Final answer:
An airplane must have a person competent to control it seated in the pilot seat while the engine is running. Flight safety measures also include strict adherence to FAA flight path regulations and safe engine design to prevent structural damage in emergencies.
Step-by-step explanation:
An airplane may not be left with an engine running unless a person competent to control the aircraft is seated in the pilot seat. This safety measure ensures that in case of any issue, quick actions can be taken to rectify the situation or safely shut down the engine. Placing danger/warning cones and remaining within the pilot's line of sight are additional safety practices, but they don't substitute for having a competent person in control of the aircraft.
Related to aviation safety and operations, there are various measures in place such as following the flight path regulations set by the Federal Aviation Administration which stipulates that aircraft maintain certain distances from each other, both horizontally and vertically. Additionally, the design of jet engines plays a crucial role in aircraft safety, designed to break apart, conserving angular momentum without causing structural damage to the plane in extreme circumstances.
Moreover, the use of checklists in the airline industry is a vital safety protocol ensuring all equipment functions correctly before takeoff, akin to procedures followed by astronauts and medical personnel to reduce the likelihood of accidents.