Taxiway incursion as passenger jet PIC confused by clrncs as issued for taxi at dtw, mi.

Attributes
ACN	519770
Time
Date	200107
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dtw.airport
State Reference	MI
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	ground : taxi
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : dtw.tower
Make Model Name	DC-9 Undifferentiated or Other Model
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : cfi pilot : commercial
Experience	flight time last 90 days : 250 flight time total : 2700 flight time type : 1500
ASRS Report	519770
Events
Anomaly	incursion : taxiway non adherence : clearance other anomaly other
Resolutory Action	controller : issued new clearance controller : issued advisory flight crew : returned to original clearance flight crew : became reoriented
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Environmental Factor Flight Crew Human Performance Airport ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

This was the last day of a 4-DAY trip with early morning shows in the EDT zone (based in CDT). While taxiing on the 'red one alpha' coded taxi route (taxiway K, taxiway H (east and at taxiway H), taxiway F, taxiway V, taxiway M) we contacted east ground on taxiway H. Ground instructed us to initially use taxiway H and hold short of taxiway H2. We read that back. Immediately thereafter, they gave us 'follow the nine (DC9) out of circle X, taxiway H short of taxiway H2, hold on a second, let me figure out what we're gonna do here (pause) follow the nine.' the DC9 was taking taxiway V and taxiway M to runway 21R, which is part of the normal coded route (red 1 alpha). We must have misheard the controller or took him too literally, because we followed the DC9, and on taxiway V just short of taxiway H2 heading east, the controller said 'I told you to take taxiway H.' at this point, we were confused and a bit taken aback. We were slightly confused with the original clearance, but because we were tired, didn't ask for clarification. It was a bit confusing after changing several times in roughly the same sentence. Our impression was that the final clearance received was to literally follow the DC9. Eventually, we were assigned (or re-assigned?) to follow the DC9, taxiway V and taxiway M to runway 21R. Next time we should remember to, when in doubt, ask for clarification of confusing clrncs (don't assume!), especially when tired or fatigued. Also, we were used to using 1 route (taxiway V, taxiway M) that a new one seemed more unfeasible.

Original NASA ASRS Text

Title: TXWY INCURSION AS PAX JET PIC CONFUSED BY CLRNCS AS ISSUED FOR TAXI AT DTW, MI.

Narrative: THIS WAS THE LAST DAY OF A 4-DAY TRIP WITH EARLY MORNING SHOWS IN THE EDT ZONE (BASED IN CDT). WHILE TAXIING ON THE 'RED ONE ALPHA' CODED TAXI RTE (TXWY K, TXWY H (E AND AT TXWY H), TXWY F, TXWY V, TXWY M) WE CONTACTED E GND ON TXWY H. GND INSTRUCTED US TO INITIALLY USE TXWY H AND HOLD SHORT OF TXWY H2. WE READ THAT BACK. IMMEDIATELY THEREAFTER, THEY GAVE US 'FOLLOW THE NINE (DC9) OUT OF CIRCLE X, TXWY H SHORT OF TXWY H2, HOLD ON A SECOND, LET ME FIGURE OUT WHAT WE'RE GONNA DO HERE (PAUSE) FOLLOW THE NINE.' THE DC9 WAS TAKING TXWY V AND TXWY M TO RWY 21R, WHICH IS PART OF THE NORMAL CODED RTE (RED 1 ALPHA). WE MUST HAVE MISHEARD THE CTLR OR TOOK HIM TOO LITERALLY, BECAUSE WE FOLLOWED THE DC9, AND ON TXWY V JUST SHORT OF TXWY H2 HDG E, THE CTLR SAID 'I TOLD YOU TO TAKE TXWY H.' AT THIS POINT, WE WERE CONFUSED AND A BIT TAKEN ABACK. WE WERE SLIGHTLY CONFUSED WITH THE ORIGINAL CLRNC, BUT BECAUSE WE WERE TIRED, DIDN'T ASK FOR CLARIFICATION. IT WAS A BIT CONFUSING AFTER CHANGING SEVERAL TIMES IN ROUGHLY THE SAME SENTENCE. OUR IMPRESSION WAS THAT THE FINAL CLRNC RECEIVED WAS TO LITERALLY FOLLOW THE DC9. EVENTUALLY, WE WERE ASSIGNED (OR RE-ASSIGNED?) TO FOLLOW THE DC9, TXWY V AND TXWY M TO RWY 21R. NEXT TIME WE SHOULD REMEMBER TO, WHEN IN DOUBT, ASK FOR CLARIFICATION OF CONFUSING CLRNCS (DON'T ASSUME!), ESPECIALLY WHEN TIRED OR FATIGUED. ALSO, WE WERE USED TO USING 1 RTE (TXWY V, TXWY M) THAT A NEW ONE SEEMED MORE UNFEASIBLE.

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.