No. 16 Operational Training Unit RAF (16 OTU) was formed at RAF Upper Heyford on 8 April 1940 from the No. 4 Group RAF (4 Gp) Pool, which comprised No 7 and No 76 Squadron, within No. 6 Group RAF (6 Gp), to train night bomber crews, for which it was equipped with Handley Page Hampdens and Herefords. Transferred to No. 7 Group RAF (7 Gp) on 15 July 1940 until 11 May 1942 when No 7 Group was renumbered No.