WASHINGTON (Reuters) - The United States aviation regulator on Tuesday ordered a immediate fix for a software glitch affecting thrust reversers on some Boeing airplanes featuring certain General Electric (GE) engines.

The Federal Aviation Administration's (FAA's) so-called airworthiness directive covers Boeing's 747-8 and 747-8F series planes with certain GE engines, and calls for removing the defective software and installing new, improved software.

The FAA said the defective software could result in "uncontrolled flight into terrain" for the airplanes under some circumstances.