Takeoff clearance is canceled by tower whose perception was that the aircraft was already slowing.

Attributes
ACN	507280
Time
Date	200104
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bwi.airport
State Reference	MD
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Person 2
Qualification	pilot : atp
Experience	flight time last 90 days : 220 flight time total : 5000 flight time type : 220
ASRS Report	507280
Events
Anomaly	other anomaly other
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

Approaching runway 28 at bwi, we informed the tower we were ready for departure and holding short. He cleared us for an immediate takeoff and reported traffic on a 3 mi final for runway 33L. I saw the 3 mi traffic as we took the runway and completed the checklist without delay. The captain gave me the aircraft as we rolled out on centerline. The tower was up and we were accelerating when the tower canceled our clearance. We were at approximately 60 KTS when we rejected the takeoff. The rejected takeoff and the subsequent takeoff were uneventful. As we were leaving tower's frequency for departure, he said he canceled our clearance because we slowed down our takeoff roll. There was no slowing or hesitation on our part.

Original NASA ASRS Text

Title: TKOF CLRNC IS CANCELED BY TWR WHOSE PERCEPTION WAS THAT THE ACFT WAS ALREADY SLOWING.

Narrative: APCHING RWY 28 AT BWI, WE INFORMED THE TWR WE WERE READY FOR DEP AND HOLDING SHORT. HE CLRED US FOR AN IMMEDIATE TKOF AND RPTED TFC ON A 3 MI FINAL FOR RWY 33L. I SAW THE 3 MI TFC AS WE TOOK THE RWY AND COMPLETED THE CHKLIST WITHOUT DELAY. THE CAPT GAVE ME THE ACFT AS WE ROLLED OUT ON CTRLINE. THE TWR WAS UP AND WE WERE ACCELERATING WHEN THE TWR CANCELED OUR CLRNC. WE WERE AT APPROX 60 KTS WHEN WE REJECTED THE TKOF. THE REJECTED TKOF AND THE SUBSEQUENT TKOF WERE UNEVENTFUL. AS WE WERE LEAVING TWR'S FREQ FOR DEP, HE SAID HE CANCELED OUR CLRNC BECAUSE WE SLOWED DOWN OUR TKOF ROLL. THERE WAS NO SLOWING OR HESITATION ON OUR PART.

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.