Takeoff aborted due to takeoff warning horn sounding after power application.

Attributes
ACN	266844
Time
Date	199403
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : msy
State Reference	LA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bgm
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 145 flight time total : 8268 flight time type : 1886
ASRS Report	266844
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : rejected takeoff
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

B-737 taxi for takeoff, all pre-departure checklist completed, flight cleared for takeoff. As throttles brought up past 1.4 EPR, takeoff warning horn sounded. Flaps, trim, and spoiler handle all were immediately rechked for proper position -- all found to be normal. Aircraft cleared the runway, recycled spdbrake handle, brought flaps up and then checked for takeoff warning horn (which sounded as it should), and then returned flaps to the proper takeoff position. Takeoff warning horn was again checked and no horn sounded as engines were brought up. We checked circuit breakers to insure no circuit breakers had popped and re-completed the before takeoff checklists. In the judgement of the captain, the aircraft was reclred for takeoff and the flight continued on uneventfully. I later asked the PIC if this had ever happened before and he confirmed he had seen it several times before and, in his opinion, the problem was in the spdbrake down detent micro switch not completely engaged, although the handle itself was in the down detent position.

Original NASA ASRS Text

Title: TKOF ABORTED DUE TO TKOF WARNING HORN SOUNDING AFTER PWR APPLICATION.

Narrative: B-737 TAXI FOR TKOF, ALL PRE-DEP CHKLIST COMPLETED, FLT CLRED FOR TKOF. AS THROTTLES BROUGHT UP PAST 1.4 EPR, TKOF WARNING HORN SOUNDED. FLAPS, TRIM, AND SPOILER HANDLE ALL WERE IMMEDIATELY RECHKED FOR PROPER POS -- ALL FOUND TO BE NORMAL. ACFT CLRED THE RWY, RECYCLED SPDBRAKE HANDLE, BROUGHT FLAPS UP AND THEN CHKED FOR TKOF WARNING HORN (WHICH SOUNDED AS IT SHOULD), AND THEN RETURNED FLAPS TO THE PROPER TKOF POS. TKOF WARNING HORN WAS AGAIN CHKED AND NO HORN SOUNDED AS ENGS WERE BROUGHT UP. WE CHKED CIRCUIT BREAKERS TO INSURE NO CIRCUIT BREAKERS HAD POPPED AND RE-COMPLETED THE BEFORE TKOF CHKLISTS. IN THE JUDGEMENT OF THE CAPT, THE ACFT WAS RECLRED FOR TKOF AND THE FLT CONTINUED ON UNEVENTFULLY. I LATER ASKED THE PIC IF THIS HAD EVER HAPPENED BEFORE AND HE CONFIRMED HE HAD SEEN IT SEVERAL TIMES BEFORE AND, IN HIS OPINION, THE PROB WAS IN THE SPDBRAKE DOWN DETENT MICRO SWITCH NOT COMPLETELY ENGAGED, ALTHOUGH THE HANDLE ITSELF WAS IN THE DOWN DETENT POS.

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.