Japan's Air and Maritime Self-Defense Forces continued Wednesday the search for four crew members who went missing in an ASDF chopper crash off Hamamatsu, central Japan, the previous day, and found three helmets.

The UH-60J chopper, carrying the four, disappeared around 10 minutes after it took off to conduct a nighttime search-and-rescue drill from the ASDF's Hamamatsu base. Those missing include Maj. Akihiro Hanafusa, the 42-year-old pilot.

(Air Self-Defense Force website)

On Tuesday, debris from the chopper, such as a door bearing the letters ASDF, tires and a tail rotor were recovered in the ocean where the helicopter is believed to have gone down.

The helicopter departed its base at 5:51 p.m. on Tuesday, the ASDF said, adding the crew carried out their last communication with the ground staff at 5:57 p.m.

The chopper disappeared from radar at 6:02 p.m. about 30 kilometers south of the Hamamatsu base.

The helicopter was deployed in October 2015 and passed a routine inspection in late August.