FLC OF AN MD-88 EXPERIENCED A JAMMED FLAP CONDITION DURING FINAL WHEN ATTEMPTING TO DISPLACE FLAPS TO 40 DEGS.

Narrative

ON VISUAL APCH TO ATL WITH GEAR DOWN AND FLAPS AT 15 DEGS; I CALLED FOR FLAPS 40 DEGS AND THE BEFORE LNDG CHKLIST. AS THE CAPT ATTEMPTED TO MOVE THE FLAP HANDLE; IT BECAME JAMMED IN THE FLAP TKOF SELECTOR (DIAL-A-FLAP) WHICH HAD BEEN LEFT AT THE 24 DEG SETTING. IN ATTEMPTING TO CORRECT THE PROB; THE FLAPS BECAME STUCK AT 15 DEGS. I ASKED THE CAPT IF HE WANTED TO GAR AND HE TOLD ME TO CONTINUE WHILE HE WORKED ON THE PROB. IT BECAME CLR THE FLAP HANDLE COULD NOT BE MOVED SO THE ACFT WAS UNEVENTFULLY LANDED AT FLAPS 15 DEGS. AFTER LNDG; I WAS FINALLY ABLE TO UNJAM THE HANDLE AND RETRACT THE FLAPS. LINE CHK AIRMEN HAVE BEEN EXPERIMENTING WITH DSCNTS AT FLAPS 24 DEGS AND CREWS HAVE BEEN WARNED VIA COMPUTER BULLETIN TO CHK THE FLAP TKOF SELECTOR TO INSURE IT'S STOWED. SINCE USE OF THE DIAL-A-FLAP IS SO RARE AND IN THE PAST HAS ONLY BEEN USED FOR TKOF; BOTH THE CAPT AND I MISSED THE IMPROPER SETTING DURING THE PREFLT. IT SEEMS TO ME CREWS ARE BEING SET UP FOR THIS PROB SINCE THE LINE CHK AIRMEN ARE FLYING THE ACFT IN AN UNUSUAL CONFIGN FOR DSCNT AND THE AFTER LNDG CHKLIST DOESN'T CALL FOR THE FLAP TKOF SELECTOR TO BE RETURNED TO ITS NORMAL (STOWED) POS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE RESETTING OF THE 'DIAL-A-FLAP' WAS NOT MADE BY HIM OR THE CAPT EVEN THOUGH IT WAS ON THE BEFORE AND AFTER TKOF CHKLIST. IT SHOULD ALSO BE ON THE AFTER LNDG CHKLIST. HE STATED THAT THE DIAL-A-FLAP IS USED SO SELDOM; MOST PLTS DO NOT PROPERLY RESPOND TO THE CHKLIST ITEM WHEN IT APPEARS. HOWEVER; SINCE IT IS NOT ON THE AFTER LNDG CHKLIST; IT IS NOT A REMINDER TO THOSE THAT HAVE USED THE PRE-SELECT FLAP SETTING. IT WAS MENTIONED THAT IT WOULD ALSO BE DIFFICULT FOR THE FLC MAKING THE PRESELECTION; TO LOWER THE FLAPS TO 40 DEGS AS ATTEMPTED BY THE RPTR! THE RPTR NOTED THAT A TEST PROGRAM IS BEING CONDUCTED WHEREIN THE FLAPS ARE PLACED DOWN TO 24 DEGS INSTEAD OF ONLY 15 DEGS FOR ENHANCING THE ENRTE DSCNT FEATURE OF THE ACFT. THEREFORE; DIAL-A-FLAP SETTING OF 24 DEGS IS USED FOR THIS TEST. THEREFORE; IF THIS PROC WORKS SATISFACTORILY; ALL MD-80 SERIES MY BE CHANGED ACCORDINGLY AND THE NEED TO RE-STOW THE DIAL-A-FLAP SETTING WOULD ALWAYS BE NECESSARY.