Long-Lost Black Box of Eastern Airlines Flight 980 Headed to NTSB Lab in Washington

Could a spool of magnetic tape solve one of aviation's biggest mysteries?

Shortly after 10 a.m. today, at a small airport in Norwood, Mass., NTSB investigator Bill English met with Dan Futrell and Isaac Stoner to pick up pieces of evidence to one of the biggest aviation mysteries of the 20th century.

Several pieces of mangled orange metal and a spool of magnetic tape are on the way to the NTSB’s laboratory in Washington, D.C.

In May 2016, two Bostonians, Dan Futrell and Isaac Stoner, climbed Bolivia’s Mt. Illimani and, at an elevation of 16,000 feet, recovered what appears to be the flight recorders from the U.S. airliner, a task many experts and investigators thought was impossible.

Flight 980 crashed on Jan. 1, 1985, on its approach to the airport outside La Paz, Bolivia. El Alto, as the airport is commonly called, is the highest international airport in the world with a runway perched at over 13,000 feet. There were 29 people on board the Boeing 727, including eight Americans. No one survived, and multiple international efforts to recover the flight recorders ended fruitlessly because of the inaccessibility of the crash site, the NTSB previously said.

International regulations dictate that the nation where an accident occurs is in charge of any investigation. After the discovery by Futrell and Stoner this spring, the NTSB offered its services, but the agency needed the green light from Bolivia before proceeding.

Months of efforts by the adventurers and ABC News to reach the Bolivian embassy in Washington, D.C., were unsuccessful.

During that time, the NTSB and the U.S. State Department awaited permission from the Bolivians to analyze the tapes.

It wasn’t until Dec. 1, when Capt. Edgar Chavez, the operations inspector at the General Directorate of Civil Aviation of Bolivia, emailed ABC News confirming the Bolivian government would allow the NTSB to look at the tape found by Futrell and Stoner.

He was unable to say when that would occur. However, he added that his agency was "still working on the paperwork."

Chavez did not respond to follow-up calls and emails from ABC News requesting an update or another interview.

On Dec. 21, the NTSB confirmed that it was arranging for the retrieval of the black box from Boston.

Today’s hand-off marks the end of months of diplomatic red tape preventing the NTSB from looking at the tapes.

The analysis of the tapes is expected to take no more than a few weeks. After that, the NTSB will report its findings to Bolivian authorities, according to the NTSB.

ABC News' Erin Dooley, Tom Thornton and Whitney Lloyd contributed to this report.