"Shortly after that we reestablished contact with the
plane, and it has been on the ground at (Reagan National Airport)
for a while. Department of Homeland Security (DHS) officials are
interviewing the pilots."
Source: The FAA's Diane Spitaliere,
describing what occured after Piedmont Airlines Flight
4352, enroute to Ronald Reagan Washington National Airport
from Hilton Head, South Carolina, lost contact during its
approach for some 15 minutes due to what was reported to be a
"readback error."