Is it legal for two planes to be on the same runway at the same time?

Not every facet of non-towered airports operations has been addressed by the FAA. That leaves some things in a solid gray area and open to interpretation. One of these gray areas: Can two planes legally occupy the same runway at the same time?

Is it legal for two planes to be on the same runway at the same time?
Not every facet of non-towered airports operations has been addressed by the FAA. That leaves some things in a solid gray area and open to interpretation. One of these gray areas: Can two planes legally occupy the same runway at the same time?