A B737-300 rejected their takeoff upon receipt of a takeoff warning horn determined to be the result...

Narrative:

All checklists/procedures were properly done prior to takeoff. We then aborted the takeoff due to the takeoff warning horn sounding. Horn did not sound until approximately three to five seconds after takeoff power was set (88.4% N1). The captain aborted takeoff at approximately 75 KIAS and cleared the runway. We ran the rejected takeoff and takeoff configuration warning horn checklists and calculated brake cooling. Horn sounded again when captain did a throttleburst.we discussed possible problems/solutions. He ran the stab trim forward 'about a dot' and redid the throttleburst with no horn. I mentioned that it was still in the green band on my side before he ran it forward; but apparently 'my side' indicated a higher setting (i.e. 5.2 vs. 4.9). The captain then notified dispatch and we told ATC we could take off again after the cooling period. We ensured the aircraft was properly reconfigured for takeoff (i.e. Rejected takeoff re-selected) and the captain made several more throttlebursts. The second takeoff was uneventful.

Original NASA ASRS Text

Title: A B737-300 rejected their takeoff upon receipt of a takeoff warning horn determined to be the result of the Captain's trim indication being in the green band; but not the First Officer's. By electing the most conservative of the two displays a subsequent takeoff was uneventful.

Narrative: All checklists/procedures were properly done prior to takeoff. We then aborted the takeoff due to the Takeoff Warning Horn sounding. Horn did not sound until approximately three to five seconds after takeoff power was set (88.4% N1). The Captain aborted takeoff at approximately 75 KIAS and cleared the runway. We ran the rejected takeoff and Takeoff Configuration Warning Horn Checklists and calculated brake cooling. Horn sounded again when Captain did a throttleburst.We discussed possible problems/solutions. He ran the stab trim forward 'about a dot' and redid the throttleburst with no horn. I mentioned that it was still in the green band on my side before he ran it forward; but apparently 'my side' indicated a higher setting (i.e. 5.2 vs. 4.9). The Captain then notified Dispatch and we told ATC we could take off again after the cooling period. We ensured the aircraft was properly reconfigured for takeoff (i.e. rejected takeoff re-selected) and the Captain made several more throttlebursts. The second takeoff was uneventful.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1010481
Time
Date	201205
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Component
Aircraft Component	Elevator Trim System
Person 1
Function	First Officer Pilot Not Flying
Experience	Flight Crew Last 90 Days 416
Person 2
Function	Captain Check Pilot Pilot Flying
Experience	Flight Crew Last 90 Days 436
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Other / Unknown

A B737-300 rejected their takeoff upon receipt of a takeoff warning horn determined to be the result of the captain's trim indication being in the green band; but not the first officer's. By electing the most conservative of the two displays a subsequent takeoff was uneventful.