The MTA’s first safety czar, who will start in December, is a top official from the National Transportation Safety Board who led the investigation into the Alaskan plane crash that killed Sen. Ted Stevens.

Chief safety officer David Mayer, 50, who will report to the agency’s chairman, will oversee all aspects of safety at all of the MTA’s top agencies — including work practices and new technology.

As a managing director at the NTSB, he has led more than 50 major investigations, such as a 2009 train crash in Washington, DC, that killed nine people the 2010 crash in which Stevens was killed when the plane’s pilot flew into a mountain.

Mayer will earn $245,000 a year, and takes the new position after a series of Metro-North mishaps last year.