 At their first series of meetings on 14 September , the Night Defence Committee began collecting a series of suggestions for improvements , which were discussed in depth on 1 October . These were passed on to Dowding for implementation , but he found that many of their suggestions were already out of date . For instance , they suggested building new radars that could be used over land , allowing the fight to continue throughout the raid . A contract for this type of radar had already been sent out in June or July . They suggested that the filter room at RAF Bentley Priory be devolved down to the Group headquarters to improve the flow of information , but Dowding had already gone a step further and devolved night interception to the Sector level at the airfields . Dowding accepted only four of the suggestions . 
