Service difficulty report · Float Valve · Gulstm

Difficulty date
December 3, 2021
Submitted
December 17, 2021
Operation
Air carrier
Aircraft
N421QS
Make and model
Gulstm
Aircraft serial
4114
Aircraft time
10,389 hours, 5,079 cycles
Part
Float Valve
Part number
16F123
Part serial
406323
Condition
Defective
Stage of operation
TO
How discovered
V
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

FUEL DUMP: SHORTLY AFTER TAKEOFF, WITH 27,000 POUNDS OF FUEL ON BOARD, VISIBLE FUEL STREAMING FROM LEFT WING NACA DUCT. LEAK APPEARED TO STOP IN LEVEL FLIGHT. SEE ATTACHED PICTURES. // SIGNOFF // GAINED ACCESS TO L/H WING FUEL TANK, AND DRAINED BOTH LH AND RH PLENURNS, FUEL DRAINED FROM LH SIDE APPROX 4 GALLONS AND RH APPROX 1/4 GALLON. VISUALLY INSPECTED ALL PLUMBING AND OVERBOARD VENT/RAM AIR INLET, VENT FLOATS, VENT PLENUM, FUEL VENTILATION SYSTEM THROUGH ACCESS PANELS ON LH WING. REF. G450 _AMM 28-15-00. FOUND OUTBOARD AFT VENT FLOAT STUCK OPEN. REMOVED AND REPLACED VENT FLOAT P/N 16F123 REFERENCE G450 AMM 28-15-01. COMPLIED WITH FUEL TANK LEAK CHECK. PERFORMED LEAK CHECK LH WING FUEL TANK PANELS. NO LEAKS NOTED. NO SQUAWKS NOTED. IAW G450 AMM 28-L0-00. PERFORMED AIRCRAFT SINGLE POINT REFUELING FULL LOAD. NO FUEL ON LEFT PLENUM AND NO LEAKS. THEN DEFUELED AIRCRAFT TO IN COMING LOAD. NO SQUAWKS NOTED. NO LEAKS NOTED. JAW G450 AMM 12-13-00.