FAA Powerplant Written Practice Test 2026 – Complete Exam Prep

In a dry sump engine lubrication system, the scavenger pump is responsible for removing oil that has drained from the engine and returning it to the oil tank. The oil pressure pump, on the other hand, is responsible for providing pressurized oil to the engine's critical components for lubrication.

The scavenger pump usually has a greater capacity compared to the oil pressure pump. This is due to the need to efficiently return a larger volume of oil that accumulates during engine operation back to the oil tank, ensuring there is a sufficient oil supply and helping to maintain optimal oil circulation within the engine. By having a greater capacity, the scavenger pump can effectively manage the excess oil and prevent any oil starvation scenarios that might arise in the system.

While the oil pressure pump must maintain a consistent oil pressure for lubrication, the scavenger pump operates with a higher volume to accommodate the engine's oil system demands. This design principle ensures that a dry sump system functions effectively, leading to improved cooling and lubrication performance.