American Airlines could be in hot water ... just like the passenger who was burned when a flight attendant spilled a hot cup of java on his arm.

George Latorre says he was minding his own business on a flight from Vietnam to NYC earlier this month when he asked for a cup of coffee. According to the lawsuit, the flight attendant was all sorts of negligent by spilling what he claims was "scalding coffee" on his left arm.

Latorre says he suffered second-degree burns to his upper left arm, as well as blistering, peeling and bleeding. He says it was so bad it damaged his tattoo.

The lawsuit claims Latorre's "cosmetic deformity and scarring" may be permanent, and he's still suffering "extreme pain and suffering, emotional harm, mental anguish and distress," among other things.

Latorre's lawyer, David Jaroslawicz, tells TMZ ... after the spill, Latorre asked for a more comfortable seat -- even offering to pay for the upgrade -- but he was denied and remained in economy for the rest of the flight.

Jaroslawicz says his client beelined it to a doctor after he landed in NYC, and was told the burn was so bad he needed to see a surgeon who specializes in burns.