June 3Rd Attempt To Read My Handbook

Front 1

Blade Flap

Back 1

The upward or downward movement of the rotor blades during rotation

Front 2

Blade Feathering

Back 2

The rotation of the blade around the spanwise (pitch change) axis

Front 3

Blade lead or lag

Back 3

The for and aft movement of the blade in the plane of rotation. Sometimes called hunting or dragging.

Front 4

Fully Articulated System
-
-
-

Back 4

-3+ blades

-blade flap, feather, and lead or lag independently

-blades attach to the hub via a horizontal hinge called a flapping hinge and a vertical hing call a drag or lag hinge, and dampers

Front 5

Purpose of drag hinge and dampers

Back 5

To absorb the acceleration and deceleration of the rotor blades

Front 6

Semi-Rigid Rotor Systems
-
-
-

Back 6

-2 blades
-blades are rigidly attached to the rotor hub
-Allows for two different movements, flapping and feathering.

Front 7

Rigid Rotor System
-
-
-

Back 7

-mechanically simple, but structurally complex
-operating loads must be absorbed in bending rather than through hinges
-blades can feather

Front 8

Notar

Back 8

"No Tail Rotor"
a fan mounted within the helicopter forces air into the tailboom, which is fed through horizontal slots on the right side of the tailboom

Front 9

Reciprocating engine

Back 9

-small helicopters
-mounted horizontally or vertically

Front 10

Gas turbine engine

Back 10

-medium to heavy lift helicopters
-large horsepower output

Front 11

airfoil

Back 11

any surface, wing or rotor blade, which provides aerodynamic force when it interacts with a moving stream of air

Front 12

center of pressure

Back 12

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

Front 13

"reflexing"

Back 13

bending the trailing edge to produce the same characteristics as symmetrical airfoils.

Front 14

Relative Wind may be affected by
-
-
-
-

Back 14

-rotation of the rotor blades
-horizontal movement of the helicopter
-flapping of the blades
-wind speed and direction

Front 15

axis-of-rotation

Back 15

the imaginary line about which the rotor rotates. it is represented by a line drawn through the center of, and perpendicular to, the tip-path plane

Front 16

Aircraft Pitch

Back 16

the movement of the helicopter about its lateral, or side to side axis.

Front 17

In summary, the production of lift is based upon the Magnus Effect, (________) and Bernoulli's Principle (_______________)

Back 17

In summary, the production of lift is based upon the airfoil creating circulation in the airstream (________) and creating differential pressure on the airfoil (_____________)

Hint 17

2-4 RFH

Front 18

The majority of lift is the result of _____ _____ _____ rather than _________ _______ _____

Back 18

The majority of lift is the result of decreased pressure above the blade, rather than the increased pressure below it

Hint 18

2-4 RFH

Front 19

Total drag is composed of three types of drag:

Back 19

Profile, induced and Parasite

Hint 19

2-5 RFH

Front 20

Profile drag (form drag and skin friction) does not change significantly with the airfoil's angle of attack, but....

Back 20

increases moderately when airspeed increases

Hint 20

2-5 RFH

Front 21

Form drag results from

Back 21

____ drag:

-Results from the turbulent wake caused by the separation of airflow from the surface of a structure.

-It is related to the size and shape of the structure that protrudes into the relative wind

Hint 21

2-5 RFH

Front 22

Induced drag
-
-
-

Back 22

-generated by the airflow circulation around the rotor blade as it creates lift

-decreases at increased speed.

-the major cause of drag at lower airspeeds

Hint 22

2-6 RFH

Front 23

Parasite drag
-
-
-
-

Back 23

-caused by any non-lifting components of the helicopter

-increases with increasing airspeed

-the major cause of drag at higher airspeeds

-doubling the airspeed increases the parasite drag 4x (it varies with the square of the velocity)

Hint 23

2-6 RFH

Front 24

The amount of torque is directly related to the amount of engine power being used to turn the main rotor system. Remember, as _______ changes, _________ changes.

Back 24

As power changes, torque changes

Hint 24

3-1 RFH

Front 25

Translating tendency

Back 25

during hovering flight, a single main rotor helicopter tends to drift in the same direction as antitorque rotor thrust

Hint 25

3-1 RFH, Figure 3-2

Front 26

ETL
-
-
-

Back 26

Effective translation lift,

-easily recognized by a transient induced aerodynamic vibration and increased performance

-around 16 to 24 knots.

-tail rotor efficiency also improves so it will be necessary to apply right pedal to correct for this tendency on take-off

Hint 26

3-5 RFH

Front 27

-Transverse Flow Effect

-and its result

Back 27

-As the helicopter accelerated in forward flight, induced flow decreases at the forward disc area and increases at the aft disc area

-the result is a tendency for the helicopter to roll slightly to the right as it accelerated through approximately 20 knots...

Hint 27

3-6 RFH

Front 28

Retreating blade stall

Back 28

-occurs at high forward speed because of a high angle of attack and slow relative wind speed

-evidenced by a nose pitch up, vibration and a rolling tendency

-avoid retreating blade stall by not exceeding the Vne

Front 29

The horizontal component of lift (centripetal force)...

Back 29

...is lift acting horizontally and opposing inertia (centrifugal force)

Hint 29

3-8 RFH

Front 30

The vertical component of lift

Back 30

...is lift acting upward and opposing weight

Hint 30

3-8 RFH

Front 31

In the case of an auto-rotation, you are using _____ as potential energy and converting it to ______ during the descent and touchdown.

Back 31

You are using altitude as potential energy and converting it to kinetic energy during an auto-rotation

Hint 31

3-9 RFH