John Blakeley,
Why a letter and not an Immediate Signal if Boscombe had ceased trials?
If the cessation of trials was Flight Safety based then why not a "Flash" signal?
Was the letter to DHP copied to HQSTC and HQ 1Gp?
Were HQSTC and HQ 1 Gp even "in the loop" as far as formal information on trials progress was concerned?
At what frequency were updates on trials progress produced?