Narrative:

Taxiing out of montreal at night from gate, we were given the taxi clearance, 'taxi east lane, north ramp and hold short of taxiway D.' once we were short of taxiway D, we contacted ground and were given the clearance, 'taxi A4, taxiway a, cleared to cross runway 28, contact tower on 119.9, holding short of runway 24L.' the clearance was read back and we taxied across taxiway a and realized we missed taxiway a and stopped the aircraft immediately, short of runway 24L on A4. At that time, ground told us we missed taxiway a, and we said we could do a 180 degrees if it was alright with them. They responded yes. We did a 180 degrees with a right turn on taxiway a and taxied to runway 24L without further incident. From the start of the taxi, we both discussed the problems with the airport diagram and the confusion of where we should hold short in relation to txwys D, a, A4 and am. As we passed taxiway D, I said, 'this is taxiway D, taxiway a is next turn left.' the captain made a comment on how diagrams are difficult. I then looked down at my charts to make sure what I told him was right, and that's when we both missed taxiway a. I think we made our best effort to comply with our taxi clearance. The #1 contributing factor was the lack of taxiway centerline markings, which are incredibly hard to see at night and the taxiway lighted signs and the confusing taxi clearance. Nowhere on any chart is the east lane, or the north ramp depicted. All these factors lead to confusion, discussion, second guessing, and constant interpretation of the charts which sets you up for problems.

Related reports:

Google
 

Original NASA ASRS Text

Title: CL65 FLT CREW DEP FROM CYUL IS CONFUSED BY GND CTLR CLRNC AND WITH ARPT DIAGRAM AND MAKES WRONG TXWY TURN.

Narrative: TAXIING OUT OF MONTREAL AT NIGHT FROM GATE, WE WERE GIVEN THE TAXI CLRNC, 'TAXI E LANE, N RAMP AND HOLD SHORT OF TXWY D.' ONCE WE WERE SHORT OF TXWY D, WE CONTACTED GND AND WERE GIVEN THE CLRNC, 'TAXI A4, TXWY A, CLRED TO CROSS RWY 28, CONTACT TWR ON 119.9, HOLDING SHORT OF RWY 24L.' THE CLRNC WAS READ BACK AND WE TAXIED ACROSS TXWY A AND REALIZED WE MISSED TXWY A AND STOPPED THE ACFT IMMEDIATELY, SHORT OF RWY 24L ON A4. AT THAT TIME, GND TOLD US WE MISSED TXWY A, AND WE SAID WE COULD DO A 180 DEGS IF IT WAS ALRIGHT WITH THEM. THEY RESPONDED YES. WE DID A 180 DEGS WITH A R TURN ON TXWY A AND TAXIED TO RWY 24L WITHOUT FURTHER INCIDENT. FROM THE START OF THE TAXI, WE BOTH DISCUSSED THE PROBS WITH THE ARPT DIAGRAM AND THE CONFUSION OF WHERE WE SHOULD HOLD SHORT IN RELATION TO TXWYS D, A, A4 AND AM. AS WE PASSED TXWY D, I SAID, 'THIS IS TXWY D, TXWY A IS NEXT TURN L.' THE CAPT MADE A COMMENT ON HOW DIAGRAMS ARE DIFFICULT. I THEN LOOKED DOWN AT MY CHARTS TO MAKE SURE WHAT I TOLD HIM WAS RIGHT, AND THAT'S WHEN WE BOTH MISSED TXWY A. I THINK WE MADE OUR BEST EFFORT TO COMPLY WITH OUR TAXI CLRNC. THE #1 CONTRIBUTING FACTOR WAS THE LACK OF TXWY CTRLINE MARKINGS, WHICH ARE INCREDIBLY HARD TO SEE AT NIGHT AND THE TXWY LIGHTED SIGNS AND THE CONFUSING TAXI CLRNC. NOWHERE ON ANY CHART IS THE E LANE, OR THE N RAMP DEPICTED. ALL THESE FACTORS LEAD TO CONFUSION, DISCUSSION, SECOND GUESSING, AND CONSTANT INTERP OF THE CHARTS WHICH SETS YOU UP FOR PROBS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.