Date: 201303
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: 2
Light: Night
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Tower ZZZ
Second aircraft: B737 Undifferentiated or Other Model
Aircraft component: Winglet
Reporter organization: Air Carrier
Reporter function: Captain
Human factors: Other / Unknown
Anomaly: Conflict Ground Conflict; Critical; Ground Event / Encounter Aircraft
Detector: Person Flight Crew; Person Ground Personnel
When detected: Taxi
Contributing factors: Human Factors; Weather
Primary problem: Human Factors

Narrative: The paperwork indicated that the air portion of the APU was inoperative and the electric portion was available and operative. This required an airstart at the gate and was to be followed by a crossbleed start off of the gate. I had a discussion with Ramp personnel as to the deice procedure and an agreement that deice would be accomplished at the remote site with the engines running. This would alleviate the need to take a start cart to the remote deice site where deice is normally accomplished with the engines shut down. No other discussions as to airstart procedures were made with Ramp. We; as a flight crew; had a brief discussion as to the airstart procedure and crossbleed procedure once we were off of the gate. To begin the start procedure; I informed the Tug Driver that they could disconnect the ground power because we had functioning electrics from the APU. I was informed that ramp procedure required ground power to be connected for an air start. I agreed as this presented no major issues. I did inquire as to the area being clear around the Number 1 Engine because the jetway was still up to the aircraft providing ground power. The Number 1 Engine was started and ground power and air were disconnected. Pushback clearance was given and rearward movement commenced. During pushback and prior to the command to 'set brakes' the aircraft suddenly stopped with an accompanying loud noise. I inquired as to 'what was that' and the First Officer responded that we had made contact with another aircraft. The next few minutes went by deliberating what had happened and trying to return to the gate. We could not immediately return to the gate because a snow plow had pushed a snow bank up in front of our departure gate and it needed to be cleared. I communicated this with Ramp and asked if communication could be made with the plow to accomplish this and then clear the area so we could return to the gate. This was done. We also requested that the county be informed that FOD from the aircraft was on the tarmac and needed to be removed. At this time; we shutdown the Number 1 Engine and were towed back into the gate area where the passengers disembarked. Additionally; we did communicate with the passengers and flight attendants prior to returning to the gate.   The only thing I could suggest is additional wing walkers during night operations with reduced visibility. I don't know what the Tug Drivers perspective was or the other aircraft in question. Our R3 window which is not heated was completely covered in snow and ice reducing the First Officer's visibility on that side. The only solution to that is to deice at the gate. Pushback procedures; i.e. distance from gate; straight back; canted; do vary some from station to station. If specific instructions are needed; that is always communicated between cockpit and Ground; otherwise; I rely on ground to be my eyes behind the aircraft and to determine the stopping point on the tarmac. In some instances; Ground protocol places aircraft in close proximity to one another; increasing risk; when it is not necessary. If there is room; expand the gap; if there is not; additional wing walkers may alleviate future mishaps.


Second narrative: On pushback from the gate; [another B737] was pushing off of the adjacent gate just prior to our push. The tug pushed us slow but did push us toward [the other B737] that was pushed out already.  The tug was correcting his path away from the B737 on our right but I guess he had pushed further to the right than I realized.  The aircraft off our right powered up to make a right turn out and as he did his left wing struck our right winglet and severed our right winglet. The ramp was dark and covered with snow.  Also; the aft windows in the cockpit on both aircraft were still covered with snow restricting our visibility to accurately see the winglets.


Synopsis: B737 flight crew reports having their right winglet removed during pushback by the left wingtip of a B737 to their right as it begins to taxi away from the gate. This event occurred during darkness with cockpit windows partially obsecured with snow.