In the "Flight Levels", altitudes are referred to not in feet above sea level but as "FLxxx" where xxx is a nominal altitude in 100s of feet.
Altimetry is done using barometric pressure. Since this varies with weather, airplanes at lower altitudes set their altimeters to the local barometric pressure for a reasonably accurate reading. In the flight levels, where planes are typically covering ground quickly and there is very little chance of your path conflicting with the surface of the Earth, every plane sets to an agreed-upon reference of 29.92 inches of mercury as the altimeter setting.
It means any aircraft transitioning over the area at high altitude isn't impacted, because they're too high to care.
It is a ground and "everything near the ground" stop. Meaning low altitude helicopters and private aircraft have to consider it, even transitioning, but realistically commercial aircraft not taking off/landing in the area won't.
satiated_grue|19 days ago
Relevant chapter from FAA "Pilot's Handbook of Aeronautical Knowledge": https://www.faa.gov/sites/faa.gov/files/17_phak_ch15.pdf
In the "Flight Levels", altitudes are referred to not in feet above sea level but as "FLxxx" where xxx is a nominal altitude in 100s of feet.
Altimetry is done using barometric pressure. Since this varies with weather, airplanes at lower altitudes set their altimeters to the local barometric pressure for a reasonably accurate reading. In the flight levels, where planes are typically covering ground quickly and there is very little chance of your path conflicting with the surface of the Earth, every plane sets to an agreed-upon reference of 29.92 inches of mercury as the altimeter setting.
petesergeant|19 days ago
Someone1234|19 days ago
It is a ground and "everything near the ground" stop. Meaning low altitude helicopters and private aircraft have to consider it, even transitioning, but realistically commercial aircraft not taking off/landing in the area won't.
bombcar|19 days ago
reactordev|19 days ago
anovikov|19 days ago