Narrative:

Aircraft X started takeoff roll before aircraft Y had exited runway. There were two front line managers in the tower and one was monitoring local control when this occurred.arrivals; which formerly landed on the right runway; were now landing on the center runway. Adding to the complexity of the operation; the ceiling was such that restrictions were imposed on line-up-and-wait operations (luaw) in that landing clearances had to be withheld until the luaw aircraft was cleared for takeoff; causing more transmissions than normal.intending to launch aircraft X after aircraft Y and another aircraft on final; local control tried to hustle aircraft Y off the runway but gave the wrong taxiway designator; with his exit instructions. Aircraft Y had already passed the taxiway and was coming up on the next taxiway; which he had slowed enough to exit. Unfortunately; aircraft Y must have been confused and continued his roll out to an even further away taxiway.local control anticipating aircraft Y's runway exit; issued a takeoff clearance to aircraft X without ensuring that aircraft Y had; in fact; exited the runway. After realizing that aircraft Y was still rolling down the runway; local control tried to cancel aircraft X's takeoff clearance. This was not effectively communicated and aircraft X continued his takeoff roll. The subsequent arrival; continued his approach to landing. The distance between aircraft X and aircraft Y was over 6000 feet when aircraft Y was at their runway exit point. This did not meet asde-X parameters for an alert.local control's incorrect exit instructions caused this loss of separation.1) using the correct taxiway designator with runway exit instructions (instead of saying next exit or next high speed) has been emphasized at this facility -- as per 7110.65. That presumes that the controller knows his airfield geography. Maybe 'next high speed' would have worked better. Perhaps the FAA needs to re-examine the 7110.65 in this regard.2) the controller needs to be told how to command the frequency in these situations -- using pause; inflection; and emphasis. 'Aircraft X; dulles tower; cancel takeoff clearance!' this was not effectively communicated by local control.

Related reports:

Google
 

Original NASA ASRS Text

Title: A report from a Front Line Manager; a Controller and a flight crew about a Local Controller that used non-standard phraseology 'stop your roll' which was not understood by foreign flight crew. The foreign aircraft was originally cleared for takeoff while another aircraft was clearing the same runway after landing.

Narrative: Aircraft X started takeoff roll before Aircraft Y had exited runway. There were two Front Line Managers in the tower and one was monitoring Local Control when this occurred.Arrivals; which formerly landed on the Right runway; were now landing on the Center runway. Adding to the complexity of the operation; the ceiling was such that restrictions were imposed on Line-Up-And-Wait operations (LUAW) in that landing clearances had to be withheld until the LUAW aircraft was cleared for takeoff; causing more transmissions than normal.Intending to launch Aircraft X after Aircraft Y and another aircraft on final; Local Control tried to hustle Aircraft Y off the runway but gave the wrong taxiway designator; with his exit instructions. Aircraft Y had already passed the taxiway and was coming up on the next taxiway; which he had slowed enough to exit. Unfortunately; Aircraft Y must have been confused and continued his roll out to an even further away taxiway.Local Control anticipating Aircraft Y's runway exit; issued a takeoff clearance to Aircraft X without ensuring that Aircraft Y had; in fact; exited the runway. After realizing that Aircraft Y was still rolling down the runway; Local control tried to cancel Aircraft X's takeoff clearance. This was not effectively communicated and Aircraft X continued his takeoff roll. The subsequent arrival; continued his approach to landing. The distance between Aircraft X and Aircraft Y was over 6000 feet when Aircraft Y was at their runway exit point. This did not meet ASDE-X parameters for an alert.Local Control's incorrect exit instructions caused this loss of separation.1) Using the correct taxiway designator with runway exit instructions (instead of saying next exit or next high speed) has been emphasized at this facility -- as per 7110.65. That presumes that the controller knows his airfield geography. Maybe 'next high speed' would have worked better. Perhaps the FAA needs to re-examine the 7110.65 in this regard.2) The controller needs to be told how to command the frequency in these situations -- using pause; inflection; and emphasis. 'Aircraft X; Dulles TWR; cancel takeoff clearance!' This was not effectively communicated by Local Control.

Data retrieved from NASA's ASRS site 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.