Narrative:

I was the PF on a visual approach to runway 12L. I called for flaps 5 degrees and as I slowed to 180 KTS it is my habit to check the flap gauge before calling for landing gear down and flaps 15 degrees. I noticed the flaps indicated only F1 and about 1 1/2. I verified that the flap handle had been placed to the 5 degree position. We were 6 mi from touchdown at this point; so I initiated a go around. I called for flaps up on the go around. We coordinated with ATC for an extended downwind so we could get out the QRH and work the problem. The flaps initially did not come up; but as we got out the QRH and established ourselves on the ATC assigned heading and altitude the flaps then came up. We checked the circuit breakers; hydraulics and led status and the airplane seemed to be back to normal. We started running the QRH for flaps; trailing edge: asymmetrical. At this point we had only about 5800 pounds of fuel. We realized we made an error by putting the flaps up on the go around after reading the first procedure (west); however; because the aircraft never showed any rolling tendency during the initial configuring for the go around it didn't immediately occur to me that they were actually asymmetric. Since we were now clean on downwind with what appeared to be a normal airplane; we began to configure the aircraft. We made an uneventful flaps 15 degree landing with symmetrical flap indications. We did not correctly conform to the QRH checklist because I called for a go around and as is a habit to clean up the aircraft on a go around I commanded flaps up. Perhaps there can be more emphasis to the crews that in any split flaps situation the flaps should not be moved. Perhaps have a boxed item for step one of any asymmetric flap indication. As the PF I noted no rolling tendency so in my mind I'm mentally going through the mantra 'maintain aircraft control; analyze the situation; take the appropriate action; and maintain situational awareness.' I was not thinking 'split flap indication; don't touch the flap handle.' only after I got the airplane safely away from the ground and directed the first officer to the QRH did I realize my error. Once the airplane was cleaned up and the flaps retracted we no longer had an asymmetric problem. At that point we still used the QRH to configure and the flaps came down symmetrically. A little bit confusing at the time; but we were preparing ourselves for the worst case scenario.

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Original NASA ASRS Text

Title: B737-300 INDICATED ASYMMETRICAL FLAPS ON APCH. FLT CREW EXECUTED GAR AND INADVERTENTLY RETRACTED FLAPS. FLAPS EXTENDED SYMMETRICALLY AND NORMAL LNDG ACCOMPLISHED.

Narrative: I WAS THE PF ON A VISUAL APCH TO RWY 12L. I CALLED FOR FLAPS 5 DEGS AND AS I SLOWED TO 180 KTS IT IS MY HABIT TO CHK THE FLAP GAUGE BEFORE CALLING FOR LNDG GEAR DOWN AND FLAPS 15 DEGS. I NOTICED THE FLAPS INDICATED ONLY F1 AND ABOUT 1 1/2. I VERIFIED THAT THE FLAP HANDLE HAD BEEN PLACED TO THE 5 DEG POS. WE WERE 6 MI FROM TOUCHDOWN AT THIS POINT; SO I INITIATED A GAR. I CALLED FOR FLAPS UP ON THE GAR. WE COORDINATED WITH ATC FOR AN EXTENDED DOWNWIND SO WE COULD GET OUT THE QRH AND WORK THE PROB. THE FLAPS INITIALLY DID NOT COME UP; BUT AS WE GOT OUT THE QRH AND ESTABLISHED OURSELVES ON THE ATC ASSIGNED HDG AND ALT THE FLAPS THEN CAME UP. WE CHKED THE CIRCUIT BREAKERS; HYDS AND LED STATUS AND THE AIRPLANE SEEMED TO BE BACK TO NORMAL. WE STARTED RUNNING THE QRH FOR FLAPS; TRAILING EDGE: ASYMMETRICAL. AT THIS POINT WE HAD ONLY ABOUT 5800 LBS OF FUEL. WE REALIZED WE MADE AN ERROR BY PUTTING THE FLAPS UP ON THE GAR AFTER READING THE FIRST PROC (W); HOWEVER; BECAUSE THE ACFT NEVER SHOWED ANY ROLLING TENDENCY DURING THE INITIAL CONFIGURING FOR THE GAR IT DIDN'T IMMEDIATELY OCCUR TO ME THAT THEY WERE ACTUALLY ASYMMETRIC. SINCE WE WERE NOW CLEAN ON DOWNWIND WITH WHAT APPEARED TO BE A NORMAL AIRPLANE; WE BEGAN TO CONFIGURE THE ACFT. WE MADE AN UNEVENTFUL FLAPS 15 DEG LNDG WITH SYMMETRICAL FLAP INDICATIONS. WE DID NOT CORRECTLY CONFORM TO THE QRH CHKLIST BECAUSE I CALLED FOR A GAR AND AS IS A HABIT TO CLEAN UP THE ACFT ON A GAR I COMMANDED FLAPS UP. PERHAPS THERE CAN BE MORE EMPHASIS TO THE CREWS THAT IN ANY SPLIT FLAPS SITUATION THE FLAPS SHOULD NOT BE MOVED. PERHAPS HAVE A BOXED ITEM FOR STEP ONE OF ANY ASYMMETRIC FLAP INDICATION. AS THE PF I NOTED NO ROLLING TENDENCY SO IN MY MIND I'M MENTALLY GOING THROUGH THE MANTRA 'MAINTAIN ACFT CTL; ANALYZE THE SITUATION; TAKE THE APPROPRIATE ACTION; AND MAINTAIN SITUATIONAL AWARENESS.' I WAS NOT THINKING 'SPLIT FLAP INDICATION; DON'T TOUCH THE FLAP HANDLE.' ONLY AFTER I GOT THE AIRPLANE SAFELY AWAY FROM THE GND AND DIRECTED THE FO TO THE QRH DID I REALIZE MY ERROR. ONCE THE AIRPLANE WAS CLEANED UP AND THE FLAPS RETRACTED WE NO LONGER HAD AN ASYMMETRIC PROB. AT THAT POINT WE STILL USED THE QRH TO CONFIGURE AND THE FLAPS CAME DOWN SYMMETRICALLY. A LITTLE BIT CONFUSING AT THE TIME; BUT WE WERE PREPARING OURSELVES FOR THE WORST CASE SCENARIO.

Data retrieved from NASA's ASRS site as of January 2009 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.