Small aircraft X had less than standard separation from aircraft Y. System error.

Attributes
ACN	170052
Time
Date	199102
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : dab
State Reference	FL
Altitude	agl bound lower : 0 agl bound upper : 100
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	ground other : taxi
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : takeoff
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	170052
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : ground critical non adherence : required legal separation non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 0 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Small aircraft X was taxiing on 'north' taxiway to the ramp. The aircraft was not instructed to hold short of runway 16. An aircraft was cleared for takeoff on runway 16. The taxiing aircraft stated 'I almost hit that airplane that was too close.' from the control tower it did not appear that the aircraft xed the runway. I made a mistake of not telling small aircraft X to hold short of the runway. I thought I had told small aircraft X to hold short. It was late at night and I was working all the tower positions combined. All frequencys were combined. There were a couple of people talking to me at the same time creating some confusion. The only solution I could think of would be to be more observant. The pilot of the aircraft was taxiing excessively fast, probably in a hurry to get home. The taxiing pilot heard my transmission to aircraft Y to be cleared for takeoff on runway 16 but it didn't register or he didn't hear it. They were the only 2 aircraft on frequency. Small aircraft X pilot did not look before crossing the runway. Aircraft Y had a landing light on when departing.

Original NASA ASRS Text

Title: SMA X HAD LESS THAN STANDARD SEPARATION FROM ACFT Y. SYSTEM ERROR.

Narrative: SMA X WAS TAXIING ON 'N' TXWY TO THE RAMP. THE ACFT WAS NOT INSTRUCTED TO HOLD SHORT OF RWY 16. AN ACFT WAS CLRED FOR TKOF ON RWY 16. THE TAXIING ACFT STATED 'I ALMOST HIT THAT AIRPLANE THAT WAS TOO CLOSE.' FROM THE CTL TWR IT DID NOT APPEAR THAT THE ACFT XED THE RWY. I MADE A MISTAKE OF NOT TELLING SMA X TO HOLD SHORT OF THE RWY. I THOUGHT I HAD TOLD SMA X TO HOLD SHORT. IT WAS LATE AT NIGHT AND I WAS WORKING ALL THE TWR POSITIONS COMBINED. ALL FREQS WERE COMBINED. THERE WERE A COUPLE OF PEOPLE TALKING TO ME AT THE SAME TIME CREATING SOME CONFUSION. THE ONLY SOLUTION I COULD THINK OF WOULD BE TO BE MORE OBSERVANT. THE PLT OF THE ACFT WAS TAXIING EXCESSIVELY FAST, PROBABLY IN A HURRY TO GET HOME. THE TAXIING PLT HEARD MY XMISSION TO ACFT Y TO BE CLRED FOR TKOF ON RWY 16 BUT IT DIDN'T REGISTER OR HE DIDN'T HEAR IT. THEY WERE THE ONLY 2 ACFT ON FREQ. SMA X PLT DID NOT LOOK BEFORE XING THE RWY. ACFT Y HAD A LNDG LIGHT ON WHEN DEPARTING.

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.