B737-300 crew had the takeoff warning horn sound at the beginning of the takeoff roll at sna.

Attributes
ACN	521812
Time
Date	200108
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sna.airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 225 flight time total : 23000 flight time type : 12000
ASRS Report	521812
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : published procedure non adherence : company policies non adherence : far other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : tkof warning horn, flap indicators other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

At sna. My leg (captain). Planned standard air carrier, flaps 5 degrees, noise abatement takeoff. Running late due to a medical emergency that delayed departure on the previous leg. This was leg 4 of 6 for the day. I taxied to taxiway left to hold short, then immediately advised to turn the corner, cross runway 19L and hold short of runway 19R, expedite, traffic on short final. I called for taxi checklist going around the corner. I think the first officer configured the bleeds at this time. Before we reached 'flaps,' the checklist was interrupted while taxiing between the 2 runways by the tower clearing us for takeoff on runway 19R. The first officer then made the 'flight attendants, please be seated' call. In an 'expedite' mode because of the tempo of sna operations in general and the previous request to 'expedite,' I taxied into takeoff position and called for the takeoff checklist. The first officer said 'what about the checklist?' referring to the interrupted taxi checklist. Since I remembered initiating the taxi checklist, I assumed we had completed it and said 'we did that, didn't we?' I guess he had enough doubt about it to think maybe I was right and acquiesced. He then did the takeoff checklist, I did the takeoff flow and then started up with the throttles. As I advanced the throttles, the first officer noticed the flap handle in the up detent and immediately placed it in the flaps 5 degrees position. As the autothrottles took the throttles up further, the takeoff warning horn sounded, and still in the 'expedite' mode, for some unfathomable reason, totally contrary to 35 yrs of experience and training, I continued the takeoff. Several seconds later, the takeoff warning horn ceased and I glanced down at the flap position indicator which, at that point, was going through 2 degrees. At the 'rotate' call I again glanced at the flap position indicator and flaps indicated 5 degrees. We continued the flight uneventfully to las. Causal factors: crew haste due to strong, partially subconscious desire to expedite/regain lost time/ return to schedule, interruption of checklists, tempo of operations, long day.

Original NASA ASRS Text

Title: B737-300 CREW HAD THE TKOF WARNING HORN SOUND AT THE BEGINNING OF THE TKOF ROLL AT SNA.

Narrative: AT SNA. MY LEG (CAPT). PLANNED STANDARD ACR, FLAPS 5 DEGS, NOISE ABATEMENT TKOF. RUNNING LATE DUE TO A MEDICAL EMER THAT DELAYED DEP ON THE PREVIOUS LEG. THIS WAS LEG 4 OF 6 FOR THE DAY. I TAXIED TO TXWY L TO HOLD SHORT, THEN IMMEDIATELY ADVISED TO TURN THE CORNER, CROSS RWY 19L AND HOLD SHORT OF RWY 19R, EXPEDITE, TFC ON SHORT FINAL. I CALLED FOR TAXI CHKLIST GOING AROUND THE CORNER. I THINK THE FO CONFIGURED THE BLEEDS AT THIS TIME. BEFORE WE REACHED 'FLAPS,' THE CHKLIST WAS INTERRUPTED WHILE TAXIING BTWN THE 2 RWYS BY THE TWR CLRING US FOR TKOF ON RWY 19R. THE FO THEN MADE THE 'FLT ATTENDANTS, PLEASE BE SEATED' CALL. IN AN 'EXPEDITE' MODE BECAUSE OF THE TEMPO OF SNA OPS IN GENERAL AND THE PREVIOUS REQUEST TO 'EXPEDITE,' I TAXIED INTO TKOF POS AND CALLED FOR THE TKOF CHKLIST. THE FO SAID 'WHAT ABOUT THE CHKLIST?' REFERRING TO THE INTERRUPTED TAXI CHKLIST. SINCE I REMEMBERED INITIATING THE TAXI CHKLIST, I ASSUMED WE HAD COMPLETED IT AND SAID 'WE DID THAT, DIDN'T WE?' I GUESS HE HAD ENOUGH DOUBT ABOUT IT TO THINK MAYBE I WAS RIGHT AND ACQUIESCED. HE THEN DID THE TKOF CHKLIST, I DID THE TKOF FLOW AND THEN STARTED UP WITH THE THROTTLES. AS I ADVANCED THE THROTTLES, THE FO NOTICED THE FLAP HANDLE IN THE UP DETENT AND IMMEDIATELY PLACED IT IN THE FLAPS 5 DEGS POS. AS THE AUTOTHROTTLES TOOK THE THROTTLES UP FURTHER, THE TKOF WARNING HORN SOUNDED, AND STILL IN THE 'EXPEDITE' MODE, FOR SOME UNFATHOMABLE REASON, TOTALLY CONTRARY TO 35 YRS OF EXPERIENCE AND TRAINING, I CONTINUED THE TKOF. SEVERAL SECONDS LATER, THE TKOF WARNING HORN CEASED AND I GLANCED DOWN AT THE FLAP POS INDICATOR WHICH, AT THAT POINT, WAS GOING THROUGH 2 DEGS. AT THE 'ROTATE' CALL I AGAIN GLANCED AT THE FLAP POS INDICATOR AND FLAPS INDICATED 5 DEGS. WE CONTINUED THE FLT UNEVENTFULLY TO LAS. CAUSAL FACTORS: CREW HASTE DUE TO STRONG, PARTIALLY SUBCONSCIOUS DESIRE TO EXPEDITE/REGAIN LOST TIME/ RETURN TO SCHEDULE, INTERRUPTION OF CHKLISTS, TEMPO OF OPS, LONG DAY.

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.