Narrative:

On dec/xa/01 at approximately XA40, I was shooting the ILS runway 18 into jac. Night conditions prevailed with light snow. The control tower was not in operation. It would open at XB00. We broke out on the ILS approximately 500 ft AGL with 4-5 mi of visibility. We landed without incident. Upon opening the door of the aircraft, the local sheriff was there. He told me that we had landed right over top a man working at the threshold on a snow blowing machine. The crew never saw any equipment on the runway. This information is strictly secondhand from the sheriff. He said that the workers had not heard my calls on the CTAF frequency. I told him I gave position calls on the localizer at 18 mi, 8 mi, and 4 mi out. This was on the jac tower/advisory frequency. I have no explanation why they did not hear us. ZLC had told me of men and equipment on txwys and runways NOTAM prior to me switching over to CTAF. If what the sheriff told me was correct, a hazardous condition existed for the aircraft. Because the airport was open our aircraft had a right to land. I believe there should be a way for an en route center to contact airport workers of an approaching aircraft. Obviously, this situation begs a back-up form of notification to just the CTAF.

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Original NASA ASRS Text

Title: AN ALLEGED LNDG OVER MEN AND EQUIP WORKING ON A RWY FOR SNOW REMOVAL AT NIGHT WITH TWR CLOSED.

Narrative: ON DEC/XA/01 AT APPROX XA40, I WAS SHOOTING THE ILS RWY 18 INTO JAC. NIGHT CONDITIONS PREVAILED WITH LIGHT SNOW. THE CTL TWR WAS NOT IN OP. IT WOULD OPEN AT XB00. WE BROKE OUT ON THE ILS APPROX 500 FT AGL WITH 4-5 MI OF VISIBILITY. WE LANDED WITHOUT INCIDENT. UPON OPENING THE DOOR OF THE ACFT, THE LCL SHERIFF WAS THERE. HE TOLD ME THAT WE HAD LANDED RIGHT OVER TOP A MAN WORKING AT THE THRESHOLD ON A SNOW BLOWING MACHINE. THE CREW NEVER SAW ANY EQUIP ON THE RWY. THIS INFO IS STRICTLY SECONDHAND FROM THE SHERIFF. HE SAID THAT THE WORKERS HAD NOT HEARD MY CALLS ON THE CTAF FREQ. I TOLD HIM I GAVE POS CALLS ON THE LOC AT 18 MI, 8 MI, AND 4 MI OUT. THIS WAS ON THE JAC TWR/ADVISORY FREQ. I HAVE NO EXPLANATION WHY THEY DID NOT HEAR US. ZLC HAD TOLD ME OF MEN AND EQUIP ON TXWYS AND RWYS NOTAM PRIOR TO ME SWITCHING OVER TO CTAF. IF WHAT THE SHERIFF TOLD ME WAS CORRECT, A HAZARDOUS CONDITION EXISTED FOR THE ACFT. BECAUSE THE ARPT WAS OPEN OUR ACFT HAD A RIGHT TO LAND. I BELIEVE THERE SHOULD BE A WAY FOR AN ENRTE CTR TO CONTACT ARPT WORKERS OF AN APCHING ACFT. OBVIOUSLY, THIS SIT BEGS A BACK-UP FORM OF NOTIFICATION TO JUST THE CTAF.

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.