Chug, One also has to remember what 553 says about airworthiness beyond the headline that you quote (often):
For peacetime flying, the design standard of a UK military aircraft type, its associated equipment and software may be considered airworthy where the conditions in a and b, or a and c, are met as appropriate:
a For all military aircraft types, their associated equipment and software, the Aircraft Designer has satisfactorily demonstrated, in a Safety Case, the airworthiness of the design. The demonstration of airworthiness may include design analysis, application of specified standards (such as Def Stan 00-970) and procedures, historical evidence of successful use of particular design features, system tests, and ground and air tests to arrive at an overall assessment of airworthiness. The demonstration should be as specified in the aircraft or modification contract including the operating conditions to be applied, and should be undertaken during the development phase for the aircraft or modification.
b The cumulative probability of the loss of an aircraft due to a technical fault and the cumulative probability of a technical failure of the aircraft (inclusive of its systems, structure and stores) which could result in the death of any air crew or passengers, should both be assessed to be of the order of one in a million per flying hour (probability of occurrence 1x10-6 per flying hour) when operated within the conditions used for the airworthiness demonstration.
c Aircraft derived from civil passenger aircraft and used by the MOD in the passenger‑carrying airliner role should meet a higher standard of safety. Such aircraft may be considered to be airworthy if the cumulative probability of the loss of the aircraft due to a technical fault and the cumulative probability of a technical failure of the aircraft (inclusive of its systems, structure and stores) which could result in the death of any aircrew or passengers, are both assessed to be of the order of one in ten million per flying hour (probability of occurrence 1x10‑7 per flying hour) when operated within the conditions used for the airworthiness demonstration.
The Principles of War also apply - Selection and Maintenance of the Aim - diverting into other areas of Aviation Safety is going to dilute what has already been achieved post XV230.
sw