FALMOUTH — Federal investigators in New York have recovered an engine module and iPad that could provide insight into the June 13 small plane crash that killed Dr. Richard Rockefeller, son of banker and philanthropist David Rockefeller.

But they said  it could be a year before a probable cause of the accident is determined.

With the on-scene phase of its investigation complete, the National Transportation Safety Board will now begin further fact-gathering, spokesman Eric Weiss said on Monday. That will include examinations of aircraft maintenance records, pilot certification, autopsy and toxicology reports, Rockefeller’s activity over the 72 hours leading up to the crash, and possibly tests on aircraft components.

The final phase of the investigation will include analysis and determining probable cause. Wreckage from the crash is being taken to a secure location in Delaware, Weiss said.

Rockefeller, an experienced pilot, flew to New York on June 12 to celebrate his father’s 99th birthday, family spokesman Fraser Seitel said.

On Friday, his Piper Meridian single-engine turbo prop took off from Westchester County Airport in White Plains at 8:06 a.m. and crashed in nearby Purchase at 8:08 a.m. Rockefeller, 65, was the only person aboard the plane when it crashed.

Air traffic control personnel had given Rockefeller clearance for take-off, Weiss said. After he failed to respond for two minutes, they prepared to institute a search; but before a search could begin, the 911 calls started.

“This is a terrible tragedy, and the family is in shock,” Seitel said. “Richard was a wonderful and cherished son and brother, husband, father and grandfather. It’s just horribly sad.”

Rockefeller was father to two adult children and had several grandchildren, Seitel said. He was one of David and Peggy Rockefeller’s six children.

Rockefeller practiced and taught medicine in Portland from 1982 to 2000, according to the Rockefeller Brothers Fund website.

During the 1980s, he practiced at Bayview Pediatrics in Yarmouth with a group of physicians including Dr. Donald Abbott.

On Friday, Abbott remembered Rockefeller as “down-to-earth, caring … just a regular guy.”

“He had very high principles about how he wanted to lead his life,” Abbott said. “He went into family medicine because he really believed in it and thought it was a great way to help people. He did a great job at it and patients really liked him.”

Rockefeller was active in Doctors Without Borders, founded an institute to improve medicine using computer-based technology, and most recently had worked with veterans diagnosed with post-traumatic stress disorder.

“He thought it was tragic what’s happening with veterans who came back from Iraq and Afghanistan, and he set about some years ago to try to find a treatment,” Seitel said. “He was making great progress.”

Former Maine Gov. John Baldacci met with Rockefeller several years ago at Bangor International Airport to discuss the physician’s research into PTSD.

“He would go anywhere to see anyone in regards to this very important issue,” Baldacci said by phone. “What struck me about him was that he had found something that would be very helpful and he wanted to bring that to everybody’s attention. He was doing it at his own expense because he really cared deeply for the military – active duty and retired and the veteran community.”

Rockefeller also chaired the board of Maine Coast Heritage Trust from 2000 until 2006.

Maine’s congressional delegation offered condolences to Rockefeller’s family, and noted his dedication to improving health care in the country and around the world.

Rockefeller’s plane was scheduled to take off from Westchester County Airport at 8:13 a.m. Friday and arrive in Portland at 9:27 a.m.

At 8:15 a.m., Harrison police received a report that a plane had crashed in the backyard of a home and horse stable in Purchase, New York, about a half-mile from the runway, Harrison Police Chief Anthony Marraccini said. The plane landed about 20 feet from the home, but no one on the property was injured. There was no post-crash fire.

Staff writer Brendan Twist of The Forecaster contributed to this report.