How high do commercial airlines fly?

John Cox , Special for USA TODAY Published 6:02 p.m. ET Feb. 2, 2014 | Updated 6:08 p.m. ET Feb. 2, 2014 Commercial aircraft are certified for a maximum altitude, but the limit is exceeded slightly during test flights. read more

While some long flights go above the average altitude, the Federal Aviation Administration allows flights that are 500 miles or shorter to fly at significantly lower altitudes of between 8,000 and 23,000 feet. read more

Typically a commercial airliner will fly anywhere from 23,000 feet, spoken as Flight Level 230 (FL230), on up to FL410. The lower altitudes are usually for altitude restricted routes. For instance, Chicago to Dayton, Ohio. These flights are restricted to FL230 to keep them from getting caught up in the arrival stream to the Chicago metro area. read more