Transcript for Rescue mission underway for 3 Marines off Australia

way at this hour. Three U.S. Marines missing after their aircraft, an osprey, crashed in the waters off Australia. The Pentagon says they took off for regularly scheduled operations. The osprey going down trying to land. 23 service members have been rescued. No word yet on the cause of the crash. The osprey with a history of problems in recent years. ABC's Stephanie Ramos starts us off. Reporter: Tonight, that desperate search for three Marines missing at sea. U.S. Military aircraft and boats scouring the water off the east coast of Australia. The marine unit was on board an osprey for a routine practice flight when it hit the water, the crash happening at 4:00 P.M. Local time. Crews managing to rescue 23 of the 26 Marines. The fact that 23 of the 26 personnel have already been recovered tells me the that initial impact to the water was controlled enough that obviously they were able to survive. Reporter: The osprey belonging to a unit based out of okinawa, Japan, which had just wrapped exercises with the Australian military. Tonight, with that search for the missing Marines now going on for more than 16 hours, new scrutiny on the osprey and its spotty safety record. The aircraft is a hybrid, it flies like an airplane, but lands like a helicopter. There are so many things that can happen in that landing phase. The bottom line is landing an air craft aboard a ship is very demanding. Reporter: In January, three U.S. Soldiers were wounded in an osprey hard landing in Yemen. And in 2015, an osprey crashed during a military exercise in Hawaii. Images showing it erupting in a ball of fire, two Marines killed. Yet despite these incidents, due to its versatility, the osprey is still one of the most important aircraft in the military. There's really nothing else in the world like it. And Stephanie Ramos is live from outside the Pentagon with an update. You have an update. What they're searching for right now? Tom, that's right. Right now rescuers are searching of signs of life. They are also looking for the data recorder of the air craft that could provide as to why the air kraft went down. Tom? Stephanie, thank you. Also breaking tonight, the American airlines flight rocked

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