Date: 201509
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Dusk
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class C ZZZ; Class E ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: Fuel Quantity-Pressure Indication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Workload; Communication Breakdown; Distraction; Training / Qualification
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate; In-flight
Result: Flight Crew Took Evasive Action; Flight Crew Returned To Departure Airport; Flight Crew FLC complied w / Automation / Advisory; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: After takeoff; we retracted the gear and received a 'gear disagree' master warning message. The left main gear was indicating unsafe (red). I turned the autopilot on; and kept the airspeed below 200 KTS. I called for the after takeoff checklist; then the gear unsafe QRH checklist. We followed the QRH; which called to use the manual gear extension handle. We extended the gear; which now showed 3 green; and followed the rest of the checklist which said to land at the nearest suitable airport. I elected to return to the departure airport. We informed ATC of our intentions. We then informed the dispatcher through ACARS; the FA; passengers; and the station. Since we only had 21 passengers on board; we were already below landing weight (44000 LBS). Approach vectored us back for a landing. The checklist mentioned the possibility of nose wheel steering failure; so I asked for the CFR trucks to be standing by just in case. We landed normally with no steering problems; and taxied to the gate. The FO called me to the ramp during his post flight inspection; and showed me the left main gear. Attached to the left main appeared to be a fueling bonding cable and clamp. It was near the uplock latch. I was shocked to see this. I took a picture; and sent it to Maintenance control as requested. The flight was later canceled.It appears that the fueler attached a bonding cable clamp to an unapproved place on the aircraft; and drove off after fueling; leaving it attached to the aircraft. My FO had already done his preflight by the time the fueler finished; so we were unaware of the problem.UPDATE: During fueling operations; the fueler mentioned to my FO that he was having difficulty pressure refueling the left wing tank; and might need to over wing fuel. The FO told him to let us know if he needed to do this; so we could calculate the gallons for him. In the cockpit; the FO and I saw the fuel levels rising in both wing tanks simultaneously; so we believed that the fueler had gotten the pressure system to work (this is the usual indication). However; the next morning; a ramp agent who had worked our flight informed us that the fueler had called a second fuel truck to over wing fuel the left wing; and had fueled both wings at the same time; giving us the false impression that the pressure system was working. We had not been informed that the second truck was there; or that over wing fueling was happening.Obviously; the 2nd over wing fueler left the bonding cable attached; and drove off.In [all my] years with the company; I have never even heard of this happening. Even if we had waited until after fueling to preflight; the FO might not have seen the bonding cable; because it should never be placed there and we are not expecting to see that. Clearly the fueler needs to be better trained on proper fueling procedures with the CRJ200.UPDATE: Now that we understand what took place with the over wing fueling; fuelers should always inform flight crews that over wing fueling is taking place. This would let us know that there might be a mechanical problem with the aircraft; calculate the proper gallons per wing; and check the fuel caps in the wings (not to mention the bonding cables). As is turns out; there was a problem with the high level fuel sensor in the left wing; which would not allow pressure fueling in the left side. We realized this after a reposition flight when we tried to refuel. Maintenance deferred the left wing high level sensor.




Synopsis: A CRJ-200 left wing fuel tank full sensor malfunctioned requiring over wing fueling which a second truck driver completed. After takeoff; the left main landing gear indicated unsafe so the flight returned to the departure airport where the fueler's grounding clip was found still attached.