Narrative:

I was working the radar north position with very light traffic. I was looking at airspace beyond what I normally would; about 20 miles beyond my airspace boundary (versus the normal 10 miles beyond the boundary). The salt lake center/billings TRACON LOA requires salt lake center (ZLC) to have all arrivals at or descending to 13;000 ft MSL. ZLC initiated an automated hand off on aircraft X. I was not working with the MVA map on at this time. I don't recall what altitude aircraft X was at when I took the hand off; though the aircraft came over to my frequency descending to 13;000. As the aircraft got closer to my airspace; I turned on the MVA map. The aircraft was in an area of higher MVA. (I believe the MVA in this area is high due to the floor of controlled airspace being approximately 14;300 ft MSL). The billings MVA in this particular area is 14;600 ft MSL. I realized then that the aircraft was below the MVA and about to enter a 7;500 ft MSL MVA area. The MSAW did not alarm nor was there a visual la (low altitude alert) in the data block. The aircraft then entered the lower MVA and continued to the airport and landed. I do not know ZLC's mia (minimum instrument altitude) in this area. Recommendation; in this particular airspace; the salt lake center/billings TRACON LOA should be amended to have these arrivals descending to 15;000 ft MSL to keep them in controlled airspace and above billings TRACON MVA. This would prevent an aircraft from being handed off descending to an altitude below the MVA. A review of why the center's mia in this area is so much lower than the TRACON's MVA may be in order. In addition; I should work with the MVA on for all arriving aircraft; all of the time.

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Original NASA ASRS Text

Title: BIL Controller described a questionable MVA event when his/her display was expanded further than normal; a hand off was accepted from ZLC only to discover the aircraft was below BIL MVA minima.

Narrative: I was working the Radar North position with very light traffic. I was looking at airspace beyond what I normally would; about 20 miles beyond my airspace boundary (versus the normal 10 miles beyond the boundary). The Salt Lake Center/Billings TRACON LOA requires Salt Lake Center (ZLC) to have all arrivals at or descending to 13;000 FT MSL. ZLC initiated an automated hand off on Aircraft X. I was not working with the MVA map on at this time. I don't recall what altitude Aircraft X was at when I took the hand off; though the aircraft came over to my frequency descending to 13;000. As the aircraft got closer to my airspace; I turned on the MVA map. The aircraft was in an area of higher MVA. (I believe the MVA in this area is high due to the floor of controlled airspace being approximately 14;300 FT MSL). The Billings MVA in this particular area is 14;600 FT MSL. I realized then that the aircraft was below the MVA and about to enter a 7;500 FT MSL MVA area. The MSAW did not alarm nor was there a visual LA (low altitude alert) in the data block. The aircraft then entered the lower MVA and continued to the airport and landed. I do not know ZLC's MIA (Minimum Instrument Altitude) in this area. Recommendation; in this particular airspace; the Salt Lake Center/Billings TRACON LOA should be amended to have these arrivals descending to 15;000 FT MSL to keep them in controlled airspace and above Billings TRACON MVA. This would prevent an aircraft from being handed off descending to an altitude below the MVA. A review of why the Center's MIA in this area is so much lower than the TRACON's MVA may be in order. In addition; I should work with the MVA on for ALL arriving aircraft; all of the time.

Data retrieved from NASA's ASRS site as of April 2012 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.