Alpena Combat Readiness Training Center; Alpena, MI
From The RadioReference Wiki
The following were found at the 2010 airshow Exact usages otherwise unknown.
173.5875 NAC 293 - Medical
163.5375 was used as a 'need more ice' here/there - just general grounds activity 163.5875 Parking
Airshow:
Airboss was on 123.550
P.A. mic 72.1