FAA Sport Pilot Airplane (SPA)WeatherHard
A pilot obtains a morning weather briefing indicating a strong temperature inversion exists from the surface up to 2,000 feet AGL, with smoke and haze trapped below the inversion top. What flight hazard is most directly associated with climbing or descending through this inversion layer?
- AGuaranteed encounter with severe icing regardless of temperature
- BAn immediate loss of engine power due to fuel vaporization
- CA sudden increase in visibility due to mixing of air masses
- DPossible wind shear and turbulence at the inversion boundary along with reduced visibility below it
Show answer & explanationAnswer & explanation
Correct answer: D. Possible wind shear and turbulence at the inversion boundary along with reduced visibility below it
A temperature inversion, where temperature increases with height instead of decreasing, often traps smoke, haze, and moisture near the surface, reducing visibility, and can create abrupt wind shifts or shear at the top of the inversion layer, posing a hazard during climb or descent.
Why the other options are wrong
- A. Icing depends on temperature and moisture, not automatically present with every inversion.
- B. Fuel vaporization/vapor lock is unrelated to a temperature inversion layer.
- C. Inversions trap pollutants and typically reduce, not increase, visibility below them.
Temperature Inversion
A temperature inversion is a layer in which temperature increases with height rather than decreasing, often trapping moisture, smoke, and haze near the surface and creating wind shear at its boundary.
- Temperature increases with altitude instead of the normal decrease
- Commonly forms overnight under clear, calm conditions (radiation inversion)
- Traps pollutants/moisture below, reducing surface visibility
- Can produce wind shear/turbulence at the inversion top
Memory trick: Inversion = the atmosphere wearing its layers backward, trapping the smog below.