Chapter 4 Principled of Flight Flashcards
Oxygen composes what percentage of the atmosphere?
21%
Nitrogen composes what percentage of the atmosphere?
78%
Most of the atmosphere’s oxygen is contained below what altitude
35,000 ft.
Is air considered a fluid or a liquid?
Fluid
What is the property of a fluid that causes it to resist flow
Viscosity
High viscosity fluids are ________ and resist flow
THICK
Air has a _____ viscosity, and flows _______
LOW / EASILY
Are all fluids viscous
YES / TRUE
Another factor at work when a fluid flows over or round an object is called what?
Friction
Molecules of air passing over the surface of the wing actually ________________ to the surface because of friction
adhere (stick)
The layer of molecules that adhere to the wing surface is referred to as what?
Boundary layer
When “viscosity” and “friction”had to get it to resist airflow over when it is called what?
Drag
What is the force applied in a perpendicular direction to the surface of an object?
Pressure
If the pressure on one side of an object becomes less than the pressure on the other surfaces, the object will
Move in the direction of the lower pressure.
What kind of pressure are pilots mainly concerned with?
Atmospheric pressure.
Atmospheric pressure actuate some of the important fly instruments, these instruments are?
Altimeter, airspeed indicator, vertical speed indicator, and manifold pressure gauge.
Air has mass?
True
Under standard conditions at sea level, the average pressure exerted by the weight of the atmosphere is approximately how many pounds per square inches (psi)? How many millibars (mb)?
14.70 per sq inch. / 1,013.2 mb.
At what altitude is the weight of the atmosphere one - half of what it is at sea level?
18,000 ft.
The “Standard” atmosphere at sea level is a surface temperature of ________ degrees Fahrenheit, _________ degrees Celsius and a surface pressure of _______ Hg, _________ mb.
59F / 15C / 29.92Hg / 1,013.2mb
A “Standard” temperature lapse rate is when the temperature decreases at the rate of approximately ________ degrees Fahrenheit, _________ degrees Celsius, per _______ ft, up to _________ ft.
3.5F / 2C per thousand ft , up to 36,000ft
Above __________ ft temperature is considered constant up to _______ ft.
36,000ft / 80,000 ft.
The “standard” lapse rate of pressure is _______ Hg; per __________ ft of altitude gain to _________ ft.
1Hg / 1,000ft / 10,000 ft.
The acronym “ICAO” stands for?
International Civil Aviation Organization
The acronym “ISA” stands for?
International Standard Atmosphere
Any temperature or pressure that differs from the “standard” lapse rate is considered what
Non-standard temperature and pressure.
Pressure altitude can be determined by two methods, those two methods are?
- Setting the barometric scale of the altimeter to 29.92 and reading the indicated altitude.
- Applying a correction factor to the indicated altitude according to the reported altimeter setting.
Density altitude is ___________ corrected for ___________.
Pressure altitude / corrected for nonstandard temperature
As the density of air increases, aircraft performance _________.
Increases.
At high density altitude air density ________.
Decreases.
Increasing the temperature of a substance _______________ its density
Decreases.
Pilots can expect the density of air to _____________ with an increase in altitude
Decrease.
Is water vapor heavier or lighter than air
Lighter
Will warm air hold less or more water vapor?
Holds more water vapor.
A wing moving through air generates the force called?
Lift
Define Newtons 3rd Law?
“For every action, there is an equal and opposite reaction.”
Bernoulli’s Principle states?
As a velocity of a moving fluid (liquid or gas) increases, the pressure within the fluid decreases
As the wing moves through the air, the flow of air across the curve top surface __________ in velocity creating an area of _____ pressure.
Increases / LOW
A straight line drawn through the profile of a wind connecting extremities of the leading edge to the trailing edge is known as?
Chord Line
As the angle of attack of a wing increases the center of pressure on the wing moves?
Forward
An airplane arrow dynamic balance and controllability are governed by changes in the
CP (Center of Pressure)
