What type of lubrication system is installed on each engine?

• A. Dry sump
• B. Wet sump
• C. Splash lubrication
• D. Central lubrication

Answer: (A)

The concept being tested is how lubrication systems keep engine bearings reliably supplied under varying operating conditions. A dry sump means the oil is stored in a separate external tank, not in the crankcase, and is circulated to the bearings by a pressure pump while scavenger pumps remove oil from the crankcase back to the tank.

This arrangement provides a constant, dependable oil supply and pressure, even during high-speed operation or unusual orientations, because the oil volume is not limited by the crankcase space and the external reservoir can hold a larger amount of oil. It also helps prevent oil foaming and oil starvation, facilities easier oil cooling and filtration, and allows engines to be installed in different positions or configurations with more flexible space use.

Wet sump stores oil inside the crankcase itself, which can lead to oil pressure drops or starvation during rapid accelerations or climbs where oil can move away from bearings. Splash lubrication is a simple method suitable only for small, low-speed engines where oil is distributed mainly by splash from moving parts. Central lubrication is designed to distribute small amounts of lubricant to multiple points in a system and isn’t used as the primary engine lubrication method.

So, for an arrangement where reliability and flexibility of oil supply are priorities for every engine, a dry sump system is the best fit.