C04 - Atmospheric Density Flashcards
Define Air Density?
A measurement of the mass of air contained within a specified volume.
The greater the mass of air inside a volume, the ‘____’ the density?
Greater.
What is the Lift Equation?
L = Cₗ x ½ pV² x A.
What is the ISA Mean Sea Level Density?
1.225 kg/m³.
Name three factors which affect Density?
- Temperature.
- Pressure.
- Humidity.
As Temperature increases, the density of the air ‘____’?
Decreases.
True or False. Rising air is a trigger for many weather phenomena?
True.
As Temperature decreases, the density of the air ‘____’?
Increases.
Cold denser air tends to ‘____’?
Sink.
As air pressure increases, the density of air ‘____’?
Increases.
As air pressure decreases, the density of air ‘____’?
Decreases.
True or False. Pressure changes generally have a lower effect on the Air Density than Temperature changes?
False. Pressure has a greater effect.
Define Humidity?
The amount of water vapour in the atmosphere.
Increasing Humidity ‘____’ the Air Density?
Decreases.
The Density of the air ‘____’ with Altitude?
Decreases.
Density decreases with ‘____’ and it does so much faster at ‘____’ levels than at ‘____’ levels (3)?
- Altitude.
- Lower.
- Higher.
In cold air density decreases more ‘____’ with height than in warm air?
Quickly.
Low density reduces ‘____’ and decreases ‘____’ and therefore increases the ‘____’ distance and severely degrades the Aircraft’s ability to ‘____’ (4)?
- Lift.
- Engine Thrust.
- Take-off.
- Climb.
Name the three least favourable conditions for Aircraft Performance?
- High Altitude.
- High Temperature.
- High Humidity.
Define Density Altitude?
The Pressure Altitude corrected for Temperature Variation.
Density Altitude is not used for Altimetry, it’s used to estimate ‘____’?
Aircraft Performance.
What is the Density Altitude formula?
120ft per 1°C ISA Deviation.
Define Relative Density?
Compares Actual Density against ISA Mean Sea Level Density as a percentage.
What is the Relative Density at 40,000ft?
25%.
What is the Relative Density at Mean Sea Level?
100%.
What is the Relative Density at 22,000ft?
50%.
What is the Relative Density at 10,000ft?
75%.
