aero 5

flight control rigging involves

• Involves adjustment and travel of movable flight controls

• Involves setting cable tension adjusting travel limits of flight controls and setting travel stops

where to find flight control surface movements

TCDS

flight control cables are made from

carbon steel or corrosion resistant stainless steel (CRES)

some CRES have nylon coating

flight control cables consists of

cables made of wires made of strands

cable designation

based on number of strands and number of wires in each strand

7×19

7 strands of 19 wires/strand

very flexible

used in primary flight controls

7×7

7 strands of 7 wires/strand

medium flex

used for trim tab and engine controls

cable identifier 1st number

number of strands

cable identifier 2nd number

number of wires in each strand

cable terminations type

woven splice

swage type

nicopress splice

woven splice

maintains 75% of original cable strength

used on antique aircraft

swage type is made by

compressing the shank of the terminal on the control cable

swage type terminal fittings

threaded, fork, eye, single shank ball, double shank ball

swage type - threaded, fork, eye used for

connect turnbuckle or bellcrank

swage type - ball end used for

attaching to control quadrants

swage type - inspection

inspect terminal shank diameter using go/no-go gauge

go gauge

if it goes, it passes

no-go gauge

if it doesn’t go, it passes

testing swage type

apply test load equal to 60% of the rated breaking strength of cable for 3 minutes

nicopress consists of

sleeves and thimbles to make a looped end

nicopress inspection

dimension of nicopress sleeve

nicopress - thimble

AN100

nicopress - sleeve

MS51844

nicopress advantage

use up to its full rated strength

replace woven cables

flight control cable inspection

• wire or strand breakage using cloth

• wear, corrosion, distortion

turnbuckle made of

brass

turnbuckle used for

join 2 cables and adjust cable tension

turnbuckle consists of

externally threaded cable ends and internally threaded barrel

how do you differentiate left and right hand thread on turnbuckle

left hand thread has a groove

turnbuckle rules

maximum 3 threads exposed

minimum 4 lockwire wraps

pulley used for

guide cables and change direction of cable movement

cable guards used for

prevent cable from slipping off pulleys

do pulleys need lubrication

no they are sealed

normal wear pattern

excessive cable tension

pulley too large for cable

pulley misalignment

cable misalignment

frozen bearings

fairlead

guides cable where it passes through bulkheads and structure

pressure fairlead

used where cables move through pressurized bulkheads

fairlead precaution

must not deflect the alignment of a cable more than 3 degrees from a straight line

split fairlead

allows replacement without removing cable

tensiometer

measures amount of tension on a cable by measuring amount of force needed to make an offset in the cable

flight control spring back

extra push needed for control to hit its mechanical stop providing a small cushion

push pull rod purpose

push pull motion

torque tube purpose

angular or twisting motion

control drums purpose

used in trim tab systems to wind or unwind trim tab cables

bellcrank purpose

change motion through an angle

push pull rod inspection

• General condition and safety 

• Free and non-binding motion

• Installation, fit, alignment

• Corrosion

• Bending, twisting, deforming damage 

• Witness hole should not allow a piece of lockwire to pass through

adjust push pull rod

adjust length at either side

torque checknut to secure the rod end from loosening

rigging checks

• Wing dihedral angle

• Wing incidence angle

• Verticality of the fin

• Engine alignment

• Asymmetry check

• Horizontal stabilizer incidence

• Horizontal stabilizer dihedral

dihedral angle

upward angle of wing

how to check dihedral of wing

use inclinometer

vertical fin verticality

measure between top of fin and left and right horizontal stab

when do you check vertical fin verticality

after rigging horizontal stab

check wing incidence

check 2 positions on surface of wing

why do you check wing incidence

ensure wing is free from twist

check engine symmetry

measure center line of engine mount to longitudinal center line

fuselage symmetry check

measure distance between specific points on aircraft