The very length of this debate just goes to show that there is no 'right or wrong' verdict which can be applied to this case.
....... at the end of the day the sole concern shown by most who do not support the ba view is that it is the overall level of risk exposure which ba is prepared to inflict on its customers which needs to be re-examined. That level is the product of degree of risk multiplied by the time during which that risk applies.
......
Exactly. In order to assess this dispassionately one needs to understand that no 2 flights operate with the same level of risk. The risk is made up of known problems which have known statistical probabilities, which have not been totally eliminated but are being managed (engine reliability and/or blown out windshields as divergent examples of numerous others). In addition there are known risks associated with air-turn-Backs, heavy landings, diversions etc. by placing the crew into higher than normal workload for a flight. Then there is the biggie, which is latent but unknown risk like the fuse pins in the engine mounts were before they were identified and managed.
The regulatory agencies are aware of the relative contribution of these risks and
do permit time limited exceedences of
identified risks based on their expected overall contributions to the historical total risk. Each of these identified risks are accepted on a day-to-day basis on the presumption that they will be managed over a time period so as not to seriously degrade over affect overall risk.
Thus you have required inspections retrofits and
managed operations
The issue, as I see it, is how pervasive or widespread is the continuation of flight with and engine shutdown and what level of increased risk is abosrbed, if any, compared to Air-turn-back, fuel dumps, diversions etc. if an alternate course of action is chose.
If this level of risk is so small that it does not appreciably contribute to the overal avergage level per flight and that if its pervasiveness is so unlikely that it doesn not occur on a daily basis to the extent that increases overall fleetwide risk to the product, and if it is not prohibitied by the FAR/JARS, then
it is acceptable
Of course there will be some squirming to be done in order for BA to answer those
ifs