World's Largest Aircraft Crash Lands After 2nd Test Flight

The 300-feet long Airlander 10 nosedived on its return to an airfield north of London after spending more than an hour and half in the air.

"The Airlander experienced a heavy landing and the front of the flight deck has sustained some damage which is currently being assessed," Hybrid Air Vehicles, the British company behind the aircraft, said in a statement.

The company did not explain what caused the crash but said all planned tasks were completed during the flight. The pilots were unhurt, it added.

The U.K. government's Air Accident Investigation Branch has begun an investigation, a spokesperson said.

Part airship, part helicopter, part plane, the aircraft is about 50 feet longer than the biggest passenger plane.

Airlander completed its maiden test flight just last week.

Airlander is designed to stay airborne for up to five days at a time if manned, and for more than two weeks if unmanned. It should be able to carry up to 10 tons of cargo at a maximum speed of 91 miles per hour.