Delta Air Lines Pilot Didn't Know He Hit Another Plane, New Audio Reveals

One of the pilots involved in the Delta Air Lines runway collision had no clue he hit another plane ... new audio reveals.

In audio from the cockpit, a pilot asks ... "We just hit something on the taxiway, could you tell us what it was?"

The culprit was another Delta Air Lines passenger jet ... and air traffic control responded, "The whole tail of that CRJ is off."

The plane collision went down Tuesday at Hartsfield-Jackson Atlanta International Airport ... and video and photos from the aftermath shows exactly what air traffic control describes here ... a plane with its tail chopped off, and dangling to one side.

Delta says the wing of an Airbus A350 hit the tail of a smaller, Endeavor Air CRJ-900 while both planes were on the taxiway ... and it sounds like the pilots in the larger jet were caught totally off guard.

Fortunately, Delta Air Lines says no injuries were reported in this incident.