How can you determine if an aircraft part or appliance is serviceable?

To determine if an aircraft part or appliance is serviceable, it is essential to rely on proper documentation that confirms its condition and compliance with regulatory standards. An approval for return to service included in the maintenance record or a completed FAA Form 337 signifies that the part has been properly repaired or modified and meets the necessary safety and performance standards established by aviation regulations. This documentation serves as a formal acknowledgment from a qualified technician or maintenance organization that the part is fit for use.

Visual inspections may provide initial indicators about an item’s condition, but they do not replace the necessary formal validation through documentation. Similarly, knowing the manufacturing date or testing performance during flight may provide contextual information but cannot alone assure serviceability without the appropriate return to service documentation. Hence, the presence of an official approval or completed Form 337 is critical in declaring an aircraft part or appliance as serviceable.