What is the maximum duration for ground operations using DC only?

The maximum duration for ground operations using DC power only is 5 minutes. This limitation is in place to prevent potential overheating and to ensure that the aircraft's systems remain operational without draining the battery excessively.

Ground operations can place significant power demands on the aircraft's electrical systems, leading to a risk of battery depletion if the duration exceeds this limit. By adhering to the 5-minute restriction, pilots can ensure that there is sufficient battery power available for critical systems should it be needed for engine start or in case of an emergency.

It's important to note that any operation beyond this timeframe could compromise the reliability of electronic systems and reduce safety margins, which is why the 5-minute limit is established as a safe operational practice. Understanding and following these limitations is crucial for maintaining aircraft performance and safety.