A Chetak helicopter of the Navy, carrying two officers and a sailor, today crashed at Dabolim airport while landing and caught fire, officials said. The fate of the three men onboard the chopper was not immediately known. The rotor of the helicopter, which had flown from Mumbai to Dabolim, broke off while landing, Navy sources said. The chopper then caught fire, they said. Civilian flights from the airport were likely to be delayed as the chopper had crashed on the runway, they said.