Narrative:

Approach to sjc 30 left at dusk with haze sun in your eyes GS notammed out ILS runway 30 left. Flying localizer only picked up vasis and were tracking VASI for GS guidance. You could see the VASI 2.3 mi before runway came into view. Between 4-5 mi from runway VASI's went out. Asked twer if they turned them off, response was VASI's are hooked up to photoelectric cell that turns them off as it gets dark and they can't turn them back on. Very disconcerting to lose VASI's on approach in this situation. Recommendation, VASI's should be tower controled at all times regardless of time of day. Callback conversation with reporter revealed the following information: the PIC reporter stated that he crew had the PAPI lights in sight. Those are the lights to the left of runway 30L. It seems that at dusk the lights go out as controlled by the photo-electric cell but are readable later at night. The PIC made another flight into sjc at dusk and the same thing occurred to his flight, the lights went out. He maintains that the light cell is controlled by the city, not the FAA.

Google
 

Original NASA ASRS Text

Title: A B737-700 PIC'S RPT REGARDING THE AUTO SHUT DOWN OF VASI REFERENCE DURING A LOCALIZER ONLY APCH TO RWY 30 L AT DUSK AT SJC, CA.

Narrative: APCH TO SJC 30 L AT DUSK WITH HAZE SUN IN YOUR EYES GS NOTAMMED OUT ILS RWY 30 L. FLYING LOC ONLY PICKED UP VASIS AND WERE TRACKING VASI FOR GS GUIDANCE. YOU COULD SEE THE VASI 2.3 MI BEFORE RWY CAME INTO VIEW. BTWN 4-5 MI FROM RWY VASI'S WENT OUT. ASKED TWER IF THEY TURNED THEM OFF, RESPONSE WAS VASI'S ARE HOOKED UP TO PHOTOELECTRIC CELL THAT TURNS THEM OFF AS IT GETS DARK AND THEY CAN'T TURN THEM BACK ON. VERY DISCONCERTING TO LOSE VASI'S ON APCH IN THIS SIT. RECOMMENDATION, VASI'S SHOULD BE TWR CTLED AT ALL TIMES REGARDLESS OF TIME OF DAY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE PIC RPTR STATED THAT HE CREW HAD THE PAPI LIGHTS IN SIGHT. THOSE ARE THE LIGHTS TO THE LEFT OF RWY 30L. IT SEEMS THAT AT DUSK THE LIGHTS GO OUT AS CONTROLLED BY THE PHOTO-ELECTRIC CELL BUT ARE READABLE LATER AT NIGHT. THE PIC MADE ANOTHER FLT INTO SJC AT DUSK AND THE SAME THING OCCURRED TO HIS FLT, THE LIGHTS WENT OUT. HE MAINTAINS THAT THE LIGHT CELL IS CONTROLLED BY THE CITY, NOT THE FAA.

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.