Flight Operations
- Review Aerodynamics & Airplane Systems
- 1.1Explain the four forces which act on an airplane in flight
- 1.2Explain the angle of attack- Commercial Pilot-Aerodynamics and Performance
- 1.3Explain the basics of Aerodynamics
- 1.4Explain drag
- 1.5Explain thrust, stability, and center of gravity
- 1.6Explain weight and balance
- 1.7Demonstrate knowledge of aircraft components
- Pressure, Temperature & Density
- Weather
- 3.1Identify and explain the structure of the earth’s layers of the atmosphere, and become knowledgeable of the history of the study of meteorology
- 3.2Describe atmospheric conditions using appropriate weather terminology
- 3.3Demonstrate an understanding of frontal systems
- 3.4Demonstrate an understanding of wind speed, temperature, pressure & dew point
- 3.5Employ meteorological terminology and coding procedures
- 3.6Identify air masses and monitor daily weather phenomena
- 3.7Demonstrate an understanding of synoptic weather structure
- Weather Forecasting
- Weather Hazards
- Weather Tools
- IFR
- IFR
- IFR Navigation
Pressure, Temperature & Density
Understanding Temperature and its Effects on Aircraft Performance
Physical property of matter that quantitatively expresses the common notions of hot and cold.
Temperature is a fundamental concept in aviation. It is a measure of the average kinetic energy of the particles in a system. In simpler terms, it is a measure of how hot or cold something is. The standard unit of temperature in the International System of Units (SI) is the Kelvin (K), but in aviation, it is commonly measured in degrees Celsius (°C) or degrees Fahrenheit (°F).
Standard Temperature and Lapse Rate
In aviation, the term "standard temperature" is used to refer to the average temperature at sea level, which is 15°C or 59°F. This is the temperature used as a baseline in many aviation calculations.
As an aircraft ascends, the temperature generally decreases. This decrease in temperature with increasing altitude is known as the lapse rate. Under standard atmospheric conditions, the temperature decreases by approximately 2°C (or 3.5°F) per 1,000 feet of altitude gain. This is known as the standard lapse rate.
Effects of Temperature Variations on Aircraft Performance
Temperature variations can significantly impact aircraft performance. As the temperature increases, the air becomes less dense. This decrease in air density can reduce the aircraft's engine power, lift, and propeller efficiency.
On a hot day, an aircraft may require a longer runway for takeoff, climb more slowly, and have a lower service ceiling. This is because the aircraft's engine takes in less air (due to the lower air density), resulting in less fuel combustion and therefore less power. Similarly, the wings generate less lift in less dense air, and the propeller or jet engine is less efficient.
Conversely, in colder temperatures, the air is denser, which can enhance the aircraft's performance by increasing engine power, lift, and propeller efficiency. However, extremely cold temperatures can also present challenges, such as the risk of icing.
Density Altitude
The concept of density altitude is a way of accounting for the effects of non-standard temperature (and pressure) on aircraft performance. Density altitude is the altitude in the standard atmosphere at which the air density is the same as the actual air density at the place of observation.
On a hot day, the density altitude is higher than the actual altitude because the air is less dense. On a cold day, the density altitude is lower than the actual altitude because the air is denser. Pilots need to calculate the density altitude before each flight to understand how the aircraft will perform under the current temperature and pressure conditions.
In conclusion, understanding temperature and its effects on aircraft performance is crucial for safe and efficient flight operations. By considering the current temperature and its impact on air density, pilots can make informed decisions about flight planning and aircraft operation.