RAD-44 crashed

One day, the modified RAD-44 “Sturmvogel-Xa” was undergoing a test flight.

Then this incident occurred...
Suddenly, the right wing exploded, and the aircraft lost control.
The RAD-44 crashed into the sea, and no parts were recovered.

The following month, while RAD worked on developing a new model of the RAD-44, a shadow lurked in the darkness of the deep sea at the crash site...