EMB ERJ 170/175 ER/LR
Human-Machine Interface; Training / Qualification
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew FLC complied w / Automation / Advisory
Chart Or Publication; Procedure
We called for pushback from the gate and once we were cleared I told the ramp personnel that 'brakes off; steer off and we were cleared for the push.' After just a few feet the tow bar broke and the ramp personnel brought another tow bar to continue the push back. Before they replaced the tow bar the parking brake was set so they could replace the tow bar. After the tow bar was replaced the ramp personnel then asked for us to release the brake so we can continue the pushback. I released the brake again and I told them 'brakes off; steer off and we were cleared for the push.' After a few feet the new tow bar broke. The ramp personnel said that the tow bar broke again and asked if the brakes were still set of there was anything that was keeping the plane from being pushed back. I told them that the brakes were off but then that was when I noticed the STEER OFF message was not showing on the EICAS. I then disengaged the steering and set the parking brake so they could replace the tow bar again. After the tow bar was replaced I explained to the ramp personnel that the previous crew left the steering engaged; I did not notice it and disengage the steering prior to pushback; and that was causing the tow bar to break. When I released the brake for the pushback I told them 'brakes off; steer off and we were cleared for the push' and I asked the ramp personnel if there was a green light showing on the tow light. They confirmed that there was a green light on the tow light and we finished the pushback without any further problems. I am not sure if the previous crew forgot to disengage the steering or if I accidentally engaged it while sitting at the gate. Regardless; the problem was that I did not verify that the STEER OFF message was displayed indicating that the steering had been disengaged prior to pushback even though I told the ramp personnel that it was. Also the ramp personnel should ensure that there is a green light showing on the tow lights before a pushback is started to ensure the plane is properly configured for pushback. I am not sure of ramp procedure but I also thought that the exterior steering disengage switch should have been used during pushback to avoid these sort of problems.
A EMB-170 Captain twice reported 'Brakes off; steer off and we were cleared to push' but the steering was not off and two tow bars were broken before he discovered the steering not off. The third push was successful.