Narrative:

Factors: 1) 10 1/2 hour all night flight - fatigue, 2) new trifocal glasses - first flight flown, 3) CAT ii autoland - first autoland approach in over a yr, 4) distrs - external and internal, 5) the jfk runway 4R ILS approach itself - LOM closer to runway. ATIS gave 200 overcast, wind calm, RVR 6000 ft plus, runway 4R ILS. Briefed CAT I approach. On vector, approach said 'RVR just went belly up.' some cockpit discussion on the meaning - did RVR go below minimums or did the RVR itself become inoperative. RVR came back on. Approach said RVR now 2200 ft. Visibility was not given. Briefed CAT ii/III autoland. Was told to maintain minimum 180 KTS to abbee at 1500 ft. Intercept heading was given to be about 1/2 mi from ebbee. Engaged left and right autoplts but lights did not appear to come on. Pushed engage buttons again - no change. The lights were on but about 1/3 as bright as the light from the center autoplt. I neglected to arm approach mode at this time. We went through the localizer on a 30 degree off heading. I used heading select to turn right back to intercept just outside of ebbee. I armed the approach mode - after intercept of localizer and GS. I called for 20 degree flaps, gear down, speed 160 KTS (approach was 142 KTS). We noted the autoplt doing its internal testing at about 1400 ft AGL. I called for 25 degree flaps. Shortly after that we got an aural warning. I looked and could see no problems. In this area, the first officer said 'altitude checks at conda.' on localizer on GS. Discussion on meaning of aural warning. Who saw what. I called for 30 degree flaps and set 142 KTS approach speed. Still fast over conda. On GS, on localizer, flaps set, speed coming back, rate of descent normal. Aural warning 'too low terrain' sounded. An, to me, impossible warning to be valid considering where we were and what was happening. Although very uncomfortable with the high airspeed (155 KTS at 450 ft AGL) and what had preceded the last few mins. I was very confident that the 'too low terrain' was false warning. On GS on localizer on runway 4R approach. We went around. I saw the lead in lights as we were going around. We were truly mystified by the warning. The second approach was uneventful (RVR 5000-6000 ft). As I have heard, sometimes false GPWS warnings occur over water and this airplane is notorious for transient warning problems. The GPWS tested ok on the ground. We had a generator drive oil light flickering for about 4 hours. We chalked up the warning as a transient false warning and did not write it up. I ascertained that the airplane was going in for a check that day and thought it would be checked. After considerable thought to this incident, I know exactly what I did wrong and what I will do to prevent not being stabilized by 1000 ft or go around by then. Supplemental information from acn 302081: at 350 ft AGL there was a GPWS warning 'too low, terrain, too low, terrain, too low, terrain.' I said 'let's get out of here.' so we did a go around. Underlying all that happened, we were up all night, 10:20 flight, 12 hours on duty. I had just come up from my break and had trouble getting back into the flying mode again (PNF). The captain was late configuring the plane. The visibility went down just prior to intercepting final so we had to scramble and set up for a CAT III autoland which should have been done in the first place. A quick flash of a red gear unsafe light at 800 ft made it more confusing then the GPWS warning at 350 ft. A go around was needed because we were IMC and the confusion rate was high. We probably should have written up the GPWS but it worked fine on the next landing. We did not know what set it off. The gear unsafe light may have come on because the flaps were moved to land position 25 degrees before the gear was all the way down.

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Original NASA ASRS Text

Title: UNSTABILIZED APCH LEADS TO A GAR. FLC PLANNING INFLT POOR. SPD DEV. STABILIZED APCH CONCEPT NOT USED.

Narrative: FACTORS: 1) 10 1/2 HR ALL NIGHT FLT - FATIGUE, 2) NEW TRIFOCAL GLASSES - FIRST FLT FLOWN, 3) CAT II AUTOLAND - FIRST AUTOLAND APCH IN OVER A YR, 4) DISTRS - EXTERNAL AND INTERNAL, 5) THE JFK RWY 4R ILS APCH ITSELF - LOM CLOSER TO RWY. ATIS GAVE 200 OVCST, WIND CALM, RVR 6000 FT PLUS, RWY 4R ILS. BRIEFED CAT I APCH. ON VECTOR, APCH SAID 'RVR JUST WENT BELLY UP.' SOME COCKPIT DISCUSSION ON THE MEANING - DID RVR GO BELOW MINIMUMS OR DID THE RVR ITSELF BECOME INOP. RVR CAME BACK ON. APCH SAID RVR NOW 2200 FT. VIS WAS NOT GIVEN. BRIEFED CAT II/III AUTOLAND. WAS TOLD TO MAINTAIN MINIMUM 180 KTS TO ABBEE AT 1500 FT. INTERCEPT HDG WAS GIVEN TO BE ABOUT 1/2 MI FROM EBBEE. ENGAGED L AND R AUTOPLTS BUT LIGHTS DID NOT APPEAR TO COME ON. PUSHED ENGAGE BUTTONS AGAIN - NO CHANGE. THE LIGHTS WERE ON BUT ABOUT 1/3 AS BRIGHT AS THE LIGHT FROM THE CTR AUTOPLT. I NEGLECTED TO ARM APCH MODE AT THIS TIME. WE WENT THROUGH THE LOC ON A 30 DEG OFF HDG. I USED HDG SELECT TO TURN R BACK TO INTERCEPT JUST OUTSIDE OF EBBEE. I ARMED THE APCH MODE - AFTER INTERCEPT OF LOC AND GS. I CALLED FOR 20 DEG FLAPS, GEAR DOWN, SPD 160 KTS (APCH WAS 142 KTS). WE NOTED THE AUTOPLT DOING ITS INTERNAL TESTING AT ABOUT 1400 FT AGL. I CALLED FOR 25 DEG FLAPS. SHORTLY AFTER THAT WE GOT AN AURAL WARNING. I LOOKED AND COULD SEE NO PROBS. IN THIS AREA, THE FO SAID 'ALT CHKS AT CONDA.' ON LOC ON GS. DISCUSSION ON MEANING OF AURAL WARNING. WHO SAW WHAT. I CALLED FOR 30 DEG FLAPS AND SET 142 KTS APCH SPD. STILL FAST OVER CONDA. ON GS, ON LOC, FLAPS SET, SPD COMING BACK, RATE OF DSCNT NORMAL. AURAL WARNING 'TOO LOW TERRAIN' SOUNDED. AN, TO ME, IMPOSSIBLE WARNING TO BE VALID CONSIDERING WHERE WE WERE AND WHAT WAS HAPPENING. ALTHOUGH VERY UNCOMFORTABLE WITH THE HIGH AIRSPD (155 KTS AT 450 FT AGL) AND WHAT HAD PRECEDED THE LAST FEW MINS. I WAS VERY CONFIDENT THAT THE 'TOO LOW TERRAIN' WAS FALSE WARNING. ON GS ON LOC ON RWY 4R APCH. WE WENT AROUND. I SAW THE LEAD IN LIGHTS AS WE WERE GOING AROUND. WE WERE TRULY MYSTIFIED BY THE WARNING. THE SECOND APCH WAS UNEVENTFUL (RVR 5000-6000 FT). AS I HAVE HEARD, SOMETIMES FALSE GPWS WARNINGS OCCUR OVER WATER AND THIS AIRPLANE IS NOTORIOUS FOR TRANSIENT WARNING PROBS. THE GPWS TESTED OK ON THE GND. WE HAD A GENERATOR DRIVE OIL LIGHT FLICKERING FOR ABOUT 4 HRS. WE CHALKED UP THE WARNING AS A TRANSIENT FALSE WARNING AND DID NOT WRITE IT UP. I ASCERTAINED THAT THE AIRPLANE WAS GOING IN FOR A CHK THAT DAY AND THOUGHT IT WOULD BE CHKED. AFTER CONSIDERABLE THOUGHT TO THIS INCIDENT, I KNOW EXACTLY WHAT I DID WRONG AND WHAT I WILL DO TO PREVENT NOT BEING STABILIZED BY 1000 FT OR GAR BY THEN. SUPPLEMENTAL INFO FROM ACN 302081: AT 350 FT AGL THERE WAS A GPWS WARNING 'TOO LOW, TERRAIN, TOO LOW, TERRAIN, TOO LOW, TERRAIN.' I SAID 'LET'S GET OUT OF HERE.' SO WE DID A GAR. UNDERLYING ALL THAT HAPPENED, WE WERE UP ALL NIGHT, 10:20 FLT, 12 HRS ON DUTY. I HAD JUST COME UP FROM MY BREAK AND HAD TROUBLE GETTING BACK INTO THE FLYING MODE AGAIN (PNF). THE CAPT WAS LATE CONFIGURING THE PLANE. THE VISIBILITY WENT DOWN JUST PRIOR TO INTERCEPTING FINAL SO WE HAD TO SCRAMBLE AND SET UP FOR A CAT III AUTOLAND WHICH SHOULD HAVE BEEN DONE IN THE FIRST PLACE. A QUICK FLASH OF A RED GEAR UNSAFE LIGHT AT 800 FT MADE IT MORE CONFUSING THEN THE GPWS WARNING AT 350 FT. A GAR WAS NEEDED BECAUSE WE WERE IMC AND THE CONFUSION RATE WAS HIGH. WE PROBABLY SHOULD HAVE WRITTEN UP THE GPWS BUT IT WORKED FINE ON THE NEXT LNDG. WE DID NOT KNOW WHAT SET IT OFF. THE GEAR UNSAFE LIGHT MAY HAVE COME ON BECAUSE THE FLAPS WERE MOVED TO LAND POS 25 DEGS BEFORE THE GEAR WAS ALL THE WAY DOWN.

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.