Hinton-In-The-Hedges accommodated 104 Sqn FV-*/KQ-*/OY* and 108 Sqn SL-*/XD-*/XJ-* flying the Bristol Blenheim I. These squadrons merged to form No 13 Operational Training Unit from 27 November 1940 until 23 August 1942. Initially training Blenheim crews for daylight operations, its role was later extended to include night intruder training.