Air carrier flight crew reported entering an active taxiway at ORD without clearance after following instruction from Ramp and looking at the charts. During cruise; the flight crew discovered that the airport diagram and terminal charts were different from one another; with the same taxiway having a different identifier between the two charts.
Synopsis
Air carrier flight crew reported entering an active taxiway at ORD without clearance after following instruction from Ramp and looking at the charts. During cruise; the flight crew discovered that the airport diagram and terminal charts were different from one another; with the same taxiway having a different identifier between the two charts.
Narrative
While taxiing out of the 'Y' in ORD; Ramp Tower gave us clearance to hold short of U taxiway and contact Metering. I; the FO; read back that we will taxi via A and hold short of U. Once we started taxiing; the Captain noticed that we will be exiting non-movement area by following instructions. He taxied very slowly and asked me to go to Metering and after that to Ground; as instructed. Ground told us that we have entered an active taxiway without permission and after giving us our taxiing clearance to the runway; they also gave us a number to call for possible pilot deviation. We did not understand what was wrong because we followed instruction according to what was on the Jeppeson Chart 20-9; which hasn't been updated to show that Taxiway 'U' continues south behind Terminals E and F. The Captain thought it was odd that Ramp cleared us onto an active taxiway. We should have verified what seemed like a non-standard clearance. The Captain called back to Ramp and they said Taxiway U had been extended two days ago. Later in the flight; at a time of low area of vulnerability; we reviewed the charts and realized that Chart 20-9B shows the updated U taxiway; but 20-9 does not. There were also no NOTAMs about the change. The Captain called the phone number given to us upon landing in ZZZ; but no one was there to take the call. He called again this morning and was told that there have been numerous other aircraft making the same mistake. He explained to them that the Jepp charts are not correctly showing the updated U taxiway; and they thanked him for the information and recommended filing a report.Cause: Poor airport diagram layout from Jepp charts. Additionally; the Captain and I assumed the charts should match so we did not double-check the terminal chart; 20-9. We should have verified the clearance with Ground as soon as the Captain had a bad feeling of being cleared onto an active taxiway by Ramp Tower. Jeppesen charts should update the airport diagram and make sure that the taxiway south of the 'Y' is correctly labeled U to avoid future incursions. We will also be more diligent about confirming clearances when they do not seem right.
Second reporter narrative
While taxing out of the 'Y' in ORD; Ramp Tower gave us a clearance to hold short of U taxiway and contact Metering. My FO read back that we will taxi via A and hold short of U. Once we started taxiing I noticed that we will be exiting non-movement area by following instructions. I taxied really slow and asked my FO to go to Metering and after that to Ground as instructed. Ground told us that we have entered an active taxiway without permission and after giving us our taxiing clearance to the runway; they also gave us a number to call for a possible pilot deviation. We did not understand what was wrong because we followed instructions according to what we could see on the chart; even though for me it was weird that Ramp Tower cleared us onto an active taxiway. I should have verified what seemed as a nonstandard clearance. I talked back to Ramp and they told us that U taxiway changed two days ago; and I kept that thought until we got to cruise flight and entered a low area of vulnerability. We reviewed the charts with my FO and realized that the airport diagram; which we used to taxi out; does not match the terminal chart. On the airport diagram; the taxiway south of the 'Y' does not have a name and the closest letter to it is 'A;' while on the terminal chart that taxiway has been renamed from A to U. There were no NOTAMs about the change. I talked with Tower one day after and the controller told me that the same event has happened multiple times since the change; and they asked me why do I think it has been happening. I explained her that Jepp charts are not correctly laid out; and then they thanked me for the information and recommended filing a report. Cause: Poor airport diagram layout from Jepp charts. Additionally; the FO and I assumed the charts should match so did not double-check the terminal chart. Also; I should have verified the clearance with Tower as soon as I had the bad feeling of being cleared to taxi on a taxiway by Ramp Tower. Suggestions: Jeppesen charts should update the airport diagram layout and make sure that the taxiway south of the 'Y' says U clearly to avoid future events. Double-check clearances when they do not seem right.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.