Commercial Fixed Wing
Troubleshooting; Training / Qualification; Situational Awareness; Communication Breakdown
Deviation / Discrepancy - Procedural Weight And Balance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Hazardous Material Violation
Flight Crew Returned To Gate; General Maintenance Action
Human Factors; Procedure
Dangerous goods were labeled as an AOM; which was planned for pit (6). Upon loading the last and the heaviest AOM; I realized it was a DG. I then added a pit during the flight and placed both DG's in pit (5) and proceeded to bring more bags from the cart located in the front (where we were loading) to the back to make sure it was SOP for the DG with 15 bags around them. When trying to close out Aircraft X; I was unable to. I radioed for a trainer to help with closing out the flight; while the flight was still on the gate. I received no response from the trainer. When the flight was being pushed out; I called again; explaining the flight was leaving the gate and there was an urgency for the help. I then called for the Zone 4 Supervisor and received no response as well. It was not until the flight was in line to take off that a trainer showed up at the gate. He explained that the DG was not secure after checking the computer. The trainer never gave me a close out screen for the DG. Upon the flight returning; the supervisor that was working Zone 3 and myself discovered that neither of the DG's were surrounded by the 15 bags. One of the DG's was located in pit 6 with no bags around it. The other DG was located in pit 5 and had 13 bags; however the DG was located on top of the bags. This DG also had one of the required 15 bags located in pit 4; and the trainer counted the DG as the 15th bag making it actually only 14 bags.
Airline Ground Personnel reported Dangerous Goods cargo incorrectly loaded for air transport. Gate return to correct prior takeoff.