Service difficulty report · Housing · Dhav DHC8301

Difficulty date
October 4, 2006
Submitted
December 4, 2006
Operation
General aviation
Make and model
Dhav DHC8301
Engine
Pwa PW123
Propeller
Hamstd 14SF23
Part
Housing
Condition
Failed
Location
Sequence Valve
Part time
13,093 hours
Component
Sequence Valve · Tactair
Component part number
54C546349
Stage of operation
AP
How discovered
O
Nature of condition
K
Precautionary procedure
A

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

What was found

(CAN) DURING APPROACH WHEN CREW SELECTED GEAR DOWN, NR 2 HYD ENG PUMP CAUTION LIGHT ILLUMINATED DURING EXTENSION CYCLE. NOSE GEAR DOORS AND RT MAIN GEAR DOORS REMAINED OPEN, LT MAIN GEAR DOOR CLOSED. QRH ITEMS FOR NR 2 HYDRAULIC SYSTEM AND GEAR DOORS OPEN WERE COMPLETED. INVESTIGATION BY ENGINEERING DETERMINED THAT THE LEAK WAS ORIGINATING FROM THE RT MLG DOOR SOLENOID SEQUENCE VALVE. (3) OF THE FOUR BOLTS SECURING THE SOLENOID TO THE VALVE BODY HAD SHEARED RESULTING IN THE PARTIAL SEPARATION OF THE SOLENOID FROM VALVE BODY. THIS CAUSED A LOSS OF NR 2 HYDRAULIC SYSTEM QUANTITY AND PRESSURE. NO SECONDARY DAMAGE WAS CAUSED AS A RESULT OF THE FAILURE. THE SOLENOID SEQUENCE VALVE ASSEMBLY WAS REPLACED IAW THE AIRC