Helicopter recovered by civilian salvage ship, and delivered to hangar at JMSDF Oominato.
Analyse flight data recorder for one to two months.
On JDS Matsuyuki, damage was 15 m above sea surface.
Helicopter height was 5 m.
Helicopter was altitude 10 m above sea surface.
On April 19, Lieutenant Commander Miyanaga's funeral ceremony at base, then delivered to actual home in Miyazaki City.
JMSDF press conference said helicopter had no malfunction.
Cause was possibly control mistake or human error.
During accident, pilot Lieutenant Commander Miyanaga controlling helicopter.