Reciprocating Engine Lubrication Systems – Oil Tanks

Lubrication and Cooling Systems

Oil tanks are generally associated with a dry sump lubrication system, while a wet sump system uses the crankcase of the engine to store the oil. Oil tanks are usually constructed of aluminum alloy and must withstand any vibration, inertia, and fluid loads expected in operation. Each oil tank used with a reciprocating engine must […]

Read the full article →

Reciprocating Engine Lubrication Systems – Dry Sump Oil Systems

Lubrication and Cooling Systems

Many reciprocating and turbine aircraft engines have pressure dry sump lubrication systems. The oil supply in this type of system is carried in a tank. A pressure pump circulates the oil through the engine. Scavenger pumps then return it to the tank as quickly as it accumulates in the engine sumps. The need for a […]

Read the full article →

Reciprocating Engine Lubrication Systems

Lubrication and Cooling Systems

Aircraft reciprocating engine pressure lubrication systems can be divided into two basic classifications: wet sump and dry sump. The main difference is that the wet sump system stores oil in a reservoir inside the engine. After the oil is circulated through the engine, it is returned to this crankcase based reservoir. A dry sump engine […]

Read the full article →

Requirements and Characteristics of Reciprocating Engine Lubricants (Part Two) Specific Gravity

Lubrication and Cooling Systems

Specific gravity is a comparison of the weight of the substance to the weight of an equal volume of distilled water at a specified temperature. As an example, water weighs approximately 8 pounds to the gallon; oil with a specific gravity of 0.9 would weigh 7.2 pounds to the gallon. In the early years, the […]

Read the full article →

Requirements and Characteristics of Reciprocating Engine Lubricants (Part One)

Lubrication and Cooling Systems

While there are several important properties that satisfactory reciprocating engine oil must possess, its viscosity is most important in engine operation. The resistance of an oil to flow is known as its viscosity. Oil that flows slowly is viscous or has a high viscosity; if it flows freely, it has a low viscosity. Unfortunately, the […]

Read the full article →

Principles of Engine Lubrication

Lubrication and Cooling Systems

The primary purpose of a lubricant is to reduce friction between moving parts. Because liquid lubricants or oils can be circulated readily, they are used universally in aircraft engines. In theory, fluid lubrication is based on the actual separation of the surfaces so that no metal-to-metal contact occurs. As long as the oil film remains […]

Read the full article →

Air Turbine Starters

Engine Starting Systems

Air turbine starters are designed to provide high starting torque from a small, lightweight source. The typical air turbine starter weighs from one-fourth to one-half as much as an electric starter capable of starting the same engine. It is capable of developing considerable more torque than the electric starter. The typical air turbine starter consists […]

Read the full article →

Electric Starting Systems and Starter Generator Starting System

Engine Starting Systems

Electric starting systems for gas turbine aircraft are of two general types: direct cranking electrical systems and starter generator systems. Direct cranking electric starting systems are used mostly on small turbine engines, such as Auxiliary Power Units (APUs), and some small turboshaft engines. Many gas turbine aircraft are equipped with starter generator systems. Starter generator […]

Read the full article →

Gas Turbine Engine Starters

Engine Starting Systems

Gas turbine engines are started by rotating the high-pressure compressor. On dual-spool, axial flow engines, the high pressure compressor and N1 turbine system is only rotated by the starter. To start a gas turbine engine, it is necessary to accelerate the compressor to provide sufficient air to support combustion in the combustion section, or burners. Once […]

Read the full article →