SAN ANGELO, Texas (AP) _ Two people making a curiosity flight over a West Texas wildfire were killed when their small airplane crashed.

Federal Aviation Administration spokesman Lynn Lunsford said the wreckage of the single-engine experimental aircraft was found Monday afternoon 12 miles east of San Angelo.

Lunsford said witnesses told investigators that the pair, believed to be Air Force lieutenants, had taken off from Mathis Field/San Angelo Municipal Airport in their two-seat Christen Eagle biplane Sunday afternoon. There were no injuries or damage on the ground. Lunsford said no flight plan was filed, but none was required.

The National Transportation Safety Board and the FAA will investigate.