Service difficulty report · Valve · Robsin R44RAVENII

Difficulty date
September 22, 2011
Submitted
September 14, 2015
Operation
General aviation
Make and model
Robsin R44RAVENII
Engine
Lyc IO540AE1A5
Part
Valve
Part number
D7571
Condition
Failed
Location
Float Cylinder
Part time
507 hours
Component
Float Cylinder · Robsin · D6793
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

(CAN) WHEN PERFORMING A SCHEDULED 3 YEAR EMERGENCY INFLATION TEST ON POP-OUT FLOAT SYSTEM, THE FLOATS FAILED TO DEPLOY. STIFFNESS IN RELEASE VALVE ALLOWED RELEASE CABLE OUTER SHEATH TO SLIP WITHIN HOLD-DOWN CLAMPS. THIS IN TURN DID NOT ALLOW APPLIED CABLE MOVEMENT TO BE FULLY APPLIED TO RELEASE VALVE, SINCE THE MOVEMENT OF THE OUTER SHEATH TOOK-UP THE MAJORITY OF THE RELEASE LEVER MOVEMENT. DUE TO CONCERN THAT THE HIGH PRESSURE CYLINDER WAS NOW IN AN UNSAFE CONDITION, FLOAT DEPLOYMENT WAS PERFORMED BY TEMPORARILY LOCKING DOWN MOVEMENT OF OUTER CABLE SHEATH WITH VISE-GRIPS. THIS CONDITION HAS BEEN THE TOPIC OF A NEWLY ISSUED MFG SB-80. REPLACEMENT BOTTLE ASSY HAS SINCE BEEN FITTED WHICH CONTAINS A NEWER REVISION VALVE ASSY AS LISTED WITHIN THE SB.