A Mi-8 military helicopter crashed in central Russia\'s Saratov region Tuesday, killing a pilot and prompting the air force to ground all choppers of the type. The two others on board escaped unharmed in the crash, which occurred during a routine training flight, according to investigators. Regional emergency authorities said flight recorders have been found. The cause of the accident is yet to be found. Investigators said they have opened a criminal case. Air Force Commander Victor Bondarev ordered to ground all Mi-8 helicopters until the cause is determined. Kremlin spokesman Dmitry Peskov said the accident will not affect the use of Mi-8 helicopters by President Vladimir Putin.