Las controller described a ground conflict event when traffic issued a 'give way' instruction to ano...

Narrative:

I was working ground control east. Air carrier X had crossed runway 25R at A5 and was instructed to 'taxi via B; C6; to the ramp' by the local control 1 controller. Air carrier Y called me for taxi around the same time; and was told 'give way to air carrier X right to left; runway 25R; taxi via B;' to which the pilot acknowledged. I then received a call for taxi on the other side of the airport. As I turned around to observe the new aircraft's position; I heard the local control 1 controller say 'hey tell air carrier Y to give way to air carrier B.' as I looked to see what the problem was; I noticed air carrier Y had taxied out in front of air carrier X at a high rate of speed; causing air carrier X to hit the brakes pretty hard. At the same time air carrier Y asked me 'were we supposed to go in front of air carrier X?' I replied 'negative; you were instructed to give way.' air carrier Y acted like nothing was wrong and simply said 'oh we must have missed that.' air carrier X complained to the local control 1 controller and later called the supervisor in the tower cab. Pilots need to listen carefully to instructions; and ask for clarification before acting upon them if they are unsure what was heard.

Original NASA ASRS Text

Title: LAS Controller described a ground conflict event when traffic issued a 'give way' instruction to another taxing aircraft out in front of the same; causing a hard break stop; the reporter suggests pilots be more vigilant to ATC clearances.

Narrative: I was working Ground Control East. Air Carrier X had crossed Runway 25R at A5 and was instructed to 'Taxi via B; C6; to the ramp' by the Local Control 1 Controller. Air Carrier Y called me for taxi around the same time; and was told 'give way to Air Carrier X right to left; Runway 25R; Taxi via B;' to which the pilot acknowledged. I then received a call for taxi on the other side of the airport. As I turned around to observe the new aircraft's position; I heard the Local Control 1 Controller say 'hey tell Air Carrier Y to give way to Air Carrier B.' As I looked to see what the problem was; I noticed Air Carrier Y had taxied out in front of Air Carrier X at a high rate of speed; causing Air Carrier X to hit the brakes pretty hard. At the same time Air Carrier Y asked me 'were we supposed to go in front of Air Carrier X?' I replied 'negative; you were instructed to give way.' Air Carrier Y acted like nothing was wrong and simply said 'oh we must have missed that.' Air Carrier X complained to the Local Control 1 Controller and later called the supervisor in the Tower Cab. Pilots need to listen carefully to instructions; and ask for clarification before acting upon them if they are unsure what was heard.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	985636
Time
Date	201112
Local Time Of Day	1201-1800
Place
Locale Reference	LAS.Tower
State Reference	NV
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Route In Use	None
Flight Plan	IFR
Person 1
Function	Ground
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	Conflict Ground Conflict Critical

Las controller described a ground conflict event when traffic issued a 'give way' instruction to another taxing aircraft out in front of the same; causing a hard break stop; the reporter suggests pilots be more vigilant to ATC clearances.