EMB-175 flight crew reported a loss of directional control while attempting to park on an icy ramp area with nil braking action. The aircraft slid uncontrolled during a turn while taxiing; but stopped short of ground equipment.
Synopsis
EMB-175 flight crew reported a loss of directional control while attempting to park on an icy ramp area with nil braking action. The aircraft slid uncontrolled during a turn while taxiing; but stopped short of ground equipment.
Narrative
Entering the ramp after arrival; I attempted to make a right turn to park where the Marshaller was indicating. I would estimate speed about 5 kt.; maybe a little more. However; the airplane did not turn when the tiller was turned. So; I immediately stepped on the brakes to stop; but we continued to slide straight ahead! As a last-ditch effort; the other pilot suggested I pulled thrust reverse; but it didn't seem to have much effect. However; the airplane finally stopped 15 - 20 ft. short of some equipment and some freighter cans. Since this position was too close to turn out again; we shut down to conserve fuel for the return flight. ZZZ Operations tried to bring the stairs over; but a snow pile prevented it from position at Door 1L; so stairs were positioned to Door 1R and the passengers deplaned. As soon as we had the local phone; Dispatch and the Duty Officer was consulted.When I was able; I did walk" around the airplane; but it was very obvious why the airplane slid. There was water over ice; and it was so slippery it was hard to stand up. Also; the wind was blowing - wind 080 at about 20 plus gusts; so we had a tailwind plus 2 engines at idle thrust as we entered the ramp. The runway itself seemed good; but braking on the ramp was nearly nil.After surveying the situation and consultation with the Duty Officer [and] Station Operations; Operations moved the equipment in front of the airplane to provide room to turn; and the ramp was sanded. With about 5 or 6 wing walkers; we started the left engine and were able to spin out of the tight spot. We shut down; put the stairs up to Door 1L and boarded the passengers for the return flight. No damage to any equipment nor injury to any person. The station personnel were super helpful and moved every object that I asked them to move. Also; I was fortunate to have a very sharp Captain and Check Airman in the right seat. We discussed everything before deciding what to do. I wish the sand truck had sanded the icy ramp before we arrived! Proceed very sloooowly on icy ramps."
Second reporter narrative
During a flight from ZZZ1 to ZZZ we were spending a considerable amount of time briefing threats for the approach and landing. I was acting as PM (Pilot Monitoring) in the right seat; and the Captain was PF (Pilot Flying). The Captain was fully qualified for ZZZ2 flying but mentioned a threat that he had yet to see [at] ZZZ. We were not doing [pilot training] but we used the opportunity to discuss the operation before going in. The threats were plentiful; including a runway condition code of 3 and a crosswind component threatening the limits for the conditions with gusty winds.During the approach; the Captain did well to maintain a stable approach and landing; even with last-minute gusts. Once on the ground; we experienced good braking action and reported to Tower that all but the shoulders of the runway were mostly just wet. Temperature was 3 degrees with intermittent rain but had been freezing earlier in the day. We landed Runway XX and back taxied without incident. We exited at Taxiway XX and I was explaining the parking scenario at ZZZ. We followed the taxi line and I pointed out the ground equipment that needed to be cleared before starting the right turn. I was monitoring the right side of the aircraft as we approached the turn-in point and heard the Captain struggling a bit. I noticed he was braking and turning the nose wheel steering but we were now sliding straight across the ramp with a strong tailwind and nil braking. I joined him on the brakes and suggested reversers as we headed towards a line of ground equipment. We thankfully stopped short of any contact; and I don't believe the reversers even had time to deploy before we were stopped and they were stowed.I don't recall seeing what our taxi speed was exiting the runway but don't remember thinking it was excessive for the expected conditions. However; what was reported as 1/8 inches of slush and snow on the ramp ended up being a significant amount of water over compact snow and ice; and no sand. This; combined with a tailwind gust that was likely near 20 - 30 kt. and a lightly loaded aircraft; sent us right past the obscured J-line. Once stopped; we shut down and called Operations. The ground equipment was too close to the L1 door to safely maneuver the air stairs in the slippery conditions so we elected to have the right side of the aircraft sanded and deplaned through the R1 service door. At this point; we contacted Dispatch; [the] Flight Controller; and [the] Duty Officer. We then shut down the APU to conserve fuel for the return flight.Since ZZZ has no fuel and no ability to push back the airplane; we now had a problem to solve as we were too close to the ground equipment to spin out from our spot. Through joint discussion with all parties; we elected to have the area heavily sanded and all the ground equipment removed. This took considerable time in the slippery conditions. At this point we both went to walk the ramp and try to get a better idea of the conditions. I saw the solid ice covered in standing water had started just before where we should have started turning in for parking and was fairly solid to the point where we stopped. When I turned to walk back to the aircraft a gust of wind hit my back. As I tried to stop my feet; the wind pushed my standing feet across the wet ice and I slid.Once all the ground equipment was removed; we assessed the situation. We made a joint decision that the required clearances could be maintained if we were able to start an immediate turn. The area was heavily sanded; much of the ice had melted; and the winds had died down considerably. At the Captain's suggestion we discussed starting only Engine 1 to aid in the right turn. Everyone involved agreed with this strategy with the caveat that if the nose wheel did not immediately grip for a turn; we would stop and shut down. We sent pictures to the Duty Officer to help frame the scenario. We gathered up about 6 wing walkers and successfully repositioned as planned.We boarded the passengers and departed normally after a final debrief with the Duty Officer. It was surprising to me how much of an improvement the sanding made on the ramp. I will be much more likely to request this ahead of time in the future.We debriefed heavily throughout the event. We discussed being very conservative with taxi speeds. I did notice taxi speeds in ZZZ1 to be a bit faster than what I would use with my typically conservative nature for contaminated surfaces. However; I don't remember having this feeling in ZZZ during this event. It's possible I missed it while trying to mitigate other threats. That being said; I don't know that any speed would have made that turn possible after surveying the ramp conditions on foot and considering the wind. In the future; I will be more pessimistic about ramp condition reports and ask for sanding if I am at all concerned. This will also be a great emphasis point for any future ZZZ2 [pilot training] activities.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.