EMB 170/175 flight crew reported a critical ground conflict with an aircraft during taxi. The Captain made an immediate stop to avoid the other aircraft. Flight crew cited communication issues between pilots and with ATC as contributing to the event.
Synopsis
EMB 170/175 flight crew reported a critical ground conflict with an aircraft during taxi. The Captain made an immediate stop to avoid the other aircraft. Flight crew cited communication issues between pilots and with ATC as contributing to the event.
Narrative
During pushback ZZZ changed the airport from a north to south flow. This caused a high degree of taxiway congestion. The flight was moving to join departing flights lining up for XXL via taxiway 1 by way of the orange taxi route southbound to join on taxiway 2 via spot 3. During the taxi; our flight received a clearance to spot 4; which was unexpected. As we approached 3; the PF made a short pause to confirm the clearance with ramp. At that time another aircraft was paused directly across seemingly beyond 5. This aircraft contacted ramp first- asking for clarification of taxi instructions as they were nose-on to another aircraft- specifically our own. The call for clarification was thus never completed from our end- as ramp asked us if we could make a U-turn to 4. This was not received clearly as a U turn does not specifically describe the maneuver required to move to 4. The crew thinking that the Controller meant simply turn two lefts onto taxiway 2; asserted they could; intending to ask for further clarification. Again; the opposite traffic aircraft keyed onto ramp before the call was made and asserted there would not be enough room. Taking a conservative approach; the PF agreed that they could not. The Controller then commanded 'You need to get back to the ramp'; the PF; focused outside; asked the PM to confirm they were in fact on ramp frequency- this was affirmed- and with understanding of this as a command to make room for appropriate separation for the opposite traffic aircraft; the PF repositioned north by 45 degrees and approximately 25 feet. At this point the PF assessed that all taxiways had aircraft waiting; and this was either Controller or their own error; and called back to ramp asserting that there was nowhere for them to reposition; and asked for permission to reposition immediately via a left turn on taxiway 2 to clear the area. The Controller affirmed this movement; and the PF began to reposition per the given clearance. At this time; another operator on the net announced 'watch out' and the PF initiated an immediate stop and set the parking brake. Without any radio transmissions that registered to my crew; the opposite traffic aircraft that had been in vicinity of 5 had begun taxiing and passed onto taxiway 2. The PF called ramp and announced that they were clear; and requested approval to continue onto 2; ramp affirmed this; and the flight continued with no further incident.A high workload of all parties involved caused an atmosphere of ready miscommunication and high stress. This was further exacerbated inside my own aircraft as the PM is new and a non native English speaker and the PF had not operated in ZZZ in some time. Barriers to clear and effective communication were present in every level of the operation; and only quick communication from other aircraft and according reaction inside my own prevented a near miss. After 2 more flights on the same day with an elevated level of scrutiny; it is my opinion that when stressed; the PM may possibly confirm questions in the affirmative even when he is unsure of the answer. This reaction to stress or communications barriers may have had something to do with the breakdown in communications on the ramp.The color coded taxiway system in use in ZZZ is an improvement over the previous system. There are areas; however where high traffic density and taxiway consolidation can make for tighter than average margins for both physical safety and clear communications. I can only attribute the majority of the moving pieces to this report to effected aircraft being on opposite frequencies. The southern extension of the controlled ramp area that covers spots 5 and 4 should account for this; but it is a simple issue of human error for both inbound and outbound aircraft anticipate changes to ground and miss critical information in such a congested area. With regard to the inter-flight deck communication issue that may be at play; the PF has revised his preflight brief toinclude specific focus areas to prevent this.
Second reporter narrative
Original location was holding short at 3. When east ramp gave us the instruction to do a left U turn to 4 and contact Ground; there was a Aircraft Y between 5 an 4 on taxiway 2 that's facing the opposite side. As we contacting Ground letting them know about the turn; the Aircraft Y said the turn was not possible because it'll be too close. I switched back and contact ramp to let them know we are repositioning due to the tight spot. The Aircraft Y continued to taxi through 2 and we had to immediately stop the aircraft to make sure clear of the Aircraft Y. We then contact Ground and followed his instruction to the assigned runway. Cause: High traffic taxi operations with break down in communication.Suggestions: Enhance vigilance and monitor Ground on com 2.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.