Narrative:

Takeoff aborted for abnormal airspeed indication on takeoff. Returned to gate. Left passenger on aircraft, called maintenance. They advised me to turn on pitot heat and leave on. I did this and airspeed indications went back to normal. We departed bis without incident. I failed, however, to complete the related paperwork in a timely manner (logbook write-up, incident report). Abnormal airspeed indication was 80 KTS when sitting on the ramp apparently due to water in pitot static system. The abnormal indication was observed before taxi, but since it had been raining during the hour the airplane was sitting on the ramp, I decided to attempt to take off with the expectation the airspds would normalize with airflow. This did not happen, and we aborted the takeoff as briefed in the takeoff briefing. The pressure of passenger with connections to make on a flight that was already late helped me make a poor decision about the takeoff and then forget to complete the write-up and incident report.

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Original NASA ASRS Text

Title: CAPT OF A SWEARINGEN SA227 REJECTED TKOF DUE TO ABNORMAL AIRSPD INDICATIONS. AFTER RETURNING TO PARKING, MAINT ADVISED TO TURN ON PITOT STATIC TUBE HEAT RESULTING IN CLRING UP THE PROB AND MAKING A SUCCESSFUL TKOF. HOWEVER, THERE WAS NO ENTRY IN THE ACFT LOG MADE OF THE INCIDENT.

Narrative: TKOF ABORTED FOR ABNORMAL AIRSPD INDICATION ON TKOF. RETURNED TO GATE. LEFT PAX ON ACFT, CALLED MAINT. THEY ADVISED ME TO TURN ON PITOT HEAT AND LEAVE ON. I DID THIS AND AIRSPD INDICATIONS WENT BACK TO NORMAL. WE DEPARTED BIS WITHOUT INCIDENT. I FAILED, HOWEVER, TO COMPLETE THE RELATED PAPERWORK IN A TIMELY MANNER (LOGBOOK WRITE-UP, INCIDENT RPT). ABNORMAL AIRSPD INDICATION WAS 80 KTS WHEN SITTING ON THE RAMP APPARENTLY DUE TO WATER IN PITOT STATIC SYS. THE ABNORMAL INDICATION WAS OBSERVED BEFORE TAXI, BUT SINCE IT HAD BEEN RAINING DURING THE HR THE AIRPLANE WAS SITTING ON THE RAMP, I DECIDED TO ATTEMPT TO TAKE OFF WITH THE EXPECTATION THE AIRSPDS WOULD NORMALIZE WITH AIRFLOW. THIS DID NOT HAPPEN, AND WE ABORTED THE TKOF AS BRIEFED IN THE TKOF BRIEFING. THE PRESSURE OF PAX WITH CONNECTIONS TO MAKE ON A FLT THAT WAS ALREADY LATE HELPED ME MAKE A POOR DECISION ABOUT THE TKOF AND THEN FORGET TO COMPLETE THE WRITE-UP AND INCIDENT RPT.

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.