Basic Aerodynamics Flashcards
What is a standard day?
29.92 in Hg
59 F
Acc. due to gravity 32.141 ft/sec2
specific weight 0.76474 lb/ft3
density 0.0023769 lb-sec2/ft4
What is the Boundary Layer, and what aids in creating a good laminar flow?
Air immediately above the surface of the airfoil that tends
to “stick” to the surface. Vortex generators, help airflow
separation by forcing the air to stick to the surface
Difference between AOI and AOA?
AOI-Angle of the wing chord line and the longitudinal axis to which its mounted (fuselage)
AOA-Angle of the chord line of an airfoil and relative wind
Define “Wing Tip Vortices and give 3 examples of how to
prevent them.
WTV are created by high pressure air from the bottom of
the wing “swirling’ around the top (creates loss of wing
efficiency).
i. Winglets
ii. Tip Tanks
iii. Drooped Tips
iv. Higher aspect ratio wings
v. Tip Plates.
Explain what the wing “Wash-in” and “Wash-out”
Wash-out= AOI of wing decreased at the tip compared to
root.
Wash-in= AOI of wing increased at the tip compared to
root.
What is wrong if the aircraft has flutter or excessive vibration?
The flight control surface is out of static balance
After rigging is complete on a control surface using push-pull rods, what needs to be checked and how?
Safety wire should not be able to go through the witness hole
Pulleys are used to accomplish what?
To change the direction of control cables
When inspecting a turnbuckle after you have safety wired it, what are you checking for?
No more than 3 threads are exposed on either side of the
turnbuckle
there is a minimum of 4 wraps of safety wire around the shank
of the turnbuckle
verify that the correct method and wire were used
that everything is tight and uniform
When would you need/want to rig fixed and moveable components of an aircraft?
After remove and install of components
if a/c was damaged
scheduled MTC inspections
pilot complains that the aircraft requires excessive trim
What should not be used to cut aircraft cable?
Cut-off wheels
grinding wheels
cutting torch
hacksaw (Heat disturbs the temper of the cable)
*Use mechanical cutting tool
What is a tensiometer?
A tool to measure tension on aircraft cables.
What is the smallest size cable allowed for use to control PFC?
1/8”
Name 5 system operating methods.
Cable systems
Push-pull rods
torque tubes
fly-by-wire systems
fly-by-light systems
Explain the process of Nicopress cable swagging
Properly wrap the cable around the thimble and through the
sleeve at a proper length
make your 1st swag at the center of the sleeve
2nd swag at the base of the thimble
3rd swag at the other end of the sleeve
