Military aircraft may participate in civil aviation activities under certain circumstances. In some emergency situations, military aircraft may be used to perform rescue missions, medical evacuations, humanitarian assistance and other tasks. In addition, the governments of some countries may also allow military aircraft to perform civilian transportation tasks to meet the transportation needs of the people or other special needs. However, generally speaking, military aircraft and civil aviation operate in different fields. Civil aviation usually refers to civil aviation transportation, cargo and general aviation activities for commercial purposes. In addition, military aircraft often have additional military systems and equipment to meet operational and military needs. Therefore, the participation of military aircraft in civil aviation activities is relatively rare and needs to be determined based on specific circumstances.