During the preflight check, what must be confirmed about the first aid kit?

Confirming that the seal of the first aid kit is intact during the preflight check is crucial because it ensures that the kit has not been tampered with and that all of its contents are secure and sterile. An unbroken seal indicates that the kit is ready for use in case of an emergency, providing confidence that it contains all necessary supplies in proper condition.

While it's also important to check that the contents are full, that the kit is located in an appropriate place, and that the expiration date is valid, the primary concern during the preflight phase is the integrity of the seal. This step helps prevent any potential issues during an actual emergency, as tampered or improperly stored equipment could compromise its effectiveness.