Gulfstream Aerospace has resumed testing of its new 650 flagship after the April 2 crash of a 650 test aircraft that took the lives of the pilots and engineers aboard. An investigation by the National Transportation Safety Board is continuing. Tests will be conducted with a limited flight envelope while the investigation is in progress. The reduced envelope will limit use of low speeds and increase V speeds. The crash occurred as the aircraft was performing a single-engine takeoff–simulating loss of an engine after liftoff. The test flight took place May 28, with Serial Number 6001 flying for 1 hour and 39 minutes. The crew included senior experimental test pilots Jake Howard and Tom Horne, and Flight Test Engineer Bill Osborne. The company still anticipates certification in 2011, with entry into service in 2012, as originally announced in 2008.