A plane appeared to bounce after landing at the Caribbean Island airport of Sint Maarten and skidding down the runway.
"While they are all unrelated, I want you to know that these incidents have our attention and have sharpened our focus," United CEO Scott Kirby said.
Passengers were evacuated from a United flight at Houston's George Bush Intercontinental Airport, according to an airport spokesperson.
A Southwest Airlines passenger remains hospitalized after opening an emergency door and jumping out of the plane while it was still on the tarmac in New Orleans.
A Delta passenger describes what it was like to be stuck on that plane that reached temperatures up to 111 degrees.
Passengers aboard a Delta flight to Los Angeles came across a frightening scene Saturday when the plane's emergency slide accidentally deployed inside the cabin, injuring a crew member.