What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Pf (SIC) started engines while pm (PIC) was briefing passangers in the back.
During startup of the second engine, the aircraft started to move forward. The parking brake was set and the pf attempted to apply more brake pressure with no success. PIC jumped into the front right seat and told the SIC to stop, he stated he could not, no brakes. He then told him to turn, which the SIC did. The aircraft started a left turn, but it was too late and the right wing made contact with a corner fence post, bringing the aircraft to a stop in the grass.
No injuries or damage other than the leading edge of the wing (no spar damage).
Parking brake was not released during the attempt to brake. Emergency braking system was not used or attempted during the event.
As the FAA filed it
PF (SIC) STARTED ENGINES WHILE PM (PIC) WAS BRIEFING PASSANGERS IN THE BACK.
DURING STARTUP OF THE SECOND ENGINE, THE AIRCRAFT STARTED TO MOVE FORWARD. THE PARKING BRAKE WAS SET AND THE PF ATTEMPTED TO APPLY MORE BRAKE PRESSURE WITH NO SUCCESS. PIC JUMPED INTO THE FRONT RIGHT SEAT AND TOLD THE SIC TO STOP, HE STATED HE COULD NOT, NO BRAKES. HE THEN TOLD HIM TO TURN, WHICH THE SIC DID. THE AIRCRAFT STARTED A LEFT TURN, BUT IT WAS TOO LATE AND THE RIGHT WING MADE CONTACT WITH A CORNER FENCE POST, BRINGING THE AIRCRAFT TO A STOP IN THE GRASS.
NO INJURIES OR DAMAGE OTHER THAN THE LEADING EDGE OF THE WING (NO SPAR DAMAGE).
PARKING BRAKE WAS NOT RELEASED DURING THE ATTEMPT TO BRAKE. EMERGENCY BRAKING SYSTEM WAS NOT USED OR ATTEMPTED DURING THE EVENT.