FAA Powerplant Written Practice Test

Who determines the oil and grease specifications for propeller lubrication?

1. The FAA

2. Propeller manufacturers

3. Aircraft manufacturers

4. Maintenance engineers

The correct answer is: Propeller manufacturers

The proper determination of oil and grease specifications for propeller lubrication is primarily the responsibility of propeller manufacturers. These manufacturers design and test their propellers to operate under specific conditions, which include the type and viscosity of lubricants that will ensure optimal performance and longevity of the propeller. Propeller lubrication specifications are influenced by the materials used in the propeller construction and the operational environment expected during use. By defining suitable lubrication products, propeller manufacturers ensure that the propeller maintains proper function, reduces wear, and minimizes the risk of failure. This is paramount in sustaining airworthiness and reliability during flight operations. While other entities, such as aircraft manufacturers and maintenance engineers, may have input or need to follow guidelines based on the propeller manufacturer’s specifications, the foundational determination lies with the propeller manufacturers themselves, as they have the expertise and testing data to support those choices.