Air India engineers were working on the aircraft, a leased Boeing 777-200 ER (Extended Range) when the accident occurred, an Air India spokesperson said in Mumbai on Friday.
However, no one was injured, he said.
An alternative aircraft was made available to operate the flight (AI 717) which took off for Dubai at 1600 hrs more than an hour, he said.
This is the second incident involving an Air India aircraft within two days. On Thursday, a Mumbai-Chennai flight was delayed for more than four hours when its door was damaged after an aerobridge (passenger boarding bridge) slammed against it.