"One male, is believed to have sustained a broken shoulder; his injuries are not life-threatening or life-changing," the Metropolitan Police said in a statement.
"Another male, aged in his 40s, was taken to a west London hospital with serious injuries. He has since died."
Some passengers had to disembark from a plane due to the incident, a spokeswoman for the airport said.
The airport was not closed as a result of the accident.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)