From London CTR review group report:
2.12.4 Additionally, there was a strong opinion that some formal airspace restriction to prevent the operation of single-engined fixed wing aircraft over extensive built up areas might now be required. It was the opinion of the Group that the application and interpretation of the Rule 5 “alight clear” rules were being misused.
2.12.5 Detailed discussion on any proposals to modify or remove the Restricted Area R160 would be needed within the CAA and also with the DfT.
Away for a week now..will return to the thread i.d.c