Factbox-Flights, airports affected by U.S. system outage

FILE PHOTO: American Airlines planes are seen at the Tampa International Airport as airports around the country are awaiting for Verizon and AT&T to rollout their 5G technology, in Tampa, Florida, U.S., January 19, 2022. REUTERS/Octavio Jones

LONDON (Reuters) - U.S. flights were grounded or delayed on Wednesday as the Federal Aviation Administration (FAA) scrambled to fix a system outage, with passengers told to check with airlines for updates.

Here's what we know so far: