What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The aircraft was being operated on a flight under CFR part 135 by Mccall aviation (M2LA) and returning to Mccall from sulphur creek, Idaho during the time of the incident. The sole pilot and 3-PAX were on board the aircraft during this event. While landing runway 34 at myl, the pilot reported upon touchdown, the aircraft pulled to the right departing the runway. He indicated he was unable to correct loss of directional control with the use of left rudder. The aircraft narrowly missed a runway marking sign, however traveled into a small drainage ditch causing minor damage to the propeller. Airworthiness personnel of the boi FSDO inspected the aircraft and found no other damage. A detailed statement was received from the pilot. It indicates the pilot inadvertently took off from sulphur creek gravel airstrip with the parking break partially set. Evidence of heavy skidding and rubber transfer marks on the runway caused by breaking appear to support this.
As the FAA filed it
THE AIRCRAFT WAS BEING OPERATED ON A FLIGHT UNDER CFR PART 135 BY MCCALL AVIATION (M2LA) AND RETURNING TO MCCALL FROM SULPHUR CREEK, IDAHO DURING THE TIME OF THE INCIDENT. THE SOLE PILOT AND 3-PAX WERE ON BOARD THE AIRCRAFT DURING THIS EVENT. WHILE LANDING RUNWAY 34 AT MYL, THE PILOT REPORTED UPON TOUCHDOWN, THE AIRCRAFT PULLED TO THE RIGHT DEPARTING THE RUNWAY. HE INDICATED HE WAS UNABLE TO CORRECT LOSS OF DIRECTIONAL CONTROL WITH THE USE OF LEFT RUDDER. THE AIRCRAFT NARROWLY MISSED A RUNWAY MARKING SIGN, HOWEVER TRAVELED INTO A SMALL DRAINAGE DITCH CAUSING MINOR DAMAGE TO THE PROPELLER. AIRWORTHINESS PERSONNEL OF THE BOI FSDO INSPECTED THE AIRCRAFT AND FOUND NO OTHER DAMAGE. A DETAILED STATEMENT WAS RECEIVED FROM THE PILOT. IT INDICATES THE PILOT INADVERTENTLY TOOK OFF FROM SULPHUR CREEK GRAVEL AIRSTRIP WITH THE PARKING BREAK PARTIALLY SET. EVIDENCE OF HEAVY SKIDDING AND RUBBER TRANSFER MARKS ON THE RUNWAY CAUSED BY BREAKING APPEAR TO SUPPORT THIS.