Artist's concept of the X-51

Artist’s concept of the X-51

An experimental jet that was aiming for Mach 6 speeds has reportedly crashed into the Pacific Ocean.

The X-51A “Waverider” had reached Mach 5 in tests last year, and it dropped from a B-52 bomber on Wednesday for a test that had been gunning for the elusive speed of six times the speed of sound.

“An unmanned aircraft designed to fly six times the speed of sound crashed over the Pacific Ocean, Air Force says,” CNN reports on its homepage.

The test began successfully, but it appears something went wrong. NBC News reports something went wrong with the X-51’s control fins:

“The U.S. Air Force says its most ambitious test of its X-51 WaveRider hypersonic aircraft ended in failure less than a minute after launch on Tuesday, due to a flaw in one of the craft’s control fins. The X-51 broke apart after it was dropped from a B-52 bomber, with pieces falling into the Pacific Ocean, a spokesman for the project told me today,” wrote Alan Boyle at NBC.

A statement released by the Air Force shows that the “Waverider” launched successfully over Point Mugu Naval Air Warfare Center Sean Range in the Pacific off the coast of California at 11:36 a.m. Pacific Time. The rocket booster fired as planned but a fault occurred 16 seconds later.

The X-51’s scramjet never got to fire. NASA and the Department of Defense each see civilian and military applications for ultra-fast scramjets including fast missiles and eventually flights that could go from New York to Los Angeles in an hour.