As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT COMPLAINED OF FLUCTUATING QTY INDICATION. MX SUSPECTED A DEFECTIVE QTY TRANSMITTER. WHEN ACCESSED QTY TRANSMITTER HE FOUND THE FLOAT IN AN UNUSUAL POSITION. UPON FURTHER INSPECTION HE FOUND THE ROLL PIN ATTACHING THE FLOAT SWING ARM TO THE VARIABLE RESISTOR MISSING. THIS ALLOWED THE FLOAT TO MOVE FREELY AROUND THE AXIS OF THE RESISTOR & PROVIDE AN ERRONEOUS INDICATION OF 600 LBS. WHEN THE TANK WAS DRAINED ONLY 150 LBS WAS OFFLOADED.