Federal aviation safety investigators say there's been unacceptable progress made toward two of their recommendations stemming from the 2006 Comair 5191 plane crash that killed 49 people in Lexington.

The National Transportation Safety Board says it's gotten unacceptable responses from the FAA on recommendation involving checks to make sure its planes are on the right runway prior to take off.

One involves air traffic control checks, and the other cross-checks from inside the cockpit.

Comair 5191 crashed two years ago this Wednesday, when it took off from the wrong runway.