C02 - Air, Atmosphere and Airspeed Flashcards
Define Fluid?
Is a liquid or gas that has an ability to flow.
What happens to Air Pressure, Temperature and Humidity if Air Density decreases (3)?
- Air Pressure decreases.
- Temperature increases.
- Humidity increases.
Define Static Pressure?
A force acting over an area.
What is Static Pressure measured in?
Newtons per Square Metre (N/m²).
Static Pressure reduces as Altitude ‘____’?
Increases.
What is the definition of Temperature?
The measure of heat energy associated with the movement and collision of molecules in a gas, liquid or solid.
How does Temperature affect Air Density (2)?
- Higher the Temperature the Density decreases.
- Lower the Temperature the Density increases.
Air Density is ‘___’ proportional to the absolute Temperature?
Inversely.
What is +20°C in K?
293K (273K + 20K).
What is -50°C in K?
223K (273K - 50K).
Define Viscosity?
The stickiness of the fluid.
True of False. Viscosity over a wing can cause turbulence and disruption in air flow?
True.
Define Humidity?
The amount of water vapour in the atmosphere.
True or False. Air Density reduces with decreasing Humidity?
False. Increasing with Humidity.
What is the MSL Temperature?
+15°C.
What is the MSL Pressure (3)?
- 1013.25 hPa.
- 29.92 inHg.
- 760 mmHg.
What is the MSL Density?
1.225 kg/m³.
What is the Temperature Lapse Rate from the surface to the Tropopause (2)?
- 1.98°C per 1,000ft.
- 0.65°C per 100m.
What is the height of the Tropopause?
- 36,000ft.
- 11km.
What is the Temperature above the Tropopause?
-56.5°C.
Define Temperature Lapse Rate?
The term used to describe the reduction in Temperature with Altitude.
An Aircraft can only become airborne, and stay airborne, if it does ‘____’ on the air to produce a force to oppose ‘____’ (2)?
- Work.
- Gravity.
What is the formula for Kinetic Energy?
½ mV².
Define Dynamic Pressure?
The additional air pressure in a volume of air which relates to its Kinetic Energy.
What is the formula of Dynamic Pressure?
½ pV².
Dynamic Pressure ‘____’ if the Air Density increases?
Increases.
Dynamic Pressure increases rapidly if the True Airspeed ‘____’?
Increases.
Define IAS (2)?
- Indicated Airspeed.
- Airspeed found on the Airspeed Indicator.
What is Total Air Pressure?
Static Pressure + Dynamic Pressure.
How can you calculate Dynamic Pressure?
Total Pressure - Static Pressure.
What instrument is used to measure Total Pressure?
Pitot Tube.
Name three types of errors found in basic Airspeed Indicators?
- Instrument Error.
- Pressure Error.
- Compressibility Error.
Define Instrument Error on Airspeed Indicators?
Limitations of the manufacturing process.
Define Pressure Error on Airspeed Indicators?
The error in the measurement of both Total and Static Pressure due to the position of the Pitot and Static ports.
Define Compressibility Error on Airspeed Indicators?
High speed air entering the Pitot Tube which can falsely increase the Density.
Define CAS (2)?
- Calibrated Airspeed.
- IAS corrected from its instrument and pressure errors.
Define EAS (2)?
- Equivalent Airspeed.
- CAS correct from compressibility error.
What is the equation for working out EAS when given a TAS?
EAS = TAS √(Air Density of Aircraft ÷ Air Density at MSL).
The EAS provides the most accurate indication of what?
Dynamic Pressure.
Define TAS (2)?
- True Airspeed.
- The actual speed of the Aircraft through the air.
The TAS can be used to determine the Aircraft’s speed over the ground once it the ‘____’ is taken into account?
Wind Velocity.
