Medium large transport told cancel takeoff clearance as maintenance taxi aircraft crosses runway.

Attributes
ACN	265409
Time
Date	199403
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mia
State Reference	FL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground other : taxi
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : instrument
ASRS Report	265409
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument
Events
Anomaly	conflict : ground less severe incursion : runway non adherence : clearance
Independent Detector	other controllera
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 7000 vertical : 0
Supplementary
Air Traffic Incident	other

Narrative:

Cleared on runway 12 and received clearance for takeoff. First officer was PF and he set takeoff power setting. I then took control of thrust levers and was adjusting power per sopa when tower advised takeoff clearance was canceled -- unauthorized aircraft on runway without a clearance. I then aborted takeoff at approximately 60 KTS and after having rolled about 1000 ft. After clearing the runway we were advised a B-737 maintenance taxi aircraft had taxied onto the active runway without clearance from ground or tower. After reaching destination I called tower supervisor in mia and discussed the incident with him.

Original NASA ASRS Text

Title: MLG TOLD CANCEL TKOF CLRNC AS MAINT TAXI ACFT CROSSES RWY.

Narrative: CLRED ON RWY 12 AND RECEIVED CLRNC FOR TKOF. FO WAS PF AND HE SET TKOF PWR SETTING. I THEN TOOK CTL OF THRUST LEVERS AND WAS ADJUSTING PWR PER SOPA WHEN TWR ADVISED TKOF CLRNC WAS CANCELED -- UNAUTH ACFT ON RWY WITHOUT A CLRNC. I THEN ABORTED TKOF AT APPROX 60 KTS AND AFTER HAVING ROLLED ABOUT 1000 FT. AFTER CLRING THE RWY WE WERE ADVISED A B-737 MAINT TAXI ACFT HAD TAXIED ONTO THE ACTIVE RWY WITHOUT CLRNC FROM GND OR TWR. AFTER REACHING DEST I CALLED TWR SUPVR IN MIA AND DISCUSSED THE INCIDENT WITH HIM.

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.