JACKSONVILLE, Fla. -

The family of one of the men killed when a helicopter chartered by Mayo Clinic crashed last month in Clay County is suing the operator of the aircraft.

The children of 57-year-old David Hines are suing SK Logistics for wrongful death. They're also suing Abraham Holdings, the company that owned the helicopter.

SK Logistics was owned by Hoke Smith, who was piloting the Bell 206B helicopter when it crashed about dawn on Dec. 26.

The helicopter was making its way from Jacksonville to Gainesville to pick up a heart for an organ transplant when it went down in the woods of a hunt club in southern Clay County. In addition to Hines and Smith, Mayo Clinic cardiac surgeon Luis Bonilla died in the crash.

The lawsuit claims the crash was caused by pilot error.

The National Transportation Safety Board continues to investigate what caused the crash. The NTSB issued a one-page report earlier this month. Spohrer believes the evidence indicates Smith made a mistake.

"We believe the pilot became spacially disoriented and flew into trees," said Robert Spohrer, attorney for the Hines family. "On that day with those weather conditions, this flight was unsafe, and that's the basis of the lawsuit."

Spohrer believes Smith was trying to navigate through cloudy weather in the dark and should not have taken off in those conditions.

"I'm saying the pilot should have checked the weather, seen that the weather minimums were below what could safely be navigated, and said to the folks at the Mayo Clinic, 'The weather is going down. It's not good enough to make this trip. We need to put the doctor and the ambulance technician in an ambulance and get them down to Shands, and then get them back here,'" Spohrer said.

The lawsuit seeks damages in excess of the $15,000.

SK Logistics has not responded to Channel 4's request for comment on the lawsuit.

Hours before Hines died in the helicopter crash, he called his oldest daughter and left a message. It was Christmas night.

"Hey, sweetheart. It's your dad," he said. "I'm sorry I missed your call. Give me a call. Bye. I've got my phone on my hip now. I'll talk to you later. Hope everything is OK. Talk to you later, love you guys. Bye bye.

That's the last time Christine Hines heard her father's voice. She said she listens to the message often.

"I just want to hear his voice," she said.

Christine Hines talked Monday about filing the lawsuit.

"It's not out to get anybody. It is justice," she said. "I don't want this happening to somebody else's family. This is horrible."

NTSB continues to investigate

According to the preliminary report by the National Transportation Safety Board, no distress call was sent before the helicopter struck several trees as it crashed to the ground southwest of Keystone Heights.

Investigators said the helicopter took off from the Mayo Clinic at 5:37 a.m. without a flight plan. The last communication from the helicopter came at 5:49 a.m. when Smith of SK Jets, contacted the air traffic control tower at Jacksonville International Airport to inquire about the status of restricted airspace. Air traffic controllers told Smith the restricted areas were inactive, and Smith acknowledged their reply, investigators said.

Documents:  Estate of David Hires vs. SK Logistics | NTSB's preliminary report

The helicopter, a Bell 206B, was last recorded on radar at 5:53 a.m. at an altitude of 300 feet and about a mile north of the Clay County crash site, investigators said. Its altitude varied from 200-700 feet througout the flight.
The helicopter crashed at 5:54 a.m. in a remote wooded area about 12 miles northeast of the Palatka Municipal Airport in overcast, somewhat misty conditions, according to the report.
Mayo Clinic staff alerted authorities that the team was overdue and a Jacksonville Sheriff's Office aircraft spotted the wreckage about four hours later.
Several trees that were severed by breaks at descending altitudes marked the start of the debris field, investigators said. The first tree strike was at an estimated height of 30 feet above the ground, which severed a roughly 50-foot tree at a ground elevation of 118 feet, according to the report.

"In a very short period of time, he goes from 300 feet to hitting trees. So a lot was going on," said attorney Don Maciejewski, who specializes in aircraft accidents. "I don't think he had visual perspective. I really don't."

The crash ignited a fire that burned about 10 acres of woods and investigators said most of the wreckage was consumed by the fire.

Maciejewski said conclusions can be drawn from the size of the debris field. The NTSB report says the debris stretched 320 feet one way and 70 feet the other way. Maciejewski said that for a helicopter crash, that's a relatively small debris field, and he said his experience tells him that rules out mechanical error.

"I think he clipped a tree. That's my opinion at this point," Maciejewski said. "He clipped a rather high, large tree, and after that, if you knock your rooter system out of balance, you're just along for the ride."

"The whole picture of the crash site, if you've done a lot of these cases, shows that this was a controlled flight into terrain," Maciejewski added. "That sounds funny, but it means the pilot thought he was here when he wasn't here, and he flew it into the ground. ... That's what 35 years of flying and doing air crash cases tells me."

The NTSB investigation into what caused the crash may take up to a year and a half to complete.

Smith, 68, was a Vietnam combat veteran and his son said he frequently piloted organ transplant flights.  Hines, 57, was a transplant technician.