The 9D6 Helo Dunker flips over during the aircrew refresher course July 28. The 9D6 Helo Dunker simulates a sinking aircraft in which the students have to escape through a specific window. “This training helps keep people alive,” said Petty Officer 2nd Class Matthew P. Johnson, an in-flight technician with Fleet Air Reconnaissance Squadron 4, Naval Air Station Patuxent River.