FRESNO, Calif. (KFSN) -- The National Transportation Safety Board is investigating a helicopter crash in southeast Fresno on Saturday morning.
The NTSB's preliminary information indicates that during a maintenance check flight, the helicopter lost tail rotor control.
The tail rotor is the smaller blade at the rear of a helicopter and counters the torque forces created by spinning the main blades on top of the helicopter. Without a working tail rotor, the helicopter body spins in the opposite direction of the main rotor.
NTSB investigators will look at the human, machine and environmental factors of the crash before publishing its preliminary report, within the next three weeks.
The full investigation will take between 12 and 24 months to complete.
This is a breaking news update, our original story follows.
An investigation is underway after a helicopter crash in southeast Fresno on Saturday morning.
Fresno police who responded to the scene said a civilian helicopter went down in a the front yard of a home in a neighborhood near Willow Ave and Jensen Ave.
FPD said both the pilot and their passenger survived the crash.
The Pilot and his passenger told police they heard a "pop" before losing altitude.
Both were transported to Community Regional Medical Center to be treated for injuries. The extent of their injuries is unknown, but FPD said they are expected to survive.
Neighbors were visibly shaken as they waited to get back in their homes. It's not clear when the neighborhood will reopen.
Ring footage from a neighbor's front porch captured the moment when the helicopter crashed into the yard.
The helicopter was a Bell 206B, according to the Federal Aviation Administration.
The FAA and the National Transportation Safety Board will investigate the cause of the crash.