The crankshaft is one of the most important parts of a reciprocating aircraft engine. It converts the up-and-down motion of the pistons into rotary motion, which ultimately turns the propeller. Because it handles so much force, the crankshaft must be strong, precisely balanced, and supported by the crankcase. Understanding its design, construction, and balance is … Read more
The relationships between pressure, volume, and temperature of gases are the basic principles of engine operation. An internal combustion engine is a device for converting heat energy into mechanical energy. Gasoline is vaporized and mixed with air, forced or drawn into a cylinder, compressed by a piston, and then ignited by an electric spark. The … Read more
Aircraft reciprocating engines are internal combustion engines that convert the chemical energy of fuel into mechanical energy through a series of controlled explosions within cylinders. These engines operate on the four-stroke cycle of intake, compression, power, and exhaust, which produces the rotational motion necessary to drive a propeller. Despite advances in turbine engine technology, reciprocating … Read more
Both wet and dry sump lubrication systems are used in gas turbine engines. Wet-sump engines store the lubricating oil in the engine proper, while dry-sump engines utilize an external tank mounted on the engine or somewhere in the aircraft structure near the engine, similar to reciprocating piston engines. Turbine engine’s oil systems can also be … Read more
The following component descriptions include most found in the various turbine lubrication systems. However, since engine oil systems vary somewhat according to engine model and manufacturer, not all of these components are necessarily found in any one system. Oil Tank Although the dry-sump systems use an oil tank that contains most of the oil supply, … Read more
Maintenance of gas turbine lubrication systems consists mainly of adjusting, removing, cleaning, and replacing various components. Oil filter maintenance and oil change intervals for turbine engines vary widely from model to model, depending on the severity of the oil temperature conditions imposed by the specific airframe installation and engine configuration. The applicable manufacturer’s instructions should … Read more
Draining Oil Oil, in service, is constantly exposed to many harmful substances that reduce its ability to protect moving parts. The main contaminants are: Because of the accumulation of these harmful substances, common practice is to drain the entire lubrication system at regular intervals and refill with new oil. The time between oil changes varies … Read more
There are many requirements for turbine engine lubricating oils. Due to the absence of reciprocating motion and the presence of ball and roller bearings (antifriction bearings), the turbine engine uses a less viscous lubricant. Gas turbine engine oil must have a high viscosity for good load-carrying ability but must also be of sufficiently low viscosity … Read more
Pre-Oiling Before the new engine is flight tested, it must undergo a thorough ground check. Before this ground check can be made, several operations are usually performed on the engine. To prevent failure of the engine bearings during the initial start, the engine should be pre-oiled. When an engine has been idle for an extended … Read more
Proper inspection and maintenance of spark plugs and ignition system components are essential for reliable engine operation and maximum ignition system performance. Regular servicing helps prevent fouling, excessive electrode wear, ignition failures, and harness-related faults while ensuring efficient combustion and dependable engine starting. This section describes common spark plug problems, recommended inspection and reconditioning procedures, … Read more
Aviation Knowledge & Technical Study
Aero Guide provides structured aviation study materials, technical explanations, and educational resources based on FAA handbooks and other aviation references. Explore aviation fundamentals, aircraft systems, airframe structures, powerplant systems, weight and balance, and more to support your aviation learning journey.
Site Information
© 2026 Aero Guide. All rights reserved.