SDR G5203

Service difficulty report · Control Valve · Cessna 441

Difficulty date
February 6, 2004
Submitted
August 11, 2004
Operation
General aviation
Aircraft
N988AE
Make and model
Cessna 441
Aircraft serial
4410175
Part
Control Valve
Part number
99102791
Part serial
495
Condition
Failed
Location
Mlg
Stage of operation
IN
How discovered
C
Nature of condition
L
Precautionary procedure
K

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

What was found

THIS MLG CONTROL VALVE FOUND TO BE REASON THE MLG FAILED A SCHEDULED EMERGENCY EXTENTION CHECK. FOUND THE RETURN PORT CLOSED WHEN VALVE NOT ENERGIZED, PORT SHOULD BE OPEN IN THIS CONDITION & THIS CAUSED MLG TO HYDRO-LOCK IN UP POSITION. TEAR DOWN REVEALED ON 2ND VALVE NOT ASSEMBLED CORRECTLY, SPOOL WAS INSERTED BACKWARDS RESULTING IN PORTING NOT FUNCTIONING. VALVE FAILURE WAS NOT DEFINED DURING TEAR DOWN. VALVE S/N 1152 RETURNED AND FOUND THAT PIN NR 17 IN THE CORE ASSEMBLY BROKEN AT THE TIP. IT IS ASSUMED THAT THIS FAILURE OCCURED DURING THE REQUIRED TEST PROCEEDURE.

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