11:40 AM PT -- A United Airlines spokesperson tells TMZ ... "United flight 762 from Miami to Newark stopped in Orlando on Tuesday evening after a passenger became aggressive and disruptive. Our flight attendants worked to de-escalate the situation and protect other customers and after landing in Orlando, law enforcement met the flight, and the passenger was removed. We’re grateful to our team for their professionalism and for looking out for the safety of our customers and their fellow United employees."

A United passenger bit off more than she could chew during a recent flight ... quite literally, 'cause the disgruntled flier ripped off a chunk of a flight attendant's uniform in a new video.

TMZ has obtained footage from United Flight 762 from Miami to Newark, New Jersey Tuesday ... and, it shows an upset passenger screaming at other passengers while the flight crew tries to restrain her, wrapping zip ties around her wrists.

With no hands available, the passenger takes a different tack ... biting the flight attendant's shoulder and ripping fabric from it while other employees jump to their comrade's aid.

Another clip shows the woman with her hands restrained behind her, screaming profanities at other passengers and threatening to kill one woman who she says should "go back to Russia."

We've also obtained audio that appears to capture the woman spitting at a fellow passenger before telling everyone to read her T-shirt ... a "Scarface" shirt seemingly meant to intimidate. An eyewitness told us she did indeed spit at someone and throw punches at other individuals.

We're told the flight was delayed 3.5 hours ... and, a gate attendant announced the flight crew had to be changed out because of the ordeal per another clip. Police are seen escorting the biter out of the airport.

Anyhoo ... seems like the crew's lucky the passenger only bit their heads off figuratively -- and kept her literal biting below the neck!

We've reached out to United, the Greater Orlando Aviation Authority and Orlando Airport Police ... so far, no word back.