The crash involved World War Two-era planes - a Boeing B-17 Flying Fortress bomber and a Bell P-63 Kingcobra fighter - that were flying at the Wings Over Dallas Airshow at Dallas Executive Airport, the Federal Aviation Administration (FAA) said in a statement.
The P-63 is manned by a single pilot, Coates added, but he would not say how many people were aboard the aircraft at the time of the crash.