An air carrier mdt crew aborted their takeoff when the ahsi failed in heading.

Attributes
ACN	256596
Time
Date	199311
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pia
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Navigation In Use	Other Other
Flight Phase	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 100 flight time total : 3400 flight time type : 3300
ASRS Report	256596
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : rejected takeoff flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During takeoff roll, #2 ahrs failed, which caused attitude and heading reference loss on first officer side. Takeoff was immediately aborted. While taxiing to a spot to work on the problem, first officer tried the quick erect button the ahrs did not come back up -- but I don't believe my first officer kept the button depressed the complete 15 seconds. By this time, I had brought the aircraft to a complete stop at a spot we could wait out a system reboot. I pulled the #2 ahrs circuit breakers and the system came back indicating that it was in a proper 3 min initialization. I asked my first officer if he would be comfortable now continuing the flight. He said he would have been comfortable continuing without aborting! I let him know I disagreed -- that if it had occurred after V1, I would have continued to the hub, but not prior to V1. As far as I am concerned, this first officer's judgement exemplifies his experiences with other company capts. We discussed now continuing the flight, and agreed the system most likely was still just cold-soaked, and could not handle the 90 degree into position on the runway and took a second to fault.

Original NASA ASRS Text

Title: AN ACR MDT CREW ABORTED THEIR TKOF WHEN THE AHSI FAILED IN HDG.

Narrative: DURING TKOF ROLL, #2 AHRS FAILED, WHICH CAUSED ATTITUDE AND HDG REF LOSS ON FO SIDE. TKOF WAS IMMEDIATELY ABORTED. WHILE TAXIING TO A SPOT TO WORK ON THE PROB, FO TRIED THE QUICK ERECT BUTTON THE AHRS DID NOT COME BACK UP -- BUT I DON'T BELIEVE MY FO KEPT THE BUTTON DEPRESSED THE COMPLETE 15 SECONDS. BY THIS TIME, I HAD BROUGHT THE ACFT TO A COMPLETE STOP AT A SPOT WE COULD WAIT OUT A SYS REBOOT. I PULLED THE #2 AHRS CIRCUIT BREAKERS AND THE SYS CAME BACK INDICATING THAT IT WAS IN A PROPER 3 MIN INITIALIZATION. I ASKED MY FO IF HE WOULD BE COMFORTABLE NOW CONTINUING THE FLT. HE SAID HE WOULD HAVE BEEN COMFORTABLE CONTINUING WITHOUT ABORTING! I LET HIM KNOW I DISAGREED -- THAT IF IT HAD OCCURRED AFTER V1, I WOULD HAVE CONTINUED TO THE HUB, BUT NOT PRIOR TO V1. AS FAR AS I AM CONCERNED, THIS FO'S JUDGEMENT EXEMPLIFIES HIS EXPERIENCES WITH OTHER COMPANY CAPTS. WE DISCUSSED NOW CONTINUING THE FLT, AND AGREED THE SYS MOST LIKELY WAS STILL JUST COLD-SOAKED, AND COULD NOT HANDLE THE 90 DEG INTO POS ON THE RWY AND TOOK A SECOND TO FAULT.

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.