Service difficulty report · Actuator · Bolkms BK117C2

Difficulty date
February 19, 2025
Submitted
February 19, 2025
Operation
General aviation
Filed by
QR9R369D
M1 Support Services
Make and model
Bolkms BK117C2
Aircraft serial
1572394
Aircraft time
4,273 hours
Part
Actuator
Part number
41800879001
Part serial
836
Condition
Binding
Location
Yaw Trim
Stage of operation
TX
How discovered
O
Nature of condition
F
Precautionary procedure
C

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

AFTER STARTING THE NO.2 ENGINE SEVERAL SECONDS AFTER THE STARTER DROPPED OUT, FELT A METALLIC CLUNK IN THE PEDALS. THERE WERE NO INDICATIONS OF ANY MALFUNCTIONS IN THE INSTRUMENTS. WITH THE ENGINE AT IDLE THE IP PUSHED THE PEDALS BACK AND FORTH SLIGHTLY WITH NO INDICATIONS OF ANY MALFUNCTION. AFTER SHUTTING DOWN THE ENGINE AND THE ROTOR SYSTEM STOPPED, TESTING THE PEDALS THE LEFT PEDAL WORKS CORRECTLY, BUT THE RIGHT HAS A DISTINCT RATCHETING, WHICH CAN BE SEEN WHEN OBSERVING THE TAIL ROTOR WHILE SOMEONE PUSHES THE RIGHT PEDAL IN, THE SAME RESULT REGARDLESS OF WHICH FLIGHT STATION'S PEDALS ARE USED. AFTER TROUBLESHOOTING, MAINTENANCE DETECTED THE YAW TRIM MOTOR BINDING INTERNALLY. REMOVED AND REPLACED YAW TRIM MOTOR IAW 67-14-00, 4-1; T/F SUCCESSFULLY COMPLETED.