EMB145 flight crew has airspeed differences during takeoff; rejects takeoff.

Attributes
ACN	720945
Time
Date	200612
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : stl.airport
State Reference	MO
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Weather Elements	other
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 145 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	720945
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	720946
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : pfd airspeed miscompare other flight crewa other flight crewb
Resolutory Action	flight crew : rejected takeoff
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We started our takeoff roll on runway 30L in stl. About 7-8 seconds later; first officer called out; 'indicated airspeed comparator.' I looked down and saw my indicated airspace indicator going past 75-80 KTS and the first officer's indicated airspeed going past 100-105 KTS. I aborted the takeoff and we immediately notified ATC. We exited the runway and proceeded back to the gate. We called maintenance and had them meet us at the gate. I briefed the passenger once we arrived at the gate and maintenance began troubleshooting. Approximately 40-45 mins later; maintenance advised me that the #1 pitot drain had not been seated properly and that it was fixed. We updated our flight load manifest and proceeded to depart stl. The flight continued without further incident.

Original NASA ASRS Text

Title: EMB145 FLT CREW HAS AIRSPD DIFFERENCES DURING TKOF; REJECTS TKOF.

Narrative: WE STARTED OUR TKOF ROLL ON RWY 30L IN STL. ABOUT 7-8 SECONDS LATER; FO CALLED OUT; 'INDICATED AIRSPD COMPARATOR.' I LOOKED DOWN AND SAW MY INDICATED AIRSPACE INDICATOR GOING PAST 75-80 KTS AND THE FO'S INDICATED AIRSPD GOING PAST 100-105 KTS. I ABORTED THE TKOF AND WE IMMEDIATELY NOTIFIED ATC. WE EXITED THE RWY AND PROCEEDED BACK TO THE GATE. WE CALLED MAINT AND HAD THEM MEET US AT THE GATE. I BRIEFED THE PAX ONCE WE ARRIVED AT THE GATE AND MAINT BEGAN TROUBLESHOOTING. APPROX 40-45 MINS LATER; MAINT ADVISED ME THAT THE #1 PITOT DRAIN HAD NOT BEEN SEATED PROPERLY AND THAT IT WAS FIXED. WE UPDATED OUR FLT LOAD MANIFEST AND PROCEEDED TO DEPART STL. THE FLT CONTINUED WITHOUT FURTHER INCIDENT.

Data retrieved from NASA's ASRS site as of January 2009 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.