Service difficulty report · Outflow Valve · Gulstm GIVXG450

Difficulty date
September 15, 2014
Submitted
September 15, 2014
Operation
General aviation
Aircraft
N450Z
Make and model
Gulstm GIVXG450
Aircraft serial
4012
Aircraft time
3,356 hours, 1,682 cycles
Engine
Rroyce TAY6118
Part
Outflow Valve
Part number
645471038781
Part serial
17A0265
Condition
Misinstalled
Location
Zone 100
Stage of operation
IN
How discovered
V
Nature of condition
W
Precautionary procedure
K

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

What was found

THE PRIMARY OUTFLOW VALVE ACTUATOR TO MECHANICAL DOOR CONNECTION NOT SAFETIED WITH COTTER KEY. THE BOLT USED FOR THIS CONNECTION POINT IS MOUNTED WITH HEAD ON THE BOTTOM. LOSS OF THIS CONNECTION WOULD CAUSE A TOTAL VALVE FAILURE AND NO CONTROL OF CABIN PRESSURIZATION. IN ADDITION, 2 BOLTS THAT ARE UTILIZED TO SECURE THE ACTUATOR TO THE OUTFLOW VALVE MECHANICAL DOORS WERE FINGER TIGHT AND NOT SAFETIED. THESE PARTICULAR BOLTS ARE THE ONLY 2 USED FOR CONNECTION OF THE ACTUATOR TO THE DOOR CARRIAGE UNIT. THESE 2 BOLTS HAVE DRILLED HEADS FOR SECURING WITH SAFETY WIRE AND THE MACHINED CARRIAGE ASSY HAS A DRILLED PASSAGE IN CLOSE PROXIMITY TO TERMINATE THE SAFETY WIRE. IT HAS BEEN VERIFIED WITH MFG THAT THERE BUILD UP PROCEDURES DO NOT SAFETY THE CRITICAL MOUNTING BOLTS. SEVERAL OTHER BOLTS IN THE BUILD HAVE HEADS MOUNTED ON THE BOTTOM. THESE HARDWARE CONNECTIONS ARE CRITICAL TO THE ROTATIONAL TRANSMISSION OF FORCES FOR PROPER OUTFLOW VALVE OPERATION.