TKOF ABORTED WHEN FLAPS IMPROPERLY SET FOR TKOF.

Narrative

WHILE STARTING TKOF ROLL ON ONT RWY 26R; WE GOT THE TKOF WARNING HORN AND ABORTED THE TKOF AT A SLOW RATE OF SPD. TURNED OFF AT TXWY 100. CHKED CONDITION OF ITEMS THAT COULD CAUSE THE HORN TO GO OFF AND FOUND FLAPS SET TO 1 VS 5 DEGS. WE REPOSITIONED THE FLAPS TO 5; AND WHEN CLRED; MADE A NORMAL TKOF. THE POS OF THE FLAPS WAS MISSED ON THE BEFORE TKOF CHKLIST DUE TO THE CREW BEING PREOCCUPIED WITH BOTH A CHANGE IN THE DEP CLRNC AND A DISCUSSION ABOUT AN 'AIR CONDITIONING PACKS OFF' OP. IN THE FUTURE; ANYTHING THAT REQUIRES NON ROUTINE DISCUSSION WILL BE DONE SEPARATE FROM THE READING OF ANY CHKLIST. IF THE READING OF THE CHKLIST IS INTERRUPTED; IT SHOULD BE REPEATED IN ITS ENTIRETY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: ON CALLBACK THE RPTR INDICATED THAT THIS WAS HIS FIRST EXPERIENCE WITH A RELEASE FOR UNPRESSURIZED REVENUE FLT. THE FLC DID NOT HAVE ACCESS TO THE MEL; BUT WERE ASSURED THAT THE COMPUTER PRINTOUT FOR THEIR RELEASE WITH THE ACFT IN THAT CONFIGN WAS AVAILABLE. RPTR ADMITS TO NOT CHKING THAT AVAILABILITY UPON REACHING THE DEST ARPT. THERE WAS ONLY CONTRACT MAINT AT THE DEP ARPT AND ALL THE RELEASE COORD FROM MAINT AND DISPATCH HAD TO BE DONE BY PHONE. RPTR STATED THAT THE RTE PICKED BY DISPATCH DID TAKE INTO CONSIDERATION THE FACT THAT THEY WERE TO FLY AT 10000 FT. THIS INFO REF THE UNPRESSURIZED FLT WAS PASSED ONTO ALL OF THE PAX AND NO ONE OBJECTED. THE CALLBACK WAS PROMPTED BY THE UNIQUENESS OF THIS EVENT AND AS TO WHETHER THE RPTR HAD ACCESS TO MEL INFO UNAVAILABLE TO THE ANALYST. HE DIDN'T. RPTR FELT THAT THIS WAS A PRIMARY DISTR TO BOTH HE AND HIS FO AND STATED THAT THE ACR POLICY DOES INDICATE A RESTART OF THE CHKLIST IF INTERRUPTED. SUPPLEMENTAL INFO FROM ACN 264624: ACFT HAD MULTIPLE DEFERRED MAINT ITEMS; INCLUDING A GENERATOR INOP AND BOTH AIR CONDITIONING SYS INOP. FLT WAS TO BE AN UNPRESSURIZED FLT; WHICH IS; OF COURSE; AN IRREGULAR OP FOR US. I WAS BUSY POSITIONING ALL SWITCHES FOR THIS UNUSUAL OP AND WAS DISTRACTED WHEN POSITIONING THE FLAPS AND PLACED THEM TO '1' INSTEAD OF '5.' FLAPS 1 IS A NORMAL TKOF FLAP POS FOR MOST OF OUR 737 FLEET; YET THIS AIRPLANE WAS NOT YET MODIFIED FOR THE TKOF WITH FLAPS 1. OUR DISTRS WITH THE DEFERRED ITEMS ON TAXI-OUT APPARENTLY AFFECTED OUR PERFORMANCE USING THE CHKLIST.