When an aircraft loses engine power, it begins to descend. The rate of descent depends on several factors, including the aircraft's weight, drag, and altitude. However, a typical jetliner might descend at a rate of about 500 feet per minute (fpm).

The distance a plane can glide depends on its glide ratio. The glide ratio is the ratio of the aircraft's lift to its drag. A higher glide ratio means the plane will descend more slowly and can, therefore, glide for a greater distance.

The typical glide ratio for a jetliner is between 15:1 and 20:1. For every foot the aircraft descends, it can move forward by 15 to 20 feet.

If a jetliner loses engine power at 30,000 feet, it could glide for a distance of about 225 miles. However, the actual distance will vary depending on the aircraft's weight, configuration, and weather conditions.

Pilots are trained to handle engine failures and will follow procedures to maximize the aircraft's glide distance and reach the nearest suitable airport.