A Gulfstream Aerospace Corp. business jet conducting flight tests in Roswell, N.M., crashed Saturday and burst into flames, killing the four people on board.

The new Gulfstream G650, the largest and fastest business jet ever developed by Savannah, Ga.-based Gulfstream, struck its right wingtip on the ground as it took off from Roswell International Air Center around 9:30 a.m. local time Saturday, according to a Federal Aviation Administration spokesman. The plane then hit the ground, causing the landing gear to collapse, and...