Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 553
Ground Event / Encounter Object
Aircraft Aircraft Damaged; Flight Crew Returned To Gate; General Maintenance Action
Procedure; Human Factors
We had just finished pushing from the gate. We were about to taxi out when a Ramp Agent knocked on the nose of the aircraft and motioned us not to taxi. We had no idea what the issue was and watched as he brought a tug back to the aircraft and plugged in a headset. He told us that he was passing by on another tug and saw us getting pushed back into the blast fence. Our own push crew didn't even notice it. We pulled back into the gate and had the aircraft inspected. Maintenance and ground crews noticed a dent in the APU exhaust.
It was a normal three-person ground crew with wireless headsets push from Gate XX. The pushback seemed normal. The ground crew had cleared away from the aircraft as normal. The engines had been started and all checklist run. Just as we were about to release brakes for taxi; we heard a hand rap on the aircraft nose. I looked out to see a totally different Ramp Agent that had not been part of pushback crew; standing giving me a 'do not taxi' hand signal. I held my position. He ran over and got another Ramp Agent; the tow bar; a headset and the pushback tug. When he plugged in the headset; I asked what was going on.That's when he told me that he had been driving by on his luggage tug and noticed the aircraft tail was rapidly approaching the blast fence. He had attempted to get the Wing Walker's attention but to no avail. He saw the tail impact the blast fence. Apparently; the pushback crew never saw him or the tail on the blast fence. He had run forward and luckily intercepted us before releasing brakes. After shutting down the engines and being pulled back to Gate XY; Maintenance inspected the tail area. The shroud around the APU exhaust was indeed bent and showed signs of impact with the blast fence. I wrote up the defect in the logbook and handed over the aircraft to Maintenance.
B737-800 flight crew reported Ramp Agent alerted them that they struck a jet blast fence during pushback.