ACRM (51-100) S2

Plain Flaps

the effect of these flaps is minimal, and they are seldom found in modern airplanes

Split Flaps

lift change is similar to that of a plain flap, but it produces much more drag at low lift coefficient

Fowler Flaps

the design of this wing flap not only changes the camber of the wing, but it also increases the wing area

Stall strips

Ensure that the wing root stalls first before the wing tip

Winglets

wing tips that allow for drag reduction and better airflow control

Wing Fence

a wing tip that stop or reduce span wise flow

T-tail

the stabilizer is moved away from the disturbed airflow of the wing, rudder effectiveness is improved because of the cap on its end.

Deep stall

the airflow over the horizontal tail, is blanketed by, or in the shadow of, the disturbed airflow from the wing

Angle of Incidence

angle between the chord line of the wing and the longitudinal axis of the airplane

Washing in

increasing the angle of incidence

Washing out

decreasing the angle of incidence

Fuselage stations

are numbered in inches from a reference or zero point known as the reference datum to a location in the fuselage

Buttock line

A vertical reference plane down the center of the aircraft from which measurements left or right can be made

Water line

measurement of height in inches perpendicular from a horizontal plane usually located at the ground, cabin floor, or some other easily referenced location

Aileron station

measured outboard from, and parallel to, the inboard edge of the aileron, perpendicular to a designated water line

Flap station

measured perpendicular to the rear beam of the wing and perpendicular to a designated water line

Cable system

available in both corrosion-resistant steel and carbon-steel that is used in the primary flight control system

Non-flexible cable

may be either 1x7 or 1x19 type that is used only for straight runs where the cable does not pass over any pulleys

Flexible cable

made up of seven strands, each of which has seven wires that are used only for straight runs where the pulleys are large

Extra Flexible Cable

made up of seven strands, each having 19 separate wires

Termination

connection of the wire

Woven splice

also called as Army-Navy five-tuck Splice or Roebling Roll. It is time consuming and produced a termination that was certificated for only 75% of the cable strength

Nicopress Process

Copper Nicopress sleeves may be compressed onto the cable with a special tool

Stagger

the longitudinal offset of two wings relative to each other

Decalage

difference in the angle of incidence of the two wings of a biplane

Cabane struts

the struts between the center section and the fuselage of a biplane

Cabane/Stagger Wires

runs between the rear and forward cabane struts to adjust the fore-and-aft position of the center section of a biplane

Roll/Transverse Wires

ties the bane struts and the center section to the fuselage laterally in a biplane

Landing Wires

supports the lower wing of the biplane from the center section bracing the wings against loads imposed by landing

Flying Wires

Attaches to the fuselage at the lower wing root and to the outboard portion of the upper wing are the __________, opposing loads of flight

Interplane Struts

usually made of streamlined steel tubing in the form of the letter N, are placed between the upper and lower wing out near the tip

Gyroplane

has no power to the main rotor except, in some cases, to start it spinning

Fully Articulated System

each rotor blade is attached to the rotor hub through a series of hinges, allowing the blade to move independently of the others

Flapping hinge

allows the blade to move up and down

Lead-lag/Drag Hinge

allows the blade to move back and forth

Semirigid Rotor System

uses two blades rigidly mounted to the main rotor hub

Teetering hinge

allows the blades to flap together as a unit, as one blade flaps up, the other flaps down

Rigid Rotor System

the blades, hub, and mast are rigid with respect to each other

Coning

upward bending of the blade due to lift and centrifugal force

Rigidity in Space

an inertial force that causes an object to tend to remain rigid, and it will resist any force that tries to move it

Precession

resultant action or deflection of a spinning object when a force is applied to it. This action occurs approximately 90 degrees in the direction of rotation from the point where the force is applied

Coriolis Effect

the distance between the center of mass and the axis of rotation, times the rotational velocity of the mass, will try to remain constant

Translating Tendency

A single main rotor helicopter tends to drift opposite to the opposite to the direction of anti-torque rotor thrust

Ground Effect

usually occurs less than one rotor diameter above the surface. It restricts the generation of blade tip vortices due to the downward and outward airflow, producing lift from a larger portion of the blade

Dissymmetry of Lift

the advancing blade side of the rotor disc produces more lift than the retreating blade side

Autorotation

the advancing blade side of the main rotor system is being turned by the action of the relative wind rather than engine power

Collective Pitch Control

used for the vertical movement of the rotorcraft that causes all rotor blades to increase or decrease blade pitch angle by the same amount, or collectively

Correlator

a mechanical connection between the collective lever and the engine throttle

Throttle Control

regulates the engine RPM in a helicopter

Cyclic Pitch Control

used for roll and pitch movements that tilt the main rotor disc by tilting the swash plate assembly, thus changing the pitch angle of the rotor blades in their cycle of rotation