Date: 201703
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: Mixed
Weather elements / visibility: 5
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ramp ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Flying; Captain
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Vehicle
Detector: Person Flight Crew
When detected: Taxi
Result: Aircraft Aircraft Damaged; General Maintenance Action
Contributing factors: Aircraft; Company Policy; Human Factors
Primary problem: Human Factors

Narrative: We landed on Runway 10 after a missed approach due to losing sufficient visual references below minimums (heavy rain) for Runway 15R. Runway and all taxiways were wet with standing water; as it had stopped raining just before we landed. We began taxiing to [our assigned gate] via Taxiway P and Taxiway H. While taxiing down the alley on the east side of the terminal Pier; I noted and cleared the wing of a set of air stairs on the right side of the aircraft. Once past; we observed an aircraft parked on adjacent Gate; and a Provisioning truck parked closely behind it. We observed Ground Ops Personnel moving into position at our Gate. The Captain was on the taxi line when I shifted my focus out the right windows to see if our wingtip would clear the aircraft; as well as the Provisioning truck. As we neared our Gate it became clear that the parked aircraft was not a factor; so my focus turned to the Provisioning truck. The truck was parked on the terminal side of a drainage grate that runs behind parked aircraft and parallel to the terminal pier. After looking back and forth between the wing and the Provisioning truck several times; I judged that we would be clear of the provisioning truck and told the Captain; 'You are clear on the Provo truck; but I'll keep watching it.' As we passed the truck; the lower portion of the split scimitar winglet struck the ladder on the back of the provisioning truck. The Captain immediately stopped the aircraft and made a PA. After waiting for some Ground Personnel to approach and verify that the rest of the wing was clear of the Provisioning truck; we taxied to the gate.  This event could have been prevented by stopping the aircraft short of the Provisioning truck and waiting for it to move to another location. To prevent another Crew from misjudging winglet clearance; Provisioning trucks should not park behind parked aircraft in the alley. If they must park in that area; a Marshaller should be present to assure clearance for parking aircraft.


Second narrative: We were operating a -700 aircraft with split scimitar winglets. The Ground was wet with standing water; but there was no problem identifying the taxiway center line. Once in the alley and approaching [the gate]; both Pilots visually acquired a Provisioning truck parked very near the tail of the aircraft at that gate. The vehicle appeared to be waiting to service our aircraft and was located on the terminal side of a drainage grate that runs behind parked aircraft and parallel to the Terminal. Both the First Officer and I verbalized that we believed we had sufficient clearance to proceed. Shortly after that; we felt the aircraft impact the vehicle. I was on center line and had not initiated a turn into our gate area. I stopped taxiing and made a PA asking the Passengers to remain seated. After ensuring the area was clear; I taxied to the gate and made the required notifications and logbook entry.[At another airport]; spotters are required to be positioned at each end of the Safety Zone. I've always thought this was overkill; but this procedure would be extremely valuable when parking an aircraft at any gate in the alley. An extra set of eyes would be helpful in identifying sufficient lateral clearance in a very tight area. The drainage grates that run the length of the alley visually appear to separate the taxiway and the ramp area. A painted line running parallel to the terminal which would ensure sufficient separation from Ground vehicles would be an inexpensive solution. The alley is extremely congested. Provisioning vehicles should be required to wait outside the alley until the aircraft they need to service is parked if there is an aircraft parked at the adjacent gate.


Synopsis: B737 Flight Crew reported the circumstances leading up to wing tip damage while taxiing into the gate. The right lower scimitar winglet struck the back of a catering truck.