Narrative:

As we approached runway 10L I made the before takeoff PA. At this time the #1 flight attendant came up and said they hadn't yet finished their demonstration. About 30 seconds later she returned and said 'ok, we're ready now.' I rang the chime, turned the corner onto the runway, and the first officer began the takeoff. Soon after leveloff our #1 flight attendant advised me there was an FAA safety inspector on board who wanted to discuss my taking off before the #4 flight attendant was seated. This was the first I knew this had occurred. The inspector, named mr. X, came up and said the #4 didn't get seated and strapped in until just prior to rotation. This obviously concerned him, but not unduly, and he seemed content to let us off with a warning. Subsequent discussion with the 2 flight attendants involved revealed how this had happened. First, I neglected to brief our #1 flight attendant on the short taxi, which turned out to be 8 mins but involved a fairly short distance. So she began the demonstration later than she might have, and the process was further delayed by the lack of a demonstration bag for the extra flight attendant. 1 bag evidently had to be used for first class first, then coach. Flight attendant #1 may have misjudged how long it would take me to get rolling, or how long #4 would need to put away the demonstration bag and return to her aft jumpseat, but the result was the #4 being surprised by the unexpected acceleration and having to run to her seat and strap in. Upon arrival in chicago we requested another demonstration bag.

Google
 

Original NASA ASRS Text

Title: TKOF PRIOR TO CABIN ATTENDANT BEING SEATED AND STRAPPED IN.

Narrative: AS WE APCHED RWY 10L I MADE THE BEFORE TKOF PA. AT THIS TIME THE #1 FLT ATTENDANT CAME UP AND SAID THEY HADN'T YET FINISHED THEIR DEMONSTRATION. ABOUT 30 SECONDS LATER SHE RETURNED AND SAID 'OK, WE'RE READY NOW.' I RANG THE CHIME, TURNED THE CORNER ONTO THE RWY, AND THE FO BEGAN THE TKOF. SOON AFTER LEVELOFF OUR #1 FLT ATTENDANT ADVISED ME THERE WAS AN FAA SAFETY INSPECTOR ON BOARD WHO WANTED TO DISCUSS MY TAKING OFF BEFORE THE #4 FLT ATTENDANT WAS SEATED. THIS WAS THE FIRST I KNEW THIS HAD OCCURRED. THE INSPECTOR, NAMED MR. X, CAME UP AND SAID THE #4 DIDN'T GET SEATED AND STRAPPED IN UNTIL JUST PRIOR TO ROTATION. THIS OBVIOUSLY CONCERNED HIM, BUT NOT UNDULY, AND HE SEEMED CONTENT TO LET US OFF WITH A WARNING. SUBSEQUENT DISCUSSION WITH THE 2 FLT ATTENDANTS INVOLVED REVEALED HOW THIS HAD HAPPENED. FIRST, I NEGLECTED TO BRIEF OUR #1 FLT ATTENDANT ON THE SHORT TAXI, WHICH TURNED OUT TO BE 8 MINS BUT INVOLVED A FAIRLY SHORT DISTANCE. SO SHE BEGAN THE DEMONSTRATION LATER THAN SHE MIGHT HAVE, AND THE PROCESS WAS FURTHER DELAYED BY THE LACK OF A DEMONSTRATION BAG FOR THE EXTRA FLT ATTENDANT. 1 BAG EVIDENTLY HAD TO BE USED FOR FIRST CLASS FIRST, THEN COACH. FLT ATTENDANT #1 MAY HAVE MISJUDGED HOW LONG IT WOULD TAKE ME TO GET ROLLING, OR HOW LONG #4 WOULD NEED TO PUT AWAY THE DEMONSTRATION BAG AND RETURN TO HER AFT JUMPSEAT, BUT THE RESULT WAS THE #4 BEING SURPRISED BY THE UNEXPECTED ACCELERATION AND HAVING TO RUN TO HER SEAT AND STRAP IN. UPON ARR IN CHICAGO WE REQUESTED ANOTHER DEMONSTRATION BAG.

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.