Aero-Terms!

Aero-Terms are designed to be a daily reminder of the terms, names, acronyms and explanations of the unique language that populates the aviation world. Aerospace, sport aviation, fixed wing, helo, you name it... it's all fair game.

Aero-Terms should serve as a quick but intriguing reminder of the terms you may use every day, or an introduction to an aspects of the Aero-World you may not yet be familiar with. ANN also encourages readers to go beyond the FMI link, and further research any intriguing terms.

Suggestions for future Aero-Terms are ALWAYS welcome, as are additions or discussion of the explanations given for each Aero-Term.

Phase Separation – Aviation Fuel

Phase separation is when a combined liquid separates into two different liquids and may occur when autogas used for aviation fuel.

When alcohol present in autogas, it is subject to phase separation, when the fuel is cooled as a result of the aircraft’s climbing to higher altitude. Think of an oil and vinegar salad dressing; when the dressing is shaken, the oil and vinegar combine. As the salad dressing sits, the oil and vinegar separate. A similar situation exists when autogas with ethanol is combined with water. The presence of ethanol in autogas allows an amount of water to be absorbed, rather than remaining separate.

FMI: http://aviationglossary.com/phase-separation-aviation-fuel/