What does the scavenger pump do in the oil system?

The scavenger pump's primary function within an aircraft's oil system is to remove oil from components such as the reduction gearbox and direct it to the oil cooler. This process is crucial for maintaining the appropriate temperature and viscosity of the oil. By efficiently managing oil flow from the gearbox, the scavenger pump ensures that oil does not become overheated and continues to provide effective lubrication and cooling for the engine system. This is particularly important given the high-performance demands of aircraft operations, where oil contamination and degradation can significantly impact engine efficiency and longevity.

The other functions described in the choices do not accurately reflect the role of the scavenger pump. For instance, while circulating oil to the engine's exterior, transporting oil from the tank to the cooler, or pumping oil to high-pressure systems are essential parts of the overall oil system, they do not fall under the specific responsibilities of the scavenger pump. Thus, understanding the unique function of the scavenger pump is pivotal for maintaining the efficacy of the oil system in aircraft operations.