area - which is the combined area of all the main rotor blades, to the total rotor disc area.

Front 6

L/D max

Back 6

The maximum ratio between total lift (L) and the total drag (D). This point provides the best glide speed. Any deviation from best glide speed increases drag and reduces the distance you can glide.

Front 7

Steady State Flight

Back 7

A condition when an aircraft is in straight and level, unaccelerated flight and all forces are in balance

Front 8

Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface. This statement refers to _________?

Back 8

This statement is referring to Bernoulli's principle

Front 9

Induced Flow

Back 9

The component of air flowing vertically through the rotor system resulting from the production of lift.

Front 10

Relative Wind may be affected by...

Back 10

The rotation of the rotor blades,
horizontal movement of the helicopter,
flapping of the rotor blades, &
wind speed & direction (affect....?)

Front 11

Dissymetry of Lift

Back 11

The relative wind encountered by the advancing blade is increased by the forward speed of the helicopter, while the relative wind speed acting on the retreating blade is decreased by the helicopter's forward airspeed. Therefore, as a result of the relative wind speed, the advancing blade side of the rotor disc produces more lift than the retreating blade side

Front 12

2 kinds of Profile Drag

Back 12

Form Drag and Skin Drag

Front 13

Form Drag

Back 13

results from the turbulent wake caused by the separation of airflow from the surface of a structure

Front 14

Relative Wind

(and its direction)

Back 14

Wind moving past the airfoil.

Its direction is always parallel, equal and opposite in direction to the flight path of the airfoil

Front 15

Ground Effect

Back 15

A usually beneficial influence on rotorcraft performance that occurs while flying close to the ground. It results from a decrease in upwash, downwash, and bladetip vortices, which provide a corresponding decrease in induced drag.

Front 16

Induced Drag (causes drag at ____)

Back 16

Generated by airflow circulation around the rotor blade as it creates lift. The major cause of drag at lower airspeed; amount of drag is negatively correlated with airspeed.

Front 17

Skin Friction

Back 17

Caused by surface roughness. A thin layer of air clings to rough surfaces and creates small eddies that contribute to drag.

Front 18

Centrifugal Force

Back 18

The apparent force that an object moving along a circular path exerts on the body constraining the object and that act outwardly away from the center of rotation.

Front 19

Centripetal Force

Back 19

The force that attracts a body toward it axis of rotation.

Front 20

Center of Gravity

Back 20

The point at which an airplane would balance if it were suspended at that point

Front 21

Reference Datum

Back 21

A reference vertical plane from which horizontal distances are measured for balance purposes. It is 100 inches forward of the main rotor shaft centerline for the R22

Front 22

When the angle of attack is increased...

Back 22

...Air flowing over the airfoil is diverted over a greater distance, resulting in an increase of air velocity and more lift. (When...)

Front 23

Critical Altitude

Back 23

Altitude at which full throttle produces maximum allowable power (MCP or TOP)

Front 24

Density is affected by...

Back 24

Temperature, atmospheric pressure and humidity all affect _______

Front 25

Density Altitude

Back 25

Altitude, in feet, in ISA conditions at which the air would have the same density (**it is pressure altitude corrected for OAT**)

Front 26

Emergency Codes

Back 26

Hijacked - 7500
Lost Comm - 7600
Other Emergency - 7700

Front 27

The purpose of the swash plate

Back 27

To transmit control inputs from the collective and cyclic controls to the main rotor blades

Front 28

Powerplant of an R22

Back 28

One Lycoming, 4 cylinder, horizontally opposed, over head valve, air-cooled, carbureted engine with a wet sump oil system

Front 29

VOR

Back 29

Ground base navigation system consisting of very high frequency omnidirectional stations which provide course guidance

Front 30

Purpose of fuel control system
-
-
-

Back 30

-Brings outside air into the engine,
-mixes it with fuel in the proper proportions and
-delivers it to the combustion chamber

Front 31

A clutch allows

Back 31

An engine to be started then gradually pick up the load of the rotor. (Allowed by...)

Front 32

KIAS vs KCAS vs KTAS

Back 32

Knots Indicated Airspeed
vs
Knots Calibrated Airspeed
(shown on indicator, corrected for instrument and position)
vs
Knots True Airspeed
(relative to undisturbed air, corrected for pressure, altitude, and temperature)

Front 33

ALT

Back 33

Alternator

Front 34

ILS

and 4 components

Back 34

Instrument Landing System; A precision instrument approach system. Normally consists of the following electrical components and visual aids:
-localizer,
-glide slope,
-outer marker
-approach lights

Front 35

4 forces acting on a helicopter in flight

Back 35

Lift, Weight, Thrust and Drag

Front 36

Center of Pressure

Back 36

The imaginary point on the chord line where the resultant of all aerodynamic forces are considered to be concentrated