During operations, under what condition should the HMMWV transmission be in when checking fluid levels?

The transmission of the HMMWV should be in the Park position when checking fluid levels to ensure an accurate reading. This is crucial because the Park position locks the transmission, preventing any movement during the process. Additionally, being in Park allows the fluid to settle correctly in the transmission pan, providing a more precise indication of the fluid level. Checking the fluid level in any other gear could result in an inaccurate reading due to the fluid being circulated or disturbed, leading to potential maintenance issues. This standard procedure ensures the reliability and safety of the vehicle’s operation.