Narrative:

Problem occurred on a schedule air carrier flight. Aircraft was lightly loaded so I decided to do a delayed engine start/single engine taxi. This is perfectly acceptable per our operations manual, but not actually done much during the summer due to high thrust levels needed (high temperatures, and/or high gross weight). We accomplished the delayed after start checklist then proceeded to start taxiing for the departure runway. When I saw that there were no other aircraft ahead and that we would be #1 for takeoff, I had the first officer start the 2ND engine. We had already started the delayed before takeoff checklist, and I interrupted him to have him start the engine. Normally, he would have put the flaps to the takeoff position departing the ramp. But evidently he forgot, and that is the point on the checklist that I interrupted him. After the engine start we finished the delayed before takeoff checklist and were cleared immediately for a rolling takeoff. Takeoff was normal, with a high rate of acceleration. The only time we noticed the flaps were not down was when I called for them to be retracted after takeoff. Contributing to the lack of detection is that there is no takeoff warning system on this aircraft (medium large transport). Fortunately this aircraft has no leading edge devices either, so takeoff performance was near normal. Of course, if it did have leading edge devices, it probably would have a takeoff warning system. Lessons learned: 1) don't interrupt a checklist once you have started it, 2) if you do, start it over in its entirety, 3) do a quick scan of flaps, speed brake, etc, taking the runway.

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Original NASA ASRS Text

Title: MLG FLC INTERRUPTS CHKLIST TO START SECOND ENG. MAKES TKOF WITHOUT FLAPS.

Narrative: PROBLEM OCCURRED ON A SCHEDULE ACR FLT. ACFT WAS LIGHTLY LOADED SO I DECIDED TO DO A DELAYED ENG START/SINGLE ENG TAXI. THIS IS PERFECTLY ACCEPTABLE PER OUR OPS MANUAL, BUT NOT ACTUALLY DONE MUCH DURING THE SUMMER DUE TO HIGH THRUST LEVELS NEEDED (HIGH TEMPS, AND/OR HIGH GROSS WT). WE ACCOMPLISHED THE DELAYED AFTER START CHKLIST THEN PROCEEDED TO START TAXIING FOR THE DEP RWY. WHEN I SAW THAT THERE WERE NO OTHER ACFT AHEAD AND THAT WE WOULD BE #1 FOR TKOF, I HAD THE FO START THE 2ND ENG. WE HAD ALREADY STARTED THE DELAYED BEFORE TKOF CHKLIST, AND I INTERRUPTED HIM TO HAVE HIM START THE ENG. NORMALLY, HE WOULD HAVE PUT THE FLAPS TO THE TKOF POS DEPARTING THE RAMP. BUT EVIDENTLY HE FORGOT, AND THAT IS THE POINT ON THE CHKLIST THAT I INTERRUPTED HIM. AFTER THE ENG START WE FINISHED THE DELAYED BEFORE TKOF CHKLIST AND WERE CLRED IMMEDIATELY FOR A ROLLING TKOF. TKOF WAS NORMAL, WITH A HIGH RATE OF ACCELERATION. THE ONLY TIME WE NOTICED THE FLAPS WERE NOT DOWN WAS WHEN I CALLED FOR THEM TO BE RETRACTED AFTER TKOF. CONTRIBUTING TO THE LACK OF DETECTION IS THAT THERE IS NO TKOF WARNING SYS ON THIS ACFT (MLG). FORTUNATELY THIS ACFT HAS NO LEADING EDGE DEVICES EITHER, SO TKOF PERFORMANCE WAS NEAR NORMAL. OF COURSE, IF IT DID HAVE LEADING EDGE DEVICES, IT PROBABLY WOULD HAVE A TKOF WARNING SYS. LESSONS LEARNED: 1) DON'T INTERRUPT A CHKLIST ONCE YOU HAVE STARTED IT, 2) IF YOU DO, START IT OVER IN ITS ENTIRETY, 3) DO A QUICK SCAN OF FLAPS, SPD BRAKE, ETC, TAKING THE RWY.

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.