A B-52 Stratofortress crashed and burst into flames shortly after takeoff from Edwards Air Force Base in California's Mojave Desert, killing eight people, including military personnel and contractors.
The US Air Force has opened an investigation that could take up to six months.
The B-52, a Boeing-designed aircraft, has been in service for 70 years and has been involved in several major conflicts, including the Vietnam War and Operation Desert Storm.
The aircraft that crashed was a Boeing B-52H Stratofortress assigned to the 412th Test Wing, which runs Edwards and handles developmental testing of all air force aircraft, weapons systems, and components.
The B-52 has undergone several modernization programs, including the Radar Modernization Programme (RMP) and the Commercial Engine Replacement Programme (CERP), which will replace the TF33 engines with newer, more fuel-efficient commercial turbofans.
The US Air Force currently projects B-52H service life extending to 2050, and potentially beyond.
