[Buckeye30]

Hi Franek. Kenn Rust's "Ninth Air Force Story" says R-9 was abandoned by VE Day presumaby after the 15TRS left for Furth on 24 April. Don't know more details though but the airfield must have been pretty unuseable by then.
From "media.defence.gov" all offensive operations ceased from R-9 a few days before VE. (p.46).

Regards
Nick
ADDITION... As per official "dafhistory.af.mil" the initial operational date for Erfurt was 14 April--15TRS, full complement by 16th. ("usafunithistory.com"). Date of release (abandoned or released from USAAF control) 30 April. By 9 May 76 of the 126 airfields made operational east of the Rhine were only for supply or evacuation.