https://www.faa.gov/regulations_policies/orders_notices/index.cfm/go/document.information/documentID/9739
Order 6820.9 - VOR, VOR/DME, VORTAC Installation Standard Drawings
The Federal Aviation Administration is an operating mode of the U.S. Department of Transportation.
vor dmeorder68209vortac
https://www.aopa.org/news-and-media/all-news/1999/may/17/las-vortac-outage
LAS Vortac outage - AOPA
LAS Vortac outage The LAS Vortac will be shut down on May 20, 1999, at 0900UTC (0200 local time). A temporary VOR/DME will be turned on at that time with the...
lasvortacoutageaopa