Date: 201907
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Rain; Thunderstorm
Light: Night
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground ZZZ
Second aircraft: B737 Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Aircraft
Detector: Person Flight Crew
When detected: Taxi
Result: Aircraft Aircraft Damaged; Flight Crew Returned To Gate; General Flight Cancelled / Delayed
Contributing factors: Airport; Human Factors; Procedure; Weather
Primary problem: Human Factors

Narrative: We pushed back out of Gate XX without being able to use headsets with the Pushback Crew due to safety related to lightning around the airport. It was raining heavily. We started the #2 engine during pushback as directed by hand signals. We received the set brake signal and disconnected. During pushback; I noticed that an (other carrier) aircraft had been pushed out of Gate YY on my left side. After our Pushback Crew left; we started the #1 engine and ran the After Start Checklist. We then noticed that now another one of our aircraft was being pushed back out of XY; the gate next to us in between us and (other carrier) aircraft. I felt it was sort of tight; but noticed no pushback restrictions on the airport information page. The visibility was very bad and we waited for the pushback next to us to be completed.We called Ground Control for instructions. Ground advised us of traffic to our right taxiing behind us and cleared us to taxi to the area between Spot X and Y after they passed. The First Officer looked for that traffic while I checked the clearance to my left. With the driving rain and the darkness I couldn't see very well. At this time the aircraft off Gate XY had stopped for a few minutes. I made the assumption that the aircraft had been positioned to give us enough clearance to turn away from it as it is usually the case. I gently added thrust when I felt a light bump. I didn't even realize that I contacted the other aircrafts wingtip. It felt more like my brakes were locked. As I turned I heard a pilot reporting that he got hit and I initially thought he got hit by lightning. He then asked to taxi back into Gate XY. That is when I realized that it was actually us who hit him. We immediately asked for instructions to taxi back to our gate; Gate XX.The visibility due to the driving rain was bad and what contributed to the situation was the fact that 'no headset pushbacks' were in progress. That means that the other pilots also had no communication with their Pushback Crew. The other aircraft had scimitar winglets while we just had the normal winglets. I don't know if there was a Wing Walker; but apparently that aircraft was positioned to where our wingtips almost touched. A contributing factor may have also been that the ramp was uncontrolled and yet after pushback we asked for and received taxi instructions calling out other traffic; but not the one next to us. I made an assumption that the Ground Crew would not ever position an aircraft this close to an already pushed back aircraft; based on my experience here at Company. I wrongly made the assumption that they could see our and their positioning better than I could.


Second narrative: We pushed back from Gate XX with no communication with the Ground Crew. It is their procedure to not use headsets when there is lightning in the area; which there was. Another Company aircraft started to push off Gate XY as I was starting the engines. The Captain and I both commented that it seemed odd they would do that because of the close proximity to our aircraft and another that had also pushed off YY. I started both engines; performed my after start flow; ran the Before Taxi Checklist and cleared my wing before we moved from our position. The Captain pulled forward slowly and cautiously before making a slight right turn. I felt the airplane shudder a little bit and we both thought it was the brakes. After that; the other aircraft involved reported over Ground frequency that they had been 'hit' by something. Come to find out it was our left winglet that had struck their right winglet. We both pulled back into the gate.


Synopsis: B737-700 flight crew reported striking wing tip of another aircraft during taxi.