Narrative:

WX at ZZZ1 300 ft overcast 1 1/2 mi visibility at departure. Departed for ZZZ1 since original home base WX was too low. First told to expect ILS runway 15R. Then RVR was too low. Expect ILS runway 33L. Controller was very busy. Sounded like long final to runway 33L. Approach said we could get right in to localizer xx at ZZZ2. Controller said it would be short approach. Shot approach; did not see runway and went missed approach. At this time declared emergency due to fuel level low. Did not trust gauges at low level. Vectored ILS runway 10. Controller said best approach light around. Approach did great job. Thanks. Saw runway and landed. Lessons learned: MVFR will top fuel tanks off. Not go if questionable. Limited options with just VOR; NDB; ILS; localizer. Would be nice to have GPS. Glad I declared emergency early. Ended up having 8 gals left.

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Original NASA ASRS Text

Title: WHEN DEST WX GOES DOWN; C172 PILOT ATTEMPTS LOC APPROACH AT NEARBY ALTERNATE. AFTER MISSED APPROACH A LOW FUEL EMERGENCY IS DECLARED WITH SUCCESSFUL ILS APCH AT ALTERNATE.

Narrative: WX AT ZZZ1 300 FT OVCST 1 1/2 MI VISIBILITY AT DEP. DEPARTED FOR ZZZ1 SINCE ORIGINAL HOME BASE WX WAS TOO LOW. FIRST TOLD TO EXPECT ILS RWY 15R. THEN RVR WAS TOO LOW. EXPECT ILS RWY 33L. CTLR WAS VERY BUSY. SOUNDED LIKE LONG FINAL TO RWY 33L. APCH SAID WE COULD GET RIGHT IN TO LOC XX AT ZZZ2. CTLR SAID IT WOULD BE SHORT APCH. SHOT APCH; DID NOT SEE RWY AND WENT MISSED APCH. AT THIS TIME DECLARED EMER DUE TO FUEL LEVEL LOW. DID NOT TRUST GAUGES AT LOW LEVEL. VECTORED ILS RWY 10. CTLR SAID BEST APCH LIGHT AROUND. APCH DID GREAT JOB. THANKS. SAW RWY AND LANDED. LESSONS LEARNED: MVFR WILL TOP FUEL TANKS OFF. NOT GO IF QUESTIONABLE. LIMITED OPTIONS WITH JUST VOR; NDB; ILS; LOC. WOULD BE NICE TO HAVE GPS. GLAD I DECLARED EMER EARLY. ENDED UP HAVING 8 GALS LEFT.

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.