Even een update, met name POTUS support.
RCHxxx: various ; number is part of mission number and apparently is connected to Diplomatic clearances to cross a country along their route.
RCH01: Commander AMC
RCH02: Deputy Commander AMC
RCH03: Commander of 618th Tanker Airlift Control Center & 18th Air Force?
RCH04: Commander of 618th Tanker Airlift Control Center & 18th Air Force?
RCH5Ex: Antartica Mission?
RCH6Ex: Antartica Mission?
RCH28x: seems related to POTUS support (June 2014)(June/July 2017)
RCH29x: seems related to POTUS support (April 2016)(May 2017)
RCH34x: seems related to POTUS support (June 2014)
RCH35x: seems related to POTUS support (March 2014)(April 2016)(May 2017)
RCH36x: seems related to POTUS support (March 2014)(June 2014)(April 2016)(May 2017)(July 2017)
RCH37x: seems related to POTUS support (March 2014)(July 2017)
RCH47x: seems related to POTUS support (June 2015) (Apr 2016)
RCH48x: seems related to POTUS support (March 2014)(Aug/Sep 2014)(Jan 2015)(Jun 2015)
RCH50x: seems related to POTUS support (November 2016)
RCH51x: seems related to POTUS support (November 2016)
RCHxxxT: seems related to POTUS support (March 2014)
RCHxxxH: Humanitarian (Credit Robin)
RCH181x & RCH182x: Diplomatic flights, always 437th AMW C-17
RCH802x: Always a 437th AMW C-17 (x = various letters e.g RCH802W)
RCHxxxx: derived from their tailnumber.
RCH10xx: Special Ops a/c Ferry?
RCH01x:
Quite some KC-10's with callsigns in sequence this month (Jan 2015)RCH05x: From memory, believe AAR ferry. (not sure what the difference is in regard to Coronet callsigns/missions)
RCH06x: From memory, believe AAR ferry. (not sure what the difference is in regard to Coronet callsigns/missions)
RCH07x: AAR Ferry
RCH08x: (Credit Wolbie), AAR ferry
RCH09x: (Credit Wolbie), AAR ferry
RCH0xx: Various
RCH1xx: Various
RCH2xx: Various
RCH3xx: Various
RCH4xx: Various
RCH5xx: Various
RCH6xx: Various
RCH7xx: Various
RCH8xx: Various
RCH9xx: Various