What is one purpose of a fuel tank boost pump?

A fuel tank boost pump is primarily designed to prevent vapor lock, especially in situations where the aircraft is operating at higher altitudes or lower atmospheric pressures. Vapor lock can occur when fuel vaporizes in the lines between the fuel tanks and the engine, which can lead to engine fuel starvation and potential failure. By maintaining adequate fuel pressure and ensuring that the fuel remains in a liquid state, the boost pump ensures a consistent flow to the engine.

While increasing fuel pressure is a function of the boost pump, it is not its sole purpose, as maintaining fuel flow and mitigating the risk of vapor lock are critical. Other options, such as removing contaminants from the fuel or cooling fuel before it enters the engine, are not typical functions of a boost pump. The primary focus of a fuel tank boost pump is its role in maintaining liquid fuel at appropriate pressure levels to prevent vaporization under varying atmospheric conditions.