FAA Commercial Pilot Airplane (CAX)WeatherMedium
A pilot is flying at 10,000 feet MSL and notices a significant increase in outside air temperature (OAT) while maintaining altitude. This observation suggests the presence of a(n):
- ACold front
- BDecreasing pressure system
- CInversion layer
- DOccluded front
Show answer & explanationAnswer & explanation
Correct answer: C. Inversion layer
An inversion layer is a reversal of the normal decrease of air temperature with increasing altitude, or of temperature increasing with height. Encountering an increase in OAT at a constant altitude strongly indicates flying into such a layer. Inversions can trap pollutants and often lead to stable air and smooth flying conditions, but can also contribute to wind shear and fog.
Why the other options are wrong
- A. A cold front typically brings a decrease in temperature after its passage.
- B. A decreasing pressure system might be associated with various weather, but doesn't directly cause an increase in OAT at a constant altitude; temperature trend is more related to air mass.
- D. An occluded front involves complex temperature changes but not necessarily a direct increase at a constant altitude as a primary characteristic.
Temperature Inversion
An atmospheric layer where temperature increases with altitude, contrary to the typical decrease.
- Creates very stable air conditions.
- Can trap pollutants, leading to haze and reduced visibility.
- Often associated with smooth air, but can cause wind shear below the inversion.
Memory trick: Inversion's a turn, where heat takes an upward burn.