How long are fuel samples deemed valid for use?

Fuel samples are considered valid for use for 24 hours after they are taken. This time frame is established to ensure that the samples accurately represent the current condition of the fuel. After 24 hours, changes in the fuel characteristics may occur due to settling, contamination, or other factors, which could lead to misleading results if the sample were used for testing at a later time. Therefore, adhering to the 24-hour validity period helps maintain the safety and reliability of aircraft operations.