NTSB to review data recorders from Nigerian crash

Hersman made the remarks during a speech to the IAC touting international cooperation in accident investigations.

"Multi-national interests lead to multi-national accidents," she told the group. "Our investigators have been called to many accident sites, from the Afghanistan mountains to the Amazon jungle. We are safer when we work together."

Hersman said the NTSB was similarly farming out the investigation of a recent crash between two small airplanes in Virginia. The planes that were involved belonged to the NTSB and the Federal Aviation Administration, Hersman said, so the agency was bringing in Canadian transportation officials to lead the investigation.

"I was concerned about our ability to conduct a truly independent investigation," she said after noting earlier in her speech that the NTSB's chief medical inspector was killed in the accident.

Hersman told the IAC the decision was made easier by the cooperation between Canadian and U.S. transportation safety officials.

"We're trying to work more effectively across boundaries to learn from accidents," she said.