ATCT local controller had 2 aircraft cleared onto the runway--1 for takeoff and 1 to land.

Attributes
ACN	158165
Time
Date	199009
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : bos
State Reference	MA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : rno
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	landing other
Route In Use	approach : visual arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Small Transport
Flight Phase	climbout : takeoff other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : private pilot : atp
Experience	flight time last 90 days : 225 flight time total : 2008 flight time type : 225
ASRS Report	158165
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 221 flight time total : 19138 flight time type : 1785
ASRS Report	157568
Events
Anomaly	conflict : ground less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 5700
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

During our usual approach to bos runway 33L, and cleared to land, at about 20 mi till T/D tower cleared an small transport onto the runway for an immediate takeoff. Tower then changed its mind as we approached 200' AGL, cancelled the small transport takeoff clearance and told them to exit the runway. We started a go around as we touched down and the small transport had still not completed cleared the runway at the second taxiway. We then elected to complete the landing as the small transport cleared the second taxiway. The tower controller should never have cleared the small transport onto the runway and we probably should have completed a go around.

Original NASA ASRS Text

Title: ATCT LCL CTLR HAD 2 ACFT CLEARED ONTO THE RWY--1 FOR TKOF AND 1 TO LAND.

Narrative: DURING OUR USUAL APCH TO BOS RWY 33L, AND CLRED TO LAND, AT ABOUT 20 MI TILL T/D TWR CLRED AN SMT ONTO THE RWY FOR AN IMMEDIATE TKOF. TWR THEN CHANGED ITS MIND AS WE APCHED 200' AGL, CANCELLED THE SMT TKOF CLRNC AND TOLD THEM TO EXIT THE RWY. WE STARTED A GAR AS WE TOUCHED DOWN AND THE SMT HAD STILL NOT COMPLETED CLRED THE RWY AT THE SECOND TXWY. WE THEN ELECTED TO COMPLETE THE LNDG AS THE SMT CLRED THE SECOND TXWY. THE TWR CTLR SHOULD NEVER HAVE CLRED THE SMT ONTO THE RWY AND WE PROBABLY SHOULD HAVE COMPLETED A GAR.

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.