Narrative:

IFR approach ama runway 4, 1800 ft RVR minimum required for approach. 1800 ft RVR was finally reported having held over OM for approximately 30 mins. Standard IFR briefing was given and standard company calls were made. Aircraft was flown by first officer with autoplt engaged. Captain was backing up approach with hgs. Approach was stabilized approaching decision ht. At 100 ft above decision ht, first officer 'approaching minimums.' captain 'going outside.' at decision ht, first officer 'minimums.' captain 'landing, my airplane.' first officer 'your airplane.' I then looked outside the aircraft and saw runway lights and the aircraft positioned properly for continuing the approach. I looked at the radio altimeter and made my next required call '100 ft.' I then looked back outside and noticed the aircraft drifting quickly to the left. In my opinion and later agreed to by the captain, I believe the captain mistakenly focused on the left runway edge lights and thought them to be the centerline lights. There are no centerline lights on this runway. Without hesitation and just below 100 ft AGL, I said, 'captain, those aren't centerline lights!' the captain immediately corrected to the right and we landed firmly on the runway. We taxied to the gate and inspected the aircraft because of the firm landing. When we inspected the main gear, we noticed light mud and grass in the left brake assembly. We then contacted our company and informed them of having possibly left the runway surface. We have found that the aircraft actually landed on the runway but slid and exited the runway with the #1 tire on the left main gear. Rapidly changing wind conditions and visibility I believe were the cause of this event. Supplemental information from acn 419580: as I did not turn on the landing lights the last few ft above the runway, I could not judge precisely the distance above the runway and the landing was quite firm. I found a small (3-4 inch) cut on the #1 tire and a thin (1/4 inch) layer of dirt on the underside of the wing in the wing root area. I notified dispatch and the tower controller by phone. I had not noticed that the approach plate stated that aiii mode was required for this CAT I approach. Had we used this, we would have had the approach warning light operational and had it come on, a missed approach would have been mandatory.

Google
 

Original NASA ASRS Text

Title: A B737-300 MISALIGNS ON LNDG RWY 4 AT AMA. THE RVR WAS 1800 FT AND THE CAPT THOUGHT THAT THE RWY EDGE LIGHTS WERE THE CTRLINE LIGHTS, WHICH DID NOT EXIST. TIRE CUTS DURING THE RWY EXCURSION.

Narrative: IFR APCH AMA RWY 4, 1800 FT RVR MINIMUM REQUIRED FOR APCH. 1800 FT RVR WAS FINALLY RPTED HAVING HELD OVER OM FOR APPROX 30 MINS. STANDARD IFR BRIEFING WAS GIVEN AND STANDARD COMPANY CALLS WERE MADE. ACFT WAS FLOWN BY FO WITH AUTOPLT ENGAGED. CAPT WAS BACKING UP APCH WITH HGS. APCH WAS STABILIZED APCHING DECISION HT. AT 100 FT ABOVE DECISION HT, FO 'APCHING MINIMUMS.' CAPT 'GOING OUTSIDE.' AT DECISION HT, FO 'MINIMUMS.' CAPT 'LNDG, MY AIRPLANE.' FO 'YOUR AIRPLANE.' I THEN LOOKED OUTSIDE THE ACFT AND SAW RWY LIGHTS AND THE ACFT POSITIONED PROPERLY FOR CONTINUING THE APCH. I LOOKED AT THE RADIO ALTIMETER AND MADE MY NEXT REQUIRED CALL '100 FT.' I THEN LOOKED BACK OUTSIDE AND NOTICED THE ACFT DRIFTING QUICKLY TO THE L. IN MY OPINION AND LATER AGREED TO BY THE CAPT, I BELIEVE THE CAPT MISTAKENLY FOCUSED ON THE L RWY EDGE LIGHTS AND THOUGHT THEM TO BE THE CTRLINE LIGHTS. THERE ARE NO CTRLINE LIGHTS ON THIS RWY. WITHOUT HESITATION AND JUST BELOW 100 FT AGL, I SAID, 'CAPT, THOSE AREN'T CTRLINE LIGHTS!' THE CAPT IMMEDIATELY CORRECTED TO THE R AND WE LANDED FIRMLY ON THE RWY. WE TAXIED TO THE GATE AND INSPECTED THE ACFT BECAUSE OF THE FIRM LNDG. WHEN WE INSPECTED THE MAIN GEAR, WE NOTICED LIGHT MUD AND GRASS IN THE L BRAKE ASSEMBLY. WE THEN CONTACTED OUR COMPANY AND INFORMED THEM OF HAVING POSSIBLY LEFT THE RWY SURFACE. WE HAVE FOUND THAT THE ACFT ACTUALLY LANDED ON THE RWY BUT SLID AND EXITED THE RWY WITH THE #1 TIRE ON THE L MAIN GEAR. RAPIDLY CHANGING WIND CONDITIONS AND VISIBILITY I BELIEVE WERE THE CAUSE OF THIS EVENT. SUPPLEMENTAL INFO FROM ACN 419580: AS I DID NOT TURN ON THE LNDG LIGHTS THE LAST FEW FT ABOVE THE RWY, I COULD NOT JUDGE PRECISELY THE DISTANCE ABOVE THE RWY AND THE LNDG WAS QUITE FIRM. I FOUND A SMALL (3-4 INCH) CUT ON THE #1 TIRE AND A THIN (1/4 INCH) LAYER OF DIRT ON THE UNDERSIDE OF THE WING IN THE WING ROOT AREA. I NOTIFIED DISPATCH AND THE TWR CTLR BY PHONE. I HAD NOT NOTICED THAT THE APCH PLATE STATED THAT AIII MODE WAS REQUIRED FOR THIS CAT I APCH. HAD WE USED THIS, WE WOULD HAVE HAD THE APCH WARNING LIGHT OPERATIONAL AND HAD IT COME ON, A MISSED APCH WOULD HAVE BEEN MANDATORY.

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.