Originally Posted by
mattmillard
Hello, I have a question that my 11 year old son asked me and I have no idea how to answer it. The question was when a pilot is flying a jumbo jet at 500 to 700 miles an hour does the pilot keep the plane level with the horizon when we live on a globe, does the pilot have to keep correcting the height to follow the roundness of the earth? This may seem like a strange question but the more I thought about it the more I was confused could someone tell me how to answer this please I would be very grateful.
Level with the horizon won't work because most jets fly at about 3 degrees nose up in cruise flight.
Above 18000 feet altitude(varies by country) pilots set altimeters to standard pressure, 29.92, and maintain an altitude based on that pressure setting. This compensates for the curve of the earth and variances in pressure due to temperature. Most jets are required to be on autopilot above 29,000 feet so the aircraft compensates automatically.
On a clear day you can often see the curve of the earth displayed by contrails.