B737 crew had MU2 cross runway in front of them after they had been cleared for takeoff.

Attributes
ACN	455600
Time
Date	199911
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dfw.airport
State Reference	TX
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	ground : position and hold
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : dfw.tower
Make Model Name	MU-2 Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	ground : taxi
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 220 flight time total : 9600 flight time type : 1080
ASRS Report	455600
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : ground less severe ground encounters other incursion : runway non adherence : clearance non adherence : far non adherence : published procedure
Independent Detector	other flight crewa other flight crewb
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 2000 vertical : 0
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Dfw tower cleared us for takeoff runway 35L. I took control of the aircraft after aircraft was aligned on centerline. I noticed an MU2 taxiing left to right and said 'watch that MU2.' I believe it was on taxiway a. The MU2 crossed runway 35L west to east. I verified with tower that we were cleared for takeoff. Again, we were. The MU2 was well clear of runway 35L and we began our takeoff roll (after captain had notified tower of what we saw). Callback conversation with reporter revealed the following information: crew was flying a B737-500. The MU2 was also on the tower frequency. The reporter noted the machine gun rapidity with which the tower controller was issuing clrncs. He described it as auctioneer fast. He thinks that controllers should be counseled until speech rate is slow enough to be understandable by the pilots involved in the operation. He attributes the failure of the MU2 to hold short to the controller's speech rate.

Original NASA ASRS Text

Title: B737 CREW HAD MU2 CROSS RWY IN FRONT OF THEM AFTER THEY HAD BEEN CLRED FOR TKOF.

Narrative: DFW TWR CLRED US FOR TKOF RWY 35L. I TOOK CTL OF THE ACFT AFTER ACFT WAS ALIGNED ON CTRLINE. I NOTICED AN MU2 TAXIING L TO R AND SAID 'WATCH THAT MU2.' I BELIEVE IT WAS ON TXWY A. THE MU2 CROSSED RWY 35L W TO E. I VERIFIED WITH TWR THAT WE WERE CLRED FOR TKOF. AGAIN, WE WERE. THE MU2 WAS WELL CLR OF RWY 35L AND WE BEGAN OUR TKOF ROLL (AFTER CAPT HAD NOTIFIED TWR OF WHAT WE SAW). CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CREW WAS FLYING A B737-500. THE MU2 WAS ALSO ON THE TWR FREQ. THE RPTR NOTED THE MACHINE GUN RAPIDITY WITH WHICH THE TWR CTLR WAS ISSUING CLRNCS. HE DESCRIBED IT AS AUCTIONEER FAST. HE THINKS THAT CTLRS SHOULD BE COUNSELED UNTIL SPEECH RATE IS SLOW ENOUGH TO BE UNDERSTANDABLE BY THE PLTS INVOLVED IN THE OP. HE ATTRIBUTES THE FAILURE OF THE MU2 TO HOLD SHORT TO THE CTLR'S SPEECH RATE.

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.