SDR 97ZZZX778

Service difficulty report · Servo Valve · Gulstm GIV

Difficulty date
December 19, 1996
Submitted
March 26, 2000
Operation
General aviation
Aircraft
N540W
Make and model
Gulstm GIV
Aircraft serial
1265
Part
Servo Valve
Condition
Misadjusted
Location
Nlg Steering
Part time
303 hours
Stage of operation
IN
Nature of condition
O
Precautionary procedure
K

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

What was found

NOSE WHEEL STEERING SYSTEM KEPT TRIPPING OFF LINE. UPON EXTENSIVE TROUBLESHOOTING, FOUND NWS SERVO VALVE WAS CAUSING MALFUNCTION. ALSO, WHEN SYSTEM WOULD TRIP OFF, IT WOULD KICK RIGHT. FOUND THAT THE NWS RUDDER POTENTIOMETER WAS ADJUSTED BACKWARDS (MINUS 30MV RATHER THAN PLUS 30MV). THIS TOLD THE SYSTEM TO TURN RIGHT WHEN THE SERVO FAILED. RE-ADJUSTED POTENTIOMETER. OPS CHECKS GOOD.