List of British Airworthy Engines. Issue No.4 / R.D.E., Air Ministry. 1936. [17 blueprint sheets containing the type data of all normal category engines approved for use in British Aircraft. They were issued in groups identifiable by reference to the constructor's name and the code marking entered at top right hand corner of each sheet. 14 companies are named]. Shelved at MSL 115. List of British Airworthy Engines. Issue No.4 / R.D.E. 1936