The youngest survivor of the plane crash near Dillingham headed home Sunday. A spokesperson for the Phillips family said 13-year-old Willy Phillips was released from Providence Alaska Medical Center. 

The Phillips family, including Willy Phillips, flew back to Maryland. On Friday they will hold a funeral for Willy's father, Bill Phillips, who died in the crash.

Three survivors are still in the hospital.

A spokesperson for Providence said former NASA chief Sean O'Keefe is in serious condition. His son Kevin O'Keefe, as well as lobbyist Jim Morhard, remain in fair condition.

Meanwhile, the NTSB has wrapped up its on-scene investigation of the crash.

NTSB spokesperson Clint Johnson said investigators have returned from Dillingham. The investigators examined the wreckage in a Dillingham hangar.

One question that remains to be answered: was the technology that's meant to alert the pilot to dangerous terrain turned on at the time of the crash?

In a press conference, NTSB Chair Deborah Hersman compared the technology to a car's GPS system -- and said it might have been disabled at the time of the crash.

"If you all think about this, a Garmin (GPS system) or a map feature in your car, you might want to turn the voice off when you're getting close to home because you know how to get there. It's going to tell you all the streets to turn. You can suppress that voice and you can turn that off if it's not helpful to you," said Hersman.

The NTSB said it doesn't expect a lot of new information in the coming weeks. The investigation will take 12 to 18 months.

Contact Jackie Bartz at jbartz@ktuu.com